Miscellaneous Topics

Question 1

Describe the architecture of an atom.

Answer 1

The atom is the basic building block that makes up all matter. It consists of 3 components:
* Protons (+ charge)
* Neutrons (no charge)
* Electrons (- charge)
the protons and neutrons reside at the center of the atom, and together they form the nucleus. The number of protons in the nucleus determines the atom’s atomic number.

The electrons orbit the nucleus in the electron cloud. Because electrons have a negative charge, they are attracted to the positive charge of the nucleus. This keeps the electrons from flying away.

Question 2

how do you know if an atom carries a charge? what is a charged atom called?

Answer 2

an atom will have a:
* Neutral charge if (# electrons = # protons
* Protons charge if: # electrons < # Protons
* Negative charge if: # electrons > # protons

An ion is an atom that carries a positive or negative charge
* An atom with a positive charge ( it has lost electrons) is called a cation
* An atom with a negative charge (it has gained electrons) is called an anion

Question 3

What is an ionic bond?

Answer 3

An ionic bond involves the complete transfer of valence electron(s) from one atom to another. This leaves one atom with a negative charge and the other with a positive charge. Metals tend to form ionic bonds.

Ionic bonds are common with metals as well as acids and bases

Question 4

What is a covalent bond?

Answer 4

A covalent bond involves the equal sharing of electrons. This is the strongest type of bond.

• A single bond is created when 1 pair of electrons is shared
• A double bond is created when 2 pairs of electrons are shared
• A triple bond is created when 3 pairs of electrons are shared

Question 5

what is polar covalent bond?

Answer 5

polar covalent bonds are an “in-between” type of bond

Atoms share electrons, but the electrons tend to remain closer to one atom than the other. This creates a polar molecule, where one area of the molecule is relatively positive, and the other is relatively negative

Question 6

What are Van der Waals forces?

Answer 6

Van der Waals’ forces describe a very weak intermolecular force that holds molecules of the same type together.

Electrons (an their negative charges) orbiting a molecule are in constant motion. This creates temporary partial (+) and (-) charges at different parts of the molecule at any given time. The net result is that electron-rich areas of one molecule will be attracted to electron-poor areas of another molecule.

This is the weakest type of molecular attraction

Question 7

Define Dalton’s law. List several examples of how it can be used in the operating room.

Answer 7

Dalton’s law of partial pressures says that the total pressure is equal to the sum of the partial pressures exerted by each gas in the mixture.
P total= P1+P2+P3
Ways to apply Dalton’s law of partial pressures:
* Calculate the partial pressure of an unmeasured gas
* Calculate the total pressure
* Convert partial pressure to volumes percent
* Convert volumes percent to a partial pressure

Question 8

At sea level, the agent monitor measures the end-tidal sevoflurane as 3%. What is the partial pressure of sevoflurane in the exhaled tidal volume?

Answer 8

This is an application question about Dalton’s law of partial pressures.

Partial pressure= volumes percent x total pressure

• Partial pressure = 0.03 x 760 mmHg
• Answer= 22.8 mmHg

Question 9

Define Henry’s law. List several examples of how it can be used in the operating room.

Answer 9

At a constant temperature, the amount of gas that dissolves in a solution is directly proportional to the partial pressure of that gas over the solution. Said another way, the higher the gas pressure, the more of it will dissolve into a liquid (assuming a constant temperature).
* Increase temp= decreased solubility
* Decreased temp= increase solubility

How can we apply Henry’s law:
* Anesthetic emergence is prolonged in the hypothermic patient
* Dissolved oxygen in the oxygen-carrying capacity equation (CaO2)

Question 10

Describe Fick’s law of diffusion.

Answer 10

Fick’s law of diffusion describes the transfer rate of gas through a tissue medium

Rate of transfer is directly proportional to:
* Partial pressure difference (driving force)
* Diffusion coefficient (solubility)
* Membrane surface area

Rate of Transfer is inversely Proportional to:
* Membrane thickness
* Molecular weight

Question 11

list clinical examples of Fick’s law of diffusion

Answer 11

• Diffusion hypoxia
• A patient with COPD has a reduced alveolar surface area and therefore has a slower rate of inhalation induction
• Calculation of cardiac output
• drug transfer across the placenta

Question 12

Compare and contrast Boyle’s, Charle’s, and gay-lussac’s law.

Answer 12

Boyle’s law has inverse relationship
* as one variable gets larger, the other gets smaller
* As one variable gets smaller, the other gets larger
P1 x V1= P2 x V2

Charle’s law and Gay-lussac’s law have direct relationships:
* As one variable gets larger, the other gets larger.
* As one variable gets smaller, the other gets smaller
Charles: V1/T1= V2/T2
Gay-lussac’s: P1/T1=P2/T2

Question 13

List several examples of how Boyle’s law can be applied in the operating room.

Answer 13

Boyle’s law (P x V):
* Diaphragm contraction increases tidal volume
* Pneumatic bellows
* Squeezing an Ambu bag
* Using the bourdon pressure gauge to calculate how much O2 is left in a cylinder (assumes a given flow rate)

Question 14

List an example of how Charle’s law can be applied in the operating room.

Answer 14

Charle’s law (V/T):
* LMA cuff ruptures when placed in an ambulance

Question 15

List an example of how Gay-Lussac’s law can be applied in the OR.

Answer 15

Gay-Lussac’s law (P/T)
* Oxygen tank explodes in a heated environment

Question 16

what is the function of the ideal gas law?

Answer 16

the ideal gas law unifies all 3 gas laws into a single equation, where: PV=nrT
* P= pressure
* V= volume
* n= number of moles
* r= constant 0.821 liter-atm/K/mole
* T= temperature

Question 17

Define Ohm’s law

Answer 17

Ohm’s law says that the current passing through a conductor is directly proportional to the voltage and inversely proportional to the resistance. We can adapt Ohm’s law to understand fluid flow.
Current= voltage difference/ resistance
or
Flow= Pressure gradient/ resistance

Question 18

How is Poiseuille’s law related to Ohm’s law?

Answer 18

Poiseuille’s law is a modification of Ohm’s law that incorporates vessel diameter, viscosity, and tube length

• Q blood flow
• R Radius
• change in P Arteriovenous pressure gradient (Pa-Pv)
• n Viscosity
• L Length of the tube

Question 19

How do changes in radius affect laminar flow (x2, x3, x4, and x5)

Answer 19

Altering the radius of the tube exhibits the greatest impact on flow.
* R= 1^4: 1x1x1x1= 4
* R= 2^4: 2x2x2x2= 16
* R= 3^4: 3x3x3x3= 81
* R= 4^4: 4x4x4x4= 256

Question 20

How can we apply Poiseuille’s law to the administration of a unit packed red blood cells?

Answer 20

We can deliver red blood cells faster if we:
* Increase the radius with a large-bore IV
* INcrease the pressure gradient with a pressure bag and/or increase the height of the IV pole.
* Decrease the viscosity by diluting the blood with 0.9 NaCl and/or running it through a fluid warmer
* Decrease the length by not using longer tubing than you really need

Question 21

what does Reynold’s number tell you?

Answer 21

There are 3 types of flow: Laminar, turbulent, and transitional.

Reynold’s number allows us to predict the type of flow that will occur in a given situation
* RE < 2000: laminar flow is dependent on gas viscosity (Poiseuille’s law)
* Re> 4000: turbulent flow is dependent on gas density (Graham’s law)
* Re 2,000 - 4,000: transitional flow
Reynold’s number= (Density x Diameter x Velocity)/ Viscosity

grahams: rate of effusion of gas is inversely proportional to the square root of the molar mass of its particles

Question 22

Explain how understanding Reynold’s number helps you treat status asthmaticus

Answer 22

The pt with status asthmaticus suffers from an increased airway resistance, and this increases flow turbulence and the work of breathing.
* because turbulent flow is primarily dependent on gas density, we can improve flow by having the patient inhale a lower density gas
* An oxygen/helium mixture (Heliox) improves Reynold’s number by reducing density
* The key here is that we are converting turbulent flow to laminar flow. Helium does NOT improve flow if its is already laminar

Question 23

Explain Bernoulli’s principal, and discuss it in the context of a river.

Answer 23

Bernoulli’s principle describes the relationship between the pressure and velocity
* If the fluid’s velocity is high, then the pressure exerted on the walls of the tube will be low.
* If the fluid’s velocity is low, then the pressure exerted on the walls of the tube will be high

Example: Think of a river. When the river is wide, the water moves slowly, but when it becomes narrow, the water moves much faster. This is because the same volume of water is moving through the wide and now parts of the river at any given time. When the water is moving slowly, the pressure exerted on the riverbank is higher, and when the river narrows, the velocity of the water increases, so it exerts less pressure on the riverbank

Question 24

Explain the Venturi effect, and give some examples.

Answer 24

The venturi effect is an application of the Bernoulli principle. As airflow in a tube moves past the point of constriction, the pressure at the constriction decreases (Bernoulli principle), and if the pressure inside the tube falls below atmospheric pressure, then air is entrained into the tube (venturi effect)

Adjusting the diameter of the constriction allows for control of the pressure drop and the amount of air that is sucked into the tube. The key here is air entrainment!

Examples: Jet ventilator, Venturi, and nebulizer

Question 25

Explain the Coanda effect, and give some examples

Answer 25

The Coanda effect describes how a jet flow attaches itself to a nearby surface and continues to flow along that surface even when the surface curves from the initial jet direction Examples: Wall-hugging jet of mitral regurgitation and water that follows the curve of a glass

Question 26

How do you calculate the law of Laplace for a sphere? for a cylinder?

Answer 26

in spheres and cylinders, the law of Laplace illustrates the relationship between the wall tension, internal pressure, and radius. * Pressure is a pushing force. It pushes the walls of the object apart. * Tension is a pulling force. It holds the walls of the object together Surface tension of a sphere: * Tension= (pressure x radius) / 2 * Examples: alveolus, cardiac ventricle, saccular aneurysm Surface tension of a cylinder: * Tension= (pressure x radius) * Examples: blood vessels, aortic aneurysm

Question 27

What is the yearly maximum for radiation exposure? How does this change if someone is pregnant?

Answer 27

Non-pregnant person: * The yearly maximum radiation exposure is 5 rem * The eye and thyroid are most susceptible to injury Pregnant person: * The yearly maximum exposure for the fetus of a pregnant worker is 0.5 rem or 0.05 rem/month * the fetus is most susceptible to injury

Question 28

list 3 ways to protect yourself from radiation exposure.

Answer 28

* distance * Duration * shielding

Question 29

How can we apply the inverse square law to radiation exposure?

Answer 29

Distance is an easy way to protect yourself from ionizing radiation. The minimum safe distance from the radiation source is 6 ft Radiation exposure obeys the inverse square law. It states that the amount of exposure is inversely proportional to the square of the distance of the source Intensity = 1/distance^2 We can quantify the amount of exposure at two different locations with the following equation: Intensity1= distance2^2 Intensity2= distance1^2

Question 30

What is boiling point, and how is it affected by atmospheric pressure?

Answer 30

The boiling point is the temperature at which a liquid's vapor pressure equals atmospheric pressure * Increase P atm -> increase boiling point (example: hyperbaric oxygen chamber) * Decreased P atm -> decrease boiling point (example: high altitude)

Question 31

Define specific heat

Answer 31

specific heat is the amount of heat required to increase the temperature of 1 gram of a substance by 1 degree C

Question 32

define vapor pressure.

Answer 32

In a closed container, molecules from a volatile liquid escape the liquid phase and enter the gas phase. The molecules in the gas phase exert pressure on the walls of the container. This is vapor pressure.

Question 33

Define vaporization.

Answer 33

Vaporization is the process by which a liquid is converted to a gas. This requires energy (heat)

Question 34

Define heat of vaporization.

Answer 34

Heat of vaporization is the number of calories required to vaporize 1 mL of liquid

Question 35

explain latent heat of vaporization, and apply this anesthetic vapor inside of a vaporizer.

Answer 35

latent heat of vaporization is the number of calories required to convert 1 gram of liquid to vapor WITHOUT a temperature change in the liquid. Let's apply this to what happens inside the vaporizer: * Anesthetic liquid in the vaporizer exerts a vapor pressure inside the vaporization chamber. This means some of the agent exists as a liquid, and some exists as a gas * Fresh gas flows over the anesthetic liquid, carrying away some of the agent that exists in the gas phase. * This cools the remaining liquid, which reduces the vapor pressure of that liquid. Therefore, there are fewer anesthetic molecules that enter the gas phase * The net result is a decrease in the vaporizer output * modern vaporizers compensate for this temperature change

Question 36

Explain the Joule-Thompson effect in the context of gas cylinders.

Answer 36

The joule-thompson effect says that a gas stored at high pressure that is suddenly released escapes from its container into a vacuum. It quickly loses speed as well as a significant amount of kinetic energy, resulting in a fall in temperature. This explains why an oxygen cylinder that is opened quickly feels cool to the touch. Conversely, rapid compression of a gas intensifies its kinetic energy, causing the temperature to rise Remember: Joule is cool

Question 37

What is an adiabatic process?

Answer 37

Adiabatic process describes the process that occurs without gain or loss of energy (heat). For example, a very rapid expansion or compression of a gas where there is no transfer of energy is an example of an adiabatic process

Question 38

What is critical temperature, and how does this apply to gas cylinders?

Answer 38

critical temperature is the highest temperature where a gas can exist as a liquid. Said another way, it is the temperature above which a gas cannot be liquified regardless of the pressure applied to it. The critical temp for nitrous oxide is 36.5C, which explains why it primarily exists as a liquid inside the cylinder (room temperature is abou 20 C). Conversely, the critical temperature of oxygen is -119 c, so it exists as a gas inside the cylinder. Of the gases used in the OR, only N2O and CO2 have critical temperatures above room temperature

Question 39

What is the critical pressure?

Answer 39

Critical pressure is the minimum pressure required to convert a gas to a liquid at its critical temperature.

Question 40

Know the temperature conversion formulas.

Answer 40

Cesius to Kelvin and back: * Celsius= K-273.15 * Kelvin= C+ 273.15 Cesius to Fahrenheit and back: * Cesius = (F-32) x 5/9 * Fahrenheit = (cx1.8) + 32

Question 41

Define Pressure.

Answer 41

Pressure= Force/Area * Increased area -> decreased pressure * Decreased area -> increased pressure

Question 42

Know the pressure conversion factors.

Answer 42

You should be able to convert between the common units of pressure. All of the following are equal: * 1atm= 760 mmHg = 760 torr = 1 bar = 100kPa = 1033 cm H2O = 14.7 lb/inch^2 * 1mmHg = 1.36 cm H2O * 1 cmH2O = 0.74 mmHg

Question 43

What is Avogadro's number?

Answer 43

Avogadro's number says that 1 mole of any gas is made up of 6.023 x 10^23 atoms * A mole of a gas is equal to the molecular weight of that gas in grams * if a molecule is a diatomic (O2), you must account for both atoms

Question 44

What are the 4 mechanisms of heat transfer? Rank them from most to least important

Answer 44

Radiation - infrared (60%) convection- air (15-30%) Evaporation - water loss (20%) Conduction - contact (<5%)

Question 45

explain the 3 stages of intraoperative heat transfer

Answer 45

when no attempts are made to maintain normothermia, heat transfer follows a triphasic curve Phase 1: heat redistribution from core to periphery: 0-1 hours phase 2: heat transfer > heat production: 1-5 hours Phase 3: heat transfer is same as heat production: 5-7 hours

Question 46

what are the consequences of perioperative hypothermia?

Answer 46

Cardiovascular: * SNS stimulation * Shifts oxyhemoglobin dissociation curve to the left * vasoconstriction + decreased tissue PO2 * Coagulopathy + platelet dysfunction * Sickling of hemoglobin S Pharmacologic * slowed drug metabolism * increased solubility of volatile agents Clinical relevance * Myocardial ischemia and dysrhythmias * Decreased O2 available to tissue *Surgical site infection * increased blood loss * Risk of sickle cell crises * prolonged effects of anesthetic agents * prolonged emergence

Question 47

Name 3 drugs that can be used to treat postoperative shivering

Answer 47

shivering increases oxygen consumption up to 400-500%. This increases the risk of myocardial ischemia and infarction Pharmacologic modalities used to treat postoperative shivering include: * Meperidine (kappa) * Clonidine (alpha 2) * dexmedomidine (alpha-2)

Question 48

when is hypothermia a good thing?

Answer 48

Although there are many reasons why perioperative hypothermia contributes to poor outcomes, there are several circumstances where it can improve outcomes. All of these are based on the fact that oxygen consumption is reduced by 5-7% for every 1 degree reduction of body temp. Induced hypothermia is useful during: * Cerebral ischemia (stroke) * Cerebral aneurysm clipping * Traumatic brain injury * Cardiopulmonary bypass * cardiac arrest * Aortic cross-clamping * carotid endarterectomy

Question 49

in which region of the esophagus should be an esophageal temperature probe be placed? How does misplacement affect the reading?

Answer 49

It should be placed in the distal 1/3rd - 1/4th of the esophagus (38-42cm pas the incisors) * increased is placed in the stomach due to heat created by liver metabolism * Decreased is placed in the proximal esophagus due to cool inspiratory gas

Question 50

compare and contrast various sites of temperature measurement

Answer 50

Question 51

what are the three ingredients required to produce a fire? Give examples of each

Answer 51

Fuel: ETT, drapes, surgical supplies Oxidizer- oxygen, nitrous oxide Ignition source: electrosurgical cautery, laser

Question 52

Detail the steps you would take during an airway fire.

Answer 52

Steps to take when fire is present: 1. Stop ventilation and remove ETT 2. stop the flow of all airway gases 3. remove other flammable material from the airway 4. pour water or saline into the airway 5. if the fire isn't extinguished on the first attempt, then use a CO2 fire extinguisher Steps to take after fire is controlled 1. Re-establish ventilation by mask. Avoid supplemental O2 or Nitrous oxide 2. Check ETT for damage- fragments may remain in the patient's airway 3. Perform bronchoscopy to inspect for airway injury or retained fragments Do NOT squeeze the resevoir bag as you extubate the pt. This can create a blow torch effect at the distal end of the ETT and/or push debris into the lower airway

Question 53

What does "laser" stand for? How is it different from ordinary light?

Answer 53

Laser: Light Amplification by Stimulated Emission of Radiation. Laser light differs from ordinary light because it is: * Monochromatic (the light is a single wavelength) * Coherent (the light oscillates in the same phase) * Collimated (the light exists as a narrow parallel beam)

Question 54

What is the difference between a long and short wavelength laser? What are the clinical consequences of this?

Answer 54

Long wavelength lasers: * Absorb more water and do NOT penetrate deep into tissue * The cornea is at risk Short wavelength lasers: * Absorb less water and penetrate deeper into tissue * The retina is at risk CO2 = used in Oropharyngeal and vocal cord surgeries, can damage corneas, wavelength: 10,600 Nd:Yag: used for tumor debulking, and tracheal surgeries, can damage the retina, wavelength: 1,064 Ruby: used for retinal surgeries, can damage the retina, wavelength 694nm Argon: used for vascular lesion, can damage retina, wavelength: 515nm

Question 55

What color goggles must be worn for each type of laser: CO2, ND:YAG, Ruby, and Argon?

Answer 55

* CO2= Clear * Ruby= red * Argon= Amber * nd: YAG= Green

Question 56

Discuss the flammability of ETT in the context of laser surgery on the airway.

Answer 56

Things to know about airway surgery that require a laser: * Most ETT are flammable (PVC, Red rubber, silicone) * Laser reflective tape is no longer advised. It's smarter to use a laser resistant ETT * Laser resistant ETTs are NOT laser proof! *The cuff is the most vulnerable component of the ETT * Fill the cuff with saline (dye is optional). This helps absorb the thermal energy produced by the laser, which makes the balloon less likely to ignite * Many laser resistant ETTs have 2 cuffs. The proximal cuff is filled with saline or dye. If it becomes perforated by the laser, then the distal cuff will hopefully remain intact and permit continued PPV. * Laser resistant ETTs do not reduce the risk of fire when electrosurgical cautery is used

Question 57

Describe the 4 degrees of burns. Which require a skin graft?

Answer 57

Question 58

Describe the rule of 9's. How does this apply to the adult?

Answer 58

Burn severity is a function of the depth of the burn as well as the fraction of the total body surface area (TBSA) consumed by the burn. * The TBSA is divided into areas representing 9% (or multiples of 9%) * Due to rounding, the numbers do not add to 100 * this concept is important for calculating fluid requirements

Question 59

How is the rule of 9's different for children?

Answer 59

The child's head is 19% of the TBSA (9.5% front and 9.5% back) * As a general rule: for every year of age> 1 year up to 10 years, you can decrease the head surface area by 1% and increase each leg by 0.5%

Question 60

Describe the consequences of the capillary leak that occurs after a burn.

Answer 60

Immediately after a burn, microvascular permeability increases, and this creates a capillary leak. The magnitude of the leak becomes greater in the presence of a major burn, inhalation injury, or a delay in resuscitative efforts Consequences of the capillary leak: * Increased vascular permeability -> edema formation * Loss of protein-rich fluid to the interstitial space -> decreased plasma oncotic pressure -> edema formation * Loss of intravascular volume -> hypovolemia & shock Fluid shifts and edema formation are greatest in the first 12 hours and begin to stabilize by 24hrs. This explains why fluid requirements are higher in the first 24hrs following a burn *Albumin should be avoided during the first 24 hours because it is lost to the interstitial space * Hemolysis is common during the initial stage, however, profound hypovolemia promotes hemoconcentration * Rising Hgb in the first few days suggests inadequate volume resuscitation * Consider transfusion if Hct < 20 (healthy pt) or Hct < 30 (preexisting cardiovascular dx)

Question 61

Describe the Parkland formula for resuscitation in burn pts.

Answer 61

First 24 hrs: * Crystalloid= 4mL LR x %TBSA burned x kg (1/2 in 1st 8 hours then 1/2 in the next 16hrs) * Colloid= none Second 24hrs: * Crystalloid = D5W at a normal maintenance rate * Colloid= 0.5mL x %TBSA burned x kg

Question 62

Describe the modified Brooke formula for resuscitation in burn pts.

Answer 62

First 24hr: * Crystalloid= 2mL LR x %TBSA burned x kg (1/2 in 1st 8 hr then 1/2 next 16 hrs) * Colloid= none Second 24hrs * Crystalloid = D5W maintenance rate * Colloid= 0.5mL x % TBSA burned x kg

Question 63

What is an acceptable urine output in a burned pt? is this different in children or pts who've suffered a high voltage electrical injury?

Answer 63

Urine output goals: * Adult: > 0.5mL/kg/hr * Child= >1mL/kg/hr * High voltage electrical injury = 1- 1.5mL/kg/hr * Myoglobinemia is the result of extensive muscle damage following a high voltage electrical injury. Remember that myoglobin is nephrotoxic and needs to be flushed out of the body.

Question 64

Why is the burn pt at risk for abdominal compartment syndrome? what is the diagnosis and treatment of this complication?

Answer 64

Abdominal compartment syndrome: * May result from aggressive fluid resuscitation * Intra-abdominal HTN is define at IAP > 20mmHg or >12mmHg AND evidence of organ dysfunction (hemodynamic instability, oliguria, increased PIP) * Treatment: Neuromuscular blockade, sedation, diuresis, and abdominal decompression via laparotomy

Question 65

discuss the clinical considerations for the pt with carbon monoxide poisoning.

Answer 65

Carbon Monoxide Poisoning * CO binds to Hgb with an affinity 200x that of O2 * CO shifts the oxyhemoglobin dissociation curve to the left , which impairs offloading of oxygen to the tissues * Oxidative phosphorylation is also impaired * Inadequate oxygen delivery and utilization cause metabolic acidosis * blood takes on a cherry red apearance * The pulse oximeter is NOT accurate in the pt with CO poisoning because it is unable to distinguish between HgbO2 and HgbCO * The SpO2 may give falsely elevated result * treatment includes 100% FiO2 or hyperbaric oxygen

Question 66

Discuss the use of neuromuscular blockers in a burn pt

Answer 66

Up-regulation of extrajunctional receptors begins after 24hrs * Succ's is safe within the first 24hrs following the burn, but its use can cause lethal hyperkalemia after 24 hrs * the dose of non-depolarizing NMBs should be increased 2-3 fold (there are more receptors)

Question 67

Describe the physiologic changes that accompany electroconvulsive therapy

Answer 67

the seizure caused by ECT results in profound physiologic changes. * Initial response: Increased PNS activity during the tonic phase (last approx 15 seconds) * Secondary response: increased SNS activity during the clonic phase (lasts several minutes)

Question 68

Discuss the absolute and relative contraindications to ECT

Answer 68

Contraindications are typically related to an increased SNS response or increased ICP The most common causes of death are myocardial infarction and cardiac dysrhythmias. Having said this, pts with co-existing cardiovascular dx can safely undergo ECT provided that hemodynamics are well managed

Question 69

Compare and contrast neuroleptic malignant syndrome with malignant hyperthermia

Answer 69

NMS is caused by dopamine depletion in the basal ganglia and hypothalamus * Causes: Dopamine antagonists or withdrawal from dopamine agonists * tx: Bromocriptine, dantrolene, supportive care, ECT

Question 70

What is the etiology ad tx of serotonin syndrome?

Answer 70

Serotonin syndrome occurs when there's excess 5-HT activity in the CNS and PNS. Key drug interactions that increase the risk of serotonin syndrome include: SSRI (citalopram, dapoxetine, fluoxetine (prozac), sertraline) and: * meperidine * Fentanyl * Methylene blue

Question 71

What are the determinants of intraocular pressure? what's the normal value?

Answer 71

Intraocular perfusion pressure = MAP - ICP the globe is a relatively non-compliant compartment. Therefore, IOP is determined by the choroidal blood volume, aqueous fluid volume, and extraocular muscle tone * Normal IOP = 10 - 20mmHg * Aqueous humor is produced by the ciliary process (posterior chamber) * Aqueous humor is reabsorbed by the canal of Schlemm (anterior chamber)

Question 72

what factors reduce IOP? which increase it?

Answer 72

Increase IOP: * Hypercarbia * Hypoxemia * increase CVP * increased MAP * Laryngoscopy/intubation * Straining/ coughing * succ's * Nitrous oxide (if SF6 bubble in place) * Trendelenburg position * Prone position * External compression by facemask Decreased IOP * Hypocarbia * Decreased CVP * Decreased MAP * Volatile anesthetics * Nitrous oxide * Nondepolarizing NMB * Propofol * Opioids * Benzos * Hypothermia LMA placement and/or removal has a minimal effect on IOP * Ketamine may or may not increase IOP, but it does cause rotary nystagmus and blepharospasm. For this reasons it should be avoided during eye surgery

Question 73

What is the difference between open and closed angle glaucoma?

Answer 73

Glaucoma is caused by a chronically elevated IOP that leads to retinal artery compression * Open-angle glaucoma is caused by sclerosis of the trabecular meshwork. This impairs aqueous humor drainage * Closed-angle glaucoma is caused by a closure of the anterior chamber. This creates a mechanical outflow obstruction IOP is reduced by drugs that reduce aqueous humor production or facilitate aqueous humor drainage (causes miosis)

Question 74

which drugs reduce aqueous humor production? which increase aqueous humor drainage?

Answer 74

Aqueous humor is produced by the ciliary process (posterior chamber), and it is reabsorbed by the canal of Schlemm (anterior chamber) Drugs that decrease aqueous humor production: * Acetazolamide inhibits carbonic anhydrase and decreases aqueous humor production * Timolol is a non-selective beta antagonist that decreases aqueous humor production Drugs that facilitate aqueous humor drainage: * Echothiophate is an irreversible cholinesterase inhibitor that promotes aqueous humor drainage via the canal of Schlemm * It can prolong the duration of succinylcholine and ester-type local anesthetics

Question 75

what is strabismus correction? What unique considerations apply to the anesthetic management of these patients?

Answer 75

Strabismus surgery corrects the misalignment of the extraocular muscles and re-establish the visual axis. There are 3 key considerations in this population: * Increased risk of PONV * Increased risk of activating the oculocardiac reflex (afferent CN 5 + Efferent CN 10)

Question 76

Which patient populations benefit from a TAP block?

Answer 76

The transverse abdominal plane block (TAP) is a unilateral peripheral nerve block that targets the nerves of the anterior and lateral abdominal wall. * It's best suited for abdominal procedures (general, GYN, and urologic) that involve the T9 to L1 distribution * Bilateral TAP blocks are required for a midline incision or laparoscopic surgery

Question 77

Describe the anatomy and landmarks required to perform a TAP block

Answer 77

Abdominal wall structures organized from superficial to deep: Subcutaneous tissue -> external oblique muscle -> Internal oblique->Transverse abdominis muscle -> peritoneum

Question 78

Define allodynia and give an example

Answer 78

Allodynia is pain due to a stimulus that does not normally produce pain Ex fibromyalgia

Question 79

Define dysesthesia and give an example

Answer 79

Dysesthesia is an abnormal and unpleasant sense of touch Ex. Burning sensation from diabetic neuropathy

Question 80

Define neuralgia and give an example

Answer 80

Neuralgia is pain localized to a dermatome Ex: Herpes Zoster (shingles)

Question 81

What is the defining characteristic between Type I and type II complex regional pain syndrome?

Answer 81

There are 2 types of CRPS: * Type 1 (reflex sympathetic dystrophy) * Type 2 (causalgia) Complex regional pain syndrome is characterized by neuropathic pain with autonomic involvement. The key distinction is that type 2 CRPS is always preceded by nerve injury (type 1 is not)

Question 82

Discuss the use of a thoracic paravertebral block

Answer 82

* Local anesthetic injected into the paravertebral space (a potential space) targets the ventral ramus of the spinal nerve as it exits the vertebral foramen * This creates a unilateral sensory and sympathetic block along that specific dermatome * You can think of the paravertebral block to a single shot, unilateral epidural block * You'll have to perform one block at each dermatome to be anesthetized * The thoracic paravertebral block provides analgesia for breast surgery, thoracotomy, and rib fractures

Question 83

what structures are anesthetized by a celiac plexus block? How about a superior hypogastric block?

Answer 83

Celiac Plexus Block: * The celiac plexus block innervates the upper abdominal viscera (except the left side of the colon) * It does NOT innervate the pelvic organs * therefore, it is useful for pain from the upper abdominal organs, but not the pelvic organs (useful in cancer pts) liver, pancreas, gallbladder, kidneys, intestines, adrenal glands and blood vessels Superior hypogastric plexus block * The superior hypogastric plexus innervates the pelvic organs * Blockade of the superior hypogastric plexus is useful in patients with pain involving the pelvic organs (useful in cancer pts) colon, bladder, lower intestines, uterus, ovaries, prostate

Question 84

Aside from an epidural blood patch, which regional technique is used to release post-dural puncture headache?

Answer 84

Sphenopalatine block (through the nose)

Question 85

What is post-retrobulbar block apnea syndrome?

Answer 85

The optic nerve is unique because it is the only cranial nerve that is part of the central nervous system (it is enveloped by the meningeal sheath and bathed in CSF). Because of this, a local anesthetic injected into the optic sheath is permitted direct entry to the brain. It's likely giving a subarachnoid block in the optic sheath!

Question 86

Discuss the use of cephalosporins in the PCN allergic pt also what antibiotic are grouped together and what are their side effects

Answer 86

Previous literature suggested a high rate of cross-reactivity between PCN and cephalosporins (up to 10%). These numbers are grossly overstated (due to contamination during the manufacturing process) If a pt reports an allergy to PCN, then s/he may receive a cephalosporin if the reaction: * Was NOT IgE mediated (anaphylaxis, bronchospasm, urticaria) * Did NOT produce exfoliative dermatitis (stevens-johnson syndrome) if the pt experienced any of these complications, then vancomycin or clindamycin are acceptable alternatives Cephalosporins : cefaclor, cehpalexin, Ceftriaxone, cefazolin, cefoxitin, cefuroxime

Question 87

What is the antibiotic of choice to treat MRSA? What are the special considerations for the administration of this antibiotic?

Answer 87

Vancomycin is the drug of choice for patients with active MRSA To reduce histamine release and HoTN, vanco should be administered at a rate of 10-15 mg/kg over 1 hour The histamine response to vanco can be minimized by diphenhydramine 1mg/kg + cimetidine 4mg/kg 1 hour before anesthesia

Question 88

Discuss the different levels of infection control precautions. Give examples with specific pathogens

Answer 88

Question 89

what is the rate of seroconversion following exposure to HIV infected blood

Answer 89

The most common cause of occupational exposure to HIV is needle-stick with a hollow-bore needle. Seroconversion rates after exposure to HIV-infected blood: * Percutaneous injury (needle-stick) = 0.3% * Mucous membrane exposure = 0.09%

Question 90

What are the functions of the 5 types of white blood cells?

Answer 90

white blood cells can be divided into granulocytes (neutrophils, basophils, and eosinophils) and agranulocytes (monocytes and lymphocytes): Neutrophils: * Fight bacterial and fungal infection * Make up 60% of all WBC's (most abundant WBC type) Basophils: * Are the essential component of hypersensitivity reactions * Release histamine, serotonin, heparin, and bradykinin (mast cells do the same thing) * Epinephrine prevents degranulation (release of intracellular contents) by binding to beta-2 receptors on the cell membrane Eosinophils: * Defend against parasites Monocytes * phagocytosis *release cytokines * present pieces of pathogens to T-lymphocytes

Question 91

Describe the presentation of anaphylaxis

Answer 91

Question 92

what hypersensitivity reactions stimulate the H1 and H2 receptors and what are their effects?

Answer 92

Question 93

Describe the pathophysiology of the 4 types of hypersensitivity reactions. List examples of each.

Answer 93

Type 1: Immediate hypersensitivity: * IgE- Antigen + antibody interaction in a pt who has been previously sensitized to the antigen * Examples: anaphylaxis, extrinsic asthma Type 2: Antibody-mediated: * IgG and IgM antibodies bind to cell surfaces or extracellular regions * Examples: ABO-incompatibility, heparin-induced thrombocytopenia Type 3: Immune complex-mediated * An immune complex is formed and deposited into the pt's tissue (normally, these complexes are cleared from the body) * Examples: Snake venom reaction, protamine induced vasoconstriction Type 4: Delayed * Allergic reaction is delayed at least 12 hours following exposure. * Examples: contact dermatitis, graft-vs-host reaction, tissue rejection

Question 94

what is the tx for intraoperative anaphylaxis?

Answer 94

Tx of intraop anaphylaxis: * Discontinue the offending agent * Airway support: increased FiO2 and provide airway support * Epinephrine: start with 5 - 10mcg IV for hypotension and 0.1-1mg IV for cardiac collapse * Liberal IV hydration: Crystalloid 10-25 mL/kg or colloid 10mL/kg (repeat if necessary) * H1-receptor antagonist: Diphenhydramine 0.5-1 mg/kg IV * H2-receptor antagonist: Ranitidine 50mg IV or famotidine 20mg IV * Hydrocortisone 250mg IV (prevents delayed release of inflammatory compounds - does not produce an immediate effect) * Albuterol for bronchospasm * Vasopressin for refractory HoTN,. Start at 0.01 unit/min

Question 95

What are the 3 most common causes of intraoperative anaphylaxis?

Answer 95

# 1 neuromuscular blockers (succinylcholine is most common) #2 latex #3 antibiotics

Question 96

Which pts are at the highest risk of latex allergy?

Answer 96

high-risk groups: * Spina bifida/myelomeningocele * Atopy (heightened immune response- asthma, allergic rhinitis) * Health care workers * Food allergy to banana, kiwi, mango, papaya, pineapple, tomato

Question 97

If you had to explain the "chemo man" to a friend, could you do it? practice it

Answer 97

C- Cisplatin (alkylating agent)- acoustic nerve injury + nephrotoxicity V- Vincristine and vinblastine (tubulin-binding drug= peripheral neuropathy B- Bleomycin (antitumor antibiotic)= pulmonary fibrosis (keep FiO2 <30%) D- Doxorubicin (antitumor antibiotic)= cardiotoxic 5- 5 fluorouracil (antimetabolite)= Bone marrow suppression M- Methotrexate (antimetabolite= Bone marrow suppression

Question 98

What are the 5 most important GI hormones? What is the key function of each?

Answer 98

Gastrin- when food enters the stomach, gastrin increases stomach acid and stimulates chief cells to secrete pepsinogen. In the presence of stomach acid, pepsinogen is converted to pepsin (aids in protein digestion) Secretin: Tells the pancreas to secrete bicarbonate and the liver to secrete bile Cholecystokinin: tells the pancreas to release digestive enzymes and the gallbladder to contract Gastric inhibitory peptide: Slows gastric emptying and stimulates pancreatic insulin release Somatostatin: the universal "off" switch for digestion

Question 99

What is gastric barrier pressure? why is it important?

Answer 99

the likelihood of gastroesophageal reflux is determined by barrier pressure. The higher the barrier pressure, the lower the likelihood of reflex Barrier pressure= LES pressure - intragastric pressure

Question 100

what are the 3 most important inputs to the vomiting center? what receptors are involved in each one?

Answer 100

The vomiting center resides in the nucleus tractus solitarius (medulla). Sensory input to the vomiting center arises from the chemoreceptor trigger zone, GI tract, and vestibular system

Question 101

what is the MOA of NK-1 antagonists? give an example of a drug in the class

Answer 101

Neurokinin-1 antagonists block substance P in the chemoreceptor trigger zone Ex: aprepitant

Question 102

What are the risk factors for PONV? It helps to divide them into pt, surgical, and anesthetic risk factors

Answer 102

Question 103

Name 2 antiemetics that prolong the QT interval

Answer 103

Droperidol and ondansetron

Question 104

List 2 contraindications for metoclopramide

Answer 104

As a dopamine antagonist, metoclopramide is contraindicated in the pt with Parkinson's dx As a prokinetic agent, metoclopramide is contraindicated in the pt with a bowel obstruction

Question 105

Where is the P6 acupressure point, and why is it important?

Answer 105

The P6 acupressure point is a nonpharmacologic method of reducing PONV

Question 106

How long must the tourniquet remain inflated after a bier block? why?

Answer 106

When used for a bier block, the tourniquet must remain inflated for at least 20 min after the local anesthetic is injected. Premature release increases the risk of seizure and/or cardiac arrest. * Bier block upper extremity: 250mmHg or 100mmHg over SBP (whichever is higher) * Bier block lower extremity: 350-400 mmHg or 2x over SBP (whichever is higher)

Question 107

what physiologic changes accompany tourniquet deflation?

Answer 107

Tourniquet release stresses the body in 2 ways: * restoring blood flow to the extremity produces a relative decrease in the circulating blood volume * the products of cellular hypoxia enter the systemic circulation Releasing the tourniquet produces transient changes that include: * increase EtCO2 * Decreased core body temperature * Decreased blood pressure * decreased SvO2 (SaO2 is usually normal) * Metabolic acidosis

Question 108

Discuss the role of the cyclooxygenase enzyme in the arachidonic acid cascade

Answer 108

COX-1 is always present It maintains normal physiologic function Inhibition of the COX-1 enzyme impairs platelet function, causes gastric irritation, and reduces renal blood flow COX-2 is not always present It is expressed during inflammation Inhibition of the COX-2 enzyme produces analgesic, anti-inflammatory, and antipyretic effects. Unlike opioids, there is a ceiling effect to analgesia *understanding this image will help you predict the side effects of COX inhibitors

Question 109

Compare the equianalgesic dose of ketorolac and morphine

Answer 109

ketorolac 30mg IV- morphine 10 mg IV

Question 110

what is Samter's triad? why is it important?

Answer 110

Aspirin exacerbated respiratory disease (Samter's triad) refers to the combination of asthma, allergic rhinitis, and nasal polyps. These patients can develop life-threatening bronchospasm following aspirin administration

Question 111

List 4 herbal supplements that increase bleeding risk

Answer 111

garlic ginger gingko biloba saw palmetto

Question 112

list 2 herbal supplements that reduce MAC

Answer 112

Kava Kava Valerian

Question 113

Chronic ingestion of which herbal medication can mimic Conn's syndrome?

Answer 113

licorice

Question 114

Describe the modified aldrete

Answer 114

the modified aldrete scoring system is used to assess readiness for PACU discharge. A score of 0 - 2 is awarded in 5 areas, where a score of 9 or more is generally accepted as discharge ready

Question 115

Compare and contrast android and gynecoid obesity

Answer 115

Android obesity (apple shape) * More common in men * characterized by central or abdominal visceral fat accumulation * increased risk of ischemic heart disease, hypertension, dyslipidemia, insulin resistance, and death Gynecoid obesity (pear shape): * more common in women * Characterized by gluteal and femoral fat accumulation * Unlike abdominal fat that is metabolically active, gynecoid fat is metabolically inactive and is primarily used for energy storage * increased risk of joint disease and varicose veins * This type of fat is associated with a reduced incidence of non-insulin-dependent diabetes

Question 116

What are the diagnostic indicators for metabolic syndrome?

Answer 116

MEtabolic syndrome (syndrome X) incorporates a number of disease states that coincide with obesity. Cardiovascular risk of 50-60% greater than the general population. In order to be diagnosed with metabolic syndrome, one must have at least 3 of the following signs: * Large waist circumference (men> 40 inches & women >35) * Triglycerides >150mg/dL * high density lipoprotein (HDL) < 40mg/dL for men and <50mg/dL for women * BP >135/85 * fasting glucose >110 mg/dL

Question 117

How can you use BMI to classify obesity?

Answer 117

Question 118

How can you classify obesity in children?

Answer 118

Child body weight 2- 18 yr weight percentile Overweight 85th-94th obese 95th-98th severely obese 99th

Question 119

what is the formula for BMI

Answer 119

BMI= weight (kg)/Height (m^2) (be careful with the units!)

Question 120

how can you calculate IBW for a man? for a woman?

Answer 120

Ideal body weight describes the BMI associated with the lowest risk of body weight- related comorbidities. We can estimate the IBW with the following formulas: * Men (kg)= height (cm)- 100 * Women (kg)= Height (cm)- 105

Question 121

Describe how obesity creates a restrictive ventilatory defect.

Answer 121

Lung inflation is inhibited due to the following: * Chest fat compresses the rib cage and hinders its outward expansion * Abdominal fat shifts the diaphragm cephalad and compresses the lungs * Kyphosis and lordosis develop over time and alter the geometry of the ribcage The extra weight on the chest increases the work of breathing. A rapid and shallow breathing pattern provides the most energy-efficient way to achieve this goal

Question 122

How does obesity affect respiratory gas tensions?

Answer 122

Fat is a metabolically active organ, so these patients have an increased oxygen consumption and carbon dioxide production. Minute ventilation must be increased to maintain normal blood gas tensions. While the obese patient may experience hypoxemia, PaCO2 is usually normal. This is explained by the high diffusing capacity of CO2 and the favorable characteristics of the CO2 dissociation curve. An elevated PaCO2 signals impending respiratory failure.

Question 123

How does obesity affect FRC? how about the other lung volumes and capacities?

Answer 123

FRC is inversely proportional to BMI. * the reduction in FRC (due to decrease in ERV) below closing capacity creates a situation where distal airway collapse occurs during tidal breathing * this leads to V/Q mismatch, shunt, and hypoxemia. Premature airway closure also increases dead space. * General anesthesia causes FRC to fall by 50% (non-obese around 20%) * A higher oxygen consumption coupled with a smaller FRC predisposes this population to rapid desaturation during apnea

Question 124

How can you reduce atelectasis in the morbidly obese patient who is mechanically ventilated?

Answer 124

Keep FiO2 < 80% during anesthetic maintenance to prevent absorption atelectasis. To recruit collapsed alveoli, you must do 2 things: * Re-open collapsed alveoli with a recruitment maneuver (valsalva). Give a breath to about 40cm H2O and hold for 10 seconds. This may temporarily reduce venous return, blood pressure, and heart rate * hold open the re-expanded alveoli with PEEP or CPAP 5-10 cm H2O. This improves FRC, V/Q matching, and arterial oxygenation. It may reduce venous return and cause HoTN.

Question 125

what is the optimal tidal volume for a morbidly obese pt who is mechanically ventilated?

Answer 125

Use a tidal volume of 6-8 mL of Ideal Body Weight. Higher tidal volumes only minimally increase PaO2 and may cause sheer stress to the lungs Try to control PaCO2 by adjusting the respiratory rate, not by increasing tidal volume.

Question 126

Does a morbidly obese pt require a rapid sequence induction? why or why not?

Answer 126

Obesity alone does not mandate a rapid sequence intubation There is conflicting evidence regarding the effects of obesity on gastric pH, residual gastric volume, and gastric emptying time. Despite these conflicts, there is no data that illustrate an increased incidence of pulmonary aspiration on the basis of BMI alone and that the decision for a RSI should be made on a case-by-case basis. Patients with other risk factors, such as GERD or diabetes, should be considered candidates for aspiration prophylaxis and RSI.

Question 127

How does obesity impact the cardiovascular system?

Answer 127

The expansion of intravascular blood volume and a high cardiac output state are the key changes that lead to cardiovascular complications of obesity. The proliferation of adipocytes requires that the vasculature grows in order to support their growth. This requires an increased blood volume and cardiac output. An increase stroke volume is responsible for the increased cardiac output (HR is usually normal) A larger vascular network, blood volume, and oxygen consumption place a higher workload on the myocardium. Venous return must match cardiac output, so the heart dilates to accept the larger incoming volume. Additionally, it becomes thicker to compensates for the increased wall stress. This reduces ventricular compliance and causes diastolic dysfunction. Eventually, the heart dilates beyond its ability to increase wall thickness. At this point, the pt will experience systolic dysfunction and ultimately biventricular heart failure. HTN is the result of hyperinsulinemia, SNS and RAAS activation, as well as an elevated cytokine Concentration in the plasma

Question 128

Describe the EKG changes that can accompany obesity

Answer 128

Low voltage EKG: Increased distance between heart and leads left axis deviation: the stomach pushes the heart up and to the left. Also, there is LVH secondary to volume overload and HTN Right axis deviation: Right ventricular hypertrophy from OSA and volume overload QT prolongation: Increases the risk of sudden death Ischemia: Oxygen supply and demand mismatch Dysrhythmias: Caused by fatty infiltration of the conduction system, myocardial hypertrophy, hypoxemia, hypercarbia, obesity hypoventilation syndrome, and ischemic heart dx

Question 129

What valvular defect is highly suggestive of pulmonary HTN in the obese pt?

Answer 129

The presence of tricuspid regurgitation on TEE may be the most useful confirmation of pulmonary HTN

Question 130

what factors affect volume of distribution in the obese population?

Answer 130

the volume of distribution of a drug in the obese pt is altered by: * increased blood volume- requires a higher dose to achieve a given plasma concentraiton * increased cardiac output- faster drug delivery to the vessel righ group * altered plasma protein binding- altered free fractions available * lipid solubility of the drug- large fat mass greatly increased Vd for lipophilic drugs Increased body weight comes with an increased volume of distribution for both hydrophilic and lipophilic drugs. Remember that fat mass AND muscle mass increase. This means that the Vd for water-soluble drugs will increase some because the plasma volume is larger, but the Vd for fat-soluble will increase a whole lot more because of the large fat mass: Vd lipophilic >>> Vd hydrophilic drugs *but both increase!

Question 131

how does obesity impact your selection of inhaled anesthetic agents?

Answer 131

Inhalation agents in the obese population * MAC is not changed by obesity * Volatile anesthetics are lipophilic, so agents with the lowest blood:gas coefficients should be used * Sevoflurane or des provide a faster emergence than isoflurane or propofol * Nitrous oxide is generally avoided, because it restricts FiO2 that can be delivered

Question 132

how does obesity affect the dosing of propofol?

Answer 132

the loading dose of propofol is based on Lean body weight. This is because its offset is caused by redistribution and not clearance (which would depend on Vd) * induction: LBW * Maintenance: TBW

Question 133

How does obesity affect the dosing of succ's?

Answer 133

even though succ's is a water-soluble drug, the dose for intubation is calculated with TBW. This is a clear exception to the rule for water-soluble drugs. SHortly stated, the combination of an increased blood volume (increased Vd) and increased pseudocholinesterase activity (increased clearance) necessitates a TBW dose to be given to ensure adequate paralysis * induction: TBW

Question 134

How does obesity affect the dosing of nondepolarizing neuromuscular blockers?

Answer 134

Rocuronium and vecuronium are distributed throughout body water and are dosed on LBW. Loading doses of cisatracurium and atracurium should probably be dosed on TBW. However, the recommendations for maintenance dosing are far from consistent. Roc/vec * induction: LBW Maintenance: LBW cis/atracurium Induction: TBW Maintenance: TBW or LBW

Question 135

How does obesity affect the dosing of opioids

Answer 135

Because of their fat solubility and large Vd, the initial dose of fentanyl and sufentanil are based according to TBW. Maintenance dosing is based on LBW. An increased Vd correlates with a prolonged elimination half-life. Remifentanil is the exception. Since it is rapidly cleared by plasma esterases, it does not behave like a high Vd drug, so remi is always based on LBW. Fent/sufent: * loading: TBW * Maintenance: LBW Remi: * Loading: LBW * Maintenance: LBW

Question 136

how does obesity affect the dosing of an epidural?

Answer 136

Engorgement of the epidural veins and an increased epidural fat content will cause a greater spread of local anesthetic in the epidural space. For this reason, the dose should be reduced to 75% of the normal dose

Question 137

Name the key muscles that control the diameter of the upper airway, and describe their functions

Answer 137

You can think of the pharynx as a collapsible tube. Airway patency is maintained by the balance between pharyngeal muscles that dilate that airway and the negative pressure of inspiration that collapses it

Question 138

Define Hypopnea.

Answer 138

Hypopnea is defined as a 50% reduction in airflow for 10 seconds, 15 or more times per hour, and is linked to snoring and decreased oxygen saturation

Question 139

Discuss the pathophysiology of OSA

Answer 139

OSA is defined as the cessation of airflow for at least 10 seconds (apnea) with 5 or more unsuccessful efforts to breathe (obstruction) and a greater than 4% reduction in SaO2

Question 140

What is the definitive test for OSA? What does it measure? how do you interpret the findings?

Answer 140

Polysomnography is the definitive test for OSA. The results of this test allow for the calculation of the apnea-hypopnea index (AHI), which is used to quantify the severity of OSA. AHI= number of episodes of apnea and hypopnea/hours of sleep The American academy of sleep medicine defines OSA as: * mild= 5-15 episodes/hr * Moderate= 15-30 episodes/hr * severe= >30 episodes/hr Pts with severe sleep apnea are at higher risk of difficult mask ventilation and difficult intubation

Question 141

What is the bedside test to identify undiagnosed OSA? How do you interpret the findings?

Answer 141

Most pts with OSA haven't had a sleep study, don't even realize they have OSA! the STOP-BANG scoring system is a bedside tool that allows you to predict the likelihood that a pt has undiagnosed OSA. * high risk= >3 questions answered yes * low risk = < 3 questions answered yes

Question 142

What is obesity hypoventilation syndrome? How do you identify a pt with this condition?

Answer 142

Obesity hypoventilation syndrome is a long-term consequence of untreated OSA. Over time, the respiratory center in the medulla fails to respond to hypercarbia appropriately. The classic presentation of OHS includes episodes of apnea during sleep WITHOUT any respiratory effort. Pickwickian syndrome is the old school name for OHS. Diagnostic criteria: * BMI > 30 kg/m^2 * Awake PaCO2 >45 mmHg * Dysfunctional breathing during sleep Signs: * Obesity * hypersomnolence during the day * Hypoxemia * hypercarbia * respiratory acidosis * compensatory metabolic alkalosis * polycythemia * pulmonary HTN

Question 143

What are the most common signs of an anastomotic leak following gastric bypass?

Answer 143

Gastric bypass is associated with a 2% incidence of anastomotic leak. Unexplained tachycardia is the most sensitive sign of an anastomotic leak. An unexplained HR > 120bpm should send up a red flag, even if the pt shows no other signs The most common S/sx include: * Tachycardia (72%) * Fever (63%) * abdominal pain (54%) Ketorolac probably increases the incidence of this complication, so it should be avoided in the perioperative period

Question 144

what is Ma huang? What are the complications of its use?

Answer 144

Ma huang is a natural source of ephedrine, an indirect-acting adrenergic agonist and thermogenic agent. Any drug interactions that would occur with ephedrine will apply here as well. Complications of adrenergic overstimulation including HTN, CVAs, seizures, and death, have occurred with the use of Ma huang containing drugs.

Question 145

What is Orlistat? what are the complications of its use?

Answer 145

Orlistat is a lipase inhibitor that reversibly binds to lipase and hinders the absorption and digestion of consumed fats. Since fat and the vitamins it contains (A, E, D, K) are not absorbed by the gut, they must be supplemented orally. Insufficient quantities of vitamin K will impair the synthesis of clotting factors 2, 7, 9, 10 and may cause coagulopathy.

Question 146

How does the Trendelenburg position affect the distribution of blood volume, MAP, and venous pressure?

Answer 146

Blood shifts towards the central circulation: * Increase venous return -> increase position on the Frank-Starling curve * caution with heart failure MAP stays the same or increases: * Although venous return initially increases, this is followed by vasodilation and a slower heart rate venous pressure increases: * Hydrostatic pressure -> edema of the face, eye, and airway * Intracranial HTN

Question 147

How do position changes affect respiratory function?

Answer 147

Question 148

How do position changes affect the position of the ETT?

Answer 148

Securing the ETT after intubation fixes its location. For the rest of the procedure, the position of the carina in the chest. Neck position * Neck flexion pushes the ett toward the carina. This increases the risk of endobronchial intubation * Neck extension pulls the ett tip towards the vocal cords. This increases the risk of inadvertent extubation. * Remember, "the tube goes where the nose goes" Carina position * in the trendelenburg position, the abdominal contents shift cephalad. This pushes the diaphragm towards the ett, increasing the risk of endobronchial intubation

Question 149

Which positions increase the risk of post-operative airway edema, and how can you assess the severity of this complication?

Answer 149

Edema of the face, tongue, pharynx can affect airway patency. *prone and trendelenburg: increased hydrostatic pressure -> edema formation * Sitting: Neck flexion impairs venous drainage from the head -> edema formation If you have a concern about the patency of the airway prior to extubation, you can: * perform a leak test to assess for air movement around the ETT while the pt is spontaneously ventilating * Visually inspect the larynx with direct laryngoscopy

Question 150

Discuss how the brachial plexus is susceptible to stretch and compression injury

Answer 150

Stretch injury: * Stretch injury occurs because the brachial plexus is anatomically fixed at two locations: the cervical vertebrae and the axillary fascia * As a general rule, the risk of stretch injury is highest when the arms are abducted >90 degrees and/or the head is rotated to one side Compression injury * Compression injury usually occurs when the brachial plexus is compressed as it passes between the clavicle and first rib or by an external force (shoulder brace or bean bag)

Question 151

Should shoulder braces be used for the pt in the Trendelenburg position? why or why not?

Answer 151

Although shoulder braces were developed to prevent the pt from sliding on the OR table, they cause more harm than good! * the best answer is never use shoulder braces. A non-sliding mattress is a safer option * if shoulder braces are used, they should be placed at the distal end of each clavicle (over the acromion) * Shoulder braces applied near the base of the neck or midway along the clavicle increase the risk of a compression injury

Question 152

How do you assess a pt for thoracic outlet syndrome? which surgical position increase the likelihood of this complication?

Answer 152

Thoracic outlet syndrome is more likely to occur in any position where the arms are placed over the head (prone). During the preoperative interview, ask the pt to clasp her hands behind her head. If she complains of pain, this may suggest an increased risk of thoracic outlet syndrome. It may be prudent to tuck the arms while in the prone position. Thoracic outlet syndrome occurs from compressed vessels or nerves causing pain, in the shoulder and neck and numbness, weakness, and coldness in the fingers

Question 153

Where should an axillary roll be placed for the pt in the lateral decubitus position?

Answer 153

An axillary roll is placed distal to the axilla A roll placed inside the axilla can cause neurovascular compression. A poor SpO2 signal in the dependent arm is a good monitor for this.

Question 154

describe the anatomy of the cubital tunnel.

Answer 154

Boundaries of the cubital tunnel: * medial epicondyle of the humerus * Olecranon process of the ulna * cubital tunnel retinaculum (creates the roof of the cubital tunnel) The ulna n. emerges from the cubital tunnel between the humeral and ulnar heads of the flexor carpi ulnaris

Question 155

Who is at risk for ulnar nerve injury?

Answer 155

The ulnar nerve is the most commonly injured peripheral nerve. Ulnar neuropathy isn't always caused by intraoperative positioning. Other risk factors include: * Male gender (especially if >50 yrs old) * Preexisting ulnar neuropathy * Extremes of body habitus (very thin or obese) * Prolonged hospital stay/bedrest

Question 156

Describe the presentation of ulnar nerve injury

Answer 156

* impaired sensation of the 4th and 5th digits * Inability to ABduct or oppose the pinky finger * Chronic injury presents with claw hand (muscular atrophy)

Question 157

Which nerve injury provides a greater risk for long term injury (sensory or motor)?

Answer 157

Sensory deficits are more common, less serious, and tend to resolve on their own (usually 5 days or less). Motor deficits are less common and more serious

Question 158

What are the causes of median nerve injury?

Answer 158

Etiology: * IV placed in the antecubital space * Carpel tunnel syndrome- the median nerve is the only nerve that passes through the carpal tunnel * Elbow hyperextension * Forced elbow extension during positioning after a neuromuscular blocker has been administered

Question 159

Describe the presentation of median nerve injury

Answer 159

* Reduced sensation over palmar surface of the thumb, index finger, and lateral aspect of the ring finger. * Unable to oppose the thumb (chronic injury can lead to the ape hand deformity)

Question 160

What are the causes of radial nerve injury?

Answer 160

The radial nerve passes along the spiral groove at the lateral aspect of the humerus (about 3 fingerbreadths above the lateral epicondyle) Etiology: * External compression by an IV pole * excessive cycling of the NIBP cuff * Upper extremity tourniquet * Sheets that are too tight (if the arms are tucked)

Question 161

Describe the presentation of radial nerve injury

Answer 161

Presentation= wrist drop * inability to extend the hand at the wrist

Question 162

Discuss the etiology, presentation, and prevention of obturator nerve injury.

Answer 162

Etiology: * Excessive flexion of the thigh towards the groin * Excessive traction during lower abdominal surgery * Forceps delivery Presentation: * Inability to ADDuct the leg * reduced sensation over the medial aspect of the thigh Prevention: * Minimize hip flexion

Question 163

Discuss the etiology, presentation, and prevention of femoral nerve injury

Answer 163

Etiology * Excessive traction during lower abdominal surgery Presentation: * Impaired knee extension and hip flexion * Reduced sensation over the anterior thigh and anteromedial aspect of the leg Prevention: * Avoid excessive traction during lower abdominal surgery

Question 164

Discuss the etiology, presentation, and prevention of Saphenous nerve injury

Answer 164

Etiology: * Medial aspect of the leg leans against the supporting cradle in the lithotomy position (the saphenous n. resides near the tibia) Prevention: * Place padding between leg and stirrup

Question 165

Discuss the etiology, presentation, and prevention of common peroneal nerve injury

Answer 165

Etiology: * The common peroneal nerve is highly susceptible to injury when the patient is placed in stirrups. This nerve wraps around the fibular head, and it can be compressed when the lateral aspect of the leg leans against the stirrup bar. Presentation * Foot drop * Inability to evert the foot * Inability to extend the toes dorsally TIPPED Tibial Inversion Plantar flexion, Peroneal Eversion Dorsiflexion peroneal = foot drop tibial= can't stand on (tip) toes Prevention: * Place padding between the leg and stirrup * Pad under the fibular head * Knees should be flexed with minimal rotation

Question 166

Discuss the etiology, presentation, and prevention of sciatic nerve injury

Answer 166

Etiology: * lithotomy- extreme hip flexion and/or external rotation of the legs * Sitting- straight legs Prevention: * Ample padding under buttocks * Avoid excessive external rotation of the hips * Flex table at the knees Presentation: * foot drop

Question 167

which position is most likely to cause compartment syndrome?

Answer 167

Compartment syndrome is most common in the lithotomy position. * the lithotomy position is associated with increased leg compartment pressure, and raising the legs above the heart reduces lower extremity perfusion pressure. * Taken together, these changes set the stage for leg ischemia -> edema -> more ischemia -> more edema... * this can progress to rhabdomyolysis and/or reperfusion injury compartment syndrome is treated with fasciotomy

Question 168

which position is most likely to cause venous air embolism?

Answer 168

Sitting Although the sitting position is most commonly associated with venous air entrainment, this complication can occur in any position that produces a pressure gradient between the atmosphere and the veins at the surgical site. Venous air embolism -> right heart-> pulmonary vasculature -> increased dead space & increased RV workload Paradoxical air embolism -> right heart -> patent foramen ovale -> left heart -> systemic circulation -> stroke

Question 169

which position is most likely to cause midcervical tetraplegia?

Answer 169

Midcervical tetraplegia is associated with hyperflexion of the neck (chin to chest). Ischemia occurs as a result of stretching and/or compression of the midcervical spinal cord (usually C5) * this complication is most common in the sitting position * You should be able to place at least 2 fingers in-between the chin and the chest

Question 170

what is the purpose of a positioning device for a pt in the prone position?

Answer 170

in the prone position, a positioning device (chest rolls, wilson frame, or Jackson table) and padding distribute the patient's weight to the thoracic cage and the boney pelvis. This allows the abdomen to hang freely, which promotes normal diaphragmatic excursion throughout the respiratory cycle. * if the abdomen is compressed, intraabdominal pressure increases, which reduces pulmonary compliance and increases intrathoracic pressure * venous pressure is also increased, and this can cause back bleeding via the epidural veins during spinal surgery. the jackson table is better than the wilson frame or chest rolls

Question 171

which position provides the most optimal V/Q matching in the patient with ARDS?

Answer 171

The prone position optimal V/Q matching, which explains why we use the prone position for patient with ARDS

Question 172

List 3 factors that worsen tracheobronchial compression in the patient with an anterior mediastinal mass.

Answer 172

Supine position induction of general anesthesia positive pressure ventilation

Question 173

What is the best induction technique for a patient with an anterior mediastinal mass?

Answer 173

Spontaneous ventilation preserves the normal airway distending pressure gradient, but this gradient is often abolished during positive pressure ventilation. The sitting position and maintenance of spontaneous ventilation will minimize, but not always prevent, compression of the vital chest structures.

Question 174

what are your options if you lose the airway during induction in the patient with an anterior mediastinal mass?

Answer 174

If the mass compresses the tracheobronchial tree before the airway is secured, it may be impossible to advance the ETT beyond the tumor. It is also possible for the tumor to compress the tracheobronchial tree past the distal tip of the ETT, causing complete obstruction of the airway. Should airway collapse occur, repositioning the pt laterally or prone may restore patency to the airway. A rigid bronchoscope should be available. Emergent femoral-femoral cardiopulmonary bypass may be required if ventilation via the lungs becomes impossible

Question 175

What is the AANA Code Of Ethics?

Answer 175

Dictates the principles of conduct and professional integrity that guide the decision-making and behavior of nurse anesthetists. The document speaks to the anesthetist's responsibilities as a professional, which holds the individual CRNA accountable for his or her own actions and judgements, regardless of institutional policy or physician orders

Question 176

what are practice guidelines?

Answer 176

Practice guidelines are systematically developed statements to assist providers in clinical decision-making that are commonly accepted within the anesthesia community Guidelines "should" be adhered to

Question 177

what are practice standards?

Answer 177

Practice standards are authoritative statements that describe minimum rules and responsibilities for which anesthetists are held accountable. Standards "must" be adhered to

Question 178

what are position statements?

Answer 178

Position statements express the AANA official positions or beliefs on practice-related topics; they may also define that knowledge, skills, and abilities considered necessary for a nurse anesthetist.

Question 179

Define autonomy.

Answer 179

Autonomy refers to the patient's ability to choose without controlling interference by others and without limitations that prevent meaningful choices

Question 180

Define nonmaleficence

Answer 180

Nonmaleficence asserts that a provider has an obligation not to inflict hurt or harm-in other words, the Hippocratic oath primum non ocere (first do no harm)

Question 181

Define beneficence

Answer 181

Beneficence is the principle that providers should take action for the benefit of others. This includes both preventing harm and actively helping their patients. Beneficence underpins the fundamental guiding principle of evidence-based interventions- the benefits of the treatment should be demonstrable and must clearly outweigh the risks.

Question 182

List the 6 elements of informed consent

Answer 182

* Competence * Decision-making capacity * disclosure of information * Understanding of disclosed information * voluntary consent * documentation

Question 183

What is informed refusal? list one example of this concept in a specific patient population

Answer 183

A pt has a right to refuse medical tx or therapy A common example is the refusal of blood or blood products by a Jehovah's witness. When a recommended therapy is refused, it places an even higher burden on the health care provider to disclose the risks and benefits of both the recommended and any alternative care.

Question 184

what is an advanced directive?

Answer 184

An advanced directive is a legally binding document that delineates the patient's wishes regarding healthcare interventions in the case of incapacity and/or delegates the authority to make healthcare decisions to another party Advance directives often include specific provisions that modify aspects of anesthesia management, including intubation, use of antibiotics, blood transfusion, and/or the use of CPR and advanced life support measures. Because many of these measures, when used in conjunction with a procedure/surgery, are temporary, it is recommended that advance directives be reconsidered before anesthesia is administered

Question 185

list the 4 things that must be proven in a lawsuit asserting malpractice.

Answer 185

Duty Breach of duty causation damages

Question 186

What is res ipsa loquitur

Answer 186

res ipsa loquitur ("the thing speaks for itself") can shift the burden of proof from the paintiff to the defendant. This can occur if 4 conditions can be established: 1. if the injury would not have occurred in the absence of negligence 2. the injury was caused by something under the complete control of the defendant (provider) 3. The patient did not contribute in any way to the injury 4. The evidence for the explanation of events is solely under the control of the provider

Question 187

what is the difference between libel and slander?

Answer 187

libel is defamation in the written form Slander is defamation in the verbal form

Question 188

what is the difference between assault and battery?

Answer 188

Assault is the attempt to touch another person battery is touching a person without either expressed or implied consent

Question 189

what is the vicarious liability? what's another name for this concept?

Answer 189

One person (or entity) may be liable for the actions of another person. For instance, a physician might be held liable for the actions of a PA. This concept typically does not apply to CRNAs working under a physician. Respondea superior is often used interchangeably with vicarious liability

Question 190

What is the Patient Care and Affordable Care Act?

Answer 190

the ACA mandated that all individuals carry health insurance, established standards and requirements for health insurance policies, and launched health care clearinghouses or exchanges to assist people in finding medical insurance. In addition, insurers are no longer permitted to charge more for pre-existing conditions

Question 191

What is Emergency in Medical Treatment and Active Labor Act

Answer 191

Over 30 years ago, Congress enacted the Emergency Medical Treatment & Labor Act (EMTALA) to ensure public access to emergency services regardless of their ability to pay. This is also known as the "Anti-Patient Dumping" act. This act imposes specific obligations on Medicare-participating hospitals that offer emergency services to provide a medical screening examination when a request is made for examination or treatment for an emergency medical condition (EMC) regardless of an individual's ability to pay

Question 192

What is Health Insurance Portability and Accountability Act?

Answer 192

Most health care providers are aware of HIPAA, the federal law that prohibits the disclosure of individually identifiable health information (AKA personal health information, PHI). PHI includes past and present health conditions, treatments, and payments for health care. Disclosure can occur in any form, including orally, written, or electronically. Even if you think you're keeping the patient anonymous, there's always a risk of HIPPA violation when you post any patient-related stories, data, etc., on social media

Question 193

What is the controlled substances act?

Answer 193

We all know that the federal government regulates the manufacture, importation, possession, and distribution of drugs deemed "controlled substances." The government defines what is controlled and what level of restriction various controlled substances are subject to.

Question 194

What schedule I drugs are used to provide anesthesia?

Answer 194

By its very definition, a schedule I drug has NO currently accepted medical use. Therefore, we don't use any schedule I drugs in anesthesiology. As an aside, the legalization of marijuana at the state level challenges its schedule I designation at the federal level.

Question 195

What is a schedule II drug? List some examples.

Answer 195

A schedule II drug has a high potential for abuse potentially leading to dependence. Examples: *Opioid agonists (fentanyl, morphine, *hydromorphone, etc.) * Cocaine * methamphetamine * phencyclidine (ketamine)

Question 196

what is the Health Information Technology for Economic and Clinical Health Act (HITECH)?

Answer 196

This act was intended to create a healthcare information technology infrastructure in order to improve care quality and coordination between providers, i.e., to promote the "meaningful use" of such information HITECH is essentially an amendment to HIPAA and applies to the same covered entities, including providers, health plans, and healthcare clearinghouses. HITECH precipitated a massive expansion in the exchange of electronic PHI and widened the scope of privacy and security protections available under HIPAA.

Question 197

Detail the steps involved with responding to a lawsuit.

Answer 197

Question 198

what is an emancipated minor?

Answer 198

Emancipated minors are patients younger than 18 years of age who are legally given the rights of an adult by a state court. Although variable by state law, criteria for emancipating a minor may include the fact that they are: * married * A parent or is currently pregnant * IN the military * Economically independent

Question 199

Discuss the ethical dilemma of surgery for a child of Jehovah's Witness?

Answer 199

Families should be informed that, despite all reasonable efforts to eliminate the need for transfusion, if an emergency occurs, a court order for transfusion will be sought When the likelihood for transfusion is high, a court order should be sought prior to surgery. In a lfe-threatening crisis, emergency transfusion should be given prior to obtaining a court order. As these children approach maturity, they should be involved in the decision-making regarding the use of blood and blood products.

Question 200

What is anesthesia crisis resource management?

Answer 200

In an anesthetic crisis, effective response and management are dependent upon non-technical skills. Crisis resource management (CRM) uses a simple model in which effective communication is the "glue" that holds all the other components together. Resources available in a crisis include all the personnel involved and their inherent knowledge, skills, and abilities (and limitations). Resources also include available supplies, pharmaceuticals, technology, and information. The same skill set is required to prevent and intervene when threats to patient safety occur. CRM training is detailed and extensive and is often accompanied with high fidelity simulation training.

Question 201

List 5 complications of fatigue.

Answer 201

* Diminished reaction time * Impaired decision-making * decreased situational awareness * Impaired concentration or memory * periods of microsleep

Question 202

What is microsleep?

Answer 202

Microsleep is an actual sleep episode that lasts seconds to minutes; it is insidious in a fatigued provider and cannot be predicted. Performance between microsleep episodes is impaired, and errors of omission increase when microsleep occurs.

Question 203

what is the relationship between 24-hrs of wakefulness and alcohol consumption?

Answer 203

Research has also shown that 24-hr of wakefulness is equivalent to a blood alcohol content of 0.1% (legal impairment for driving is 0.08%). Thus, scheduling or working a 24-hr shift, or working multiple long shifts with short sleep time intervals, puts both the provider and the pt at risk.

Question 204

when is sleep-related behavior most common?

Answer 204

after 16 or more continuous hours of work During the night shift

Question 205

List 6 countermeasures for fatigue

Answer 205

* Napping * Caffeine * exercise * Consistent sleep-wake pattern * Medications * Recovery between shifts

Question 206

What is the OSHA limit for occupational exposure to ionizing radiation?

Answer 206

Annual = 5 rem Lifetime= (N-18) x 5 rem * N= age in years

Question 207

what are the physiologic effects of MRI exposure?

Answer 207

Lower frequency electromagnetic fields from MRI can cause transient symptoms of nausea, dizziness, vertigo, or light flashes. There are no published regulations limiting occupational exposure to MRI fields

Question 208

What are the OSHA limits for noise exposure?

Answer 208

The OSHA limit for an 8-hour span is 90dB, and single noise levels should not exceed 115 dB

Question 209

Who is the "second victim"?

Answer 209

One of the most significant acute stressors for an anesthesia provider is being involved in a case with a bad outcome (death or significant morbidity). The effects of perioperative catastrophe on the provider are just beginning to be studied Current thinking conceptualizes the provider as a "second victim" and the provider's subsequent patients as possible "third victims"

Question 210

Define addiction

Answer 210

a need (psychological or compulsive) for a substance. There is often a loss of self-control, where the user continues using a drug despite the desire to stop drug use. This represents a severe stage of chronic substance abuse disorder

Question 211

Define impairment

Answer 211

the inability to safely participate in life (or professional) activities

Question 212

Define tolerance

Answer 212

More drug is needed to achieve a given effect (intoxication) - or - a lesser effect is produced by a given dose of a drug

Question 213

Define withdrawal

Answer 213

a characteristic syndrome that is the direct result of stopping or reducing the use of a drug

Question 214

list the factor for developing substance use disorder

Answer 214

Question 215

What are some typical behaviors of the impaired provider?

Answer 215

* Frequent and unexplained tardiness, absences, or illnesses often with elaborate excuses * Poor performance with errors, accidents, or injuries that are inadequately explained * Confusion, memory loss, difficulty concentrating or recalling details * Severe mood swings, changes in personality * Visibly intoxicated * Refuses drug testing * Track marks, bloodshot eyes, significant weight loss or gain

Question 216

What are the key issues regarding re-entry to clinical practice following a substance abuse disorder

Answer 216

Safe return to work is determined on an individual basis- not all providers will be able to return to practice safely Readiness for re-entry is a collaborative decision of the monitoring program, certified drug and alcohol counselor, and employer. One full year in recovery is recommended prior to returning to anesthesia practice Due to the high risk of relapse, abstinence-based recovery and refraining from substitute treatments is also recommended Of the ten criteria that should be met prior to considering re-entry, the most salient point is participation in a monitoring program at least 5 years in length with random drug testing

Question 217

What should you do if you suspect a fellow anesthesia provider is impaired?

Answer 217

* Do not let the person out of your site, and do not let them drive * have a bed in a treatment facility available * Do not let the impaired person decide their treatment. (they are sick, and an intervention can make them suicidal) * Only when all else fails, threaten to call the police.

Question 218

what are the 6 elements of high-quality care?

Answer 218

* patient-centered * safe * effective * timely * efficient * equitable

Question 219

Discuss the cultural competence in the context of anesthesia delivery

Answer 219

Cultural competence is emphasized as a strategy to reduce health care disparities and improve equity. What does this mean? you should be providing the same level of care and consideration to a homeless drug user that you would to the hospital's CEO! the ethnicity, race, religion, sexual orientation, cultural background, or status in the community simply may not play into your interactions, communication, and planning process with the patient and family. Thus, cultural competence requires the anesthesia provider to: * Know and apply current standards of care * Offer and use evidence-based interventions * Have a keen awareness of their own biases and assumptions * Be sensitive to the presence of health disparities and discrimination

Question 220

At sea level, the agent monitor measures the end-tidal sevo as 16mmHg. Convert this to volumes percent.

Answer 220

2.1% sevo * Volumes % = (partial pressure/total pressure) x 100

Question 221

what effect does a fever have on blood flow?

Answer 221

It decreases viscosity which reduces resistance to blood flow

Question 222

why is ionized radiation so dangerous to healthcare workers?

Answer 222

it can remove electrons from atoms, which produces free radicals. This wreaks havoc at the cellular level. Risks include tissue injury, chromosomal damage and malignancy

Question 223

what is an adiabatic process?

Answer 223

A process that occurs without gain or loss of energy (heat).

Question 224

what is the boiling point of water in Fahrenheit?

Answer 224

212F

Question 225

convert 120 mmHg to cm H2O

Answer 225

1 mmHg= 1.36 cm H2O 163cm H2O

Question 226

Convert 40cmH2O to mmHg

Answer 226

1 cm H2O = 0.74mmHg 29.6mmHg

Question 227

hypothermia is defined as a core body temperature less than:

Answer 227

36 degrees C

Question 228

list two perioperative medications that can lead to anticholinergic poisoning.

Answer 228

atropine scopolamine

Question 229

what are 3 clinical features of anticholinergic poisoning?

Answer 229

1. red, dry, hot skin 2. Delirium 3. Mydriasis

Question 230

what is the MOA of neuroleptic malignant syndrome?

Answer 230

Dopamine depletion in the basal ganglia and hypothalamus

Question 231

what three key drug interactions increase the risk of serotonin syndrome?

Answer 231

1. SSRI (fluoxetine, citalopram) combined with : Meperidine and fentanyl 2. MAOI(Selegiline, phenelzine, isocarboxazid) combined with: Meperidine and ephedrine 3. Methylene blue combined with: Other serotonergic drugs

Question 232

when should N2O be discontinued before placement before placement of an SF6 bubble in the eye? and how long should N20 be avoided for gas bubble used?

Answer 232

15 minutes how many days to avoid N20 silicone oil= 0 days air bubble= 5 days SF6= 7-10 days Perfluoropropane (c3F8)= 30 days

Question 233

what causes open-angle glaucoma?

Answer 233

It's caused by sclerosis of the trabecular meshwork. This impairs aqueous humor drainage

Question 234

what is the most common side effect of antibiotic prophylaxis?

Answer 234

Pseudomembranous colitis

Question 235

what is the antibiotic of choice for an active MRSA infection?

Answer 235

Vancomycin

Question 236

What is the first line treatment for Tuberculosis?

Answer 236

Isoniazid

Question 237

list 3 things that reduce gastric barrier pressure

Answer 237

anticholinergics, pregnancy, cricoid pressure

Question 238

when should ondansetron be administered in surgical cases?

Answer 238

30 min prior to emergence

Question 239

what is the best class of antiemetics for patients undergoing mastoidectomy?

Answer 239

anticholinergics

Question 240

list 2 early signs of BCIS (bone cement implantation syndrome) in an awake pt

Answer 240

dyspnea, and altered LOC

Question 241

what 3 symptoms are most commonly seen with fat embolism syndrome?

Answer 241

1. Respiratory insufficiency (hypoxemia, bilateral infiltrates on CXR, ARDS) 2. Neurologic involvement (confusion to coma) 3. Petechial rash (skin of neck and axilla, oral mucosa, conjunctiva)

Question 242

what is the tx for fat embolism

Answer 242

supportive, but some texts say corticosteroids help outcomes