Flashcards in Anesthesia 1st year Deck (374):
Larynx C6 level?
3 unpaired cartilages
3 paired cartilages
Laryngeal Extrinsic muscles (Elevators) (6)
1 - Digastric
2 - Stylohyoid
3 - Geniohyoid
4 - Omohyoid
5 - Stylopharyngeus
6 - Palatopharyngeus
Laryngeal Extrinsic muscles (Depressors) (3)
1 - Sternohyoid
2 - Sternothyroid
3 - Omohyoid
Laryngeal Intrinsic muscles that narrow the inlet (1)
oblique arytenoid muscle
Laryngeal Intrinsic muscles that widen the inlet (1)
Tensors: cricothyroid muscle
Relaxors: thyroarytenoid (vocalis) muscle
Adductors: lateral cricoarytenoid muscle
Abductors: posterior cricoarytenoid muscle
Approximates arytenoids: transverse arytenoid muscle
Laryngeal Blood Supply
Comes from the
which are derived from the 1.
Comes from the superior & inferior laryngeal artery and veins which are derived from the superior & inferior thyroid vessels
Larynx Nerve Supply
Innervated bilaterally by two branches of each vagus nerve:
superior laryngeal nerve
recurrent laryngeal nerve
Larynx Nerve Supply
Sensory and motor?
Larynx Nerve Supply
Sensory above vocal folds?
Internal branch of superior laryngeal nerve
Larynx Nerve Supply
Sensory below vocal folds?
Recurrent laryngeal nerve
Larynx Nerve Supply Motor?
All supplied by?
1. Recurrent laryngeal nerve
Cricothyroid muscles nerve supply?
External branch of the superior laryngeal nerve
Normal adult? (1) or (3)
Full term infant? (1) Infant/child? (3)
Preterm infant? (1)
Normal adult - C5
Adult - C4,C5,C6
Full term infant - C4 Infant/child - C3,C4,C5
Preterm infant - C3
Adult: Vocal cords
Infant: cricoid ring
Length in adults?
How many C-shapaed cartilages?
1st tracheal ring is located?
C6 - T5
Anterior to the C6 vertebrae
at the carina ( 5th thoracic vertebra), where it bifurcates in the principal bronchi
A line drawn between the iliac crests crosses the body of L5 or the L4-L5 interspace
Ligamentum flavum is composed of?
Where is it thickest?
Thickest in the midline, measuring 3 to 5 mm at the L2–3 interspace of adults
3 - 5 mm
3 spinal meninges
It is a meninge where it is largely acellular except the one that forms the border between the dura and the arachnoid mater
It is a delicate, avascular membrane composed of overlapping layers of flattened cells with connective tissue fibers running between the cellular layers
It is the principal physiologic barrier for drugs moving between the epidural space and the spinal cord
It lies between the arachnoid mater and the pia mater and contains the CSF and the spinal nerve roots and rootlets
Is adherent to the spinal cord and is composed of a thin layer of connective tissue cells interspersed with collagen
Spinal cord ends
1. At birth?
2. In adults?
3. How many pairs?
3. 31 pairs
Muscles of inspiration (4)
2. External intercostal muscles
3. Sternocleidomastoid muscle
4. Pectoralis muscle
Muscles for expiration (5)
1. Rectus abdominis
2 & 3. External and internal oblique muscles
4. Internal oblique muscles
5. Transversus abdominis muscle
Has dichotomous division of the airway?
Involves how many divisions?
1. Tracheobronchial Tree
3 types of functional airway divisions?
1. Trahcea to terminal bronchioles
2. Respiratory bronchioles o alveoalr ducts
Conducting zones (4)
3. Terminal bronchiole
Last airway component that does not participate in gas exchange
Gas exhange begins to appear at the?
Gas flow in the lungs (2)
Can be predicted by?
1. Laminar or turbulent
2. Reynolds number
3. linear velocity x diameter x gas density x gas viscosity
Low Reynolds no 1500 -
What flow occur only at distal to small bronchiole?
occur in larger airways?
occurs at high gas flow, at sharp angles, at abrupt changes in airway diameter?
Ratio of FEV1 to FVC is directly proportional to degree of obstruction
>/= to 80%
Forced mid expiratory flow ?
More reliable measurement for obstruction
Forced mid expiratory flow
Distribution of pulmonary perfusion
Represents alveolar dead space (alveoli not perfused)
Alveolar pressure occludes pulmonary capillaries
Pulmonary capillary flow is INTERMITTENT
Flow varies during respiration according to the arterial-alveolar pressure gradient
Pulmonary capillary flow is CONTINUOUS
Flow is proportional to the arterial-venous pressure gradient
Nice to know
Lower (dependent) - greater blood flow, LOWER V/Q
Upper (nondependent) - lower blood blood flow, HIGHER V/Q ratio
1. V/Q = 0
2. V/Q= infinity
1. V/Q = 0 no ventilation
2. V/Q= infinity no perfusion
Normal alveolar ventilation (VA) =
Normal pulmonary capillary perfusion (Q)=
Overall V/Q ration=
Normal alveolar ventilation (VA) = 4L/min
Normal pulmonary capillary perfusion (Q)= 5L/min
Overall V/Q ration= 0.8
What is an increase in blood hydrogen ion concentration reduces O2 binding to Hgb?
Oxyhemoglobin dissociation curve (left) (6)
2. Alkalosis, Abn hgb (fetal)
3. 2,3 BPG(decreased)
4. E (neurophysiology)
5. Temperature (Hypothermia)
Oxyhemoglobin dissociation curve (right) (5)
1. Inc Co2
2. Acidosis, abn hemoglobin
3. 2,3 BPG (increase)
Cerebral metabolic rate (CMRO2)?
2. Gray matter of cerebral cortex
1. CBF in gray matter?
2. CBF in white matter?
3. Total CBF in adults?
3. 750 ml/min
40-60 mL/100 gm/min
(15-20% of cardiac output)
1. Cerebral impairment?
2. Flat (isoelectric) EEG?
3. Irreversible brain damage?
Pressures > how much can disrupt BBB (cerebral edema,he)
CBF changes (% ?) per 1 degree change in temperature
2. normal CSF production per hour? per day?
3. total CSF per day
1. choroid plexus of lateral ventricles
2. 21 mL/H or 500 mL/day
3. 150 mL
Cerebral blood volume inc by how much of CSF in per 1 mmHg increase in PaCO2
Systemic absorption of local anesthetics : decreasing order (5)
4. brachial plexus
2. Duration of action
3. Speed of onset
1. Lipid solubility
2. Protein binding
1. ( 8.1 )
2. ( 8.1 )
3. ( 7.9 )
4. ( 7.9 )
5. ( 7.7 )
6. ( 7.6 )
Dose dependent effects of lidocaine (mcg/mL)
2. 5-10 ( 3 )
3. 10 - 15 ( 2 )
4. 15 - 25 ( 2 )
5. >25 ( 1 )
1 - 5
5 - 10
3. Numbness of tongue
2. Respiratory arrest
1. Cardiovascular depression
What content of esters induces allergic reaction?
p-amino benzoic acid
What content of amides induces allergic reaction?
Myotoxic local anesthetics according to order (most to least)
What local anesthetic has?
Are the pure S- form of the drug, less cardiotoxic than the R isomer
Compared to bupivacaine, it is half as lipid soluble, onset and duration of action are similar but provides less motor block, lower potency
Ropivacaine / levobupivacaine
What local anesthetic has?
A 50:50 racemic mixture of both the S- and R- enantiomers
Drug of choice for treatment of bupivacaine induced ventricular arrhythmia
Local anesthetic with low risk of sytemic toxicity because it is rapidly metabolized?
2 - chlorprocaine
Local anesthetic nice to know
The concentration of the nonionized portion is significant because this is the amount available to pass through the lipophilic membrane.
However, once inside the membrane, it is the ionized portion which then blocks the sodium channels.
EMLA cream is composed of?
Adverse effect of
1. prilocaine (> 600 mg) and benzocaine
give intravenous methylene blue (1 to 2 mg/kg)
2. intense vasoconstriction
Local anesthetic nice to know
LA with epinephrine is more acidic.
This is why “fresh” epinephrine is added to LA prior to administration.
LA are less effective in acidic environments such as infected tissue. Low tissue pH increases the ionized portion of the LA
Which is rapidly metabolized esters or amides?
Has been implicated as a cause of Transient Neurologic Symptoms.
Use of the lithotomy position may be a contributory factor.
Has stretch receptors in the walls of the heart and blood vesses(carotid sinus CN IX, aortic arch CN X receptors).
Increased in blood pressure is the stimulus while response is sympathetic inhibition and increase in parasympathetic activity
The stimuli is forced expiration against glottis closure, while the response is increased cerebral venous pressure, decrease right heart venous return causing decreased BP, CO and reflexed increased in HR.
VALSALVA MANEUVER REFLEX
LV mechanoreceptor with afferent pathway in vagal C fiber.
The stimuli is noxious stimuli to LV wall (as in myocardial infarct) the response is hypotension, bradycardia and coronary vasodilation induced by parasympathetic.
Increased right atrial pressure directly stretches SA node and enhances it automaticity. This response occurs only in increased vagal tone (low initial HR) while rapid infusion of blood or saline distends right atrium and central veins.
The stimuli is traction on the extraocular muscles(medial lateral rectus) or pressure on the globe, response is bradycardia and hypotension. This reflex can be attenuated by IV atropine.
The stimuli is vagal stimulation via mesenteric traction, rectal distensionm traction on the gall bladder, response is bradycardia, apnea, hypotension with narrow pulse pressure.
Carotid baroreceptors sense MAP most effectively between pressures of?
Left coronary artery supplies the (5)
1. Anterior descending branch
2. Right bundle branch
3. Left bundle branch
4. Anterior and posterior papillary muscles (mitral)
5. Anterolateral left ventricle
Circumflex branch supplies the (1)
Lateral left ventricle
Right coronary artery supplies the (5)
1. SA and AV node
2. R atrium and ventricle
3. Posterior interventricular septum
4. Posterior fascicles of the left bundle branch
5. Interatrial septum
Occlusion of right coronary artery
1. ECG leads affected
2. Area of mycoardium involved? (3)
1. II, III, aVL
2. Right atrium and ventricle, AV node
Occlusion of left anterior descending artery
1. ECG leads affected
2. Area of mycoardium involved? (1)
1. V3 - V5
2. Anterolateral portion of left ventricle
Occlusion of left circumflex coronary artery
1. ECG leads affected
2. Area of mycoardium involved? (1)
1. I, aVL
2. Lateral left ventricle
Define the phases of cardiac action potential
1: early rapid depolarization
3: final repolarization
4: resting potential and diastolic repolarization
Cardiac action potentials events
0: Activation (opening) of fast Na+ channels
( Na+ in and decreased permeability to K+ )
1: Inactivation of Na+ channel and transient increase in K+ permeability
(K+ out, Na- in)
2: Activation of slow Ca2+ channels
( Ca2+ in )
3: Inactivation of Ca2+ channels and increased permeability to K+
( K+ out )
4: Normal permeability restored (atrial and ventricular cells)
( K+ out Na+ in )
Intrinsic slow leakage of Ca2+ into cells that spontaneously depolarize
( Ca2+ in )
Cardiac waves (4)
Cardiac wave that is due to atrial systole?
Cardiac wave that coincides with ventricular contraction and is said to be caused by bulging of the AV valve into the atrium.
Cardiac wave that is the result of pressure buildup from venous return before the AV valve opens again.
Cardiac wave that is the decline in pressure between the c and v waves and is thought to be due to a pulling down of the atrium by ventricular contraction.
Incompetence of the AV valve on either side of the heart abolishes the x descent of that side, resulting in a prominent what wave?
Follows the v wave and represents the decline in atrial pressure as the AV valve opens.
Liver nerve supply (3)
1. sympathetic T6- T11
2. parasympathetic (R & L vagus)
3. Right phrenic nerve
Normal hepatic blood flow
70 - 75%
Supplies 45-50% of liver's oxygen requirement?
Supplies 50-55% of liver's oxygen requirement?
Normal hepatic oxygen saturation?
% of total cardiac output which goes to the liver?
25 - 30 %
What the drug does to the body
What the body does to the drug?
The time necessary for the plasma drug concentration to decrease to 50% DURING THE ELIMINATION PHASE?
The time necessary for the plasma drug concentration to decrease by 50% AFTER DISCONTINUING AN INFUSION of a specific duration (context means infusion duration)?
Elimination half time
Context-sensitive half time
Is directly proportional to its Vd and inversely proportional to its clearance.
(inc. elimination half time,inc. volume of distribution, decrease clearance)
Renal or hepatic disease that alters Vd and/or clearance will alter it.
Elimination half time
The time necessary to eliminate 50% of the drug from the body after its rapid IV injection
The amount of drug remaining in the body is related to the number of elimination half times that have elapsed
For ex. If 50% of a drug is eliminated in 10 minutes, another 10 minutes will be needed for elimination of one-half of the remaining drug.
It considers the combined effects of distribution and metabolism as well as duration of continuous IV administration on drug pharmacokinetics.
It bears no constant relationship to the drug’s elimination half-time
Is a mathematical expression of the sum of apparent volumes of the compartments that constitute the compartmental model.
Calculated as the dose of drug administered IV divided by resulting plasma concentration of drug before elimination begins.
Volume of distribution
Factors that affect volume of distribution (3)
1. Lipid solubility
2. Binding to plasma proteins
3. Molecular size
Of poor lipid soluble drugs with Vd similar to ECF volume are (1)
A lipid soluble drug, highly concentrated in tissues, results in low plasma concentration, will have a calculated Vd that exceeds total body water example (2)
Ionized or non-ionized?
Active, lipid soluble, cross lipid barriers, no renal excretion, undergoes hepatic metabolism
The largest anterior segmental medullary artery.
It typically arises from a left posterior intercostal artery between T9-T11, which branches from the aorta and supplies the lower two thirds of the spinal cord via the anterior spinal artery
Artery of adamkiewicz
(arteria radicularis magna)
Chassaignac tubercle is found at what level?
Stellate ganglion block complications (
1. Horners syndrome ( intra arterial or IV injection )
2. Difficulty of swallowing
3. Vocal cord paralysis
Location of stellate ganglion?
Lies in front of the neck of the 1st rib
Femoral nerve block/“Three-in- one” block (blocks 3 nerves)
1. Femoral nerve
2. Lateral femoral cutaneous nerve
3. Obturator nerve
Ankle block( 5 nerves blocked)
1. Saphenous nerve
2. Deep peroneal nerve
3. Common peroneal nerve
4. Superficial peroneal nerve
5. Posterior tibial nerve
6. Sural nerve
Paramedian approach in spinal anesthesia
1. TAYLOR APPROACH
For Routine “Awake” Extubation
1. Subjective (6)
2. Objective (4)
Subjective Clinical Criteria:
1. Follows commands
2. Clear oropharynx/hypopharynx (e.g., no active bleeding, secretions cleared)
3. Intact gag reflex
4. Sustained head lift for 5 seconds, sustained hand grasp
5. Adequate pain control
6. Minimal end-expiratory concentration of inhaled anesthetics
1. Vital capacity: ≥10 mL/kg
2. Peak voluntary negative inspiratory pressure: >20 cm H2O
3. Tidal volume >6 cc/kg
4. Sustained tetanic contraction (5 sec)
Criteria for difficult mask ventilation (6)
1. Inability for one anesthesiologist to maintain oxygen saturation >92%
2. Significant gas leak around face mask
3. Need for ≥IS 4 min gas flow (or use of fresh gas flow button more than twice)
4. No chest movement
5. Two-handed mask ventilation needed
6. Change of operator required
Independent risk factors for difficult mask ventilation
1. Beard ( 3.18 )
2. BMI >26 ng/m2 ( 2.75 )
3. Lack of teeth ( 2.28 )
4. Age >55 ( 2.26 )
5. Snoring ( 1.84 )
This devastating injury occurs after hyperflexion of the neck, with or without rotation of the head,
and is attributed to stretching of the spinal cord with resulting compromise of its vasculature in
the midcervical area.
An element of spondylosis or a spondylotic bar may be involved.116,117
result is paralysis below the general level of the fifth cervical vertebra.
Although most reports in
the literature have described the condition as occurring after the use of the sitting position,
midcervical tetraplegia has also occurred after prolonged, nonforced head flexion for intracranial
surgery in the supine position.
Lithotomy (nerves affected)
1. Injured when the head of the fibula (lateral aspect of the knee is compressed against the leg support device;most commonly injured lower extremity nerve? What is the clinical condition?
2. Can be stretched by exaggerated flexion of the hips during positioning
3. From extreme flexion and abduction of the thighs
1. Common peroneal nerve
2. Sciatic nerve
3. Femoral nerve
Pressure from the vertical bar of an anesthesia screen or a similar device against the lateral aspect of the arm and excessive
cycling of an automatic blood pressure cuff have been implicated in causing damage to the radial
Radial Nerve Compression
Most frequently injured peripheral nerve because of its superficial location at the elbow. During OR, nerve may be compressed between the patient and the OR table.
Use to monitor depth of anesthesia
1. BIS value of 0
2. BIS of 40 and 60
3. BIS of 65-85
4. More than 85
1. Isoelectric encephalogram
2. Appropriate for GA
4. Awake, memory intact
1. Hypothermia is body temperature of?
2. Mild hypothermia
1. Less than 36 C
Shivering is modulated through the hypothalamus and can increase the body’s heat production by up to how many percentage?
1. 300 - 400%
MAC of inhalational agents is decreased about how many percent per centigrade decrease in core temperature
Refers to rays emanating from all objects above absolute temperature
Refers to the transfer of heat from contact with objects
Refers to the transfer of heat from air passing by objects
Monitor P waves, inferior wall ischemia, dysrhythmisas
Most sensitive for detection of anterior and lateral ischemia
Muscle most sensitive?
In neuromuscular blockade IOP increases by how much?
5 - 15 mmHg
Succinyl is rapidly hydrolyzed by?
Is an abnormal genetic variant of the plasma cholinesterase enayme that lacts the ability to hydrolyze ester bonds in drugs like succyl and mivacurium. Clinically, the presence of these enzyme manifests as prolonges skeletal muscle paralysis.
Atypical plasma cholinesterase
A local anesthetic which inhibits normal pseudocholinesterase activity by 80% but inhibits atypical enzyme activity by only 20%.
Normal no. is?
80 (the percentage of inhibition of pseudocholinestearse activity)
Conditions with decreased plasma cholinesterase (6)
2. Liver disease
6. Oral contraception
Drugs that also decrease pseudocholinesterase activity (8) PNP CEEMO
1. Echothiopate- organoPO4
2. Neostigmine,pyridostigmine-cholinesterase inhibitor
8. Oral contraceptive
POISEULLE’S LAW ANESTHESIA IMPLICATIONS (3)
1. GAS THROUGH FLOWMETERS
2. SELECTION OF ETT SIZE
3. SELECTION OF IV CATHETER SIZE
The amount of gas dissolved in a liquid is directly proportional to the partial pressure of the gas over the liquid and indirectly proportional to temperature
HENRY’S LAW ANESTHESIA IMPLICATIONS
HENRY’S LAW ANESTHESIA IMPLICATIONS (3)
1. OVERPRESSURIZING ANESTHETIC GASES
2. INCREASING DELIVERY OF O2 BY INCREASING CONCENTRATION/INCREASING MAC
3. HYPERBARIC CHAMBER
BOYLES LAW ANESTHESIA IMPLICATIONS (4)
1. SQUEEZING BAG TO VENTILATE A PATIENT
2. DIAPHRAGM CONTRACTS AND INSPIRATION BEGINS, DIAPHRAGM RELAXES AND EXHALATION BEGINS
3. HYPERBARIC O2 THERAPY
4. THE BELLOWS
BERNOULLI’S PRINCIPLE ANESTHESIA IMPLICATIONS (3)
1. BENTRAIN, JET VENTILATION
2. VENTURI MASK
3. SCAVENGE SYSTEM
What law describes equal volumes of gasses at a constant temperature and pressure have equal amounts of atoms and molecules
1. STEEL TANKS WILL EXPLODE WHEN HEATED
2. REGULATION OF ANESTHETIC GAS THROUGH METAL STRIP
3. MEDICAL GAS CYLINDERS, ETT TUBES AND HYDORGEN THERMOMETERS
4. Desflurane vaporizer heated to allow vaporization of the gas
3RD GAS LAW OR GAY LUSSACS LAW
1. THE AMOUNT OF INHALATION AGENT DELIVERED TO A PATIENT WOULD INCREASE OF DECREASE DEPENDING ON TEMPERATURE COMPENSATIVE VALUES
2. EMPTYING OF AN E-CYLINDER
UNIVERSAL GAS LAW OR IDEAL GAS LAW
What law explains the rate of diffusion of gas is inversely proportional to square root of their molecular weight
1. FLOW METERS MUST BE CALIBRATED WITH CORRECT GAS OR THEY WOULD BE INACCURATE
2. HOW ANESTHETIC GAS DIFFUSE AND EFFUSION
What law has the ff:
1. VENTILATION AND PRESSURE
2. AORTIC STENOSIS AND PRELOAD
3. COLLAPSING PRESSURE OF ALVEOLI AND ABILITY TO KEEP OPEN
4. SURFACE TENSION, ALVEOLI RADIUS, LUNG COMPLIANCE
Law of Laplace
THE TOTAL PRESSURE OF MIXTURE OF GASES IF EQUAL TO EACH GASES’ INDIVIDUAL PARTIAL PRESSURE
A PATIENT WITH COPD WILL HAVE A REDUCED AREA FOR GAS EXCHANGE TO TRANSPIRE AND THEREFORE DECREASED SPEED OF ONSET OF ANESTHETIC AGENTS
Increase surface area, increase diffusion
Increase distance, decrease diffusion
Increase concentration gradient, increase diffusion
NITROUS OXIDE AND OXYGEN COMBINED 50:50
Metabolized by Hoffmann reaction (one third);
Ester hydrolysis (two third)
Causes hypotension and tachycardia
NMBAs which releases histamine (4)
What muscle is used for monitoring recovery?
Adductor pollicis muscle
Good indicator of intubating conditions
Response of the facial nerve around the eye (corrugator supercili-response of eyebrow)
A modified gamma cyclodextrin, with a lipophilic core and a hydrophilic periphery
High affinity for rocuronium
Forms a complex and the complex is excreted
No autonomic istability like neostigmine and atropine
Less affinity of other steroidal NMBS like vecuronium and pancuronium
Does not bind benzylisoquinoline type NMBS
Extremely insoluble volatile anesthetic.
Patient goes to sleep and wakes up very quickly.
The minimum concentration of anesthetic agent at which 50% of population will not move in response to a surgical stimulus
Agent Blood/Gas Brain/Blood Muscle/Blood Fat/Blood
Nitrous oxide 0.47 1.1 1.2 2.3
Halothane 2.4 2.9 3.5 60
Isoflurane 1.4 2.6 4.0 45
Desflurane 0.42 1.3 2.0 27
Sevoflurane 0.65 1.7 3.1 48
Volatile anesthetic that is
hepatotocic and sensitizes the heart to arrhythmogenic effects of beta agonists
Results in isoelectric EEG at very high concentration
May cause seizure with high dose and hypocarbia
Rapid awakening and change in depth of anesthesia
Not for inhalation induction-cause laryngeal spasm
Special vaporizer, dictated by low boiling point
Some fluoride ion release with high does
Very satisfactory for inhalation induction
Suppress airway reflexes and very useful for inhalation induction
Will expand volume of closed gas spaces within the body
% decrease in MAC per decade of age regardless of volatile anesthetic
Highest MAC value?
Prone to cns irritability?
Unstable under sunlight?
Inhibits methionine sythetase?
Highest BGPC- methoxyflurane
Highest MAC value- nitrous oxide
Highest metabolized- methoxyflurane
Prone to cns irritability- enflurane
Unstable under sunlight- halothane
Inhibits methionine sythetase- N02
Acidic drugs bind to?
Alkaline drugs bind to?
2. a1 - acid glycoprotein
Vd is inversely related to protein binding.
High protein binding limits passage of drugs into tissues, thus resulting in high drug plasma concentration and a small calculated Vd)
A constant fraction of available drug is metabolized in a given time period
This kinetics depends on the plasma concentration of drug
First order kinetics
Order kinetics that occurs when the plasma concentration of drug exceeds the capacity of metabolizing enzymes.
This reflects saturation of available enzymes and results in metabolism of a CONSTANT amount of drug per unit of time.
Zero order kinetics
Distribution half-lives of all of the opioids are fairly rapid.
Opioid with a more rapid onset of action, shorter duration of action than fentanyl, eventhough it is less lipid soluble
High non-ionized fraction, small Vd increase the amount of drug available for binding in the brain
Has small volume of distribution, short elimination half-life
75-100X more potent than morphine
Short duration of action than morphine
Highly lipid soluble, longer elimination half-time, larger volume of distribution due to its greater lipid solubility
In comparison with morphine, it does not evoke the release of histamine
Poorly lipid soluble
Metabolized by liver to morphine-3-glucuronide about 75-85%
and morphine-6-glucuronide about 5%
Morphine-6-glucuronide produces analgesia and depression of ventilation
Morphine-3-glucoronide is pharmacologically inactive
Barbiturate is determined by? and not metabolism or elimination.
Repetitive administration of barbiturates saturates the peripheral compartments, so that redistribution cannot occur and the duration of action becomes more dependent on?
Less lipid soluble
Less ionized at physiologic pH than thiopental
Shorter elimination half life 3-4x more rapidly than thiopental
Greater hepatic extraction, is cleared by the liver
Metabolized more rapidly than thiopental
Excreted in feces
Intraarterial injection of this drug causes arterial spasm, venous thombosis and allergic reactions
Shorter elimination half-time than diazepam
Similar volume of distribution with diazepam
More rapid clearance than diazepam
Shorter context-sensitive half-life
Metabolized by cytochrome p450
Hepatic clearance rate of midazolam is 10x greater than that of diazepam
Lipid soluble, highly protein bound
Injection is painful
Prolonged elimination half-time
How much drugs actually makes it into the system
Microsomal enzymes are located in the?
Phase I enzymes (3)
1. cytochrome P-450
2. noncytochrome P-450
3. flavin-containing monooxygenase enzymes
Phase II enzymes (4)
Study Gas Cylinder Table in Morgan
Study Gas Cylinder Table in Morgan
Operating room noise is normally at?
RISK OF ELECTROCUTION
Leakage current is present in all electrical equipment as a result of (3)
The magnitude of such leaks is normally imperceptible to touch (less than 1 mA and well below the fibrillation threshold of 100 mA).
1. capacitive coupling
2. induction between internal electrical components
3. defective insulation
maximum leakage allowed in operating room equipment is?
Types of tubes (3)
1. Polyvinyl chloride
2. Silicone rubber
3. Red rubber
This type of tracheal tube is
Low melting point
This type of tracheal tube is :
This type of tracheal tube is:
Turns to toxic ash
This type of tracheal tube is:
Thick-walled flammable cuff
What ETT tube most resistant to fire?
What ETT tube highly combustible?
PVC>red rubber>silicone rubber>metal
is the most efficient Mapleson circuit for spontaneous ventilation?
The Mapleson type circuit is efficient during controlled ventilation, because fresh gas flow forces alveolar air away from the patient and toward the APL valve.
Controlled ventilation (best to worst)
D>B>C>A (DEAD BODIES CANT ARGUE)
A>D>C>B (ALL DOGS CAN BITE)
Mapleson type with Ayre's T-piece?
Mapleson type with Jackson-Ree's Modification?
Most commonly used for pediatric populations?
The disadvantage is that it needs high fresh gas flow to prevent rebreathing, has lack of humidification and possibility of airway pressure?
Most common absorbent used?
Capable of absorbing how much?
1. Soda lime
2. 23 L (26 L in barash) per 100 g of absorbent
1. Mesh size of soda lime
3. Usual indicator dye
4. Absorptive capacity
5. Method of hardness
2. CaOH (76-81%)
Sodium OH (4%)
3. Ethyl violet
5. Silica added
Barium OH lime
1. Mesh size of baralyme
3. Usual indicator dye
4. Absorptive capacity
5. Method of hardness
2. Barium OH (20%)
3. Ethyl violet
5. Water of crystallization
Commercial soda lime water content?
Space of air in CO absorber?
2-3x the tidal volume
End products of co2 absorber (3)
How much usage of absorber is used after replacing a new one?
A part of anesthesia machine used to prevent the delivery of hypoxic gas mixture from the anesthesia machine in the event of failure of the oxygen supply.
Fail-safe valve is triggered when the pressure in the oxygen delivery line decreases to?
less than 30 psi
Designed to prevent misconnections of PIPELINE?
Diameter index safety system
Designed so that only the correct tank can be attached?
Pin index safety system
ALL MACHINES HAVE OXYGEN SUPPLY LOW PRESSURE SENSOR THAT ACTIVATES A GAS WHISTLE OR ELECTRIC AL ALARM SOUNDS WHEN INLET GAS PRESSURE DROPS BELOW A THRESHOLD VALUE OF?
To provide a large volume of of oxygen to the patient quickly, oxygen bypasses the fowmeters and manifold.
Flow of oxygen delivered to the patient is at?
Where is the dead space in the circle system? (2)
Between the Y-piece and the patient.
Anesthesia machine high pressure areas? (4)
2. Pressure regulators
4. Fail-safe valves
Anesthesia machine lown pressure areas? (2)
2. Flow proportioning device
POST OP pacU
ALDRETE SCORE (READ MORGAN )
; TOTAL 10- DISCHARGED, MINIMUM-9
POSTANESTHESIA DISCHARGE SCORING (PADS)
1. VITAL SIGNS
2. ACTIVITY LEVEL
3. NAUSEA AND VOMITING
4. PAIN: MINIMAL OR NONE ACCEPTABLE TO PATIENT CONTROLLED WITH ORAL MEDICATION
5. SURGICAL BLEEDING
; SCORE >/= 9 REQUIRED FOR DISCHARGED
Examples of muscarinic antagonists (4)
4. ipratropium bromide
Is the volume in the lungs at the end of passive
Normal value (range)
1.7 - 3.5 L
Is the point during expiration when small airways begin to close
The FRC depends on position; the closing capacity is independent of position.
Involves the work of overcoming the elastic recoil of the
lung (compliance and tissue resistance work) and the resistance to gas flow.
Physiologic work of breathing
Formula for Hagen-Poiseuille relationship.
1. For laminar flow?
2. for turbulent flow?
1. R = (8xLxu)/(pi x r to the 4th)
At low flow, or laminar flow (nonobstructed breathing), the viscosity is the major
property of the gas that affects flow. Clearly the major determining factor is the radius of the
2. R ap/r to the 5th
At these flows the major determinants of resistance to flow are the density of the gas (r) and
the radius of the tube, r.
Describes the relationship between pressure (P), tension (T), and the radius
(R) of a bubble and can be applied to the alveoli.
What is the formula?
P = 2T/R
What zone has Interstitial pressure (Pinterstitium) is greater than venous and alveolar pressures;
thus flow is determined by the arterial-interstitial pressure difference.
(Ppa > Pinterstitium >
Ppv > PAlv).
Causes of hypoxemia (4)
1. Low inspired oxygen tension
2. Alveolar hypoventilation
3. Right-Left shunting
4. V/Q mismatch
5. Diffusion abnormality
Is the volume of lung that does not exchange gas. This includes the nose, pharynx,
trachea, and bronchi. This is about 2 ml/kg in the spontaneously breathing individual and is
the majority of physiologic dead space.
Anatomic dead space
Is the volume of gas that reaches the alveoli but
does not take part in gas exchange because the alveoli are not perfused.
Alveolar dead space
VD/VT is the ratio of the physiologic dead space to the tidal volume (VT), is usually about how many percent?
VD=VT(alveolar PCO2 -expired PCO2)/alveolar PCO2
A condition where blood reaches the arterial system without passing
through ventilated regions of the lung.
Is a local response of pulmonary arterial
smooth muscle that decreases blood flow in the presence of low alveolar oxygen pressure,
helping to maintain normal V/Q relationships by diverting blood from under ventilated areas.
Hypoxic pulmonary vasoconstriction
is inhibited by volatile anesthetics and vasodilators but is not affected by intravenous anesthesia.
Where is the respiration center located in the brain?
The respiratory center is located bilaterally in the medulla and pons.
Three major centers contribute to respiratory regulation.
1. dorsal respiratory center
(inspiration) (most impt)
2. ventral respiratory center
(inspiration and expiration)
3. pneumotaxic center
(breathing rate and pattern)
Is located within the nucleus solitarius where vagal and glossopharyngeal nerve fibers terminate and carry signals from peripheral chemoreceptors and baroreceptors (including the
carotid and aortic bodies) and several lung receptors.
Dorsal repiratory center
What are the major buffering systems of the body? (4)
What is the primary organ involved in rapid acid-base regulation?
3. intracellular proteins
What is meant by pH?
Severe acidemia is defined as blood pH
Severe alkalemia is defined as blood pH >?
pH is the negative logarithm of the hydrogen ion concentration ([Hþ]). pH is a convenient descriptor for power of hydrogen.
Discuss issues associated with estimating volume status in outpatients.
A patient’s hourly metabolic requirement is roughly 4 ml/kg for the first 10 kg, 2 ml/kg for the
second 10 kg, and 1 ml/kg for the remainder of his or her weight.
Solution (dissolved in either normal saline or lactated Ringer’s
solution) is another colloid preparation. The heterogeneous preparation contains polymerized
molecules with molecular weights of between 20,000 and 100,000 daltons. Metabolized by
amylase, it accumulates in the reticuloendothelial system and is renally excreted.
Hydroxyethyl starch in a 6% solution
recommended that not more than 20 ml/kg be administered.
What is the normal range for serum osmolality?
Normal serum osmolality ranges
between 285 and 305 mOsm/L.
How do you estimate fluid loss during a surgical procedure?
Surgical sponges can be weighed; a large laparotomy sponge can hold more than 100 ml of blood.
Blood pressure is not significantly affected until approximately ___ of blood volume is lost.
If potassium is administered, how much should be administered and how fast
should it be administered?
Potassium should be administered at a rate no greater than 0.5 to 1 mEq/L. As a safety measure, no more than 20 mEq of potassium, diluted in a carrier and run through a controlled infusion pump, should be connected into a patient’s intravenous lines at any one time.
Hyperchloremia has been increasingly recognized after administration of what
standard resuscitation fluid?
Hyperchloremia is associated with massive resuscitation with normal saline and with metabolic
acidosis caused by dilution of sodium bicarbonate.
What type of blood should be used in an emergency situation?
Type-specific, uncrossmatched blood
would be the next choice, followed by type-specific, partially crossmatched blood and finally fully crossmatched blood.
Three intertwined processes ensure that blood remains in a liquid state until vascular injury
1. primary hemostasis
2. secondary hemostasis
Binding of fibrinogen to activated platelets is facilitated by:
Within seconds of vascular injury, platelets become activated and adhere to the
subendothelial collagen layer of the denuded vessel via glycoprotein receptors; this
interaction is stabilized by: (1)
von Willebrand’s factor (vWF)
When a clot is formed, ________ is incorporated and then converted to
plasmin by __________ and fragments of factor XII
2. tissue plasminogen activator (tPA)
It is a potent vasodilator that inhibits platelet activation and helps confine primary hemostasis to the injured area.
1. Intraoperative bleeding can be severe with platelet counts of? (range)
2. Spontaneous bleeding usually occurs at counts: (value)
1. 40,000– to
A disease where there is a decrease of both factor VIII antigen and factor VIII:vWF.
Is necessary for both platelet adhesion and
formation of the hemostatic plug through regulation and release of factor VIII antigen
Vitamin K-dependent clotting factors
IX, X, VII, II
The _____ pathway is affected first by vitamin K
deficiency because the factor with the shortest half-life is factor ___, found only in the extrinsic
pathway. With further deficiency both extrinsic and intrinsic pathways are affected.
Is a polyanionic mucopolysaccharide that accelerates the interaction between antithrombin
III and the activated forms of factors II, X, XI, XII, and XIII, effectively neutralizing each.
Measures the clotting ability of all factors in the intrinsic and common pathways except
Partial thromboplastin is substituted for platelet phospholipid and eliminates
platelet variability. Normal PTT is about 40 to 100 seconds; >120 seconds is abnormal.
1. Normal bleeding time:
2. Normal PTT
3. Normal aPTT
4. Normal ACT
5. Normal PT
6. Normal INR
1. 4 to 9 mins
2. 40 100 seconds
3. 25 to 35 seconds
4. 90 to 120 seconds
5. 10 to 12 seconds
6. 2 to 3 (standard)
2.5 to 3.5 (high-dose)
Is widely used to monitor heparin therapy in the operating
Activated clotting time
Measures the extrinsic and common pathways. Tissue thromboplastin is
added to the patient’s plasma.
Prothrombin time (PT)
Was introduced to improve the consistency of oral
Is the cold-insoluble white precipitate formed when FFP is thawed. It is removed by centrifugation, refrozen, and thawed immediately before use.
It contains (4)
Will increase finrinogen levels to?
2. factor VIII, vWF, fibrinogen, and factor XIII
3. 50 mg/dL
Factor VIIa complexes with tissue factor to activate factors __ and X__.
Factor __ subsequently
aids in the conversion of prothrombin to thrombin, which leads to the activation of fibrinogen
1. IX and X
Measures the viscoelastic properties of blood as it is induced
to clot in a low shear environment resembling venous flow, providing some measure of clot
strength and stability, including the time to initial clot formation, the acceleration phase,
strengthening, retraction, and clot lysis.
Examination of the neck:
A neck circumference of greater than ___ inches has
been reported to be associated with difficult airways.
Is the largest and most prominent cartilage of the neck, forming the anterior and lateral walls.
Cartilage that is shaped like a signet ring, faces posteriorly, and is the only complete cartilaginous ring of the laryngotracheal tree.
In a patient with an anterior airway the _____ may be the only visible structures.
The superior and recurrent laryngeal nerves, both branches of the ____, innervate
The superior laryngeal nerves decussate into internal and external branches.
The ____ branches provide sensory innervation of the larynx above the vocal cords.
Whereas the external branches provide motor innervation to the _____ muscle
2. Circothyroid muscle, a tensor
The recurrent laryngeal nerves provide sensory innervation below the level
of the cords and motor innervation of the posterior _____, the only abductors of
the vocal cords.
Most frequent cause of
The ____ blades are inserted into the vallecula, immediately ___ to the epiglottis, which is literally flipped out of the
visual axis to expose the laryngeal opening.
The ___ blade is inserted past the epiglottis,
which is simply lifted out of the way of laryngeal viewing.
What structures must be aligned to accomplish visualization of the larynx? (3)
Elevation of the head
about __ cm with pads below the occiput and with the shoulders remaining on the table
aligns the laryngeal and pharyngeal axes.
Internal diameter of ETT ranges from:
2 to 10 mm
Is the sum of IRV, tidal volume (TV), ERV, and RV.
Total lung capacity (TLC)
Is the sum of IRV, TV, and ERV.
Vital capacity (VC)
Is the volume of air in the lung at the end of a normal expiration and is the sum of RV and ERV.
Is the cornerstone for determining the remainder of the lung volumes.
Functional residual capacity (FRC)
Is the sumof IRV and TV.
Inspiratory capacity (IC)
Is most accurate for determining FRC in patients with obstructive airway
disease and applies Boyle’s law, which states that the volume of gas in a closed space varies
inversely with the pressure to which it is subjected.
Measures the rate of uptake of the nonphysiologic gas carbon monoxide (CO).
diffusing capacity for the single-breath diffusion capacity (DLCO)
Upper abdominal procedures result in a decrease in FRC within ___; FRC gradually returns
to normal by ___.
1. 10 to 16 hours
2. 7 to 10 days
Which is the concentration required to block autonomic reflexes to nociceptive stimuli (1.7 to
The concentration required to block appropriate voluntary reflexes and measure perceptive awareness (0.3 to 0.5 MAC)
For every Celsius degree drop in body temperature, MAC decreases
approximately how many %?
2% to 5%
Describes the distribution of a given agent at equilibrium between two
substances at the same temperature, pressure, and volume
Which anesthetic agent is most associated with:
1. cardiac dysrhythmias
Soda lime can also degrade sevoflurane. One of the metabolic by-products is a vinyl ether known as:
Volatile anesthetics that produce CO (3) (least to greatest)
desflurane > enflurane > isoflurane
Volatile anesthetic that is teratogenic in rats. Which causes inhibition of methionine synthesis. It iprevents cobalamin (vitamin B12) to act as a coenzyme for methionine synthase.
Are analgesic and sedative drugs that contain opium or an opium derivative from the poppy plant (Papaver somniferum).
Is any substance with morphine-like activity that acts as an agonist or antagonist at an opioid receptor.
Is not specific for opioids and refers to any substance with addictive potential that induces analgesia, euphoria, or altered sensorium.
3 classes of endogenous peptides
Is a diminution in the physiologic effects of a substance resulting from repeated administration.
May be physical or psychological and refers to the repeated use of a substance to avoid withdrawal symptoms.
Refers to the habitual use of a substance despite adverse consequences, including social and interpersonal problems.
Examples of u and k opiod receptor partial agonists (4)
Most opioids cause bradycardia except?
Which opioids are associated with histamine release? (3)
Treatment of opioid-induced constipation? (1)
Which opioids may be associated with seizure activity in patients with renal failure?
Is an ultrashort-acting opioid with a duration of 5 to 10 minutes and a contextsensitive half-time of 3 minutes.
Is a codeine analog that acts as a m-, d-, and k-receptor agonist and a reuptake inhibitor of norepinephrine and serotonin.
All intravenous induction agents with the exception of?
is an N-methyl-D-aspartate receptor antagonist with profound analgesic properties.
Chemically related to phencyclidine.
Also causes bronchodilation.
Decreases serum cortisol levels by blocking two enzymes in the cortisol pathway:
11-b-hydroxylase and 17-a-hydroxylase.
Is the best induction agent for hypovolemic trauma patients as long as there is no risk for increased intracranial pressure.
Critically ill children are at
the highest risk. Risk is increased with the administration of exogenous steroids and catecholamines and inadequate carbohydrate intake. Manifestations include cardiac failure, rhabdomyolysis, severe metabolic acidosis, hyperlipidemia, renal failure, and sometimes death.
Propofol infusion syndrome
This receptor is contained within the motor cell membrane and consists of five
glycoprotein subunits: two alpha and one each of b, d, and e
When between _% and _% of the receptor channels are open and a threshold potential is reached, a muscle action potential (MAP) is generated.
5% and 20%
Tachycardia is usually a
side effect of what NMBa because of ganglionic stimulation and vagolysis.
A nerve stimulator should be capable of delivering single-twitch stimulation at ___ (1 stimulus every 10 seconds), train of four (TOF) at ___ (2 per second), and tetanic stimulation at ___ (50 per second).
1. 0.1 Hz
2. 2 Hz
3. 50 Hz
Which mode is most commonly used to assess degree of blockade? How is
TOF stimulation is the most common modality used to assess degree of blockade.
The four twitches of the TOF disappear in reverse order as the degree of blockade deepens.
Loss of contraction during tetanic stimulation, known as ___, is a sensitive
indicator of residual neuromuscular blockade.
Is a modified cyclodextrin that forms extremely tight water-soluble complexes with relaxants having steroidal nuclei
(rocuronium > vecuronium > pancuronium)
What determines local anesthetic potency?
The higher the solubility, the greater the potency.
Maximum safe doses:(mg/kg)
1. ( 7 )
2. ( 8-9 )
3. ( 1.5 ) topical
4. ( 5 or 7 ) (w/ epinephrine)
5. ( 5 )
6. ( 2.5 )
7. ( 5 )
Epinephrine, usually in ___ concentration, is also a useful marker of
inadvertent intravascular injection.
Which local anesthetic is associated with the risk of methemoglobinemia? (2)
States that increased myocardial fiber length (i.e., end-diastolic volume) improves contractility up to a point of optimal
contractile state, further stretching results in declining performance.
This drug acts to increase contractility without elevating
intramyocardial calcium levels. This is achieved by stabilizing troponin C in an active form, thus providing inotropic support in similar fashion to other agents but with much lower intracellular
it is acceptable to allow patients to take preoperative medications, including the patient’s
usual medications, with up to ___ of water in the hour
How often does the preoperative evaluation alter care plans?
It has been found that care plans were altered in 20% of all patients (including 15% of
American Society of Anesthesiologists [ASA] class 1 and 2 patients) because of conditions
identified at the preoperative evaluation.
The minimal number of normally functioning platelets to prevent surgical bleeding is
Leaving out the safety features and monitors, the anesthesia machine is divided into three
1. A gas delivery system
2. The patient breathing system
3. A scavenger system
Oxygen and air in the E-cylinders is pressurized up to approximately ___ psig?
But the anesthesia machine needs to work with gas at an initial pressure of about __ psig
Wall gas pressures are typically about __ psig.
Tank pressure is
generally regulated by the first-stage regulator to __ psig.
A full green E-cylinder of O2 has a pressure of __ psi and contains about L of O2.
At room temperature N2O condenses into a
liquid at ___ psi.
E-cylinders of N2O contain the equivalent of about _ L of gas when full,
whereas E-cylinders of O2 and air hold only about 600 L.
All wall-supply gas connectors are keyed so only the O2 supply hose can be plugged
into the O2 connector on the wall, the N2O hose into the N2O outlet, and so on. This is
The gas cylinders are keyed using a ___, so
that only the correct tank can be attached to the corresponding yolk on the anesthesia machine
Flowmeters, also known as ___, are also specific to the gas for which they have been designed and are not interchangeable with other gases.
What happens if you put the wrong agent in a vaporizer calibrated for another agent?
If an agent with a high vapor pressure is put into a vaporizer meant for a less volatile agent, the output will be excessive. If an agent with a vapor pressure lower than the agent intended for the vaporizer is accidentally used, the anesthetic output will be lower than anticipated.
Desflurane has a vapor pressure of ___mm Hg at 20 C
664 mm Hg
What circuit is most commonly used in anesthesia delivery systems today?
The circle system provides the most advantages
How can you check the competency of a circle system?
You should close the pop-off valve, occlude the Y-piece, and press the O2 flush valve until the pressure is 30 cm H2O.
Is a measure of distensibility and is expressed as the change in volume for a given
change in pressure.
Is measured during the delivery of airflow at the end of inspiration.
is measured during an end-inspiratory pause, during a no-flow condition, and reflects the static compliance of the respiratory system, including the lung parenchyma, chest wall, and abdomen.
Static or plateau pressure
What leads are most helpful when looking for a bundle-branch block?
V1, V6, I, and to some extent II
In V1 there is a broad, deep S wave (or QS wave), with ST segment elevation, that may be preceded by a very narrow R wave. Clinical condition?
Is ST-segment depression that occurs in patients with an ST-elevation MI.
Essentially states that the intensity of transmitted light
passing through a vascular bed decreases exponentially as a function of the concentration of the absorbing substances in that bed and the distance from the source of the light to the detector.
Is the most common method of CO2 analysis.
The baseline of the capnogram may not return to zero at high respiratory rates. However, if the
baseline is elevated more than approximately ______ CO2, the patient is receiving CO2 during inspiration, and this is often termed _____
2 mm Hg
Possible causes of
rebreathing include the following: (4)
An exhausted CO2
Channeling of the gas
within the CO2
administration of CO2
(perhaps from a CO2 tank used for laparoscopy)
Inadequate fresh gas flow
CVP (SUBCLAVIAN APPROACH)
The skin puncture is made just lateral to, and one fingerbreadth below,
the ____, which can be identified by a notch two thirds of the length down the clavicle.
CVP (SUBCLAVIAN APPROACH)
The needle is directed along the posterior border of the ___ in the
direction of the __ until VENOUS blood is aspirated.
Describe the external jugular vein approach.
The needle is advanced in a direction paralleling the vessel and is introduced into the vein approximately two finger widths below the inferior border of the mandible.
How is a catheter introduced into the central venous circulation?
An 18- or 20-G needle is introduced into the vessel, and a guidewire is threaded through the needle and into the vein.
At what point on the body should central venous pressure be measured?
The ideal point at which to measure CVP is at the level of the tricuspid valve.
An external landmark for the tricuspid is a point 2 inches behind the sternum, roughly the anterior axillary line, at the fourth intercostal space.
The normal CVP waveform shows a pattern of __ upstrokes and ___ descents that correspond to certain events in the cardiac cycle
What pressures are measured by pulmonary artery catheters?
The PA catheter continuously measures right atrial pressure (or central venous pressure [CVP]) and pulmonary artery pressures.
Strategies to decrease the risk of pulmonary hemorrhage include not advancing the PA catheter beyond __ cm
There are three phases of thermoregulation:
1. afferent sensing
2. central thermoregulatory
3. efferent response
Impulses travel through what fibers?
2. C fibers
One unit of refrigerated
blood or 1 L of room-temperature crystalloid decreases the body temperature about ___ C.