Final Review - All Content Flashcards
(316 cards)
1
Q
Unacceptable Conditions / Patients for Outpatient Procedures
A
- Unstable ASA, physical status classification III or IV (eg cardiac renal, endocrine, pulmonary, hepatic, or cancer diagnoses)
- Active substance / alcohol abuse
- Psychosocial difficulties (ie responsible caregiver not available to observe the patient on the evening of surgery)
- Poorly controlled seizures
- Severe obesity with significant comorbid conditions (ie angina, asthma, OSA)
- Previously unevaluated and poorly managed moderate to severe OSA
- Ex- premature infants younger than 60 weeks of post-conceptual age requiring general anesthesia with endotracheal intubation
- Uncontrolled diabetes
- Current sepsis or infectious disease necessitating separate isolation facilities
- Anticipated postoperative pain not expected to be controlled with oral analgesics or local anesthesia techniques
2
Q
How long is the “optimal” outpatient surgery duration?
A
- Less than 2 hours used to be considered the standard
- (However now it is not uncommon to have procedures as long as 4 hours without issue. )
3
Q
Human Factors regarding Resilience and Root-Cause Analysis
A
- Resilience refers to a person’s ability to recover from setbacks like illness or stress. In healthcare and safety systems, it also reflects a human factors approach that focuses on how errors are avoided and how learning occurs from both success and failure — not just reacting to mistakes.
4
Q
Instead of only counting or blaming human errors, resilience encourages a systems-based view. This helps organizations:
A
- Understand why errors didn’t happen (successes),
- Learn from near misses and recoveries,
- And use that insight to improve processes and prevent future errors.
- By building resilience into systems, root cause analysis (RCA) shifts from focusing solely on individual mistakes to examining broader system weaknesses, helping separate human lapses from organizational contributors.
5
Q
Postoperative Cognitive Dysfunction Disorders in the Elderly - two most common?
A
- Postoperative cognitive problems can be categorized as postoperative cognitive dysfunction (POCD), delirium, dementia, confusion, learning, and memory problems.
- The two most common postoperative cognitive disorders in the elderly are delirium and POCD, and both can be difficult to diagnose.
6
Q
National Surgical Quality Improvement Program. In the cohort over 80 years of age, the top five variables associated with 30- day mortality were:
A
(1) ASA physical status,
(2) preoperative plasma albumin concentration,
(3) emergency surgery,
(4) preoperative functional status, and
(5) preoperative renal impairment.
7
Q
Pediatric Neuro Apoptosis linked to?
A
- Exposure to certain anesthetic agents during sensitive periods of brain development in animal studies has been postulated to result in widespread neuronal apoptosis and functional deficits later in development.
- So far, N- methyl- D- aspartate (NMDA) receptor antagonists and γ- aminobutyric acid (GABA) agonists have been implicated; however, no safe doses of these agents or safe duration of administration of these agents has been defined.
- However, significant increased risk of learning disabilities was associated with two or more anesthetics and increased with greater cumulative exposure to anesthesia
8
Q
Child Outpatient Surgery Requirements
A
- No URI in children absent for two weeks before surgery
- Off antibiotics for 8 weeks
9
Q
When is tonsillectomy post-op bleeding most common?
A
75% of post-operative tonsillar hemorrhages occur within 6 hours of the surgical procedure
10
Q
What is the most common emergency pediatric airway surgery?
A
- Post-tonsillectomy hemorrhage (PTH)
11
Q
What are some correct steps when dealing with post tonsillar bleeding?
A
- Appropriate laboratory tests, including hemoglobin, hematocrit, and coagulation profile, should be performed to determine patient status.
- Restoration of intravascular volume and/or blood based on the volume lost should precede induction.
- RSI - Assume every pt has a full stomach!
- Induce in head down position
- Sevo for induction: 4-8%
12
Q
What increases the likelihood or risk of an AIRWAY fire?
A
Laser Surgery
13
Q
What is the Fire Triad / Triangle
A
- Fuel: Patient, Drapes, Alcohol Prep, Etc
- Oxidizer: Gassssss. Oxygen, N2O, and Air
- Ignition Source: Lasers, electrocautery (ESU: Electrosurgical Unit)
14
Q
What steps can you take to PREVENT a surgical field fire?
A
- Use room air is possible
- If oxygen is needed, try to use less than 30% FiO2
- Secure a closed oxygen delivery system
- Avoid Nitrous
- Prep patient with wet gauze, water based lube, eye patches
- Stop supplemental FiO2 at least 1 min before and during the use of electrocautery or laser.
15
Q
How do you assess for Fire Risk?
A
- On a scale of 1-3.
◦ 3 = High Risk
◦ 2 = Low risk w/ potential to convert to high
◦ 1 = Low Risk
- Is the surgical site or incision above the xiphoid
- Is there an open oxygen source (facemask or nasal cannula)
- Available ignition (ESU, laser, fiberoptic light source)
16
Q
When should you use a cuffed ETT?
A
- Patients older than age 8-10 years old
17
Q
What are some complications of an Intraconal Retrobulbar Block
A
- Trauma to the optic nerve, the blood vessels, and the globe, all of which can lead to loss of vision.
- Most common complication: Hemorrhage d/t trauma of blood vessels and the globe
- Respiratory arrest if LA enters CSF
- Seizures if LA gets into vasculature
18
Q
What nerves are blocked by a Retrobulbar Block?
A
- designed to anesthetize multiple cranial nerves
◦ III, - Oculomotor
◦ IV, - Trochlear
◦ V, - Trigeminal
◦ VI, - Abducens
◦ VII - Facial
19
Q
Describe the Oculocardiac Reflex. Afferents and Efferent Nerves. Triggers. How to interrupt it?
A
- Trigger:
◦ Manual pressure on the globe
◦ Ocular manipulation
◦ Traction on extraocular muscles (esp. medial rectus)
◦ Retrobulbar Block - Afferent Nerve:
◦ Trigeminal V1 via the long and short ciliary nerves to the ciliary ganglion - Efferent Nerve:
◦ Vagus Nerve - Tx/Intervention
◦ Instruct surgeon to cease pressure / traction on orbit
◦ Atropine (0.01mg/kg) 2-3mg for full vagal blockade
◦ Glycopyrrolate (10-20mcg/kg or (.01-.02mg/kg) for less severe bradycardia
20
Q
What are two common anesthetic drugs that increase intraocular pressure?
A
- Ketamine
- Succinylcholine
- Side Note: HyPOventilation increases intraocular pressure - due to hypercarbia
21
Q
How do you calculate BMI?
A
BMI = weight (kg) / meters^2
Feet to inches, inches to cm, cm to meter then square.
2.54cm = 1inch
100cm = 1meter
12inches = 1 foot
22
Q
What are the classifications of obesity based on BMI
A
Underweight = BMI < 18.5
Normal = 18.5-24.9
Overweight = 25-29.9
Obesity I = 30-34.9
Obesity II = 35-39.9
Extreme Obesity = BMI > 40
23
Q
What are the classifications of Metabolic Syndrome?
A
Presence of three of more of the following:
1. Elevated Waist Circumference
Men: greater than or equal 40in.
Women: greater than or equal 35in
2. Elevated Triglycerides
greater than 150
3. Reduced HDL
men < 40mg/dL
women <50mg/dL
4. Elevated BP
greater or equal 130/85
5. Fasting BG greater or equal to 100
24
Q
Diagnostic Criteria for OSA
A
- OSA syndrome is diagnosed by polysomnography (PSG) using an apnea- hypopnea index (AHI).
- Accepted minimal clinical diagnostic criteria for OSA are an AHI of 10 plus symptoms of excessive daytime sleepiness.
◦ AHI is the number of abnormal respiratory events per hour of sleep. - At least 5 obstructive apneas or hyponeas or both per HOUR while pt is sleeping.
25
Android Body Shape & its consequences
* Central, android, or abdominal visceral obesity (apple shape), with a waist:hip ratio greater than 0.85 in women and greater than 0.92 in men, is correlated with a higher risk of comorbidities in obese patients.
* Increased risk for ischemic heart disease, diabetes mellitus, hypertension, dyslipidemia, and death.
* Waist:hip ratio is calculated by dividing the narrowest waist measurement by the broadest hip measurement, taken while the patient is standing
26
Pharmacokinetic Changes Associated with Obesity
Increased Fat Mass
Increased CO
Increased blood volume
Increased Lean Body Weight
Increased Renal Clearance
Increased volume of distribution of lipid soluble drugs
Reduced total body water
reduced pulmonary function
Changes in plasma protein binding
Abnormal liver fxn
27
Dosing of Propofol in Obese Patients
Induction: LBW
Maintenance: TBW
28
Dosing of Succinylcholine in Obese Patients
Induction: TBW
increased fluid compartment and pseudocholinesterase levels require higher doses
29
Classification of TXA
Synthetic Plasminogen-Activator
(Clot Stabilizer)
Tranexamic acid: InHIBITS plasminogen activation. Impedes the formation of plasmin which is what breaks down fibrin.
1-2g IV or topically 1g at the start 1g at the end
30
Contraindications of TXA?
-Hypersensitivity to TXA
-Coronary or vascular stent placed within past 6 mos.
-DVT,PE
-MI, stroke within last 6 months
-Subarachnoid hemorrhage
-Bleeding disorders
-Hypercoagulable state
-Retinal vein or artery occlusion
31
What sort of questions might you ask yourself when creating an anesthetic plan for an orthopedic case?
What type of surgery?
How long will the procedure take?
What comorbidities are present?
Does the patient have preferences (regional/general)
Does the patient's airway present any challenges?
What position with the patient be in for the surgery?
32
What is the most common type of arthritis and leading cause of joint replacement (99%)?
Osteoarthritis
33
What is the etiology of rheumatoid arthritis? What percent of men and women will develop RA?
Inflammatory autoimmune rheumatic disease
4% of women, 2% of men
34
what genetic and environment factors influence the development of rheumatoid arthritis?
Smokers: with a greater than 20 pack/year history
Obesity
Periodontitis and Viral Infections
35
Rheumatoid nodules often form on places of chronic pressure such as elbows and fingers, however, they can develop other places that have more anesthetic, implications, such as:
Cervical spine - decreased ROM
TMJ - limits mouth opening
Larynx - fixation of vocal cords in adduction
Pulmonary - SOB
36
What is the most common cause of death in patient with rheumatoid arthritis?
D/t cardiovascular disease
37
Which form of arthritis is the most debilitating disease a.k.a. systemic effects?
Rheumatoid arthritis
38
What are some airway management techniques for patients with rheumatoid arthritis?
-Consider the patient has a difficult airway
-Proper positioning is important d/t decreased cervical mobility
-Consider regional technique versus General Anesthesia
-Subarachnoid Block (spinal) difficult, d/t higher than normal spread
-Awake Fiberoptic/Glidescope
-Use smaller ETT
39
RA patients take _______, _____________, or _______________ need careful assessment of the airway, including cervical spine x-rays
steroids, immune therapy, or methotrexate
40
The primary concern when caring for a patient with either RA or AS is the?
Patient's Airway
41
What medications or lab values should be evaluated before ortho surgery?
-Current anticoagulation status
-MRSA Screening
-Total Joints: baseline lab values: CBC, Type and Screen (hips usually), and Urinalysis
42
When should antibiotics be administered during ortho surgery? And when should they be redosed?
Administered within 1 hour of incision
Re-dosed every 4 hours
43
What is the normal preoperative antibiotic and dose used for prophylactic coverage? When should you increase the dose?
Ancef (Cefazolin) 2 gram IV
if pt is >120kg, administer 3 grams
44
If patient has an allergy to cephalosporins, what antibiotic is commonly used as an alternative in orthopedic surgery?
Vancomycin
(clindamycin in other specialties)
45
What are the common variables the Joint Commission measures/recommends to decrease surgical site infections?
- Temperature Monitoring: >36 celcius
- Abx Admin within 1 hour of incision
- Continue Beta Blockers on day of surgery
46
How do you calculate maximal accepted blood loss value?
MABL =
[EBV × (Initial Hct – Lowest Acceptable Hct)] / Initial Hct
(EBV based on age/sex/obesity and kg weight)
47
True or False: Local infiltration analgesia for knee replacement has a high recommendation grade. *red item Torabi*
TRUE *red item Torabi*
48
Benefits to the use of a pneumatic tourniquet?
Reduces intraoperative blood loss
Aides in the identification of vital structures
Expedite the procedure
49
What is an example of a non-pneumatic tourniquet? When is it used and how does it compare to pneumatic tourniquets?
Silicone ring tourniquet (SRT)
Used for brief procedures
Application time is more rapid
Tourniquet pain and blood loss are the same
No device attached to monitor the time
50
When should tourniquet application occur?
Applied after anesthesia
(could theoretically be done before but NOT while inducing and intubating patient)
51
Inflation pressure of tourniquet is determined by:
Patient's blood pressure and shape/size of extremity
52
what is the maximum time a pneumatic tourniquet can be inflated?
Max of two hours is considered safe
53
Pneumatic tourniquet application leads to interruption of blood supply to distal extremity, which leads to?
Tissue hypoxia, and acidosis
The degree of hypoxia/acidosis is influenced by duration of tourniquet time
54
Can a patient who received a spinal still feel tourniquet pain/pressure?
Yes, so a low-dose prop drip might help
55
When using a pneumatic tourniquet nerve conduction is abolished after ___________ minutes. And tourniquet pain starts around _______________ after application.
30 minutes
45-60 minutes after application
56
Postop neuropraxia (temporary nerve injury) can occur after how many hours after pneumatic tourniquet application?
Can occur after 2 hours
57
Enothelial capillary leak can develop how many hours after pneumatic tourniquet application?
Can occur after 2 hours
58
Upper extremity tourniquet pressure should be how much greater than a patient's SBP?
70-90mmHg > SBP
(usually 250mmHg for arm)
59
Lower extremity tourniquet pressure should be how much greater than a patient's SBP?
Twice the patients SBP
(needs to be at least 250- 300mmHg)
60
What will be released when the tourniquet is deflated? What can this cause?
Anaerobic metabolites into systemic circulation
Hypotension, metabolic acidosis, hyperkalemia, myoglobinuria, and possible renal failure. Cardiac Arrest worst case scenario.
61
What happens to etCO2 when tourniquet is deflated?
Initial increase peaking at 1-3 minutes, returns to baseline 10-13min
62
What happens to cerebral blood flow when tourniquet is released?
Increased d/t increased etCO2. Goal to maintain normocapnia.
63
How does blood clotting change after tourniquet removal?
Increase fibrinolytic activity. increased bleeding for about 15 min.
64
After tourniquet release, how long does it take for metabolic changes to normalize?
~30min
65
How does body temperature after tourniquet release?
transient decrease in temperature, redistribution of core temp.
66
When does tourniquet pain usually occur?
45-60min after inflation
67
What kind of pain does tourniquet pain resemble?
Thrombotic vascular occlusion and peripheral vascular disease.
68
Tourniquet pain starts as dull and aching and progresses to?
Burning and excruciating pain that may require general anesthesia.
69
The burning and aching pain from tourniquet is from what fibers?
Slow-conducting, unmyelinated C fibers
70
The pin prick, tingling and buzzing sensations patients feel from pneumatic tourniquet are from what fibers?
Faster myelinated A-Delta fibers
71
Systemic Effects of Tourniquet Release (6)
-transient decrease in core temperature
-transient metabolic acidosis
-transient decrease in central Venus oxygen tension, but systemic hypoxia is unusual
-acid metabolites, such as Thromboxane A2 are released.
-transient fall and pulmonary and systemic arterial pressures
-transient increase in etCO2
72
Muscle changes that occur distal to pneumatic tourniquet (4)
Cellular hypoxia develops within two minutes
Cellular creatinine value declines
Progressive cellular acidosis
Endothelial capillary leak develops after two hours
73
Which local anesthetic may offer an advantage to lowering the incidence of tourniquet pain? Why?
Bupivacaine due to becoming enhanced by an increase in the rate of nerve stimulation
74
Which fibers may be more difficult to anesthetize due to tourniquet pain? *red item Torabi*
C fibers may be more difficult to anesthetize than A-Delta fibers and tourniquet pain therefore seems more consistent with pain sensation carried by C fibers
[🧬 Reason: Ischemia + C Fiber Physiology
C fibers are more sensitive to ischemia and metabolic stress than A-delta fibers.
Over time, ischemia irritates and excites C fibers, even if they were previously anesthetized.
This is why tourniquet pain often has that burning, aching quality — it's C-fiber dominant.]
75
As the concentration of local anesthetic decreases, the activation of ___ fiber increase increases, but the _____ fiber activation is still suppressed
C
A-Delta
76
Nerve injury occurs at what area of the skin from pneumatic tourniquet?
skin level at edge of tourniquet
77
pneumatic tourniquet nerve damage is due to?
Rupture of the Schwann cell basement membrane
78
What are some steps to prevent postoperative tourniquet paresthesia?
Proper padding
Correct tourniquet size
Limit time to two hours
79
What are some responsibilities of the anesthetist to reduce the chance of pneumatic tourniquet injury?
Proper cuff size and application (OR Nurse apply)
Minimal effective pressure
Tourniquet set at appropriate pressure
Informed surgeon when tourniquet time >2hr
Over 2 hours, deflate for five minutes for reperfusion
80
what is a severe adverse condition that can occur from prolonged pneumatic tourniquet time?
Compartment syndrome
81
Compartment syndrome can develop due to prolong tourniquet time from?
Increased capillary permeability
Prolongation of clotting
82
What are some signs of compartment syndrome?
Tense skin
Swelling
Weakness
Parasthesia
Absent pulse - reversible paralysis
83
For a patient undergoing a procedure using a pneumatic tourniquet, If hemodynamics won't be easily controlled what should you try?
Try decreasing tourniquet pressure
84
In the upright sitting/standing position, what is the distribution of ventilation and perfusion in the three lung zones? *red Torabi item*
Zone 1: Apex of Lung. Lowest blood flow, most ventilation.
Zone 2: Moderate blood flow, ventilation and perfusion are relatively well matched.
Zone 3: Highest blood flow, reduced ventilation
85
What nerve is most likely to be injured by a fracture of the proximal humerus?
Axillary, median, radial, or ulnar
Axillary
86
What method best diagnosis an extremity compartment syndrome?
A. needle measurement of compartment, pressure.
B. serum creatine phosphokinase level.
C. Doppler detection of extremity pulses.
D. extremity diastolic pressure.
A. needle measurement of compartment, pressure.
> 30mmHg
87
Which procedure is most associated with bone cement implantation syndrome?
A knee arthroplasty
B hip arthroplasty
C vertebroplasty
D ankle arthroplasty
B. hip arthroplasty
All can be associated, but hip is the most associated
88
What is the difference between arthroscopy vs arthroplasty?
Arthroscopy: scope inserted into joints for diagnosis or treatment
Arthroplasty: open surgical
procedure to restore the joint
89
What is the immediate tx for tension pneumo
14-18g IV angiocatch into 2-3 intercostal space anteriorly mid-clavicular.
Insert need at 90-degree angle
Followed by chest tube insertion
90
Benefits of Beach Chair Position
* Improved Visualization for surgeon
* Decreases distortion of the anatomy
* Minimizes potential for brachial
plexus injury (compared to lateral
position)
91
The beach chair position is often used for shoulder surgery.This position can cause:
venous pooling, reduced cardiac output, hypotension, and reduced cerebral perfusion.
92
Risks associated with Beach Chair Position
* Cerebral Hypoperfusion
* POVL
* Deterioration of cognitive
function
* Memory Deficit
* Seizures
* Cerebral death/TIA/Stroke
93
Hemodynamic changes in beach chair position
MAP,
Pulmonary artery occlusion pressure,
Stroke Volume,
Cardiac Output (decreases 20%) and
PaO2 all decrease
94
How does the PAO2-PaO2 gradient change in beach chair position? What hemodynamics are increased?
*Increased Alveolar-arterial oxygen gradient (PAO2-PaO2), pulmonary vascular resistance, and total peripheral resistance increase.
95
How does cerebral perfusion pressure change in the beach chair position?
Decreases by 15%
96
What rate in mL/min and % CO go to the brain? (Red item Torabi)
750-900mL/min
15% of resting CO
97
What is cerebral perfusion pressure?
The difference between mean arterial
pressure and intracranial pressure (or
central venous pressure, whichever is
greater).
CPP=MAP-ICP (or CVP)
98
What is normal Cerebral Perfusion Pressure?
~60-80mmHg
99
What is the calculation for MAP?
[SBP + 2DBP] / 3
100
What cerebral perfusion pressure suggests ischemia? What suggests irreversible brain damage?
30-40mmHg
<25 mmHg
101
Cerebral blood flow is autoregulated when MAP is between?
50-60 and 150mmHg
102
How does the autoregulation of Cerebral Blood Flow change in poorly controlled hypertensive patients?
Autoregulation of CBF is shifted to the right, requiring higher CPP/MAP to ensure adequate cerebral perfusion.
103
If patient is in beach chair position, and their MAP at the arm 65 what is the CPP?
50mmHg (In general subtract 15) unless given a specific measurement
104
Where should your a-line transducer be when patient is in beach chair?
At the external auditory meatus. Best represents the location of the base of the brain and circle of willis.
105
Pearls for Beach Chair
* Maintain normocarbia: (↓ETCO2 reduces CBF). Keep ETCO2 at higher levels,
do not hyperventilate.
* Keep MAP ~60-150 mm/Hg; higher MAP if pt. has HTN
* Aline transducer at tragus/external auditory meatus
* Deduct 15mm/Hg from arm
MAP, Avoid BP cuff in lower
extremity
106
What is the conversion factor for arm blood pressure
to cerebral map in beach chair?
1 cm rise = 0.75 mmHg drop in map
107
Normal cerebral oximetry values (NIRS)
60-80
108
What classifies a hypotensive bradycardic episode? *red item torabi*
Decrease in heart rate of at least 30bpm within a 5-minute interval
Any heart rate < 50 bpm and/or a decrease in SBP of more than 30 mmHg(ex: 120-40=80) within a 5-minute interval or a SBP < 90 mmHg.
109
What is the proposed mechanism of a hypotensive bradycardic episode?
Activation of Bezold-Jarisch reflex
110
What is one procedure and one block associated with hypotensive bradycardic episodes?
Common and shoulder arthroscopy – 30%
Interscalene block: LA with epinephrine
111
When activated, the bezold-jarisch reflex results in a triad of what symptoms?
Bradycardia
Hypotension
Peripheral vasodilation
112
What is the mechanism of the bezold-jarisch reflex?
This cardio inhibitory reflex occurs in the sitting position & after ISB with epi (15-30%)
► The ↓ venous return results from pooling of blood in the lower extremities
► Stretch receptors located in the ventricles are triggered resulting in decreased sympathetic tone and increased vagal tone.
113
How should you treat the bezold-jarisch reflex?
o Treat fluid deficits and blood loss
o Use support stockings to minimize venous pooling
o Avoid use of local anesthetics with epi
o Treat with ephedrine or epi
114
To prevent compression of the dependent brachial plexus an axillary roll is placed. Where do you place it? *red item torabi*
The roll is actually a “chest roll” and should
never be placed in the axilla. Place caudal to the axilla and avoids compression of axillary nerves.
115
What dermatome level should the spinal reach for a hip surgery?
T10 - umbilicus
For longer cases will need to be higher bc it'll wear off before case is done.
116
What percent of patients who need a hip replacement are obese?
50%
117
What approach is most common for total hip replacements? Where is the incision made?
Most common is posterior with a large incision from iliac crest to mid thigh
118
What is your overall anesthetic plan for a total hip arthroplasty?
* Spinal block, Fascia Iliaca Block, Propofol gtt
* General Anesthesia (ETT vs LMA)
* Avoid Nitrous Oxide
* Ancef 2gm IVPB (within 1 hour incision)
119
Intraoperative blood loss during a total hip arthroplasty may exceed 1 L. what medication can help reduce blood loss and what is its MOA?
Transexamic Acid (TXA) 1-2g IV or Topical
Synthetic plasminogen-activator
* Decreases blood loss through inhibition fibrinolysis and clot degradation.
Impedes the binding of plasminogen to plasmin. So it's stabilizers clotting by preventing clot breakdown.
120
How should you administer TXA?
1 g before incision, 1 g at end of procedure per surgeon order - knee or hip.
10-15 mg/kg should not exceed 100mg/min
Infuse over 15 minutes. Can cause hypotension.
121
In patient with renal impairment, how should TXA dose be adjusted?
↓ dose in patients with renal impairment (500mgIV)
122
Contraindications for TXA use
* Hypersensitivity to TXA
* Coronary or vascular stent placed within past 6 mos.
* DVT,PE
* MI, stroke within last 6 months
* Subarachnoid hemorrhage
* Bleeding disorders
* Hypercoagulable state
* Retinal vein or artery occlusion
123
Intra-articular infusions of local anesthetics
following Arthroscopic and other surgical
procedures is a ? *red item torabi*
unapproved use!
124
What is bone cement? How does it work?
Methyl methacrylate (MMA)
-Strongly binds the prosthetic device to the patient’s bone.
-Mixing the powder with a liquid causes an exothermic reaction resulting in hardening of the cement and expansion against the prosthetic components.
125
How can bone cement syndrome develop? What can it produce?
Bone cement can cause Intramedullary hypertension (>500 mm Hg) occurs when the bone cement is applied to the prosthesis.
This intramedullary hypertension can force debris into the patient's circulation causing serious complications.
Systemic absorption of residual methyl methacrylate monomer can produce vasodilation and a decrease in systemic vascular resistance.
(intramedullary - pressure in bone marrow)
126
Bone cement implantation syndrome is most commonly associated with what procedure?
Total hip arthroplasty
127
What is usually the first indication of bone cement syndrome under general anesthesia? What are some other signs/ symptoms?
* Abrupt decrease in End tidal CO2 (1st indication under GA)
* Hypoxia (increased pulmonary shunt)
* Systemic Hypotension
* Arrhythmias (including heart block and sinus arrest)
* Pulmonary hypertension (increased pulmonary vascular resistance)
* Decreased cardiac output
* Mental status change (LOC) in patients with regionalanesthesia
* Dyspnea, altered sensorium in awake pt.
* Right ventricular failure and cardiac arrest
* Etiology: Embolus mediated
128
Risk Factors for bone cement, implantation syndrome
■ Preexisting pulmonary HTN
■ Preexisting CV disease
■ ASA class III or higher
■ New York Heart Association Class 3-4
■ Surgical technique
■ Pathologic fracture
■ Intertrochanteric fracture
■ Long-stem arthroplasty
129
Prior to cementing, how should you optimize your patient?
Optimize blood pressure
100% FiO2
Lavage before implantation
130
if you suspect your patient has bone cement implantation syndrome how do you treat?
► ↑ FiO2 (100%) if not already done
► Treat CV collapse as right sided heart
failure
► Aggressive fluid resuscitation
► Treat hypotension
131
What is fat embolism syndrome? (FES)
* Occurs with long/pelvic
bones surgery (hip)
* Fat globules are released and enter circulation via tears in vessels
* Emboli travels to the right side of
heart and lung→ pulmonary
hypertension
132
How does fat embolism syndrome manifest?
Manifestation of FES can be gradual. It classically presents ~ 72 h following long-bone or pelvic fracture, leading to acute respiratory distress and cardiac arrest.
Mortality rate:10-20%
133
What is the classical triad of clinical manifestations in fat embolism syndrome?
* Classical Triad: dyspnea, confusion, and
petechiae
* A petechial rash (conjunctiva, oral mucosa, and skin folds of the neck and axillae)
* Respiratory manifestations: mild hypoxemia , pulmonary edema, bilateral alveolar infiltrates. (fat droplets act as emboli)
* Neurologic manifestations:
✓ Drowsiness, confusion, obtundation and coma
134
What orthopedic procedures have the greatest risk for thromboembolism?
hip surgery and knee replacement,
major operations for lower extremity, trauma
135
What is Virchow's Triad?
Venous Statsis
Endothelial Injury
Hypercoaguable State
136
A thigh tourniquet is applied with pressures usually set between?
250-300mmHg
137
What are some neurologic complications of prone position? *Torabi Red*
Neck rotation can result in decreased
cerebral perfusion
❑ Peripheral Neuropathies: Brachial plexus
❑ Eye and tongue swelling
❑ POVL: Post op vision loss
138
What is thoracic outlet syndrome?
■ Compression of brachial plexus
■ Swelling and coldness in arm/hand
■ Hypoxemia noted via pulse oximetry
■ No SSEPs in affected arm
■ Occurs in prone position
139
At what intraocular pressure is the risk of POVL increased?
IOC > 40mmHg
140
What is an artificial pneumoperitoneum?
The installation of air or gas into the peritoneal cavity under controlled pressure
141
although rare, more than 50% of all complications during laparoscopic surgery occurr during?
During initial surgical entry into the abdominal cavity and establishment of the pneumoperitoneum - Trocar Insertion
142
what is the leading cause of morbidity and mortality during laparoscopic procedures?
Severe vascular injury at the time of abdominal entry
143
evidence indicates that patients who are extremely _______ or______, or_________ at increased risk for laparoscopic entry related injuries at the umbilical entry point
Extremely thin, obese, or known to have abdominal adhesions
144
Describe the "closed technique"
Use of a spring loaded needle (Veress needle) to pierce the abdominal wall. Trocar is blindly inserted AFTER insufflation.
145
Describe the "open technique"
"Hasson" technique, minimize the risk of major vascular injury when creating pneumoperitoneum. A small incision up to 3 cm is made immediately inferior to the umbilicus through skin and fascia..
Insertion of trocar, then insufflation.
(studies are mixed if open is actually superior)
146
Why do we use carbon dioxide for insufflation?
Readily available, inexpensive, does not support combustion, rapidly absorbed from the vascular space, easily excreted by respiratory system
147
What are some disadvantages to the use of carbon dioxide in laparoscopic surgery?
Hypercapnia-respiratory acidosis
Peritoneal and diaphragmatic irritation manifesting as postop shoulder pain
148
What two hemodynamic variables increase, regardless of whether the pneumoperitoneum is created under low pressure (12mmHg) or high pressure(20mmHg)?
MAP and SVR
149
At around 20-40mmHg, heart rate usually stops trending upwards. what causes the heart rate to trend down with pneumoperitoneum? How do you treat if necessary?
In some patients, the perennial stretch that coincides with the induction of pneumoperitoneum may stimulate a vaguely mediated bradycardia response can be relieved by releasing pressure maintained below 16 treat with anticholinergics if needed.
150
True or false: positioning appears to have a greater effect on central pressures than the pneumoperitoneum itself
True
Steep Trendelenburg or reverse Trendelenburg influence, Venous return and cardiac output
151
How does the pneumoperitoneum affect the cardiac conduction system even in healthy patients?
Prolonged QT dispersion in patients and undergoing laparoscopic procedure with high-pressure insufflation.
QTd reflects ventricular instability prolongation of this parameter is associated with an increased risk of arrhythmias.
[An increased QTd suggests that different parts of the heart are repolarizing at different rates, which can create an electrically unstable environment and increase the risk of cardiac arrhythmias.]
152
What are some factors that influence patients response to the creation of pneumoperitoneum?
-length of surgery
-patient position
-patient age
-degree of intra-abdominal pressure during creation of pneumoperitoneum
-preoperative volume status
-presence of pre-existing pulmonary and or CV disease
153
under normal insufflation pressures. (~15mmHg) what CV affects are seen and why?
Increase HR, MAP, SVR
(could see bradycardia d/t vagus nerve)
-Due to the release of Neuro endocrine hormones(vasopressin, Renin, norepinephrine, cortisol, aldosterone)
-Pressure on abdominal aorta and organs
154
Distention of the abdominal wall viscera, especially patients with high vagal tone in young women predisposes them to vagaly mediated reflexes such as:
Bradycardia and bronchospasm
155
Increased intra-abdominal pressure displace is the diaphragm in a cephalad direction. What does this do to functional residual capacity and V/Q matching
Reduced FRC and predisposes to V/Q mismatching
156
Increased intra-abdominal pressure could have what effect on your ET tube?
Displace the carina cephalad, which predisposes to inadvertent mainstem bronchial intubation
157
What sort of hemodynamic changes should you expect in the elderly patient undergoing a laparoscopic surgery
Exaggerated hemodynamic responses compared to healthy younger patients
Moderate decreases in CO
Increased afterload and CVP, but decrease MAP
158
what capacities or volumes are reduced due to the effects of pneumoperitoneum
-Decreased forced vital capacity (FVC)
-Dec. forced expiratory volume in one second(FEV1), and
-Dec. functional residual capacity (FRC)
Creating areas of atelectasis in making ventilation difficult
159
How does Positive Inspiratory Pressure (PIP) change with pneurmoperitoneum?
Increased
160
Increased PaCO2 and etCO2 from the carbon dioxide insufflation can cause?
acidosis
Characterized as respiratory acidosis.
161
How does pulmonary compliance change with insufflation?
Decreases
(less change in volume / change in pressure)
162
What are peak plateau pressures? When are they measured?
Relationship between volume and compliance. Is a reflection of lung compliance. Reflects the pressure. It takes to hold a given volume inside the lungs.
Measured during end inspiration
163
How would you expect venous return to change with reverse Trendelenburg position?
Reduces venous return which may lead to a fall in cardiac output and arterial pressure
164
Steep Trendelenburg position decreases Venus return from the head, which can result in?
Increase intracranial and intraocular pressures
Venus engorgement of face and neck
165
What position would you expect to put a patient in for a laparoscopic appendectomy?
Trendelenburg
166
In Trendelenburg position by about what percent does pulmonary compliance and peak Plateau pressures change?
Pulmonary compliance decreased by ~ 50%
Peak plateau pressures increased by ~50%
167
How do you expect to position a patient for a laparoscopic Cholecysectomy? How do you expect functional residual capacity in venous return to change?
Reverse Trendelenburg
Increase FRC
Decrease Venous Return
168
How do you expect etCO2 to change during laparoscopy?
Increase. CO2 used for insufflation of the abdomen, is highly soluble and will dissolve across tissues into the bloodstream.
169
Will etCO2 reflect PaCO2 during laparoscopy?
Unlikely. etCO2 will often still UNDERestimate the arterial CO2 by as much as 10mmHg
170
Renal effects of pneumoperitoneum?
-transient increase in creatinine clearance
-decreased urine output due to decreased renal blood flow, release of ADH, and PACO2 levels, create a sympathetic response leading to renal vasoconstriction
171
Hepatic and Splanchnic Effects of pneumoperitoneum
Decrease in splanchnic and liver perfusion
-intestinal ischemia
172
What three major organs could be damaged during umbilical entry for laparoscopic procedures?
Bladder, bowel, uterus
173
the migration of gas to create the pneumoperitoneum can result in what complications?
-Pneumothorax
-Pneumomediastinum
-Pneumopericardium
-Subcutaneous emphysema
-Gas embolism
174
What are some signs of gas embolism?
Hypotension
Hypoxemia
Dysrhythmias
"mill-wheel" murmur
Wheezing
Decreased SPO2
Pulmonary edema
Abrupt decrease in ETCO2
175
Treatment of gas embolism:
-100% 02
-Release pneumoperitoneum
-Stop nitrous oxide if using
-Flood field with NS
-Left lateral decubitus position (Durant Maneuver)
-Aspirate CVP line
-Supportive measure measures
176
Signs of subcutaneous emphysema
-late hypercarbia
-decreased lung compliance
-increase CO2 absorption, increased ET CO2 above 50
-cardiac arrhythmias, tachycardia, hypertension
-crepitus around abdomen chest, neck or groin
177
Management of sub Q emphysema
-Evaluate for pneumothorax
-check, etCO2 CO2 and arterial CO2
-increase, ventilation rate entitled volume (Ve)
-increase oxygen to 100%
-check CO2 absorber in circuit
-decrease inter-abdominal pressure
-d/c N2O if in use
-assess airway to ensure there is no compression before extubating
178
Shoulder pain is due to insufflation, pushing up on the diaphragm, causing which nerve to be irritated? When does it usually resolve?
phrenic nerve
Normally resolve spontaneously in one to two days
179
What ventilator setting is usually preferred during laparoscopic cases?
Pressure controlled ventilation
Able to use recruitment maneuvers and add peep
180
Describe the recruitment maneuver an anesthesia provider could use via the ventilator during a laparoscopic case?
Apply pressures of 35-40cmH2O x40s to inflate alveoli. Apply PEEP after this maneuver
181
PONV is as high as ___% in laparoscopic surgery
72%
182
PONV post laparoscopic surgery is associated with?
-Surgical wound dehiscence
-Aspiration
-Unanticipated hospital admission
183
For higher risk PONV patients what might be your anesthetic management plan for a laparoscopic case?
TIVA combined with anti-emetics
184
What drugs can cause the Sphincter of Oddi to spasm?
Morphine
(meperidine as well)
185
What are some anesthetic considerations when working a robotic surgery case?
-prolonged surgical times
-spatial restrictions
-inability to alter patient position after "docking"
-physiological changes d/t extreme positioning
-risk of postop visual loss
-physiological changes related to pneumoperitoneum
-implementation of ERAS protocol
186
In steep Trendelenburg (40-45 degree head down tilt), what are some CV changes you expect?
Increased MAP, CVP, SVR, PAOP
187
In steep Trendelenburg (40-45 degree head down tilt), what are some respiratory changes you expect?
Increased: airway resistance, peak pressure, plateau, pressure, ETC O2, upper airway edema
Decreased: Lung compliance, vital capacity, FEV1
188
In steep Trendelenburg (40-45 degree head down tilt), what are some cerebrovascular changes you expect?
Increase: ICP, hydrostatic pressure gradient, cerebral vascular resistance
Decrease: Cerebral venous drainage
189
Effects of increased systemic CO2
Respiratory Acidosis
Arrhythmias
Cerebral Vascular Dilation: inc. ICP
190
How might the oxy – hemoglobin dissociation curve change during laparoscopic procedures?
Shift to the Right via the Haldane Effect.
Helps deliver oxygen to the tissues and results and slightly less ischemia than would be expected.
191
What are some anesthetic management considerations for a patient in steep Trendelenburg?
-keep patient paralyzed
-OG/NG to decompress stomach
-limit fluids (facial edema)
-pulse oximeter placement
-prolonged pressure on back of scalp
192
What drugs can be used to reverse a spasm of the sphincter of Oddi? (pick2)
A. Flumazenil
B. Naloxone
C. Glucagon
D. Neostigmine
B. Naloxone - opioids are a common cause of sphincter of oddi spasm
C. Glucagon - a hormone produced by the pancreas, has several effects on the body, including smooth muscle relaxation. Can also stimulate release of bile from the gallbladder.
193
The initial insulation of a pneumoperitoneum results in which adverse cardiopulmonary effect?
A: hypercarbia and acidosis
B. increased V/Q mismatch.
C. Decreased SVR.
D. increased cardiac output.
B. increased V/Q mismatch.
194
Which G.I. effects can occur patients who receive a thoracic epidural compared with those who do not receive a thoracic epidural for postoperative analgesia after major inter-abdominal/intrathoracic surgeries?
A. Dec gastric secretions
D. increased duration of ileus
C. increased peristalsis
D. sphincter contraction
Increased peristalsis due to unopposed parasympathetic activity.
195
What is considered the best diagnostic technique for assessing for abdominal compartment syndrome?
intravesicular (BLADDER) pressure measurement
196
During a laparoscopic procedure what are the effects on cerebral volume and pressure?
Increased intracranial pressure and decrease cerebral venous return
197
Renal blood flow and GFR can decrease by how much during abdominal insufflation?
By 25%
198
Which statement is most accurate regarding inhale nitrous oxide as part of a balanced anesthetic for electroscope lasting greater than one hour?
A. contraindicated due to risk of tension pneumo
B. it can have an effect on surgical visualization.
C. Likelihood of combustion and abdomen goes up greatly.
D. it should be avoided, regardless of surgical duration.
B. it can have an effect on surgical visualization.
Can lead to complex surgical visualization and prolonged procedures greater than 60 minutes due to intestinal/colonic distention, which may obstruct surgical visualization, decrease intestinal, contractility, and increase the risk of intestinal leakage and anastomotic breakdown.
199
What immediate step should be taken if crepitus from CO2 insufflation is identified intra-operatively? (select 2)
A. assess for the presence of capnothorax
B. turn to left lateral to cubitus with Trendelenburg.
C. Discontinue positive and expiratory pressure.
D. deflate the peritoneum as soon as possible.
A and D
200
What physiological change of aging occurs in the autonomic nervous system?
A. decreased beta receptor responsiveness.
B. decrease norepinephrine levels.
C. Increased acetylcholine release in response to vagal stimulation.
D. increased baroreceptor sensitivity.
A. decreased beta receptor responsiveness d/t decreased receptor affinity in altered signal transduction.
201
How is autonomic nervous system function altered with aging?
-Increase sympathetic nervous system activity (Decreased parasympathetic nervous system activity)
-Decreased beta receptor responsiveness
-Increased no epinephrine concentrations in the plasma
202
How does atrial compliance and filling pressures change with aging?
Feeling pressure should increase due to the less compliant heart and vascular system. Diastolic function is decreased due to reduce compliance and increased wall, stiffness, impairing, myocardial relaxation.
203
True or false: aging patients have no change in systolic function.
True (assuming no prev severe cardiac events)
204
What are some cardiovascular changes in the older adult?
-Reduction in arterial compliance
-Increased systemic, vascular resistance
-Increase in arterial stiffness, increasing the systolic blood pressure to a greater degree than the diastolic pressure.
!However, there is no change in systolic function!
205
What physiological change of aging occurs in the cardiovascular system?
A. increased vascular system compliance.
B. decreased mean arterial pressure.
C. Decrease pulse pressure.
D. left ventricular wall thickening.
Left ventricular wall thick
206
Medication in the elderly can increase the risk of central anticholinergic symptoms
Scopolamine
207
Compared to a 25-year-old woman, what will most likely be observed in a 65-year-old woman when rocuronium is used for neuromuscular blockade?
A. Increase duration of redosing
B. Increase initial dosing requirements
C. Onset of action will be unaffected by age
D. Onset of action will be shorter
A. Increase duration of redosing
You don't have to redose as much.
There is not a shortened onset of action in elderly patients
208
What are some pharmacokinetic changes that alter the duration and elimination of NMBA's in the elderly??
Increased total body fat
Decreased total body water
Decrease lean body mass
Decreased renal and hepatic blood flow
Decreased hepatic function
Decreased GFR
Decrease CO
209
What is the most common cardiac complication and leading cause of death in
the postoperative period? *Torabi Red Item*
MI
210
Most common CV diseases in the elderly?
HTN
HLD
CAD
CHF
211
How does ventricular ejection time change in the elderly? Why?
Prolonged Ejection Time
A thicker ventricular wall reduces chamber size and makes the heart less flexible.
When it contracts, it takes longer to squeeze the blood out because the thickened muscle isn't as coordinated and can't contract as quickly and efficiently.
Also, because the afterload is higher, more force and time are needed to eject blood from the left ventricle.
212
Prolonged circulation time in the elderly, due to CV changes, cause what sort of induction of anesthetic changes?
Faster induction time with inhalation agents, but delays the onset of IV drugs
213
Why do inhalation agents have a relatively faster onset in the elderly?
Prolonged circulation time leads to:
-Blood lingers longer in the pulmonary capillaries.
-It absorbs more anesthetic gas per unit of time while it's in the lungs.
-This increases the partial pressure of anesthetic in the blood more quickly.
-Faster rise of alveolar and arterial anesthetic partial pressures (FA/Fi) → faster delivery to the brain → faster induction.
214
What sort of conduction system changes occur in the elderly due to calcification?
Afib
Sick Sinus Syndrome
Heart Blocks
- more likely to need pacemaker
215
In an arterial BP tracing, why is there a faster propagation of the pulse pressure waveform?
D/t arterial stiffening
(Pressure tracing per beat more narrow/shorter)
216
List the age-related CV changes seen in the elderly
Myocardial Hypertrophy
Myocardial Stiffening
Reduced LV Relaxation
Reduced Beta Receptor Responsiveness
Conduction Abnormalities
Stiff Arteries
Stiff Veins
217
The elderly CV change, reduced Beta-Receptor Responsiveness, leads to?
Hypotension (less response to catecholamines) and more dependent on the Frank Starling Law (Preload)
218
The elderly CV change, stiff arteries and veins, leads to?
Labile BP and Changes in Blood Volume - more exaggerated changes in cardiac filling
219
The elderly are more dependent on ________ _________ d/t decreased beta receptor resopnsiveness.
Frank Starling Law
220
How does HR in the elderly response to hypotension, hypovolemia, and hypoxia?
Decreased capacity/ability to respond with an increase in HR.
-Barorecpetor responsiveness reduced
221
How does age related calcification in the elderly affect the heart?
Calcification of conduction system leads to loss of SA node cells --> arrhythmias
Calcification of the valvular system: aortic and mitral stenosis/regurg
222
What lung volume changes are seen in the elderly?
Increase in residual volume
Increase in FRC
Decrease vital capacity,
Decrease inspiratory reserve volume
Decrease expiratory reserve volume.
223
How does closing volume change as we age? *red item Torabi*
Closing volume exceeds FRC at 45 years in the supine position
Closing volume exceeds FRC at 65 years in upright position
224
How does closing capacity change as we age?
Gradually increases as we age
225
How do central and peripheral chemo receptors change with age? What are the consequences and anesthetic considerations?
Decreased chemo receptor sensitivity
Leads to increased hypoventilation, increased apnea, and therefore a decreased ventilator response.
Consider postop CPAP or BiPAP
Vigilant monitoring
Supplemental O2 postop
Encourage cough deep breathe/IS
226
How does pulmonary muscle strength change with age? Consequences and anesthetic considerations.
Decreased muscle strength
Increased work of breathing and decreased protective airway reflexes. Risk for resp failure and aspiration
Adequate hydration, consider RSI with GA, ensure fully reverse prior to extubation, consider CPAP or BiPAP postop, vigilant monitoring, cough/deep, breathing postop
227
How do the small airways change as we age? What are the consequences and anesthetic considerations?
There is an increase in small airway closures
Increased anatomic, dead space, decreased alveolar surface area, decreased pulmonary capillary blood flow, decreased PaO2
Consider viola recruitment maneuvers, limit high FiO2, maintain PaCO2 near normal preop value, consider regional/local with sedation
228
What are some airway anatomic changes that occur as we age along with their consequences? (red item Torabi)
Decrease in laryngeal and pharyngeal support: higher risk of obstruction
Edentulous: poor mask, ventilation
Arthritis: decreased ROM
Decrease in protective laryngeal reflexes: increased risk of aspiration
229
Postop pulmonary complications seen in the elderly
Atelectasis
Bronchospasm
Exacerbation of underlying disease
Pneumonia
Prolonged mechanical ventilation
Postop respiratory failure
230
How does creatinine change in the elderly? (red item Torabi)
Creatinine stable however, a normal level in the elderly should not be interpreted as an absence of renal impairment
231
How does renal function change in the elderly? (red item Torabi)
Progressive atrophy of renal tissue, ↓ renal mass and sclerosis of vascular structures:↓ renal blood flow and glomerular
filtration rate.
↓ ability to correct alterations in electrolyte
concentrations, intravascular volume, and free water
232
A decrease in GFR can lead to?
↓ glomerular filtration rate leads to delayed
renal drug excretion(hydrophilic drugs), ↑ risk
of CKD
233
How does hepatic function change in the elderly?
Decreased liver mass and reduced portal and hepatic blood flows result in ↓ hepatic drug clearance
Cytochrome P-450 enzyme activity decreases with aging
Phase 1 (oxidation, reduction, hydrolysis) and phase 2 (conjugation, sulfonic acid, acetylation) reactions may be depressed with aging.
234
How does hepatic blood flow change per decade?
Approximately decreases 10% per decade
235
How much muscle mass is lost by 80 years old? (red item torabi)
50%
236
How does basil metabolism and heat production change in the elderly?
Decrease due to scale to muscle atrophy, decrease physical activity, and decreased testosterone
237
How does the volume of distribution for water soluble and lipid soluble drugs change in the elderly?
Decrease Vd of water, soluble drugs
Increased Vd of lipid soluble drugs
238
What brain structure becomes impaired, resulting in a reduction in thermal regulation in the elderly?
Decrease in hypothalamus function
239
Hypothermia is more pronounced in last longer in the elderly due to?
Lower basal metabolic rate
Higher ratio of surface to body area mass
Less effective peripheral vasoconstriction in response to cold
240
how does impaired thermal regulation affect anesthesia?
Slows anesthetic elimination
Prolongs recovery
Impaired coagulation
Impaired immune system system
Blunt ventilator response to CO2
Increase risk of shivering
241
What are some neuraxial anesthesia considerations for the elderly?
* ↓ myelinated nerve fibers
* Dura is more permeable to LA
* CSF Volume ↓
* Time of onset ↓ with more enhanced spread * Epidural Test dose less reliable in elderly d/t beta adrenergic response
* Use ↓ dose of LA
242
Frailty can be diagnosed if there is the presence of three or more of the following criteria:
‣ muscle weakness, *
‣ slow walking speed,
‣ exhaustion,*
‣ low physical activity, and
‣ unintentional weight loss.*
243
What degree of weight loss suggests frailty?
Unintentional 10 pound weight loss within a year
244
What is postoperative delirium?
A transient disorder of cognition and consciousness characterized by an acute onset and fluctuating course.
245
When does postop delirium usually manifest?? (Torabi Red Item)
Manifest acutely within first few days after surgery and it last for several days/weeks
246
Symptoms of postoperative delirium
Agitation
Somnolence
Social withdrawal
Psychosis
247
Risk factors for postoperative delirium
Advanced age
Male gender
Dementia
History of alcohol, abuse
Depression
Duration of anesthesia
Poor functional status
Abnormal electrolytes and glucose
248
Treatment for postoperative delirium
Treat any underlying disorder
Encourage interaction with family members
Encourage normal sleep – wake cycles
Avoid restraints if possible
249
What are two medications that can be used to try and control or prevent postop delirium
Haloperidol (PO or IM) for acute agitation control
Dexmedetomidine Intraoperative
250
What surgical procedures have a higher incidents of postop delirium?
Aortic heart surgery
Hip surgery
251
What is postoperative cognitive dysfunction?
A subtle deterioration in memory, attention in speed of information processing associated with anesthesia and surgery
252
Alzheimer's disease is characterized by?
Diffuse amyloid-rich senile plaques and neurofibrillary tangles are the hallmark pathologic findings
* Changes in synapses and in the activity of several major neurotransmitters, especially synapses involving acetylcholine and CNS nicotinic receptors.
253
What are some symptom management medication options for Alzheimer's?
cholinesterase inhibitors such as:
tacrine,
donepezil,
rivastigmine
galantamine
memantine
254
If a patient is taking a cholinesterase inhibitor to help Alzheimer's symptoms, how might this affect one of your anesthesia drugs?
Prolongation of the effect of succinylcholine and relative resistance to
nondepolarizing muscle relaxants resulting from the use of
cholinesterase inhibitors.
255
How do MAC requirements change as we age?
➢MAC of inhalation agents ↓ by 6 % each decade after age 40
256
How should your dose of propofol accommodate an opioids change in the elderly?
Reduce bolus by 50%
257
How should your nondepolarizing and depolarizing neuromuscular blocking agent dose change for the elderly?
No significant dose adjustment
258
In obese patients, the highest risk of death is do to?
Cardiovascular causes
259
What are the two formulas for BMI?
BMI= Weight(kg)/Height(m^2)
BMI= (Weight(lbs)/Height(in.^2)) x 703
260
How much does lean body mass increase by in obese individuals due to the increased muscle developed to carry extra body weight?
30%
261
For Succinylcholine, what body weight should you use to dose?
Total body weight
262
What body weight should be used for Midazolam administration? Why? What side effects might you see?
-Total body weight
-Because of an increase central volume of distribution. Dosing this way will prolong the elimination half-life, and it duration of effect.
-may cause over sedation and obese patients who are sensitive to respiratory depressant drugs
263
What body weight should Initial doses of Fentanyl and Sufentanil be administered? Why? What about Maintenance dosing?
Initial doses should be based on total body weight because of their fat solubility in large volume of distribution (prolonged elimination half-life)
Maintenance dosing is based on lean body weight
264
What drug, even though water-soluble, is dosed for intubation using total body weight? Why?
Succinylcholine
Due to the combination of an increased blood volume (increased Vd) and increased pseudocholinesterase activity (increased clearance) necessitates a total bodyweight dose be given to ensure adequate paralysis.
This is the clear exception to the rule for water, soluble drugs!!!
265
Dosing of Propofol for Induction and Maintenance should be based off of which body weights for obese patients?
Induction Dose: Lean Body Weight
Maintenance Dose: Total Body Weight
266
Dosing of Rocuronium, Vecuronium, and Cisatracurium should be based off of which body weights for obese patients?
Ideal Body Weight
267
Dosing of Remifentanil should be based off of which body weights for obese patients?
Ideal Body Weight
268
Dosing guidelines for Precedex in obese patients?
Infusion Rates of 0.2mcg/kg/min
269
Dosing guidelines for Sugammadex in obese patients?
Total Body Weight
270
How is total body water changed in obese patients?
Reduced total body water
271
How is cardiac output and blood volume changed in obesity?
Increased cardiac output and increased blood volume
272
How is renal clearance changed in obesity?
Increased renal clearance
273
How does the volume of distribution of lipid soluble drugs change in obesity?
Increased volume distribution
274
Is liver function, usually normal or abnormal in obesity
Abnormal (per Dr. brown slides)
275
What inhalation agents are good for the obese patient?
Desflurane, Sevoflurane, and Nitrous Oxide
276
What are some cardiovascular conditions associated with obesity?
Coronary heart disease
Hypertension
Dyslipidemia
Cerebrovascular disease
Thromboembolic disease
Cardiomegaly
Congestive heart failure
Pulmonary hypertension
277
What are some endocrine related conditions associated with obesity?
Type two diabetes
Thyroid disorders
278
What are some respiratory related conditions associated with obesity?
Restrictive lung disease
Obesity hypoventilation syndrome
Obstructive sleep apnea
279
What are some gastrointestinal conditions associated with obesity?
Hiatal or inguinal hernia
Gallbladder disease
Non-alcoholic fatty liver disease: steatosis, cirrhosis, hepatomegaly
Gastroesophageal reflux disease (GERD)
280
Which obesity shape is less correlated with significant disease?
Peripheral gynecoid or gluteal femoral obesity
Pear shape
281
Central, android, or abdominal visceral obesity has an increased risk of?
Heart, disease, hypertension, diabetes
282
Health risks associated with the gynecoid body shape
Osteoporosis
Varicose veins
Cellulite
Subcutaneous, fat traps and stores dietary fat
Trapped fatty acids stored as triglycerides
283
Android body shape characteristics
Fat primarily located in the abdominal area
Fat also distributed over upper body such as neck, arms, shoulders
Greater risk for obesity related complications
284
Health risks associated with android body shape, fat distribution
Heart disease
Diabetes
Breast cancer
And endometrial cancer
Visceral fat is more active, causing
-decreased insulin sensitivity
-Increased triglycerides
-Decreased HDL cholesterol
-Increased blood pressure
-Increased free fatty acid release into blood
285
What waist circumference in men and women increase the risk of ischemic, heart disease, diabetes, hypertension, dyslipidemia, and death?
Men: waist circumference greater than 102 cm (40 inches)
Women: waist circumference greater than 88 cm (35in)
286
The American heart Association in the national heart-lung and blood institute to find metabolic syndrome as the presence of three or more of the following criteria:
1. Elevated was circumference.
2. Elevated triglycerides. (>150mg/dL)
3. Reduced HDL cholesterol.
Men<40
Women<50
4. Elevated blood pressure.
130/85
5. Elevated fasting glucose.
>100mg/dL
287
How do the demands put on the heart from obesity impact cardiac output, oxygen consumption, and carbon dioxide production?
All are increased!
288
How many mmHg does blood pressure increase for every 10% increase in body weight?
6.5mmHg!
289
The development of hypertension in obese patients is often precipitated by:
-increase blood viscosity d/t catecholamine kinetics, and possibly increased estrogen concentrations
-hyperinsulinemia, elevated mineralocorticoids, and abnormal sodium reabsorption
-arrhythmias
290
what respiratory body mechanics can be reduced up to 35% of predicted values in obese patients?
Chest wall compliance
Lung/Parenchyma Compliance
Pulmonary Compliance (chest wall + lung)
291
Why do obese patients have an increased myocardial oxygen consumption?
Metabolic needs of the fat organ and greater mechanical work of breathing
292
Respiratory muscle efficiency is reduced in obese patients which can be seen by?
Reduced FRC
Premature airway closure
Increased dead space
CO2 retention
V/Q mismatch
Shunting
Hypoxemia
293
Which lung volumes are reduced in obese patients?
Functional residual capacity
Expiratory reserve volume
Total lung capacity
294
Recurrent hypoxemia leads to?
Secondary polycythemia and is associated with an increased risk of coronary artery disease and cerebrovascular disease.
295
Is obesity create a more of a restrictive or obstructive lung disease?
Restrictive lung disease
296
Which is the most accurate statement regarding the airway evaluation of an obese patient?
A. BMI is a definitive risk factor for intubation
B. increased neck, circumference and a Mallampati class 3 our strong predictors of difficult tracheal intubation
c. Obstructive sleep apnea is a dependent risk factor for difficult mask ventilation
d. Risk factors for difficult mask, ventilation in difficult intubation overlap.
B. increased neck, circumference and a Mallampati class 3 our strong predictors of difficult tracheal intubation
297
When mechanical ventilation is initiated in an obese patient, how does oxygen consumption change?
Reduced oxygen consumption, ~15%, that is not seen in normal weight patients
298
What percent of all surgical patients are at high risk for OSA?
25% due to the under diagnosed prevalence of OSA
299
OSA is characterized by?
* OSA syndrome is diagnosed by polysomnography (PSG) using an apnea- hypopnea index (AHI).
* Accepted minimal clinical diagnostic criteria for OSA are an AHI of 10 plus symptoms of excessive daytime sleepiness.
◦ AHI is the number of abnormal respiratory events per hour of sleep.
* At least 5 obstructive apneas or hyponeas or both per HOUR while pt is sleeping.
300
What is the most common comorbidity of OSA?
Hypertension
301
What is the gold standard for OSA diagnosis?
Overnight polysomnography
302
What is the apnea-hypopnea index?
The number of abnormal respiratory events per hour of sleep
303
What is STOP-BANG?
304
Pickwickian syndrome is also known as?
Obesity hypoventilation syndrome
305
What percent of patients with extreme obesity have obesity hypoventilation syndrome? what are characteristics of OHS?
8% of obese pop.
1. OSA
2. Hypercapnia (CO2 retention)
3. Daytime Hypersomnolence (can be inappropriate and sudden)
4. Arterial Hypoxemia
5. Cyanosis-induced Polycythemia
6. Respiratory Acidosis
7. Pulmonary HTN
8. Right sided heart failure
9. Extreme: nocturnal episodes of central apnea, apnea without respiratory efforts, reflecting
progressive desensitization of the respiratory centers to nocturnal hypercarbia
306
How does the classification for obesity differ from that of pediatric obesity?
* Obesity is > than the 90th percentile or a BMI greater than or equal to the 95th percentile, age and sex specific.
* Pediatric obesity: BMI greater than the 95th percentile on the (CDC) growth chart
307
What are the 4 most common bariatric procedures: Restrictive or Malabsorptive Procedures
1) Laparoscopic adjustable gastric banding (LAGB)
2) Roux-en-Y gastric bypass (RYGB)
3) Laparoscopic sleeve gastrectomy (LSG) and 4) Biliopancreatic diversion with duodenal switch
308
Indications for Bariatric Surgery
* BMI > 40 kg/m2
* BMI < 35 kg/m2 with an associated medical comorbidity worsened by
obesity
* Failed dietary therapy
* Psychiatrically stable without alcohol dependence or illegal drug use
* Knowledgeable about the operation and its sequelae
* Motivated individual
* Medical problems not precluding probable survival from surgery
309
Most antibiotics in the bariatric surgery patient should be calculated on?
Total body weight
310
Patient with recent gastric banding are at an increased risk of?
Aspiration so do an RSI
311
What is the ideal position to intubate an obese patient?
HELP position (Ramped)
Head elevated, laryngoscopy position
Head, upper body, and shoulders elevated above chest, connect sternal notch with external auditory meatus.
312
How can you position the patient utilizing the OR table to optimize obese patient induction?
30 degree
Reverse Trendelenburg (aka feet down)
or
Back of table elevated into bring whole upper body up
313
What position should the obese patient be in during induction / extubation? What does this promote?
Position pt in reverse trendelenburg for induction/extubation.
Promotes pt comfort, reduces gastric reflux, easier mask ventilation, improves respiratory mechanics, helps maintain FRC. (These pts probably do not lay flat at home, at least not comfortable)
314
General anesthesia causes what % decrease in FRC in obese patients ?
50%!
315
Decision to extubate obese patient depends on:
-Ease of BVM ventilation and intubation prior
-Length and type of surgery (anything over ~4 hrs has increased post op risk)
-Presence of existing conditions (OSA, COPD, etc)
-Extubate patient sitting up
-if in doubt, keep intubated, extubate over an airway exchange or fiberoptic bronchoscope, or OPA or NPA
-Awake, not a deep extubation
316
Compared to nonobese patients, obese patients require how much more or less local anesthetic for spinal or epidurals?
Require ~25% less d/t more epidural fat and distended epidural veins
