Basic - General Anesthesia Flashcards
1
Q
Read the 11 non-reassuring findings from ASA as predictors of difficult airway
A
- Long incisors
- Prominent overbite
- Cannot bring mandibular incisors anterior to maxillary incisors
- < 3cm inter-incisor distance
- Uvula not visible when tongue protruded
- High arched or narrow palate
- Mandibular space stiff or occupied by mass
- < 3 ordinary finger breadth TM distance
- Short neck length
- Thick neck
- Decreased extension or flexion of neck
*Decaying teeth is NOT a predictor
2
Q
The liver receives ___% of total cardiac output
A
30%
- 3/4 by portal vein
- 1/4 by hepatic artery
3
Q
_____ cells and specialized pathways detoxify substances, rendering them into harmless compounds. This process is the primary reason why ______ metabolism is effective.
A
Kupffer cells
First-pass
4
Q
Liver synthesizes all of the procoagulants EXCEPT ____
A
Factors III, IV, and VIII
*overlaps with vit K dependent proteins 1972, giving vit K will differentiate if it is a deficiency in Vit K or hepatic procoagulants
5
Q
Factor VIII is produced in ____
A
endothelial cells and bone marrow
6
Q
Vit K dependent proteins are ______
A
Factors II, VII, IX, X
1972
*giving vit K will differentiate if pts with prolonged PT has a deficiency in Vit K or hepatic procoagulants
7
Q
(ALT/AST) is the main cytoplasmic liver enzyme
A
ALT
*AST can be found in other body tissues
8
Q
What can low albumin indicate?
A
- Chronic liver injury
- Renal loss
- Inc albumin catabolism
- Expansion plasma volume
- Maldistribution
9
Q
Laryngospasm is a reflex response that involves the ADDuction of the ______, with motor innervation by the recurrent laryngeal n.
A
true and false vocal cords.
10
Q
Individual risk factors of post op cognitive dysfunction
A
- Adv age
- Lower education level
- H.o Previous CVA with NO residual impairment
*Independent of type of surgery. ie. NOT cardiac sx
11
Q
Anyone with a MI without intervention should wait ____ days before elective sx
A
60 days
12
Q
Emergent vs Urgent surgery
A
Emergent: Life or limb is threatened if not in OR w/in 6 hours
Urgent surgery: Life or limb if not w/in 24 hrs
13
Q
After an MI, Pts should wait ___ days after balloon angioplasty before elective surgery
A
14 days
14
Q
2 antidotes for extravasation
A
- Hyaluronidase
- pediatric, TPN - Phentolamine
- alpha blocker -> vasodilates
15
Q
How to administer phentolamine if phenylephrine extravasated?
A
Dilute 5 mg of phentolamine to 0.5mg/mL, then inject 1 mL increments into area surrounding extravasation site
Elevate limb
16
Q
After fentanyl, which med is the most commonly abused opioid amongst anesthesiologist?
A
Sufentanil > Meperidine > Morphine > oral drugs
17
Q
Inhaled anesthetic induction techniques are (improved/worsened) by benzos and (improved/worsened) by opioid
A
improved
worsened
18
Q
Stage II excitation is (increased/decreased) with masked induction with sevoflurane
A
decreased
19
Q
ASA 4 vs 5?
A
4: severe systemic disease, constant threat to life
- Recent < 3 mo TIA or MI
- ESRD NOT on regular dialysis
5: Moribund pt not expected to survive w/o operation
- Massive trauma
- ICH w/ mass effect
20
Q
Severe aortic stenosis:
Valve area:
Transvalvular pressure gradient:
A
Valve area: < 0.8 cm^2
Transvalvular pressure gradient: > 50 mmHg
21
Q
Where do you want to keep HR in pts with AR?
A
> 80bpm to decrease diastolic time and decrease time for regurgitation
22
Q
Factor VII has a the shortest half life of the vit K dep factors, it has a half life of __, and can serve as an early measure of hepatic dysfunction by measuring ____
A
6 hours
PT/INR
23
Q
Platelets are produced in the _____, and can be sequestered in the ____ secondary to portal hypertension
A
bone marrow
spleen
24
Q
Factor VIII is produced by _______ (4). It is generally bound to vWF in blood.
A
- Vascular endothelium
- Renal tubular and glomerular cells
- Megakaryocytes
- Hepatic sinusoidal cells
25
Hemophilia A is d/t a defect in ____
genes for factor VIII
26
Neostigmine ____ mg/kg can be administered to reverse succinylcholine when a phase II block is present.
0. 03 mg/kg
* neostigmine during a phase I block is ineffective, since postjunctional membrane remains in state of sustained depolarization, that is completely unresponsive to ACh.
27
Prolonged neuromuscular blockade can occur in pts with abnormal _____. std intubating dose produces depolarizing phase I block ~ 10 min.
But impaired metabolism of succinylcholine can lead to _____.
plasma cholinesterase
Prolonged phase I block that can progress to nondepolarizing phase II block (several hours)
28
Progression from a phase I to a phase II block means the postjunctional membrane has ______, though it is desensitized
Become repolarized
29
During a phase II block, neostigmine can reverse succinylcholine how?
it inhibits acetylcholinesterase ->
higher ACh [ ] in the NMJ
*but it also inhibits plasma cholinesterase which is responsible for succinylcholine metabolism, so dose needs to be low
30
After an MI, pts should wait __ days after a balloon angioplasty, ___ days after a bare metal stent, ___ days if no coronary intervention, and ___ days after a drug eluting stent for elective noncardiac sx
14
30
60
180
31
The oxygen affinity for hemoglobin is (higher/lower) in children/infants than adults. making their P50 (higher/lower)
Lower oxygen affinity for hgb
Higher P50
*P50 is the partial pressure of O2 when oxygen sat (SaO2) is 50%
32
The oxygen affinity for hemoglobin is (higher/lower) in newborns than adults. making their P50 (higher/lower)
very much higher
very much lower P50
33
When the oxyhemoglobin dissociation curve shifts to the Left, the P50 will (increase/decrease)
decrease
* P50 is the partial pressure of O2 when oxygen sat (SaO2) is 50%
- neonates have very low P50 d/t hemoglobin F
34
neonates have very low P50 d/t _____
hemoglobin F
| - useful for oxygen transfer from maternal blood to the fetus
35
P50 is the lowest in ____, and highest in _____
newborns
children > 12 mo old
36
P50 increases, when the oxyhemoglobin dissociation curve shifts to the right.
What causes a RIGHT shift?
(Right) RIse in:
2,3 DPG
H+
Temp
and acidosis
37
P50 decreases, when the oxyhemoglobin dissociation curve shifts to the left.
What causes a LEFT shift?
(Left) Lowered:
Temp
CO2
2,3 DPG
and Alkalosis
38
LMAs are associated with which nerve palsy?
1. Lingual nerve
- tongue numbness, no taste
2. Recurrent laryngeal
- vocal cord palsy
3. Hypoglossal
- tongue edema, diff with phonation
*Higher risk with N2O use
39
Type of surgery with the highest risk of exacerbating liver disease
Cardiothoracic surgery
40
____ accurately predicts perioperative mortality in pts with cirrhosis
MELD scoring system
41
_____ is the most common postop peripheral neuropathy.
| ______ can be used to evaluate for motor and sensory deficits
ulnar nerve injury
Nerve conduction studies
42
Electromyograms tell you what?
Exact location of injury in the setting of motor deficits
Timing of injury
43
DOUBLING the distance from radiation sources, decrease exposure by what factor?
4
(exposure is 1/4 of the original)
Intensity = Source / Radius ^2
44
Recommended occupational exposure to radiation / year
< 5000 mrem /yr
Each CXR is 10 mrem
CT scan is 5000 mrem
45
______ flow is reduced when there is systemic hypotension or cardiac output is decreased.
_____ flow is autoregulated and can compensate if the above drops.
Portal venous blood flow
Hepatic arterial blood flow
46
Neck circumference > __cm predicts increased incidence of OSA and difficulty with mask ventilation
60 cm
47
How to calculate BMI?
weight kg / height in meters ^2
48
Methgb (Fe3+ feric, icky) is unable to bind new O2, and the oxygen dissociation curve is shifted to the _____
left.
- PREVENTS release of O2 into tissues
- HIGHER affinity to O2
49
Ischemic optic neuropathy presentation
painless sudden vision loss following long spine surgeries in prone position
50
Respiratory effects of laparoscopic surgery
- lung compliance
- V/Q
- Inspiratory pressures
- Partial pressure CO2
- blood pH
1. Decreased lung compliance
2. Increased V/Q mismatch
3. Increased inspiratory pressures
4. Increased partial pressure of CO2
5. Decreased blood pH
51
Pneumothorax presentation in GA
1. Desaturation
2. Increased Airway pressure
3. Decreased breath sounds
52
Lethal dose of CO2 for obstructive embolism?
5x that of air bc of diffusibility of CO2
53
Subcutaneous emphysema presentation in GA
1. Swelling or crepitus
2. no change in pulse ox
3. no change in airway pressure
54
Pneumoperitoneum is typically created in laparoscopic surgeries. What do you expect happens to ETCO2?
CO2 will be absorbed and equilibrate with CO2 in blood
| - After 15-30 min it plateaus
55
In laparoscopic surgeries, If pts have a sudden increase in ETCO2 after the 15-30 min plateau period, what conditions do you suspect?
1. Subcutaneous emphysema
2. Early pneumothorax
3. MH
56
Accidental endobronchial intubation would SLOW the relative rate of induction of which volatile anesthetic?
Desflurane > sevo > iso
- one lung ventilation creates a R-> L pulmonary shunt, which has greatest effect on less soluble inhalational anesthetics
57
One lung ventilation creates a R-> L pulmonary shunt, which has greatest effect on (more/less) soluble inhalational anesthetics
Less
| - ie: desflurane, an insoluble agent
58
The faster the alveolar fraction (FA) of inhaled agent approaches the fraction of inspired (FI) agent, the (faster/slower) the agent will reach equilibrium.
Why?
faster
| - the anesthetic partial pressures of the alveolus, blood, and CNS become equal
59
Insoluble agents like desflurane and nitrous oxide have (higher / lower) blood: gas partition coefficient
low
- partial pressure quickly builds in the alveoli
*The faster the alveolar fraction (FA) of inhaled agent approaches the fraction of inspired (FI) agent, the (faster) the agent will reach equilibrium.
60
More soluble agents like halothane and isoflurane will diffuse across the alveoli and into alveolar capillary bed more readily, thereby INCREASING the time needed to reach this equilibrium.
- What equilibrium is this referring to?
- the anesthetic partial pressures of the alveolus, blood, and CNS become equal
61
More soluble agents like halothane and isoflurane have (higher / lower) blood: gas partition coefficient
higher
62
What should you use to treat PONV if dexamethasone and zofran does not work?
Droperidol 0,625 mg IV
| - dopamine 2 receptor antagonist
63
Vomiting center is stimulated by which areas?
1. Chemotactic trigger zone in medulla
2. GI tract
3. Pharynx
4. VIsual centers
5. Mediastinum
64
Unique LMA 4 and 5 will fit up to what size ETT?
| What about Aura-i Size 4 and 5?
Unique 6.0, 7.0
Aura-i 7.5, 8.0
65
Top 3 Anesthetic factors leading to death and permanent brain damage in order
1. Cardiovascular events (PE, Stroke, MI, arrythmia)
2. Respiratory events
3. Equipment issues (failure, misuse)
66
When should aspirin be held for surgery?
1. Intracranial neurosurgical procedure
2. Intramedullary spine
3. Posterior eye
4. Middle ear
5. Prostate
*disastrous neurologic/neurovascular complications
67
Major type of heat loss in OR
| Second most?
1. Radiation
- loss to environment
2. Convection
- air in OR is exchanged q15 min
68
Which phase 1 or 2 is associated with DECREASE contraction in response to a single twitch stimulus?
```
both
Phase I: TOF > 70%
(all 4 twitches feel equal but diminished)
Phase II: resembles NDMB
(twitches fades)
```
69
Common monitoring sites for NMB
Facial nerve (CN VII)
- Corrugator supercilii
- Orbicularis occuli
Adductor pollicis
Flexor hallucis brevis
70
Dibucaine number 20 indicates ______
| Dibucaine number 40-70 indicates ______
Pseudocholinesterase deficiency
20: homozygous atypical
40-70: heterozygous
71
What causes a phase 2 block? how to reverse it?
Repeated doses of succinylcholine
Unpredictable reversibility
72
What happens to PAO2 under hypothermic conditions?
Increase
| - water vapor pressure decreases, allowing more parts per breath to consist of oxygen
73
By comparing PAO2 and PaO2 (A-a gradient), a determination of oxygenation can be made.
Normal A-a gradient is ___
< 10 mmHg
74
Most common complication with brachial artery catheterization?
Thrombosis
75
Brachial artery can cause which nerve damage?
Median nerve
*medial to brachial artery.
*rare
76
The axillary sheath contains which nerve?
Median
Ulnar
Radial
*musculocutaneous is OUTSIDE the sheath
77
How does use of nitrous oxide in a pt with a SBO risk small intestine ischemia?
Expansion of the mucosal area of the bowel ->
| decrease blood supply
78
Nitrous oxide can worsen Venous air embolism, but the risk is not increased in which type of surgery?
intestinal surgery
79
Nicotinic receptors are ____ channels that are typically found at the _____.
Muscarinic receptors are _____ receptors and are mostly found in the ______
ligand-gated, NMJ of skeletal muscle
G-protein coupled, peripheral visceral organs
80
Antimuscarinic drugs used in anesthesia:
atropine
glycopyrrolate
scopolamine
81
Aldrete score
- top score
- criteria
Out of 10, needs at least a 9 to bypass
```
Activity
Breathing
Circulation
Consciousness
Oxygen saturation
```
82
Pts with allergies to cosmetics are at risk for reactions to _____
Rocuronium, vecuronium, and pancuronium
Share similar quaternary ammonion ion
83
Pts with allergies to which fruits may have allergy to latex?
```
Banana
Avocado
Kiwi
Pineapple
Mango
*and spina bifida
```
84
Any pathology that causes hyperthermia is generally associated with an (increase/decrease) in ETCO2
Increase
85
Drastic drop in ETCO2 in OR can be d/t what processes?
1. Impaired elimination CO2
2. Decreased production
3. Circuit/sampling disconnect
86
Acute processes that can cause Impaired elimination CO2
1. Cardiovascular collapse: significantly reduced Cardiac index
2. Massive VAE: increased End tidal nitrogen
3. Large PE: S1-Q3
4. Dislodged/Kinked ET: low and rapidly falling SpO2
87
Acute processes that can cause decreased production of CO2
1. Hypothermia
2. Hypothyroidism
3. Neuromuscular blockade
88
The most common cause of sudden increase in physiologic dead space (impaired or absent perfusion of alveoli enhancing V:Q mismatch) is _________
a sudden drop in cardiac output
89
(True/False) Cholinesterase inhibitors (anticholinesterases) increases resistance to both depolarizing and nondepolarizing blockade
False
- they inc the amount of ACh available and therefore makes nondepolarizing muscle blockade more difficult/resistant
- They partially inhibit pseudocholinesterase and therefore potentiates depolarizing blockade
90
Burn injuries (>24 hours) results in increase RESISTANCE to which type of muscle relaxant?
Nondepolarizing
| - d/t inc in extrajunctional ACh receptors
91
Acute and chronic phenytoin and carbamazepine affect on muscle relaxants
Acute:
- augments NMBs
- Maybe due to acute reduction of stimulus-induced ACh release from prejunctional neuron
Chronic:
- resistance to nondepolarizing blockade
- decreases sensitivity at receptor sites
- prolongs succinylcholine
- increase end plate anticholinesterase activity
92
Damage to the _______ can impair Thermoregulation and temperature homeostasis
preoptic anterior nuclei in the hypothalamus
93
Damage to the _______ nuclei can impair production and secretion of oxytocin and vasopressin
Paraventricular and supraoptic nuclei
*if vasopressin is impaired -> hypotension and diuresis
94
The Broca area is supplied by the _____, if this is compromised, pt can have expressive aphasia (understand language, but unable to speak fluently)
Middle cerebral artery
95
Blood to the cerebellum is provided by the ______, which branches from the _____ arteries.
1. Superior cerebellar a.
2. Anterior inferior cerebellar a (AICA)
3. Posterior inferior cerebellar a (PICA)
_______
Vertebral and basilar arteries
96
Intraop awareness or recall risk factors
1. Cocaine or BDZ use
2. Prior intraop awareness
3. Diff intubation (planned/unplanned)
4. Chronic pain pt
5. ASA IV or V
97
Twitch characteristics of Phase I block with sux?
1. Single twitch height is decreased
2. No TOF fade
3. TOF ratio > 0.7
4. Continuous (tetanic) electrical stim usually results in SUSTAINED muscle contraction
98
Twitch characteristics of Phase II block with sux?
1. Single twitch height is decreased
2. Yes TOF fade
3. TOF ratio > 0.3
4. Continuous (tetanic) electrical stim usually results in UNsustained muscle contraction
99
How does neostigmine affect a phase I block (std induction of sux)?
Augments it
- Increases the ED95
- inhibits plasma cholinesterase (resp for sux degradation)
100
How does neostigmine affect a phase II block of sux?
Antagonizes it
| *but unpredictable
101
Std intubating doses of succinylcholine may create a phase II block in pts with _____.
Pseudocholinesterase deficiency
| - dramatic inc in duration (hours) of "succinylcholine apnea"
102
```
FIO2 correlation:
RA:
2L/min:
4L/min:
6L/min:
```
RA: 21% O2
2L/min: 29%
4L/min: 37%
6L/min: 45%
*NC <6L does not go above 50%
103
Why is Lactated ringer avoided in pts with severe liver failure?
lactate is metabolized by liver to bicarb
104
Why does the ASRA guideline recommend that pts receiving heparin for > 5 days should have a PLATELET count checked prior to epidural placement?
Risk of HIT
*note: should still hold prophylactic heparin 4-6 hours prior to epidural placement
105
Diff btwn ASA 2 and 3?
systemic illness without vs with functional limitation
106
SIMV is often used to transition pts from controlled to spontaneous breathing. How?
Attempts to sync the mandatory breaths with a pts spont inspiratory effort
* disadvantage is inc work of breathing during non-mandatory breaths
* SIMV can be used with or without PS
107
Theoretically, why is hydroxyethyl starches (HES) useful?
Volume expansion
| - significantly longer intravascular half-lives > crystalloid
108
What type of fluids are Categorized based on substitution ratio
- Higher the number, the greater the substitution
Hetastarches: 0.7 substitution ratio
Tetrastarches: 0.4 substitution ratio
*Max daily doses of hetastarches are generally LESS than tetra
109
(True/false) Hetastarches are associated with reduction in Factor VIII and vWF
True
| - by 50-80%
110
What is better for laminar flow (and preventing turbulent flow)?
- flow
- radius
- viscosity
1. Slow deep breathing with low flow rates
2. Lower radius
3. Increased viscosity (syrup vs water)
111
Most common reliable sign of cyanide toxicity
Anion gap metabolic acidosis
- impairs aerobic respiration
*note that PaO2 and SvO2 will be increased, it just cant be utilized
112
Specificity eq.
Sensitivity eq
Spec: TN / (TN + FP)
*SPIN - rules in
Sens: TP / (TP + FN)
113
Which antineoplastic agent is at risk for cardiomyopathy?
| Interstitial pneumonitis?
Doxorubicin
Bleomycin
114
Why is low tidal volume of 6 mL/kg beneficial in preventing renal injury?
Decreases cytokine release
*high PPV can hurt kidneys
115
The rate of induction of which inhaled anesthetic is MOST affected by changes in cardiac output?
Isoflurane
116
Low cardiac output states readily allow uptake of which type of volatile anesthetics?
- How does this affect gas diffusion into the blood?
- How does this affect FA:FI?
- How does this affect induction?
All of them, but mostly Blood-soluble agents
- ie. Isoflurane
- Slow diffusion of gas into blood (more delivery to brain)
- Speeding rise of FA:FI ratio
- Faster induction
117
High cardiac output states
- How does this affect gas diffusion into the blood?
- How does this affect FA:FI?
- How does this affect induction?
- Less delivery of gas to the brain, slows rate of induction
- Fast diffusion of gas into blood (less delivery to brain)
- Slowing rise of FA:FI ratio
- Slower induction
118
A R-to-L intracardiac shunt (speeds/slows) the rate of INHALATIONAL anesthetics
slows
| - anesthetic is shunted and not involved in gas exchange w/in alveoli
119
A R-to-L intracardiac shunt (speeds/slows) the rate of INTRAVENOUS anesthetics
Speeds
| - portion of the drug bypasses lungs and enters directly into L side of heart and quickly delivered to brain
120
Equation for SVR (in dynes)
[80 * (MAP - RAP)] / CO
*80 is the conversion factor from woods unit to dynes
121
Equation for PVR (in dynes)
[80 * (MAP - PAOP)] / CO
122
Components of a Child-Pugh Score for liver transplant
```
PT
Albumin
Bilirubin
Ascites
Encephalopathy
```
*Pour Another Beer At Eleven"
123
Components of a MELD score for liver transplant
```
INR
Creatinine
Sodium
Bilirubin
Dialysis
```
I Crush Several Beers Daily
124
How much sodium is in 5% albumin? 25%?
145 mEq/L for both
125
Most common cause of litigation during MAC?
1. respiratory depression from over sedation
2. Equipment failure/malfunction
3. CV events
126
What is the benefit of using an airway exchange catheter instead of elastic bougie?
Ability to use oxygen jet ventilation
| - both are small enough to allow air passage around them
127
How frequently does negative pressure pulmonary edema occur in anesthesia?
0.05-0.1%
128
How soon does negative pressure pulmonary edema result following obstruction?
Immediately -2 hours
129
What happens to preload and afterload in negative pressure pulmonary edema?
LV afterload is increased
Negative intrathoracic pressure causes an increase in preload
*Both contributes to increased pulmonary hydrostatic pressures
130
```
Antidopaminergic drugs (droperidol, metoclopramide, prochlorperazine) can cause extrapyramidal symptoms (EPS)/acute dystonic reactions -
How to treat?
```
Anticholinergic medication
- balance out the cholinergic-dopaminergic balance
- benztropine or diphenhydramine
131
What is ASA 5?
Moribund pt who is not expected to survive w/o operation
132
What ASA are these pts:
- Symptomatic CHF
- MI/CVA w/in last 6 mo
- Unstable angina
- Hepatorenal disease
ASA 4
| - severe systemic disease that is a constant threat to life
133
When is heliox (70% helium, 30% oxygen) useful?
When airway radius is decreased with resultant turbulent gas flow
134
When is turbulent flow more likely?
- velocity
- diameter
- density
- viscosity
Greater velocity, in larger diameter tubes with a dense gas with low viscosity
135
Inhaled agents with a HIGH FA/FI value are associated with (high/low) solubility.
low
136
Inhaled agents with a LOW FA/FI value are associated with (high/low) solubility.
high
137
Higher blood:gas partition coefficients (or blood solubilities) correspond with (greater/lower) degrees of volatile agent uptake, and SLOWER onset of action
GREATER
138
Blood:Gas partition coefficient of:
Isoflurane
Sevoflurane
Desflurane
Isoflurane: 1.5
Sevoflurane: 0.65
Desflurane: 0.42
*Des has the LOWEST
139
In the lithotomy position, what nerves pass beneath and through the inguinal ligament that could be injured?
1. Lateral femoral cutaneous
2. Femoral
3. Obturator
Beneath:
4. Branches of sciatic nerve
- Tibial n
- Common peroneal n
- ---Sural n.
- ---Superficial peroneal n.
140
How does cimetidine and famotidine (H2 blocker) and metoclopramide affect:
- Gastric pH
- Gastric volume
cimetidine / famotidine
- Gastric pH: increase
- Gastric volume: decrease
(does NOT speed clearance)
metoclopramide
- Gastric pH: no effect
- Gastric volume: decrease
141
Which gas augments NMB the most?
Desflurane
- directly (relaxes skeletal muscle)
- indirectly (synergistic)
142
Large quantities of albumin is lost through burned skin.
| - What anesthetic drugs need to be REDUCED with hypoalbuminemia?
1. Benzos
| - hypoalbuminemia increases free fraction of drugs (since it normally binds them)
143
Large quantities of albumin is lost through burned skin.
| - What anesthetic drugs need to be INCREASED with hypoalbuminemia?
1. LA
2. BBs
3. Opioids (rapid development of tolerance)
144
How do burns > 30 % TBSA affect NONdepolarizing NMBs?
Resistance starting 1 week following burn - peaking 6 weeks.
| - d/t increase in number of ACh receptors, inc renal excretion, protein binding
145
High flow tends to be (more/less) turbulent
More
146
Low density means (more/less) turbulent flow
less
147
Helium has an extremely LOW density and thus has an increased tendency for _____
laminar flow
| * not turbulent flow
148
Efferent limb of the laryngospasm reflex
Recurrent laryngeal nerve
149
What does using a vasoconstrictor do during nasal fiberoptic intubation?
increases diameter of the nasal passage and reduce bleeding
| - it does NOT eliminate trauma
150
Why does use of succinylcholine increase the risk of pacemaker failure?
Fasciculations -> high frequency electrical signals interpreted as cardiac activity
151
Risk of electromagnetic interference causing inappropriate shock from AICD is significantly decreased when ______ electrocautery is used
bipolar
- electrical energy is delivered between the two electrodes at the tip of the instrument
*monopolar delivers electricity to the tissues, and the path is connected to the grounding pad
152
Is obesity or BMI a risk factor for difficult intubation?
No
| - Inc neck circumference is
153
Which CO2 absorbents are most at risk for Compound A and fire production during Sevoflurane administration?
Barium hydroxide
| - carbon dioxide absorbent
154
Which CO2 absorbents are LEAST at risk for Compound A and fire production during Sevoflurane administration?
Soda lime
| - Calcium hydroxide absorbent
155
_____ is the pH indicator used in CO2 absorbents (colorless when fresh), becomes purple when pH falls < 10, indicating absorbent exhaustion
Ethyl Violet
156
Non human milk (soy, formula) requires ___ hours of NPO time
6
157
Breast milk requires ___ hours of NPO time
4
158
Is ketamine contraindicated in pts with known ischemic heart disease?
Yes
| - increase myocardial oxygen demand (HR, BP, CO)
159
Which nerve fibers are associated with pain, temp, touch?
Type A delta
- large myelinated
- Epicritic pain (sharp, immediate, well localized)
Type C dorsal root
- small unmyelinated
- protopathic pain (dull, achy, not well localized)
