ITE Flashcards
1
Q
What is the mechanism of action of midazolam?
A
positive allosteric modulator of GABAa receptor
2
Q
increased 2,3 diphosphoglyceric acid (DPG)
A
stabilizes deoxy Hg therefore shift curve to the right
3
Q
ultrasound is sound above what range?
A
20,000 cycles per second
4
Q
two most frequent CV side effects of amiodarone?
A
bradycardia and hypotension
5
Q
when do you use a t test?
A
to compare the mean outcome between two independent populations
6
Q
where are catecholamines made and name examples of catecholamines?
A
adrenal medulla. Epinephrine, norepinephrine, and dopamine
7
Q
what physiologic lung volumes increase during pregnancy?
A
inspiratory capacity, tidal volume, inspiratory reserve volume
8
Q
why should corticosteroids be used cautiously in glaucoma?
A
corticosteroids increase IOP and can cause steroid induced glaucoma
9
Q
what is the best image modality to diagnose cerebral vasospasm?
A
cerebral angiography
10
Q
what is the best treatment of vasospasm?
A
“Triple H” therapy - hypervolemia, hypertension, and hemodilution
nimodipine also reduces intracelluluar Ca availability
11
Q
what are the safest opioids in end stage renal dx patients?
A
fentanyl and methadone which are both metabolized in the liver
12
Q
normal cvp
A
2-6 mmHg
13
Q
normal PCWP
A
6-12 mmHg
14
Q
normal CI
A
2.5 - 4 L/min/m2
15
Q
normal SVR
A
800-1200 dynes x sec /cm5
16
Q
what is the mechanism of paresthesia during hyperventilation?
A
creates a respiratory alkalosis so hydrogen ions get released from negatively charged proteins like albumin. Calcium then binds to albumin decreasing its availabiliyt
17
Q
definition of oliguria
A
<0.5cc/kg/hr
18
Q
common symptoms of carcinoid syndrome
A
flushing, diarrhea, right sided heart dx, bronchoconstriction (wheezing)
19
Q
Draw and describe meaning of early decerlation
A
usually an indication of head compression. nothing to do
20
Q
Draw and describe late deccereration
A
uteroplacental insufficiency
21
Q
draw and describe variable deccelerations
A
umbilical cord compression
22
Q
what type of local anesthetic is most likely to cause allergic reaction?
A
Esthers because they get degraded into an allergen called PABA
23
Q
which enzyme does etomidate inhibit leading to adrenal insufficiency?
A
11 beta hydroxylase
24
Q
conn sydrome (primary hyperaldosteronism) causes
A
hypokalemic metabolic acidosis.
25
what are the side effects of etomidate?
adrenal insufficiency, thrombophlebitis, myoclonus, hiccoughs, burning on injection due to propylene glycol
26
what are alternatives to heparin for AC during cardiopulmonary bypass surgery?
direct thrombin inhibitors such as bivalirubin, argatropan, hirudin, dabigatran
27
why do you need a larger dose of spinal local anesthetic in infants and children?
CSF volume is higher on a ml/kg basis
28
what drug is contraindicated in MH pt being treated with dantrolene?
Any Ca channel blocker such as diltiazem
29
what benzo is the best to give to end stage renal dx patient?
lorazepam (Ativan)
30
how does hypercalcemia effect your dosing of nondepolarizing paralytics?
need to use an increased dose
31
what factors increase hoffman elimination of cisatricurium?
increased pH and temperature
32
when using epidural opioids, what factor contributes the most to spread?
lipophillicity. Highly lipophilic drugs will stay at level of injection. Whereas less lipophilic drugs like morphine will have more systemic spread
33
name your anticholinergics and their effects
glycopyrrolate and atropine
34
explain citrate toxicity
occurs due to citrate binding to calcium --> hypocalcemia. Worsened by hyperventilation
35
what is normal ICP?
5-20 cm H20
36
what is a normal urine ion gap?
0 - 5 (anything above this suggest a renal tubular acidosis because kidneys are unable to excrete enough Cl ions and therefore decreased amounts of NH4+)
37
medications that induce CYP-3A4
carbamazepine, phenytoin, phenobarbital, St. John’s wort, dexamethasone, topiramate, and oxcarbazepine.
38
cerebral metabolic rate is decreased by what % per each degree celsius?
cerebral metabolic rate of oxygen consumption is decreased by about 7.5% for each degree Celsius decrease.
39
complete burst suppression occurs at what degree of celsius?
18 degreess celsius
40
what remains constant during volume control ventilation
inspiratory flow is constant with varying pressures
41
what remains constant during pressure control ventilation
constant inspiratory pressure w/ deccelerating inspiratory flow
42
what is the difference between CAM-ICU and RASS score?
CAM-ICU is the initial screening tool for delirium and first two questions need to be positive:
1. Is there an acute change in mental status or fluctuating course – yes/no
2. Is the patient inattentive or easily distracted – yes/no
Next set of questions:
3. Is there an altered level of consciousness or RASS other than 0 – yes/no
4. Does the patient experience disorganized thinking – yes /no
An altered RASS score or an altered level of consciousness is one of the element of the second part of the CAM-ICU screen. The RASS is an agitation sedation score.
43
autonomic hyperreflexia is most likely to occur above what levels?
T5
44
What is the oxygen content of arterial blood?
CaO2 = SaO2 x (Hb x 1.34) + .0031 x PaO2
45
what is the mechanism of action of adenosine?
It acts on receptors in the cardiac AV node, significantly reducing conduction time. [This effect occurs by activation of specific potassium channels, driving potassium outside of cells, and inhibition of calcium influx, disrupting the resting potential of the slow nodal cardiac myocyte
46
myasthenia gravis patients are sensitive to what type of NMB?
non depolarizing NMB
47
lambert eaton patients are sensitive to what type of NMB?
succinylcholine and non depolarizing
48
what are the side effects of hypermagnesemia?
skeletal weakness, loss or deep tendon reflexes, depression of cardiac conduction and contractility -> bradycardia, widened qrs, hypotension
49
when is the max spinal cord edema occur after spinal cord injury?
3-6 days after injury
50
what surgeries have highest risk of delirium?
cardiac, thoracic and orthopedic
51
what anesthetic agents induce seizures?
ketamine, etomidate, lidocaine, methohexital
52
best treatment for type II second degree AV block or third degree AV block?
transcutaneous pacing
53
non depolarizing NMB dosing should be reduced for what types of patients?
myopathy disorders, MG, and Lambert Eaton
54
what preoperative risk factors MOST predicts the need for extended postoperative ventilation?
Hx of MG for > 6 years
55
what scale do you use to predict morality for a SAH?
Hunt and Hess scale
Grade 0: Unruptured aneurysm
Grade 1: Asymptomatic or mild headache
Grade 2: Moderate-to-severe headache and/or cranial nerve palsy only
Grade 3: Mild focal deficit and/or confusion/lethargy
Grade 4: Hemiparesis and/or stupor
Grade 5: Coma or decerebrate posture
56
What's another name for lambert eaton syndrome?
myasthenia syndrome
57
what are disease states that lead to upregulation of nicotinic ACH receptors?
prolonged immobilization >24hrs, certain neuromuscular disorders, including Guillain-Barré syndrome (GBS), multiple sclerosis (MS) (D), and motor neuron diseases like amyotrophic lateral sclerosis (ALS), stroke, intracranial lesion.
58
How long is succinylcholine's effect last?
9 - 13 minutes
59
what the harm of upregulation in nicotinic ACH receptors?
Prone to hyperkalemia and resistance to non depolarizing neuromuscular agents
60
how to calculate intraoperative low tidal volumes
6 ccs x kg ( predicted body weight which factors in height)
61
differentiate the drugs used for organophosphate poisoning prophylaxis vs treatment
organophosphates are anticholinesterase inhibitors causing a surge in ACH --> DUMBBELS. Prophylactically you can use pryridostigmine
Treatment you use atropine which crosses the BBB and pralidoxime which binds to the poison bound cholinesterases and uncouples them
62
describe the inverse steal phenomenon
If hypocapnia is induced, the normal cerebral vasculature will constrict, resulting in increased resistance through the remainder of the cerebral vasculature. Local vascular mediators will cause areas of impaired flow to maximally dilate even in the setting of hypocapnia. The net effect of this is to increase blood flow and oxygen delivery to otherwise ischemic portions of the brain.
63
how does altitude affect desflurane?
Desflurane vaporizers need to be adjusted for varying barometric pressures, increasing the percent volume for increasing altitude to maintain a constant partial pressure of anesthetic. Variable bypass vaporizers need no adjusting for changing barometric pressures.
64
what is the criteria for hypertensive urgency?
BP >180 / 110 . Check for end organ damage before proceeding for surgery. Dont decrease BP by more than 25%
65
which blood products are more associated with transfusion related lung injury?
plasma and platelets which have more plasma/ leukogenic factors
66
whats the analgesic onset for a fentanyl patch?
12-24 hrs
67
what's the onset and duration of IV fentanyl
onset 1 -3 minutes and duration 30-60 minutes
68
How is succinylcholine and ester local anesthetics broken down?
By pseudocholinesterases
69
what are signs of propofol toxicity?
bradycardia, metabolic acidosis, rhabdo, enlarged liver
**check triglycerides as a precursor
70
name your cardioselective beta 1 blocker
metoprolol, atenolol, esmolol
71
name your nonselective beta blockers
labetolol and carvdilol (have alpha 1 and beta 2 blocking)
72
ways to assess gas exchange via an ABG?
An arterial blood gas showing PaO2 greater than 60 mm Hg and a PaCO2 of less than 45 mm Hg.
73
which gas is more associated with emergence delirium?
sevoflurane
74
how does chronic emphysema affect your V/Q ratio?
increases ratio because the damage alveoli don't get well perfused but are still getting ventilated
75
what is the hematocrit criteria for polycythemia?
> 54%
76
what gas has the lowest fat:blood solubility?
nitrous oxide which is why it does not stay in tissues and comes off so fast
77
how long does propofol take to wear off?
6-9 minutes
78
what weight should you use for rocuronium dosing?
ideal body weight
79
what weight should you use for succinylcoline dosing?
total body weight
80
brain death occurs how many minutes after cardiac arrest ?
3-8 minutes
81
early signs of digoxin toxicity?
heart block or ventricular ectopy
82
why is hyperglycemia associated with worse neurologic outcomes in acute cerebral ischemia?
The combination of hyperglycemia + lack of adequate O2 increases anaerobic metabolism which increases your levels of lactic acid
83
what is the saturated vapor pressure?
the amount of pressure vapor in equilibrium with liquid phase. Therefore the higher the SVP, the more agent that is in vapor form
84
what is the equation for vapor output volume?
outflow = input x (saturated vapor pressure SVP / (atm P -SVP))
85
MAC decreases by what percentage for every decade of life after 40?
6%
86
what is the conversion of cmH20 to mmHg?
10 cm H20 = 7.4 mmHg
or
15 cm H20 = 10 mmHg
87
where should the ETT placed on xray?
5 - 7 cm above the carina
88
lab values for primary hypothyroidism
high TSH and low T4
89
lab values for secondary hypothyroidism
low TSH and low T4
90
recall the rule of 6's for TEG
- R time around 6 minutes
- Alpha angle around 60 degrees
- Maximal amplitude around 60 mm
- LY30 of around 6%
91
mnemonic for Aortic insufficiency
A mnemonic for both aortic insufficiency and mitral insufficiency is: fast, full, forward which means fast heart rate (or avoiding bradycardia), full preload, and forward flow (avoiding afterload).
92
what is the most potent stimulator for AVP release ?
systemic arterial hypotension mediated by aortic and carotid baroreceptors
93
what are the draw backs of PCA vs nurse given IV opioiods?
higher incidence of pruritis and higher total opioid consumption
94
What is the mechanism of a bier block?
it gets absorbed into the venous system to provide anesthesia to distal nerves
95
what organs are innervated by a celiac plexus?
stomach, pancreas, diaphragm, liver, spleen, small colon, large colon up to transverse colon, adrenal glands, and kidney.
96
what herbal supplement causes hypoglycemia
ginseng
97
what complication is seen in left central line placement vs right ?
left side is where the thoracic duct empties into the left IJ/ subclavian therefore chylothorax
98
the lateral femoral cutaneous nerve is made up of what fibers?
L2-L3
99
what layer surrounds the femoral nerve?
fascia iliaca
100
definition of abdominal compartment syndrome
>20 mmHg
101
supportive treatment measures for abdominal compartment syndrome
keep patient flat
| colonic enemas to empty the bowels and decrease the pressure
102
Abx for spontaneous bacteria peritonitis ?
ceftriaxone or piperacillin/tazobactam (zosyn)
103
what is the time onset for transfusion related lung injury ?
6 hours from transfusion
104
what is the expected blood volume for a child 1 - 12 yo?
70 - 75 mL /kg
105
appropriate perineural stimulation occurs at what mA?
.2-.5 mA
106
what is the maximum dose of acetaminophen in adults / day?
3 grams
107
what is the maximum dose of acetaminophen in children?
50 -75 mg/kg/day
108
when is the peak onset of acetaminophen?
90 mins after gut absorption
109
what is the half life of acetaminophen?
2-3 hrs
110
what does hydromorphone / morphine have more dermatomal spread than fentanyl?
because not as lipophilic and therefore more of it remains in the epidural space w/ increase cephalad spread
111
how does decreased fio2 decrease risk of atelectasis?
because you have more air (which is largely made up of nitrogen) which keeps the alveoli open
112
what are independent pre op risk factors for post op AKI w/ normal renal function?
age > 59, chronic liver disease, emergency sugery, peripheral vascular occlusive disease, BMI >32, COPD requiring bronchodilator, high risk surgery - intrathoracic, intraperitoneal, supringuinal surgery, those involving large blood loss or fluid shifts
113
what is the relationship between radiation exposure and distance?
radiation exposure = 1 / r ^ 2
114
what should be your initial bolus for pediatric resuscitation?
20 - 30 cc/kg
115
what are the four cardiac lesions that define tetralogy of fallot?
overiding aorta
pulmoninc stenosis
VSD
right ventricular hypertrophy
116
what lab value is the best determinant of synthetic liver function?
PT / INR
117
when to consider peritoneal dialysis?
for patients who cannot tolerate the hemodynamic changes induced during traditional hemodialysis
118
what nerves do you need to block for an awake fiberoptic intubation?
glossophargyngeal nerve, internal brach of the superior laryngeal nerve, and recurrent laryngeal nerve
119
what is lithiums affect on non depolarizing NMB?
it potentiates effect by activating K channels
120
what is phentolamine mechanism of action?
alpha 1 and 2 antagonist
121
what is the name and effect on HR w/ decrease cardiac preload?
Bezold - Jarisch reflex which causes increased paryasympathetic response causing bradycardia
122
when does separation anxiety begin for infants?
at 6-8 months
123
what is lusitropy
myocardial relaxation
124
what is the most sensitive test for MH?
halothane caffeine contracture test
125
what are complications with brachial artery catheterization?
thrombosis and nerve injury to median nerve because it is wrapped in sheath that covers the median, ulnar, and radial nerves. If you cause a hematoma you can cause nerve injury due to compression
126
describe the bohr effect
in alkalotic conditions like in the lungs, Hg has a higher affinity for oxygen. In acidotic conditions, like near tissues, Hg has less affinity for O2
127
what lung parameter is unchanged in obese patients?
closing capacity
128
spinal cord stimulator activates what part of the spinal cord?
dorsal column
129
what ECG findings are associated with hypocalcemia?
prolonged QT waves
130
how do acetylcholinesterase inhibitors affect a phase I block?
augments the block because they also inhibit butylrylcholinesterase which is degrades succinylcholine. Therefore, more succinylcholine around
131
what drug should be based on total body weight?
succinylcholine. Obese patients have more pseudocholinesterase
132
what compartments increase for elderly regarding drugs?
volume of distribution increases (more fat than muscle)
133
what compartment decreases for elderly regarding drugs?
central compartment volume because total body water decreases
134
what is the intrinsic INR of FFP?
1.6-1.8
135
Specific medications in anesthesia and how dosage should be calculated:
Total body weight: maintenance infusion dose of propofol, succinylcholine
Lean body weight: thiopental, induction dose of propofol, fentanyl
Ideal body weight: rocuronium, vecuronium
Specific medications in anesthesia and how dosage should be calculated:
Total body weight: maintenance infusion dose of propofol, succinylcholine
Lean body weight: thiopental, induction dose of propofol, fentanyl
Ideal body weight: rocuronium, vecuronium
136
hydralazine main mechanism of action
arterial vasodilator
137
standard error equation
standard deviation / square root of sample size
