More than 50% missed keywords Flashcards
(159 cards)
1
Q
What causes the pseudohypertrophy in Duchenne’s MD?
A
Muscle necrosis that is then replaced by fatty fibrotic infiltrates.
2
Q
Does Duchenne’s only affect skeletal muscle?
A
No, it also affects cardiac muscle and will result in a dilated cardiomyopathy involving the posterobasal and LV lateral wall.
3
Q
What is the correlation between the degree of skeletal muscle disease in Duchenne’s and the dysfunction of cardiac muscle.
A
There is no correlation between severity of the skeletal muscle disease and the cardiac muscle disease.
4
Q
What is the prevalence of cardiac disease in patient’s with Duchenne’s muscular dystrophy?
A
As much as 90%, although most of these patients have subclinical manifestations. Only 10% of those patients presenting for surgery have clinically significant cardiac disease however ECG and Echocardiography are part of the regular preop work up.
5
Q
What induction agent is the gold standard for ECT and why?
A
Methohexital.
It does not affect seizure duration.
Is better tolerated than etomidate secondary to ability to blunt hemodynamic response and better than propofol and thiopental because it does not decrease seizure duration.
6
Q
What induction agent used in ECT increases seizure duration?
A
Etomidate
7
Q
What is the utility of opioids in anesthesia for ECT?
A
They help blunt the hemodynamic response to the seizure and can be thought of as “propofol-sparing”. Which means that you can use less propofol and thus lessen propofol’s blunting of seizure activity.
8
Q
What is the relevance of PaCO2 levels and anesthesia for ECT?
A
Hypocarbia (hyperventilating the patient) will INCREASE the duration of the seizure.
9
Q
Compare and contrast thiopental and methohexital for use during anesthesia for ECT?
A
The most important difference is that methohexital does not affect seizure duration while thiopental (like propofol) decreases seizure duration. They both blunt hemodynamic responses (as does propofol) where as etomidate does not.
10
Q
What is an adequate seizure duration for ECT?
A
At least 30 seconds.
11
Q
What level of ICP is associated with worsened outcome?
A
ICP > 20 mmHg
12
Q
What value of cerebral perfusion pressure is the threshold for impaired brain tissue oxygenation and metabolism?
A
CPP < 50 mm Hg
13
Q
Preganglionic neurons of the sympathetic system use what neurotransmitter?
A
Acetylcholine at nicotinic receptors
14
Q
Postganglionic sympathetic neurons use what neurotransmitter?
A
Norepinephrine, except for sweat gland innervation which uses ACh to act on the sweat gland muscarinic receptor. The other exception involves the adrenal medulla where preganglionic sympathetic nerves synapse directly on the excretory cells and cause them to release catecholamines systemically.
15
Q
What is the minimum PaCO2 for patients with TBI?
A
In TBI, PaCO2 levels lower than 35 mm Hg are considered to result in worse outcomes.
16
Q
List ways in which an AICD may malfunction.
A
Battery failure
Sensing problems
Lead migration
May inappropriately fire during atrial tachyarrhythmias
May fail to fire during ventricular arrhythmias if the rate of the arrhythmia is too slow due to rate-controlling medications
17
Q
What pharmacological therapies are useful for HD stable atrial flutter?
A
Initial treatment targets rate-control. Thus, 1st line agents are: beta-blockers and calcium channel blockers,
For chemical cardioversion: ibutilide (Class III antiarrhythmic but can cause torsades), amiodarone
18
Q
What drugs are effective prophylactics to prevent afib/aflutter development after cardiac or thoracic surgery?
A
beta-blockers, calcium-channel blockers
19
Q
What are the risk factors of the revised cardiac index?
A
history of ischemia or heart disease CHF CVA Cr > 2.0 IDDM high risk surgery
20
Q
What is the risk stratification for cardiac complications using the revised cardiac risk index?
A
#of risk factors = % risk 0 = 0.4% 1 = 0.9% 2 = 7% 3 = 11%
21
Q
What is the difference between alpha-stat versus pH stat management during CPB with regards to neurological outcomes?
A
Multiple independent, prospective randomized trials have shown that α-stat during moderate hypothermia produces better neurologic outcomes than using pH-stat in adults. In children, pH stat may be better.
22
Q
What is the appropriate glucose goal level during CPB?
A
< 200. More aggressive treatment of hyperglycemia in cardiac surgery patients does not improve mortality and in fact increases the incidence of stroke, and possibly death.
23
Q
What agent is used for acute treatment of long-QT?
A
IV magnesium
(as well as replacement of potassium and calcium if those levels are low)
Amiodarone is contraindicated in these patients.
24
Q
What medication class is used for long-term treatment of long QT?
A
Beta-blockers (although LQT3 which is Na+ related, often needs a PPM)
25
If an ASA VI (six) class patient develops bradycardia, what is the medication of choice to treat it?
Isoproterenol. Consider other direct acting agents like dobutamine, milrinone, dopamine, epinephrine, etc....
Atropine may not work because there may not be any vagal activity present.
26
What is the major concern with pH-stat management?
Because of the decoupling of CBF and CMRO2, the increased CBF in pH-stat increases the cerebral embolic load risk to the patient.
27
What is the relationship between CBF and CMRO2 in pH-stat versus alpha-stat management?
pH-stat uncouples CBF from CMRO2 and CBF is pressure dependent.
Alpha-stat preserves the coupling and CBF is CMRO2 dependent.
28
The goal of alpha-stat management is?
Maintain the ionization state of histidine
29
How does hyperbaric oxygen help carbon monoxide poisoning?
It reduces the half-life of CO-Hgb to 15 - 30 minutes at 3 atm. However, the real benefit of HBO may be in regeneration of cytochrome oxidase and inhibition of leukocyte adherence to the microvascular endothelium which reduces ischemic reperfusion injury.
30
When should hyperbaric oxygen therapy begin in order to benefit patients with carbon monoxide therapy?
Within 6 hours.
31
What should initial treatment of carbon monoxide therapy involve?
100% O2 to reduce CO-Hgb half-life to 1 - 2 hours from 4 - 5 hours. Check and treat glucose levels since high levels are associated with worse neuronal outcomes. Get to hyperbaric oxygen therapy within 6 hours.
32
What preoperative VO2 predicts poor outcomes after lung resection?
VO2 < 10cc/kg/min is very high risk. 15cc/kg/min is a reasonable cutoff.
33
How does one calculate predicted postoperative FEV1 after lung resection?
FEV1 x (1 - %LungResected) = ppoFEV1
A value < 30% is high risk for pulmonary complications. >40% is considered safe.
34
What ppoFEV1 predicts poor outcomes after lung resection?
< 30%.
> 40% indicates that it's probably safe in the absence of other poor predictors.
35
What DLCO predicts poor outcomes after lung resection?
DLCO < 40% predicted is high risk for complications. This is independent of ppoFEV1.
36
What FEV1 value is associated with poor outcomes after lung resection?
FEV1 < 2L
37
What MVV predicts poor outcomes after lung resection?
> 50%
38
How does one calculate FENa?
FENa = 100 ((Urinary sodium X Plasma creatinine)/(plasma sodium X urinary creatinine))
39
How can positive pressure ventilation +/- hyperventilation cause intraoperative oliguria?
Decreased cardiac output and subsequent SNS response (vasoconstriction)
Increased IVC pressure (reduced pressure gradient and renal blood flow)
40
What is the mechanism of renal failure causing platelet dysfunction?
Impaired platelet factor 3, platelet adhesiveness, platelet aggregation.
Treat with desmopressin.
41
Name three things that can artificially increase creatinine levels periooperatively.
Cephalosporins (for up to 16 hours)
Ketoacidosis
Barbiturates
42
What causes the diffuse hyperpigmentation seen in Addison's disease
Addison's is primary adrenal insufficiency. Diffuse hyperpigmentation occurs secondary to a compensatory increase in ACTH and beta-lipotropin.
43
Symptoms of hyperparathyroidism are?
Neuro: CONFUSION, lethargy, psychiatric abnormalities
GI: anorexia, vomiting, constipation, pancreatitis
GU: POLYURIA, POLYDIPSIA, formation of RENAL CALCULI (in approximately 60-70% of patients with hyperparathyroidism)
Other: BONE PAIN, HTN (in 33%)
44
What foods are associated with latex allergy?
banana, pineapple, avocado, chestnut, kiwi fruit, mango, passionfruit, strawberry, and soy, as well as potato and bell pepper
45
What does vanillylmandelic acid excretion indicate?
Pheochromocytoma.
| It is 80% sensitive, 97% specific.
46
What clinical signs and symptoms are more sensitive than any blood test for pheochromocytoma?
Paroxysmal HA + sweating + HTN more sensitive than any single blood test.
47
What is the utility of alpha-blockade prior to surgery in pheochromocytoma?
It reduces risk of mortality from 50% to 5%!
48
What alpha-blockers are recommended for pheochromocytoma and when should they be started in the perioperative period?
Prazosin or phenoxybenzamine.
| Recommended to start 10 - 14 days prior to surgery.
49
What medication should be used for hypotension intraoperatively for a patient with pheochromocytoma?
Phenylephrine, preferably because it is direct acting.
50
What medication should be used for hypertension intraoperatively for a patient with pheochromocytoma?
Nitroprusside
51
When and how does hypocalcemia present as a complication after thyroidectomy?
24 - 48 hours after surgery as stridor or airway obstruction but whose first symptoms are usually lip and finger tingling.
52
What is Chvostek's sign?
A sign of hypocalcemia elicited by tapping the facial nerve in the preauricular area.
53
What is Trousseau's sign?
A sign of hypocalcemia elicited by inflating a BP cuff on the arm that then results in carpal spasm.
54
What is the most common cause of airway obstruction within 24 hours of thyroidectomy?
Hematoma
55
What is the most common cause of airway obstruction after the first 24 hours of post-thyroidectomy?
Hypocalcemia
56
What is the incidence of febrile transfusion reaction with pRBCs? with platelets?
```
RBCs = 0.5%
Platelets = 30%
```
57
What is cause of febrile reactions after transfusion?
Since most products are leukoreduced, the most common cause is recipient antibodies against HLA antigens on the donated cells.
However with platelets, it is likely to be donated leukocytes releasing their cytokines. Pre-treat or treat with tylenol and benadryl.
58
What blood type is the universal donor for plasma?
AB
59
What blood type is the universal acceptor for plasma?
Type O
60
What are the indications for FFP according to the ASA?
Recommended dose = 10-15 cc/kg
1) Urgent reversal of warfarin (only requires 5-8 cc/kg). Note, however, the prothrombin complex concentrate has been shown to be more effective
2) Correction of known coagulation factor deficiencies for which specific concentrates are unavailable
3) Correction of microvascular bleeding in the presence of INR > 1.5
4) Correction of microvascular bleeding in the presence of massive transfusion (> 1 blood volume)
61
What viruses are transmitted in donor leukocytes?
EBV, HTLV-1, CMV
62
How do changes in temperatures affect PaCO2? PaO2?
PaCO2 decreases by approximately 2 mm Hg per °C below 37°C.
PaO2 decreases by approximately 5 mm Hg per °C below 37°C.
Therefore if an ABG at 37°C showed a PaCO2 of 40 mmHg and a PaO2 of 100 mm Hg, at 27°C it would be approximately a PaCO2 of 20 mm Hg and a PaO2 of 50 mm Hg.
63
What is the formula for oxygen content?
Oxygen content = (1.39 x Hb x O2Sat/100) + (0.003 x PO2)
64
What is the Bohr effect in oxygen-hemoglobin dissociation?
It's the effect of changes in pH as blood picks up and drops off CO2 encouraging oxygen unloading in the periphery as the pH falls and increasing oxygen uptake as CO2 leaves and pH rises.
65
What is the most common cause of transfusion related mortality?
TRALI
66
What anesthetic techniques may exacerbate multiple sclerosis?
No anesthetic technique has been shown to be superior to another, although spinals may exacerbate symptoms and are not recommended.
67
What aspect of anesthetic care is especially important for patients with multiple sclerosis?
temperature management - increases as little as 1 C may lead to disease exacerbation
68
What is the end-point of treatment with atropine for organophosphate poisoning?
Decreased airway secretions and adequate oxygenation! (Not HR)
69
What is the definition and significance of the time constant with regards to volatile anesthetics?
```
Time constant (τ) is volume divided by flow. For the circuit, time constant is the volume of the circuit divided by the fresh gas flow rate .
For the lungs, the time constant is the volume of the lungs (FRC) divided by the minute ventilation.
It takes three time constants for 95% of a concentration change to be achieved.
```
70
What dose of opioids can flatten an EEG?
Opioids cannot flatten (i.e., make isoelectric) the EEG.
71
What effect do high-dose opioids have on EEG?
They cause delta waves
72
What is the pathophysiology of myasthenia gravis?
IgG antibodies to nicotinic ACh receptors
73
What are indications for postoperative ventilation in a patient with myasthenia gravis?
> 6 yrs of disease, > 750 mg/day pyridostigmine, VC < 40 mL/kg
74
Describe the susceptibility of myasthenia gravis to NDNMB and succinylcholine.
Decreased sensitivity to SCh.
Increased sensitivity to non-depolarizing neuromuscular blockers.
75
How is vecuronium metabolized?
30 - 40% liver metabolism
60% liver and 40% kidney elimination
76
What is the treatment for cyanide toxicity?
sodium thiosulfate (150 mg/kg over 15 min) or 3% sodium nitrate (5 mg/kg over 5 min), which oxidizes hemoglobin to methemoglobin
77
What are side effects of prolonged oxytocin infusion aside from increased risk of uterine atony?
Water toxicity due to cross-reactivity with ADH receptors.
78
How long does a propofol infusion need to be on and at what dose to cause propofol infusion syndrome?
Typically > 48 hours at doses > 4mg/kg/hr (>67 mcg/kg/min)
79
What is ritodrine?
A beta-2-agonist used for tocolysis (uterine relaxation), that has some association with causing pulmonary edema.
80
What is the effect of a loose lead on the ECG?
It causes baseline wandering
81
What can be evaluated via TEE in the transgastric short axis view?
The short-axis view at the midpapillary muscle level is a commonly used view for evaluating global and segmental ventricular performance. All three coronary territories are represented in this view, making it useful for detecting acute ischemia.
82
What can be evaluated in the transgastric long-axis view?
The left ventricular apex is imaged most readily in this plane. This is especially important when isolated abnormalities confined to the apex are sought by TEE. This view is also useful in measuring cardiac output through continuous wave Doppler interrogation of the aortic valve. Estimations of cardiac output with this approach correlate well with more direct measures of global function.
83
What can be evaluated in the midesophageal Four-Chamber View
The midesophageal four-chamber view allows simultaneous visualization of the left and right ventricles and is analogous to the identically named apical transthoracic echocardiographic view. Segmental function of the lateral and the septal walls is best assessed in this view.
84
What is the effect of anterior cerebral artery occlusion?
Motor, specifically leg weakness.
85
What is the location of the carotid bodies?
bifurcation of internal and external carotid
86
What is the threshold for neuronal activity of the carotid bodies?
PaO2 100 mm Hg
87
What is the threshold for increased ventilatory drive signals from the carotid bodies?
PaO2 55 - 60 mm Hg
88
What inhibits the carotid bodies?
benzos, opioids, volatile agents, possible antidopaminergic drugs
89
What PaO2 would you expect in a patient who depends on a hypoxic drive for ventilation?
PaO2 ~ 60 mm Hg
90
What nerve carries the afferent signals from the carotid bodies?
CN IX
91
What is the formula for compliance?
change in volume in liters divided by change in pressure in cm H20
92
What is the relationship between bicarb and PaCO2?
[HCO3-] falls 1-2 mEq/L for each 10 mm Hg decrease in the PaCO2
93
How does anemia affect the oxygen-hemoglobin dissociation curve?
Anemia will eventually lead to an increase in 2,3 DPG production which causes a right shift (less O2 affinity).
94
Which ankle nerves are sensory only?
Sural, saphenous, superficial peroneal
95
Which ankle nerves provide motor innervation to the foot?
Deep peroneal and tibial (they also provide sensation to their respective areas as well)
96
What is the toxicity of nitric oxide?
It can form NO2 which then forms nitric acid in the presence of water which can lead to pulmonary edema/lung irritation leading to death.
More importantly in neonates than in adults, nitric oxide can cause methemoglobinemia.
97
What is a normal apgar score?
7 - 10
98
When is the Apgar score measured
At minutes 1 and 5 of life. If the score is less than 7, it is measured at 10, 15, and 20 minutes as well.
99
What are the components of the Apgar score?
APGAR ** 2pts | 1pt | 0pts **
Appearance **pink everything | pink body | cyanotic**
Pulse ** > 100 | < 100 | asystolic**
Grimace ** crying | grimace | none **
Activity ** active | flexion | none **
Respirations ** good/crying | slow, irreg | absent **
100
What is the leading cause of death after cesarian section in the United States?
Pulmonary embolism.
In the developing world, it's hemorrhage.
101
What is the most sensitive sign of uterine rupture?
fetal bradycardia
102
What are signs of uterine rupture?
fetal bradycardia, abdominal pain, lower baseline uterine pressure, hypotension, shock, recession of presenting part
103
What is the incidence of uterine rupture with VBAC?
1%. Lower with spontaneous labor, 10-fold increase with induction!
104
What is the mechanism of Mg2+ hypotensive effect?
1) In vascular smooth muscle cells magnesium acts intracellularly and extracellularly as a calcium antagonist to inhibit contractility.
2) Magnesium also inhibits catecholamine release from the adrenal medulla and peripheral adrenergic terminals resulting in decreased vasoconstriction.
105
What are indications for uterine relaxation?
1. manual removal of a retained placenta,
2. breech delivery: obstructed after coming head or shoulders,
3. multiple pregnancy: second twin in transverse-lie,
4. inadvertent oxytocic overdose prior to delivery,
5. uterine constriction ring,
6. inverted uterus
7. (some cases of) fetal distress.
106
What are the consequences of hypothermia in the neonate?
```
Pulmonary vasoconstriction
Right to left shunt
Hypoxemia secondary to increased oxygen consumption
Metabolic acidosis
Hypoglycemia
```
107
If maternal SpO2 is 100%, what effect will increasing FiO2 further have on fetal SvO2?
None. In other words, once mom is fully saturated, raising her PaO2 further does not affect the baby.
108
What are fetal responses to hypoxemia?
Fetal stress responses to decreased DO2 includes bradycardia (2/2 vagal activity), increased alpha adrenergic activity, redistribution of blood (from splanchnic bed to heart, brain, placenta, adrenals), decrease in ventricular output, and decreased fetal breathing movements
109
What is the first line tocolytic for a woman in preterm labor whose GA is < 30 weeks?
Indomethacin. It is not given after 32 weeks because it will constrict the PDA
110
What percentage of parturients will experience atrial or ventricular ectopy?
> 50%
111
What antiarrhythmics are category B in pregnant women (i.e., no risk)?
Lidocaine, sotalol.
Most others are category C (risk unknown).
Notably Amiodarone is category D (evidence of risk)
112
What is the approach to SVT in the pregnant woman?
1) Vagal maneuvers
2) Adenosine as first-line pharmacology
3) Verapamil, digoxin, or β-blockers (category C)
4) If an accessory pathway is present, don't use verapamil and instead try procainamide or quinidine
5) If refractory, ablate or electrocardiovert
113
What is botox's mechanism of action?
Prevents presynaptic ACh release. It reduces spasticity in dystonias and migraines but not tension headaches.
Notably it is NOT helpful for myofascial trigger points, orofacial pain, and neck pain
114
What are indications for lumbar sympathetic block?
```
CRPS
labor analgesia (stage 1 only)
cystitis
phantom limb pain
hyperhidrosis
herpes zoster
vascular insufficiency (ex. in diabetic lower limb ischemia)
```
115
What are indications for stellate ganglion block?
```
CRPS (primary indication),
vascular insufficiency (ex. Raynaud's, diabetes, or frostbite), phantom limb pain,
hyperhidrosis,
herpes zoster
recurrent angina
```
116
What is the gate theory of TENS therapy?
Gate Theory: afferent input from large epicritic fibers competes out input from small pain fibers.
117
What is the conduction block theory of TENS therapy?
Conduction block theory: high rates of stimulation exhaust the small nerve fiber ability to transmit signal
118
What can reverse the effects of low-frequency TENS?
Naloxone (which suggests a role for endogenous opioids in the mechanism)
119
What is the utility of TENS in chronic lower back pain?
There are two Class I studies demonstrating that TENS is ineffective
120
What causes the PDA to anatomically close?
A decrease in prostaglandin E2 (PGE2), along with exposure to oxygenated blood, causes the ductus arteriosus to close after birth.
121
What is used to maintain PDA patency after birth?
PGE 1
122
What is alprostadil?
PGE1 (used to keep PDA open after birth)
123
What is a late, ominous sign of hypovolemia in children?
Hypotension. Yes, hypotension is a late, ominous sign. Children may maintain a normal blood pressure until 35% of blood volume is lost.
124
What are signs of hypovolemia in children?
TACHYCARDIA (sensitive, but not specific)
CAPILLARY REFILL: specific if > 2 seconds
Others: WEAK PULSES, MOTTLING, CYANOSIS, MS CHANGES (may all precede hypotension), cold skin, LOW UOP
HYPOTENSION: late, ominous finding.
125
Why is neonatal CPAP always nasal?
Babies are obligate nose breathers until 5 months of age.
126
What is the murmur of a PDA sound like?
Continuous machine-like murmur.
127
What drug has been shown to rapidly correct the metabolic alkalosis found in pyloric stenosis?
Cimetidine
128
What are the end-points of preop therapy for pyloric stenosis? (Or put another way, what minimum values do you need to say "ok, we'll go ahead with the case"?)
Correction of the electrolyte imbalance should produce:
Na level that is >130 mEq/L
K level that is at least 3 mEq/L
Cl level that is >85 mEq/L and increasing
UOP of at least 1 to 2 mL/kg/hr.
These patients need a resuscitation fluid of full-strength, balanced salt solution and, after the infant begins to urinate, the addition of potassium.
129
How is morphine helpful during a tet spell?
It sedates thus takes away distress and hyperpnea.
130
How does an ambulatory surgery center's perioperative costs compare to those performing the same procedures at an inpatient center?
There is a 25%-75% reduction in overall cost for most operations performed in an outpatient versus inpatient setting.
131
What effect does ketamine have on ECT seizure duration?
No effect.
132
What is the effect of lidocaine on ECT seizure duration?
Decreases it. It also has no hemodynamic blunting effects in the ECT setting. Don't use it for ECT.
133
What effect does diltiazem have on ECT seizure duration?
Decreases it.
| Nicardipine and nifedipine do not affect seizure duration.
134
What medication is commonly given preoperatively to increase ECT seizure duration?
Caffeine.
135
What are the periop risks of tetanus infection?
Difficult airway 2/2 trismus, neck rigidity (use FOB)
| Severe autonomic instability including BP fluctuations, arrhythmias, CHF, cardiac arrest
136
What is tetanospasmin?
Exotoxin produced by clostridium tetani.
137
What is the mechanism of tetanospasmin?
Inactivates inhibitory interneurons in glycinergic and GABA pathways resulting in spasticity of muscles and autonomic dysfunction.
138
What infusion is useful during GA in patient with tetanus?
Magnesium helps control muscle spasms, decreases autonomic instability, and decreases sedative drug requirements.
139
Describe the INR in the early post-op period in patients who have donated part of their liver?
All patients will have an increase in the INR after donor hepatectomy in the postoperative period. The INR in the majority of patients will not return to normal for at least 7 days.
The effects of hepatectomy on post-op coagulation should be considered prior to administration of epidural analgesia.
140
An asthmatic taking theophylline presents for ECT. How do you proceed?
Consider rescheduling the case to get the patient off theophylline since it can cause status epilepticus.
141
A patient with a PPM/AICD presents for ECT. How do you proceed?
It's ok. Deactivate the AICD. Have the magnet available if needed for the PPM.
142
A patient with pseudotumor cerebri presents for ECT. How do you proceed?
It's ok. Increased ICP is generally ok so long as there is not mass effect. If there's a tumor, get a neurosurgery consultation.
143
A patient with pheochromocytoma presents for ECT. How do you proceed.
Pheo is an absolute contraindication to ECT.
144
What are the physiological effects of ECT?
Large increases in CBF and ICP
Initial parasympathetic discharge: bradycardia, occasional asystole, premature atrial and ventricular contraction, hypotension and salivation.
Following parasympathetic reaction, sympathetic discharge associated with tachycardia, hypertension, premature ventricular contractions, and rarely, ventricular tachycardia and ECG changes, including ST-segment depression and T-wave inversion, may also be seen.
Glucose homeostasis is also affected. Hyperglycemia seen in insulin dependent patients
145
What are the respiratory effects of head-down (trendelenberg) position?
a. Increases Atelectasis
b. Increased work of breathing
c. Movement of the ETT (cephalad movement of diaphragm can shift carina carina leading to endobronchial intubation)
146
How does head-down position help perfusion of the brain in hypotension?
It doesn't! Although there is an initial fluid bolus (1L), it is quickly offset by reflex barostimulation, vasodilation. The decrease in HR and SV results in decreased CO, couple that with decreased venous return from the head due to gravity, it likely decreases perfusion to the brain.
147
What patients should have AICDs?
```
Patient's with:
VF or VT
long QT
HOCM (if VT or VF)
post-MI (if EF < 30%)
dilated cardiomyopathy
```
148
What is the upper limit of lidocaine exposure allowed by the american association of dermatology for liposuction/tumescent anesthesia?
55 (fifty-five) mg/kg. Our specialty says that 35 mg/kg is a better upper limit because after that the CYP 3A4 enzymes can become saturated.
149
When do plasma levels of lidocaine peak after tumescent anesthesia?
8 - 12 hours. So lidocaine toxicity usually presents later after surgery unless there was inadvertent intravascular injection. Most cardiopulmonary distress earlier is due to water intoxication/pulmonary edema due to the high volumes of dilute lidocaine+epi used.
150
What muscular disorders are associated with malignancy hyperthermia?
King-Denborough and Central Core disease
| Duchenne's and Beckers are NOT
151
What chromosome has the RYR1 gene on it?
Chromosome 19
152
Who should get infective endocarditis prophylaxis?
Previous IE: anyone with previous infective endocarditis
Prosthetic Material: prosthetic valves, prosthetic material in repaired congenital heart disease (CHD)
Existing Cardiac Defects: unrepaired cyanotic CHD or partially repaired CHD
Transplantation: heart transplant patients WITH concomitant valvulopathies
153
What are the antibiotics of choice for infective endocarditis surgical prophylaxis?
1st: Amoxicillin PO
If can't take PO, take Ampicillin or cefazolin or ceftriaxone IV.
If can't take penicillins, take Clindamycin, Cephalexin, or Azithromycin PO
If can't take PO and is PCN allergic, take Clindamycin or Cefazolin or Ceftriaxone IV.
154
What is the salient difference between moderate and deep sedation?
Moderate sedation by definition does not involve airway intervention of any kind.
155
What is the EEG end-point for inducing barbiturate coma?
Controlled burst suppression should be present on EEG.
156
What type of laser is absorbed and will heat up PVC ETTs?
CO2, the others will pass through but will still burn blood or debris within it.
157
How does one calculate the standard error of the mean?
Divide the standard deviation by the square root of the sample size.
158
What is the standard error of the mean used for?
It is used to estimate the mean for a large population in which multiple sample groups' means were calculated.
159
What is the difference between a t-test and a paired t-test?
A t-test compares the population means between two independent (and normally distributed) groups.
A paired t-test examines repeated measurements obtained from the same set of individuals. The objective of the analysis is to show that any differences between two measurements of the same individuals are due to different treatment conditions.
