Hall Ch6 Flashcards
Normal tracheal capillary arteriolar pressure is
25-35 mmHg
You should wait how many hrs after last dose of BID dosing of lovenox before giving neuraxial anesthesia?
24 hrs
Fluoride toxicity anesthesia most closely resembles what type of renal failure
Nephrogenic diabetes insipidus
Best prophylaxis against deep vein thrombosis
Early ambulation
MCC of postop hypoxemia
V/Q mismatch
Symptoms of hypocalcemia usually occur how many hours after inadvertent resection of parathyroid glands?
24-72 hrs
Damage to which nerve leads to wrist drop
Radial n.
MCC of bronchiectasis
Recurrent bronchial infections
Treatment of acute dystonic reaction following administration of an anti-dopaminergic drug
Anti-cholinergic drug that crosses blood brain barrier like diphenhydramine or benztropine
Nerve most frequently injured at antecubital fossa by extravasation of IV
Median n.
Onset of delirium tremens usually occurs how long after alcohol abstinence
2-4 days
Why is postop mechanical ventilation a relative contraindication for tracheal resection?
Risk of wound dehiscence because of positive airway pressure
Average 1 yr old weighs how much?
10 kg, triple the birthweight.
From age 1-6, children gain how much kg per yr?
2 kg
From age 6-10, children gain how much kg per yr?
3 kg
Acute threshold changes of a pacemaker are almost always associated with what electrolyte imbalance
Potassium
First signs of cerebral ischemia appear on EEG when cerebral blood flow (CBF) falls below what value?
22 mL/100 g/min
EEG becomes isoelectric when CBF falls to what value?
15 mL/ 100 g / min
Irreversible membrane damage and cellular death occur when CBF falls to what value?
6 mL / 100 g / min
Duration of action of anticholinesterase drugs from fast to slow
Edrophonium < neostigmine < pyridostigmine
Glycopyrrolate or atropine has longer duration of action?
Glycopyrrolate
Which partition coefficient is most closely associate with minimum alveolar concentration?
Oil/gas partition coefficient
Succinylcholine is hydrolyzed by?
Pseudocholinesterase
Conditions associated with increased DLCO (Diffusing capacity of carbon monoxide)
Obesity, asthma, exercise, supine position, left to right shunt, polycythemia
Most reliable early sign of MH
Increased end expiratory CO2 (PECO2)
Components of PADSS (post anesthetic discharge scoring system)
vital signs, ambulation, pain, nausea/vomiting, surgical bleeding
Does history of uncomplicated general anesthesia reassure that a malignant hyperthermia suspect can be ruled out?
No, it is not uncommon for MH-susceptible patients to not trigger initially and then develop fulminant MH with a subsequent anesthetic
Mechanism of action for montelukast (singulair)
Leukotriene receptor antagonist. Leukotrienes are inflammatory mediators.
Trismus after giving succinylcholine signals onset of MH in what percentage of patients?
Less than 50%
Head flexion can advance the ETT by how much?
1.9 cm toward carina
How many days after gas bubble is injected into vitreous for retinal detachment can nitrous oxide be used?
10 days
Myocardial oxygen demand
HR
wall tension
Contractility
Basal metabolic
Myocardial oxygen supply
HR
Oxygen content
Anatomy
Coronary perfusion pressure
Normal oxygen consumption of heart
8 mL/100 g/ min
Oxygen consumption of heart on CPB
2 mL/100g/min
Cardiac conditions to treat SAM (systolic anterior motion)
Big slow heart, decrease contractility, increase afterload
Several days after a thermal injury, how does a patient’s sensitivity to depolarizing and nondepolarizing muscle relaxants change?
Increased sensitivity to depolarizing agent
Decreased sensitivity to nondepolarizing agent
Greater than 60% of all drug-induced allergic reactions during perioperative period is attributable to…
Muscle relaxants
Succinylcholine should be used cautiously with patients with Huntington’s chorea because of
Decreased levels of pseudocholinesterase, therefore prolonging effects of succinylcholine
PaO2 is decreased by how much for each degree that body temperature is cooler than 37C?
6%
2 main causes of central cyanosis
1) Decreased arterial oxygen saturation
2) Hemoglobin abnormalities (eg. methemoglobinemia and sufhemoglobinemia)
Classic signs of fat embolism
Tachycardia, dyspnea, mental confusion, fever, petechial rash on upper part of the body
Remifentanil is metabolized primarily by
Nonspecific esterases
MC reason for unexpected hospital admission after outpatient general anesthesia
Nausea and vomiting
MC reason for prolonged recovery room stay
Nausea and vomiting
Elimination half life time of factor VIII
12 hrs
Factor VIII level for a hemophiliac should be raised to what before elective surgery
100%
What is the best screening test for hemophilia A?
PTT because hemophilia A is associated with decreased levels of factor VIII so PTT tests intrinsic coagulation cascade
90% of patients have blood to the AV node supplied by which coronary artery?
right coronary artery
Severe CAD of which coronary artery can lead to complete heart block
Right coronary artery
How does hypernatremia affect MAC?
Increase
How does abnormal thyroid function affect MAC?
No change
Minimum dermatomal level that must be achieved for testicular surgery
T10
Peak effect of neostigmine
10 min
Peak effect of glycopyrrolate
3 min
Long term lithium therapy may be associated with what conditions?
Nephrogenic diabetes insipidus, hypothyroidism, decrease MAC, prolong duration of action of pancuronium and succinylcholine. Diuretics increase lithium levels.
Best medication to treat hypotension in a patient with metastatic carcinoid
Octreotide, a synthetic somatostatin
How is insulin metabolized?
Liver and kidney, so diabetic with renal disease can have prolonged effects of insulin
Why does carboxyhemoglobin not decrease the pulse oximetry reading?
Because it has absorbable at 660 nm, which is similar to oxygen rich hemoglobin
Mechanism of action of gabapentin
Unknown but it involves inhibition of voltage dependent calcium channels
Perioperative visual loss is most commonly due to
Ischemic optic neuropathy, with associated factors of: prolonged hypotension, anemia, large blood loss, facial edema
Drugs used to treat postop shivering other than meperidine
Clonidine, droperidol, magnesium, calcium, chlorpromazine
For every 10 cm of H2O, how much change in mmHg?
7.5 mmHg
Specific cytochrome P450 enzyme that facilitates metabolism of codeine, oxycodone, and hydrocodone.
CYP2D6
Specific cytochrome P450 enzyme that facilitates metabolism of fentanyl, sufentanil, alfentanil.
CYP3A4
One of the most potent inhibitors of CYP3A4 and CYP2D6, which help metabolize narcotics.
Fluoxetine
Phase of liver transplantation where greatest degree of hemodynamic instability is expected
Reperfusion phase
Metabolic and physiologic conditions that prolong duration of action of nondepolarizing neuromuscular blockade.
Respiratory acidosis, myasthenia syndromes, hepatic/renal failure, hypocalcemia, hypothermia, hypermagnesemia.
Drugs that prolong duration of action of nondepolarizing neuromuscular blockade.
Inhaled and local anesthetics, corticosteroids, antibiotics like clinda and flagyl and aminoglycosides, calcium channel blockers, dantrolene, lasix
Why is it better to reverse muscle relaxants in pregnant patients with neostigmine and atropine instead of neostigmine and glycopyrrolate?
Because glycopyrrolate does not cross into placenta
NSAIDSs are contraindicated in patients undergoing spinal fusion because?
NSAIDs may impair bone healing
Leading causes of malpractice claims against anesthesiologists
Death (22%), nerve damage (21%), brain damage (10%)
Retinopathy of prematurity is caused by?
O2 administration to neonates up to 44 weeks, especially a hazard in extremely premature neonates
Greater auricular nerve arises from branches of what nerves?
C2 and C3 spinal nerves
4-12 days after evacuation of intracerebral hemorrhage, pt develops progressive mental deterioration over several hours
Cerebral vasospasm.
Why is aspirin contraindicated for thyrotoxicosis?
It displaces thyroid hormones from thyroglobin and can aggravate disease
The last of the classic signs of compartment syndrome to appear
Pulselessness
How is dose and duration of spinal anesthetics different in infants compared to adults?
Greater dose and shorter duration, infants have more CSF volume per kg
If a patient is trapped in MRI machine, what is the greatest hazard patient is in when the MRI machine is shutdown (quenched)
Cold
Treatment for anthrax
Ciprofloxacin (anthrax is gram positive bacillus)
Treatment for plague
Streptomycin (plague is gram negative coccobacillus)
Injury to what nerve causes impaired ankle dorsiflexion, loss of foot eversion and toe extension
Common peroneal nerve
