Anesthesia Oral Boards Flashcards
Side effects of glucagon
Increased heart rate and transient hyperglycemia
Rx for SIADH
Fluid restriction and demeclocycline: inhibits renal action of ADH, induces diabetes insipidus, alternative to demeclocycline is tolvaptan, a vasopressin receptor antagonist
Hyponatremia, euvolemia
SIADH, postop pain/stress, diuretics, hypothyroidism
Hyponatremia, hypovolemia, urine Na less than 10 mEq/L
Non renal solute loss: GI losses, skin, insensible
Hyponatremia, hypervolemia, urine Na greater than 20 mEq/L
Renal failure
Clinical features of hypernatremia
Lethargy, confusion, irritability, coma, seizures, nausea, myoclonus, tremors, muscle weakness, intracerebral bleeding
Clinical features of hyponatremia
Asymptomatic: greater than 125
Anorexia, nausea, malaise: 120-125
Headache, lethargy, confusion, agitation, obtundation: 110-120
Stupor, seizures, coma: less than 110
Drugs that cause hyperkalemia
Succinylcholine, beta blocker, ACE inhibitors, heparin, severe digitalis toxicity, cyclosporine
Diagnosis of DKA
Serum ketones > 7 mmol, serum bicarbonate < 10 meq/L, pH < 7.25
Labs to order when suspecting DKA
Urinalysis, glucose, electrolytes to determine anion gap, ABG, CBC to check for infection
Treatment for DKA
IV fluids, insulin bolus then gtt, potassium as acidosis is corrected, antibiotics for sepsis
Diagnosis and treatment of nonketotic hyperosmolar coma
Severe dehydration, no ketoacidosis, glucose very high like 1000 mg/dL, mental status changes.
Treatment: IVFs, insulin, dextrose, potassium
Anesthetic considerations for diabetic patients
Renal dysfunction; increased risk of CAD and CVA and PVD; autonomic dysfunction: delayed gastric emptying, orthostatic hypotension, resting tachycardia; infection and poor wound healing; stiff joints; poor response to ephedrine
Drugs that precipitate when mixed with barbiturates
Vecuronium, atracurium, midazolam, sufentanil, alfentanil
Sevoflurane has potential for emergence delirium and can be switched to what agent after induction?
Isoflurane
Sevoflurane given at flow rates less than 2 liters can cause what?
Formation of compound A with is nephrotoxic
Which volatile agent has greatest risk of degrading to form carbon monoxide in extremely dry CO2 absorber?
Desflurane
Virchow’s triad for venous thromboembolism
Venous stasis, vessel wall damage, hypercoagulability
Diagnostic triad for fat embolism syndrome, ways to reduce incidence/severity.
Hypoxemia, altered mental status, petechiae (12-72 hours after initial trauma), pulmonary edema. Early immobilization of fractures, limit intraosseus pressure, operative correction rather than traction alone
Triad of symptoms for severe aortic stenosis
Syncope (3 yr mortality rate is 50%), angina (5 yr mortality rate is 50%), dyspnea (2 yr mortality rate is 50%). Valve area < 1.0 cm^2, mean gradient > 40 mmHg, aortic jet velocity > 4.0 m/s
Risk of occurrence of venous air embolism in sitting crani, and why is risk greater in sitting vs prone position?
76%. Horizontal position still has 12% risk of occurrence. Sitting position increases the pressure gradient favoring entry of gas into the veins that now have less than atmospheric pressure because they are above the heart.
Why is nitrous oxide avoided in surgical procedures where there are closed air spaces
Nitrous oxide has blood gas coefficient of 0.47 compared to 0.015 of nitrogen, so nitrous oxide will enter closed gas filled spaces 34 times faster than nitrogen can diffuse out.
Oliguria is < 0.5 mL/kg/hour of urine for how many hours?
6 hours, or < 500 mL in 24 hours for adults, or < 1 mL/kg/hr for an infant.
Intraoperative narcotic of choice for ESRD patient
Fentanyl: primary liver metabolism and no active metabolites
Morphine: one small dose is okay but its metabolite 6-glucuronide can lead to prolonged respiratory depression
Meperidine: do not use. Its metabolite normeperidine is neurotoxic, leading to convulsions.