When do symptoms of ischemic optic neuropathy that result in postoperative vision loss typically occur?
(A) Immediately postoperatively
(B) 2 hours postoperatively
(C) 2 days postoperatively
(D) 2 weeks postoperatively
A. Rationale: Symptoms typically start following emergence from anesthesia, but may occur up to 12 days following surgery.
J.D. (2013). Ch 54 Morgan & Mikhail's Clinical Anesthesiology (5th ed.). New York, NY: McGraw-Hill.
During a general anesthetic you suspect an episode of malignant hyperthermia (MH). What will you do first?
(A) Call the MHAUS hotline.
(B) Administer dantrolene.
(D) Turn off inhalational agents.
D. Rationale: When suspicion of an episode of malignant hyperthermia exists, each of the responses is in order; however, turning off the inhalational agents is the first priority.
J.D. (2013). Ch 52 Morgan & Mikhail's Clinical Anesthesiology (5th ed.). New York, NY: McGraw-Hill.
W.M. (2012). Ch 87 Anesthesiology (2nd ed.). New York, NY: McGraw-Hill.
When is body temperature loss the greatest?
(A) During the preoperative preparation
(B) During the 1st hour in the operating room
(C) During the 2nd and 3rd hours in the operating room
(D) During the 4th hour in the operating room
B. Rationale: The greatest amount of heat loss occurs during the 1st hour in the operating room (0.5-1.5C). Thereafter temperature decline is gradual and then plateaus.
Management of Patient with Highly Suspicious Episode of MH
Discontinue all potent inhalational agents and succinylcholine. Maintain anesthesia with total intravenous, nontriggering anesthetics.
Increase minute ventilation to at least 10 L/min to flush out volatile anesthetics and to lower ETCO2. Administer 100% oxygen. Insert activated charcoal filters into the inspiratory and expiratory limbs of the breathing circuit. Consider switching to a freestanding ventilator as soon as possible.
Inform the surgeon to expedite or abort the procedure, if possible, and obtain assistance from MHAUS Hotline (1-800-644-9737) for acute crisis.
Administer IV dantrolene, 2.5 mg/kg. Be prepared to repeat this dose until the patient responds with a decrease in ETCO2, rigidity, or heart rate.