Journal: Anaesthesia 63(5):540-543, 2008. 10 References
Reprint: Dept of Anaesthesia, Royal Berkshire Hospital, Reading, RG1 5AN, UK (Dr S O'Neill) TT.03 SP0813/253 ©2008
Faculty Disclosure: Abstracted by T. Tilton, who has nothing to disclose.
A case report is made of a 44-yr-old man, weight 70 kg and BMI 25, scheduled for elective laparoscopic left adrenalectomy. His pertinent medical history included hypertension since age 19, Conn’s syn¬drome, and a 1.7-cm adrenal adenoma. His medica¬tions consisted of spironolactone 50 mg, amlodipine 5 mg, and labetalol 200 mg, all once daily. His surgical history included appendectomy 30 years and knee arthroscopy 17 years previously, both with unremarkable general anesthesia. Preoperative work¬up was unremarkable. A case report is made of a 44-yr-old man, weight 70 kg and BMI 25, scheduled for elective laparoscopic left adrenalectomy. His pertinent medical history included hypertension since age 19, Conn’s syndrome, and a 1.7-cm adrenal adenoma. His medications consisted of spirono¬lactone 50 mg, amlodipine 5 mg, and labetalol 200 mg, all once daily. His surgical history included appendectomy 30 years and knee arthroscopy 17 years previously, both with unremarkable general anesthesia. Preoperative workup was unremarkable.
An intravenous line and routine monitors were placed and a thoracic epidural was inserted. Anesthesia was induced with fentanyl and propofol with rocuronium for intubation. Anesthesia was maintained with sevoflurane in oxygen and air. An arterial line was placed and an esophageal temperature probe was inserted. The patient's temperature was 35.8°C; a forced-air blanket was placed over him. End-tidal carbon dioxide (ETCO2) was 76 mmHg with a minute volume of 6.7 L. About 2 hours after induction, the ETCO2 rose to 82 mmHg despite increasing ventilation to 8.1 L, which was thought due to a prolonged CO2 pneumoperitoneum, and ventilation was increased. At this point his temperature was 36.4°C with a heart rate (HR) of 74 beats/min and blood pressure (BP) of 100/54 mmHg.
Three hours after induction, new ST segment depression appeared. The patient's HR increased to 100 beats/min, BP to 120/70 mmHg, and his tem¬perature was now 37.3°C. Surgery was temporarily halted and anesthesia was deepened with no improvement. It was thought the reactions might be due to adrenal manipulation. During the next 10-15 min, ETCO2 increased to 132 mmHg and temperature to 39.9°C. Malignant hyperthermia (MH) was suspected.
Sevoflurane was immediately discontinued and the anesthesia machine changed for a volatile-free machine; anesthesia was maintained with a propofol infusion. It was considered safe to end the surgical procedure. Active cooling was achieved with ice packs to the groin, axillae, and neck and ice-cold saline bladder washouts. Dantrolene, 2 mg/kg, was administered, following which his ETCO2 and temperature decreased. Arterial blood gases showed a respiratory acidosis without a metabolic component. Two hours later, the patient’s condition had stabilized; an increased potassium was treated with insulin and dextrose. He was successfully weaned from the respirator the next day. Muscle biopsy 4 months later confirmed MH-susceptibility. Success¬ful adrenalectomy was accomplished later with total intravenous anesthesia. Nonmalignant adrenal cortical adenoma was confirmed.
Because the mean operative time for laparoscopic adrenalectomy is 164 minutes, a significant increase in end-tidal CO2 is likely, which may mask the initial signs of MH and delay diagnosis. Anesthesia providers need to remain vigilant for the early signs of MH. |
