1. Department of Anesthesiology, University of Arizona Health Science Center, Tucson, AZ ANESTHETIC MANAGEMENT OF AN ADOLESCENT WITH MITOCHONDRIAL MYOPATHY: A CASE REPORT J. C. LILJENQUIST, M.D., J. P. REINHARD, M.D. Figure 1. Representation of the electron transport chain and oxidative phosphorylation in the mitochondrion. NADH and succinate generated in the citric acid cycle are oxidized and electron transport is linked to proton pumps which create a gradient that drives ATP formation via ATP synthase. Tim Vickers Case Report A 15-year-old, 72-kg male with MM presented from an outside hospital for exploratory laparotomy indicated for small bowel obstruction (SBO). The patient’s manifestations of MM included progressive weakness, developmental delay, and episodes of lactic acidosis. Additionally, past medical history included cystic fibrosis, pancreatic insufficiency status post pancreatectomy with successful islet cell transplant, chronic colonic dysmotility status post hemicolectomy with ileostomy, and gastroesophageal reflux disease. The patient’s mother reported that general anesthesia with volatile anesthetics had previously been administered several times without complications. She did, however, report a history of severe agitation and combativeness with administration of morphine and midazolam. Hydromorphone and fentanyl were administered preoperatively for pain control with no adverse effects. Preoperative CBC revealed leukocytosis and CMP was unremarkable. Lactate and blood glucose were normal. Rapid sequence IV induction of anesthesia was achieved with propofol (2.5mg/kg) and fentanyl (1mcg/kg) bolus. Rocuronium (0.55mg/kg) was administered for muscle relaxation. After endotracheal intubation, radial arterial line was placed for monitoring of ABG and plasma lactate. Anesthesia was maintained with sevoflurane and boluses of fentanyl. Paralysis was maintained with boluses of rocuronium. Nasopharyngeal temperature, blood glucose, plasma lactate, and arterial blood gas remained normal intra- and post-operatively. The patient underwent successful exploratory laparotomy with lysis of adhesions. After completion of surgery, paralysis was successfully reversed with neostigmine (0.07mg/kg) and glycopyrrolate (0.01mg/kg) and the patient was extubated in the operating room. He made an uneventful recovery and was discharged to home on postoperative day 4. Introduction Mitochondrial myopathy (MM) refers to a clinically heterogeneous group of disorders caused by defects in the electron transport chain and oxidative phosphorylation of mitochondrial metabolism (Figure 1). The hallmark of the disease is progressive muscle weakness. Other manifestations may include cardiac conduction abnormalities, cardiomyopathies, metabolic disturbances, dysphagia, seizure disorders, and hepatic dysfunction [1]. The incidence of MM is estimated to be about 1:4,000 [2]. There are several perioperative concerns when administering anesthesia to a patient with MM and the evidence base for anesthetic recommendations is both limited and inconclusive. Discussion Mitochondrial myopathy is a rare disease that may present specific difficulties with regard to anesthesia. MM was previously thought to be associated with increased risk of malignant hyperthermia (MH) [3, 4]. However, more recent literature does not indicate increased susceptibility to MH in patients with MM. Volatile agents should not routinely be avoided out of concern for MH in patients with MM [5]. Succinylcholine should be used with caution as these patients may be susceptible to succinylcholine-induced hyperkalemia [5, 6, 7]. We administered rocuronium for induction/intubation and maintenance of paralysis. Both sensitivity and resistance to non- depolarizing neuromuscular blockers have been reported [8, 9]. This patient exhibited a normal response to rocuronium. Propofol is know to impair mitochondrial function by inhibiting the electron transport chain and uncoupling oxidative phosphorylation in vitro. It has been suggested that patients with MM may be at increased risk of developing lactic acidosis or propofol infusion-like syndrome from propofol infusion [10]. However, the extent to which these concerns apply clinically is unclear. In our review of the literature, there are no reported adverse effects from induction doses or short-term infusions of propofol in patients with MM. Regardless of the anesthesia technique employed, acid base status, plasma lactate, blood glucose, and core temperature should be monitored closely. This case report highlights important anesthetic considerations and outlines successful anesthetic management of this patient with MM. References 1. Hines RL, Marschall KE, editors. Stoelting's Anesthesia and Co-existing diseases. 6 th ed. Pennsylvania: Churchill Livingstone; 2012. 2. Miller RD, Eriksson LI, Fleisher LA, et al, editors. Miller's Anesthesia. 7th ed. Philadelphia, PA: Elsevier Churchill-Livingstone; 2009. 3. Ohtani Y, Miike T, Ishitsu T, et al. A case of malignant hyperthermia with mitochondrial dysfunction [letter]. Brian Dev. 1985;7:249. 4. Fricker RM, Raffelsberger T, Rauch-Shorny S, et al. Positive malignant hyperthermia susceptibility in vitro test in a patient with mitochondrial myopathy and myoadenylate deaminase deficiency: Anesthesiology: December 1997;97:1635-37. 5. Does mitochondrial myopathy increase an individual’s susceptibility to malignant hyperthermia? MHAUS.org. Malignant Hyperthermia Association of the United States. n.d. Web. 9 April 2014. 6. Al-Takrouri H, Martin, TW, et al. Hyperkalemic cardiac arrest following succinylcholine administration: the use of extracorporeal membrane oxygenation in an emergency situation. Journal of Clinical Anesth. 2004;16(6):449-451. 7. Larach MG, Rosengerg H, et al. Hyperkalemic cardiac arrest during anesthesia in infants and children with occult myopathies. Clin Pediat (Phila). 1997;36(1):9-16. 8. Finsterer J, Stratil U, Bittner R, Sporn P. Increased sensitivity to rocuronium in mitochondrial myopathy. Can J Anesth 1998;45:781-4. 9. Aouad MT, Gerges FJ, Bararka AS. Resistance to cisatricurium in a patient with MELAS syndrome. Paediatr Anaesth 2005;15:1124-7. 10. Morgan PG. When is propofol problematic? Pedsanesthesia.org. Society for Pediatric Anesthesia. 2007. Web. 9 April 2014.