General anesthesia without neuromuscular blockade for a child with mitochondrial myopathy

Abstract

Mitochondrial myopathies are rare diseases caused by disturbance of the mitochondrial chain of respiration or oxidative phosphorylation [1]. The mitochondria are a potential site of action for general anesthetic agents, and it is feasible that children with mitochondrial disease will respond abnormally to anesthetic drugs [2]. We experienced a case of successful management of a 2-year-old boy with mitochondrial myopathy under general anesthesia without the use of neuromuscular blockade. A 2-year-old boy weighing 10 kg and 87 cm in height, diagnosed with complex I deficiency mitochondrial myopathy by a pediatrician, was admitted for elective cochlear implantation. Neuromuscular examination showed mild muscle weakness and hypotonia, but the patient could control his head and sit alone. He During the preoperative fasting period, an intravenous cannula was inserted and a 500 ml solution containing 3% dextrose and 38.5 mEq/ L NaCl was infused at a rate of 40 ml/h to maintain glucose levels and prevent catabolism. The patient’s fasting plasma lactate and glucose levels were 0.9 mmol/L, and 90 mg/dl, respectively. Immediately before entering the operating room, the patient was premedicated with midazolam 0.03 mg/kg intravenously. Intraoperative routine monitoring included elec trocardiography, pulse oximetry, blood pressure, end-tidal capnography and esophageal temperature. Before induction, vital signs showed blood pressure 96/60 mmHg, heart rate 145 beats/min, and oxygen saturation 100%. General anesthesia was induced with 5 vol% of sevoflurane in 100% oxygen, and the patient was intubated. Anesthesia was maintained with 1.5-3 vol% of sevoflurane in 66% nitrous oxide in oxygen. No neuromuscular blocking agent was administered. Intraoperative vital signs kept showed; blood pressure 90/40-100/55 mmHg, heart rate 130-150 beats/min, end-tidal CO2 38-40 mmHg, body temperature 35.9-36.6 o C, and oxygen saturation 100%.