Anesthesia for flap surgery in a patient with polymyositis

provided the original work is properly cited. CC Polymyositis is a subacute inflammatory myopathy presenting as progressive and often symmetric muscle weakness. It is believed that the patients with polymyositis are sensitive to nondepolarizing muscle relaxants. The major concerns for the anesthesiologist are delayed recovery from muscle relaxation, aspiration pneumonitis, arrhythmias and cardiac failures [1]. A 26-year-old male with polymyositis, 170 cm in height and 76 kg in weight, had flap surgery of sacral pressure sore which developed during intensive care. He had progressive muscle weakness for one year. Three months ago, he was admitted to a hospital under the impression of viral hepatitis or nonalcoholic steatohepatitis due to elevated liver enzymes. However, viral studies and liver biopsy results were normal. Instead, elevated CK (> 11,000 U/L) and CK-MB (> 300 ng/ml) were found. Polymyositis was diagnosed according to clinical features, electromyography results and muscle biopsy findings. During the hospital stay, he presented pneumonia symptoms. Intravenous antibiotics were administered, but the patient was not improved. Three days later, dyspnea became more severe and arterial blood gas analysis (ABGA) showed PaO2 49 mmHg and SaO2 80%. Upon the diagnosis of acute respiratory distress syndrome, the patient was intubated. Despite of ventilator care, pulmonary status deteriorated and extracorporeal membrane oxygenation (ECMO) support was applied for five days. His pulmonary function improved enough to switch to conventional ventilator care and the care was maintained for another ten days. He was transferred to general ward after recovery of pulmonary function. On the day of surgery, the patent’s laboratory findings, chest X-ray and vital signs showed normal. In the operating room, direct arterial pressure, electrocardiography, end-tidal CO2, temperature, pulse oxymetry and peripheral nerve stimulator (TOFWatch, Organon Inc., Dublin, Ireland) were monitored. Neuromuscular relaxation was assessed by train of four (TOF) at the adductor pollicis with supramaximal stimulation of the ulnar nerve at 2 Hz every 12 seconds and was recorded continuously until end of anesthesia. Anesthesia was induced with glycopyrrolate 0.2 mg, propofol 120 mg and remifentanil infusion. The lungs were ventilated with 100% oxygen and 2.5% sevoflurane. TOF-ratio was assessed before administration of muscle relaxant as a reference value and was recorded continuously until end of anesthesia. Rocuronium 10 mg IV was slowly started and TOF-ratio decreased to 50% of reference value after 5 minutes. Rocuronium 10 mg was added and TOF-ratio was suppressed to 0 after another 5 minutes. The patient was presenting excellent intubating conditions according to the Copenhagen Consensus Conference score (abducted vocal cords, no vocal cords movement, no coughing, no limb movement). Anesthesia was maintained with 1.5 L/min O2, 1.5 L/min air, sevoflurane and remifentanil. Operation time was 250 minutes. TOF-ratio maintained 0 by 110 minutes after induction. Then TOF-ratio started to increase slowly but maintained < 50% by 200 minutes and increased to 75% at the end of the surgery. The surgery did not need intensive relaxation and patient did not have spontaneous respiration; therefore, no additional rocuronium was given. ABGA revealed adequate oxygenation and spontaneous respiration was restored after switching to manual ventilation. Ten mg of pyridostigmine and 0.2 mg of glycopyrrolate were injected and TOF-ratio increased > 90% after 5 minutes. He was extubated and transferred to recovery room. There was no specific complication during the hospital stay.