A 63-year-old female (149 cm, 57 kg) was scheduled for elective laparoscopic distal gastrectomy under general anesthesia for gastric cancer. Her prior medical history included cerebral infarction and cervical spondylosis, controlled with medication. When she was 37 years old, she was diagnosed with Isaacs’ syndrome. Whole-body stiffness worsened, and double filtration plasmapheresis (DFPP) was performed four times per year to treat the symptoms.
The patient had previously received a surgical arteriovenous shunt in the left forearm, a subcutaneously fixed superficial artery, and an arteriovenous graft in the upper left arm; however, all had occluded within 1 year. Additionally, she had received a thrombectomy of the right femoral vein. As her blood vessels were easily occluded due to frequent vasospasms, a temporary cervical catheter had been used when providing DFPP treatment. The patient orally received tacrolimus (3 mg/day) to suppress the symptoms of Isaacs’ syndrome; dantrolene (150 mg/day), carbamazepine (600 mg/day), and gabapentin (900 mg/day) to relieve the muscle symptoms; dabigatran etexilate methanesulfonate (320 mg/day) as an anticoagulant; cilostazol (150 mg/day) to prevent cerebral infarction; and nicorandil (10 mg/day) as a vasodilator to suppress vasospasms.
The results of preoperative examinations were not remarkable except hemoglobin of 10.8 g/dL. The patient had myokymia of the bilateral upper extremities, neuromyotonia of the bilateral thumb, and left ptosis. We classified her physical status as American Society of Anesthesiologists physical status III. She was admitted to the hospital a month prior to the operation to receive DFPP four times.
When she arrived at the operating room, she was hemodynamically stable and treated with dantrolene (50 mg), carbamazepine (200 mg), gabapentin (300 mg), and nicorandil (5 mg) as premedications. We performed preoperative monitoring, including standard monitoring, neuromuscular monitor (TOF-Watch®), and electroencephalogram using the Bispectral Index monitor.
General anesthesia was induced with 100 μg fentanyl, target-controlled infusion of 2.5 μg/mL propofol, and 50 mg lidocaine after pre-oxygenation with 100% oxygen. After induction, we confirmed that T4/T1 was 100% using the TOF; we then administered 20 mg rocuronium. The time to get a TOF ratio of 0% was 4 min, and endotracheal intubation was carefully performed without complications. Anesthesia was maintained with oxygen, air, propofol (TCI concentration, 2.3 μg/mL), remifentanil (0.15–0.3 μg/kg/min), and intermittent intravenous administration of fentanyl. We also used the minimum amount of muscle relaxant. Rocuronium (10 mg) was administered when the TOF ratio increased to 50%. The total dose of rocuronium was 90 mg. Surgery proceeded uneventfully. For postoperative analgesia, infiltration anesthesia was performed at the rectus sheath with levobupivacaine (0.25%, 20 mL) and an intravenous fentanyl pump (0.5 μg/kg/h) started 1 h before the end of surgery. At the end of the procedure, we confirmed that the TOF ratio had recovered to > 90%. The residual neuromuscular block was antagonized using sugammadex (2 mg/kg), and propofol and remifentanil were discontinued. Shortly afterward, the TOF ratio recovered completely and spontaneous respiration resumed. The patient followed our commands and showed spontaneous breathing, and tracheal extubation was performed. The total operative time was 225 min and the anesthetic duration was 355 min. Subsequent to confirming stable vital signs and neuromuscular symptoms after extubation, the patient was moved to an intensive care unit.
After transfer, she complained about abdominal pain, so the infusion rate of fentanyl was increased to 1.0 μg/kg/h, and dexmedetomidine (0.4 μg/kg/h) was added to control pain. She was discharged to the general ward the day after surgery; however, the abdominal pain worsened because myokymia frequently occurs in the rectus abdominis muscle. The patient complained about severe pain (numerical rating scale, 8/10), so the infusion rate of fentanyl was increased to 2.0 μg/kg/h, which was effective for controlling pain. Afterward, she often experienced vomiting 8 days after surgery. The clinical course seemed to originate from postoperative pyloric stenosis. She received gastric bougie procedures two times after the surgery. The symptoms of Isaacs’ syndrome were stable after the postoperative pain was relieved, and she was discharged on postoperative day 66.