LAUSR

pedic and other surgeries. While often thought to be innocuous, the use of H2O2 has led to severe and fatal consequences [1]. Published literature is unclear about the volume of H2O2 that is safe for use. We present a case in which excessive volume of H2O2 was used for deep bilateral leg wound debridement leading to sudden cardiovascular collapse and cardiac arrest. We explored the recommended volume of H2O2 safe for use and lay down recommendations to avoid future mishaps. Written consent has been obtained from the patient for publication of this report. We describe the management of a 37-year-old man who was allergic to naproxen and admitted for left knee septic arthritis and right calf cellulitis. He suffered from hypertension, uncontrolled type II diabetes mellitus, bilateral peroneal vein thrombosis (on treatment with enoxaparin) and acute kidney injury. He underwent left knee open arthrotomy, followed by second-look washout 4 days later, both under general anesthesia, uneventfully. Bilateral lower leg magnetic resonance imaging showed multiple septic emboli with deep pockets of pus in his right posterior calf and left gastrocnemius muscles. He was scheduled for his 3 surgery for exploration and drainage of abscesses in both lower limbs. A single-shot left femoral nerve block (15 ml of 0.5% ropivacaine) and a right popliteal block (20 ml of 0.5% ropivacaine) were performed before induction of general anesthesia. He received fentanyl (50 μg), lignocaine (10 mg), propofol (150 mg), and atracurium (30 mg), and airway was secured with an endotracheal tube. He had also received these drugs in the previous two surgeries. He was placed in the right lateral decubitus position for surgery. Anesthesia was maintained with sevoflurane and intermittent atracurium and morphine. End-tidal carbon dioxide (EtCO2) was maintained at 36– 42 mmHg. He remained hemodynamically stable throughout surgery. Towards the final stages of surgery, wounds on both lower limbs were irrigated with mixed H2O2 (3% w/w, PharmaKoe, ICM Pharma, Singapore) and normal saline. A total of 800 ml of 3% H2O2 was used considering extensive bilateral deep wounds. While wounds were irrigated, the patient showed signs of breathing, and atracurium (10 mg) was administered. A few minutes later, a sudden drop in EtCO2 (7 mmHg) was noted. Breathing circuits and carbon dioxide sampling line were checked. The patient was hand ventilated with 100% oxygen. Saturation remained > 97%; however, blood pressure dropped to 81/22 mmHg, and bradycardia developed (37 beats/min). Two separate doses of atropine 0.6 mg were administered without improvement. The carotid pulse was absent. Pulseless electrical activity was declared, and the patient was turned supine for external chest compressions. He received three boluses of 1 mg adrenaline before the return of spontaneous circulation. Received: July 9, 2020 Accepted: July 12, 2020