Salicylate Toxicity from Ingestion and Continued Dermal Absorption

The California Journal of Emergency Medicine VIII:1 February 2007 Page 23 Case Report Salicylate Toxicity from Ingestion and Continued Dermal Absorption Rachel L. Chin, MD*, Kent R. Olson, MD**, Delia Dempsey, MS, MD*** *Professor of Clinical Medicine, University of California, San Francisco School of Medicine. San Francisco General Hospital, SF, CA **Medical Director, San Francisco Bay Area Regional Poison Control Center, Associate Clinical Professor of Medicine, University of California, San Francisco, SF, CA ***Assistant Adjunct Professor of Pediatrics and Clinical Pharmacology and Toxicology, California Poison Control System, University of California, San Francisco, SF, CA. Correspondence: Rachel L. Chin MD, Department of Emergency Services, San Francisco General Hospital, San Francisco, CA 94110. rchin@sfghed.ucsf.edu Key Words: percutaneous salicylism, renal dialysis, renal failure, salicylate toxicity INTRODUCTION Salicylates are commonly used for their analgesic, antipyretic, anti-inflammatory and antiplatelet properties. Acute salicylate poisoning is a common overdose resulting in high morbidity and mortality. Insidious cases of salicylate intoxication may also occur, caused by either ingestion or topical absorption, most often in elderly patients with associated medical illnesses. We present a fatal case of acute methyl salicylate toxicity from both ingestion and dermal absorption of oil of wintergreen. This case highlights the point that topical absorption of salicylates, particularly in patients with renal failure, can result in severe intoxication. CASE REPORT An 80-year-old man with end-stage renal disease had oil of wintergreen (containing 35% mg/ml methyl salicylate) rubbed regularly on his lower extremities by a live-in attendant. He applied it to the patient’s legs and left the bottle on the nightstand. The patient mistakenly drank a mouthful when he mistook it for a beverage. The attendant said the patient vomited the oil of wintergreen immediately. Two hours later, the man was found seizing. When paramedics arrived the patient remained unresponsive and apneic with a wide QRS complex on the cardiac monitor. The patient’s medical history included diabetes mellitus, diabetic nephropathy requiring hemodialysis three times per week, and severe coronary artery disease. He had a coronary artery bypass graft and a pacemaker. He was dialyzed one day prior to presentation and had otherwise been in his usual health. Upon presentation to the Emergency Department, the patient was unresponsive and apneic. He had a blood pressure of 146/66 mm Hg, a palpable pulse at 55 beats per minute, and depressed respirations requiring assisted ventilation by bag valve mask. External cardiac monitoring revealed a wide QRS rhythm. The patient smelled of oil of wintergreen. Head and neck exam was normal. His lungs were clear and his heart without murmurs. Abdominal and rectal exam were unremarkable. His lower extremities demonstrated acrocyanosis and were cool to touch. Diminished pulses were noted, and no reflexes were elicited. His bilateral forearm shunts appeared intact. Resuscitation in the Emergency Department consisted of oral endotracheal intubation, followed by gastric lavage and administration of activated charcoal. The patient initial arterial blood gas on FiO2 100% was pH 6.95, pCO2 34 mmHg, pO2 400 mmHg, and the patient was given intravenous sodium bicarbonate. The serum potassium level was 8.6 mmol/L and the patient was given 1 gm of calcium gluconate intravenously. His electrocardiogram showed a wide complex QRS with pacemaker depolarizations at 80 spikes per minute. The patient also developed several runs of ventricular tachycardia, which responded to 1mg/kg (75 mg) lidocaine. The patient’s chest radiograph demonstrated cardiomegaly with no evidence of pulmonary edema. The endotracheal tube was in good position above the carina. Serum chemistries revealed the following values: sodium 134 mmol/L, potassium 8.6 mmol/L, chloride 97 mmol/L, bicarbonate 6 mmol/L, urea nitrogen 62 mmol/ L, creatinine 6.9 mmol/L. He had an anion gap of 31 (normal < 14). His salicylate level was 74.8 mg/dl. Immediate hemodialysis was initiated upon transfer to the Intensive Care Unit. Repeat arterial blood gas after 1 1/2 hrs of dialysis demonstrated a pH of 7.37, PaCO2 34 mmHg, and PaO2