Hyponatremic Coma after Bowel Preparation

Authors

• João Costelha Serviço de Medicina 2, Unidade Local de Saúde do Alto Minho, Viana do Castelo, Portugal 0000-0002-8081-6493
• Rita Dias Serviço de Medicina, Centro Hospitalar e Universitário do Porto, Porto, Portugal
• Carla Teixeira Unidade de Cuidados Intensivos Polivalente - Centro Hospitalar e Universitário do Porto, Porto, Portugal
• Irene Aragão Unidade de Cuidados Intensivos Polivalente - Centro Hospitalar e Universitário do Porto, Porto, Portugal

jpcostelha@gmail.com

Keywords

Abstract

Introduction: Colonoscopy is a useful tool in modern medicine and is increasingly employed for both diagnostic and treatment purposes. However, bowel preparations can cause electrolyte imbalance, with the risk apparently related to the type of bowel cleansing solution used, the age of the patient and their comorbidities. Symptomatic hyponatremia, especially coma, is a rare complication of oral bowel preparation for colonoscopy and is thought to result from excessive antidiuretic hormone secretion.
Case description: The authors report the case of a 48-year-old man who developed symptomatic hyponatremia (coma) after bowel preparation with sodium picosulfate/magnesium oxide/citric acid prior to a colonoscopy. The patient was admitted to an intensive care unit where other causes of coma were excluded. The symptoms of hyponatremia rapidly resolved after sodium level correction with intravenous administration of hypertonic saline.
Discussion: Hyponatremic coma is an uncommon but serious complication of colonoscopy bowel preparation. Patients at risk (>65 years old, chronic kidney disease, heart failure, history of electrolyte problems, or taking thiazide diuretics, angiotensin-converting-enzyme inhibitors or antidepressants) should be closely monitored during bowel cleansing and macrogol-based solutions should preferably be used.