Hyponatremic encephalopathy due to polyethylene glycol-based bowel preparation for colonoscopy: A case report

Adequate bowel preparation is critical for colonoscopy screening. At present, the most widely used intestinal cleaner recommended at home and abroad is Polyethylene glycol (PEG). Intestinal cleansers can cause electrolyte disturbances and hyponatremia. However, hyponatremic encephalopathy due to hyponatremia induced by PEG solution, although rare, can lead to serious irreversible sequelae and even death.

In this report, we discuss a case of neurological dysfunction due to hyponatremia, also known as hyponatremic encephalopathy, observed in a 63-year-old woman who underwent PEG-based bowel preparation for colonoscopy. She was eventually transferred to our intensive care unit for treatment due to her Glasgow Coma Scale score of 9/15 (Eye opening 2; Verbal response 1; Motor response 6) and abnormal laboratory tests.

Physicians should be thoroughly familiarized with the patient's history before prescribing PEG for bowel preparation, and timely identification of patients with hyponatremic encephalopathy is essential as delayed treatment is associated with poor neurological outcomes. An intravenous infusion of 3% sodium chloride is recommended at the onset of early symptoms. The goal of treatment is to adequately treat cerebral edema while avoiding serum sodium correction beyond 15 to 20 mEq/L within 48 h of treatment to prevent osmotic demyelination syndrome.