Case Report
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World J Gastroenterol. Sep 14, 2014; 20(34): 12350-12354
Published online Sep 14, 2014. doi: 10.3748/wjg.v20.i34.12350
Case of inappropriate ADH syndrome: Hyponatremia due to polyethylene glycol bowel preparation
Sun-Hye Ko, Chul-Hyun Lim, Jae-Young Kim, Seung Hun Kang, Myong Ki Baeg, Hyun Jin Oh
Sun-Hye Ko, Hyun Jin Oh, Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University, Seoul 137-701, South Korea
Chul-Hyun Lim, Jae-Young Kim, Seung Hun Kang, Myong Ki Baeg, Division of Gastroenterology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul 137-701, South Korea
Author contributions: Kim JY, Kang SH, Baeg MK and Oh HJ were the attending physicians; Ko SH oversaw the endocrinologic evaluation; Ko SH, Lim CH and Baeg MK wrote the paper.
Correspondence to: Chul-Hyun Lim, MD, PhD, Assistant Professor, Division of Gastroenterology, Department of Internal medicine, College of Medicine, The Catholic University of Korea, # 505, Banpo-Dong, Seocho-Gu, Seoul 137-701, South Korea. diluck@catholic.ac.kr
Telephone: +82-2-22582045 Fax: +82-2-22582055
Received: January 14, 2014
Revised: March 23, 2014
Accepted: May 23, 2014
Published online: September 14, 2014
Processing time: 246 Days and 20.8 Hours
Abstract

Colonoscopic screening has been reported to reduce deaths from colorectal cancer. Adequate bowel preparation is essential for this and safety is an important issue in choosing the methods. Polyethylene glycol (PEG) is regarded as a safe method for cleansing, especially compared with oral sodium phosphate. Here, we present a case of hyponatremia caused by the syndrome of inappropriate antidiuretic hormone (ADH) syndrome after PEG precolonoscopic cleansing resulting in generalized tonic-clonic seizures. A 62-year-old women had ingested PEG for precolonoscopic bowel cleansing. While waiting for the colonoscopy, she developed a stuporous mentality and generalized tonic-clonic seizures, which did not correlate with brain magnetic resonance imaging. Her serum sodium level was 113 mEq per liter and laboratory analyses were consistent with inappropriate ADH syndrome. Her thyroid and adrenal functions were normal. There were no malignancies, infections, respiratory disorders or central nervous disorders and she had no history of taking either diuretics or other medications, which might have caused inappropriate ADH syndrome. She was treated with 3% hypertonic saline and showed a complete neurological recovery as her sodium levels recovered. Follow-up visits showed the patient to have a normal sodium level without neurologic deficits. This case shows that inappropriate ADH syndrome can be caused by PEG preparation, which implies that physicians have to be aware of the possible side effects of this colonic cleansing approach and mindful of the possible ensuing symptoms.

Keywords: Inappropriate antidiuretic hormone syndrome; Colonoscopy; Polyethyelene glycol; Hyponatremia; Seizure

Core tip: We report a case of hyponatremia resulting in seizures after precolonoscopic polyethylene glycol cleansing due to inappropriate antidiuretic hormone (ADH) syndrome. Though inappropriate ADH syndrome has been suspected in the few reports of hyponatremia after polyethylene glycol (PEG) preparation, this is the first case to have confirmed an association between the two. Guidelines recommend that colonoscopic screening be done in patients from age 50 with PEG the first choice for bowel cleansing. As colonoscopic screening increases, hyponatremia due to inappropriate ADH syndrome will most likely increase as well. As we show, PEG induced inappropriate ADH syndrome may have severe side effects. However, if recognized and treated, it should have no long-lasting sequalae.