Severe hypocalcemia and hyperphosphatemia caused by oral sodium phosphate fleet solution in a hemodialysis patient after parathyroidectomy

Abstract

Background: Oral sodium phosphate solution (OSPS) is a commonly used agent for bowel preparation before colonoscopy or surgical procedures. It is favored by its good patient tolerability and high bowel cleansing effect. However, OSPS may cause renal failure and its use is not uncommonly associated with electrolyte disturbances that may lead to cardiac arrhythmia and even death. Case Report: A 69-year-old man on hemodialysis underwent a surveillance colonoscopy for colorectal adenoma. Two months ago, he received total parathyroidectomy. As bowel preparation, he received 45 mL of oral sodium phosphate fleet solution a day before the colonoscopy. The adjusted calcium level and phosphate level before bowel preparation were 2.39 and 0.80 mmol/L, respectively (Figure 1). Colonoscopy revealed polyps and they were snared for biopsy. Two hours after the procedure, he complained of generalized weakness, muscle cramps, and twitching. Severe hypocalcemia of 0.94 mmol/L and hyperphosphatemia of 4.73 mmol/L were detected. He received intravenous calcium replacement and urgent hemodialysis. The electrolyte disturbances normalized subsequently and the patient made an uneventful recovery. Conclusions: Previously, OSPS has been reported to cause hypocalcemia as low as 1.21 mmol/L and hyperphosphatemia as a result of the phosphate content of OSPS. This is the lowest calcium level ever documented, and may be related to his previous total parathyroidectomy. We recommend that OSPS should not be used in renal failure patients and should be replaced by safer alternatives such as polyethylene glycol.