Severe Hyperphosphatemia and Hypocalcemia Following Sodium Phosphate Bowel Preparation: A Forgotten Menace

Abstract

A 74-year-old woman was scheduled for colonoscopy due to positive fecal occult blood. On admission, her serum levels of creatinine, adjusted calcium, and phosphate were 113 µmol/l, 2.24 mmol/l, and 1.17 mmol/l, respectively. She received 90 ml of oral Fleet Phospho-Soda (C.B. Fleet Co. Inc., Lynchburg, Virginia, USA), from which she developed profuse diarrhea. Six hours later, she complained of facial and limb numbness, and appeared drowsy. Her serum phosphate level had risen to 7.29 mmol/l and her calcium level had fallen to 1.82 mmol/l. During the next hour, muscle cramps and tetany developed over her lower limbs, trunk, and face, with a positive Chvostek’s sign. Intravenous administration of 9.0 mmol (40 ml 10 %) calcium gluconate was carried out over 6 h, resulting in resolution of her tetany, while the numbness persisted over the distal limbs. Further infusions totaling 24.75 mmol calcium gluconate were required over the next 17 h to restore the calcium level to 2.32 mmol/l (Figure [1]). Extensive investigations excluded a secondary cause of the electrolyte disturbance.