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103 SEVERE HYPOKALEMIA AFTER ORAL PHOSPHATE COLONIC PREPARATION IN A PATIENT WITH RESISTANT HYPERTENSION: A CAUTIONARY TALE RF Lee, NB Hershfield Oral sodium phosphate solutions are commonly used as bowel cleansing agents before colonoscopic exams. Generally, they have been found to be cheaper, more effective and better tolerated than other colorectal cleansing regimens. However, serious electrolyte disturbances associated with their use have been described. Health Canada, released a safety alert in 2002 warning that electrolyte shifts could occur in cases where greater than 45 cc of phosphate solution was consumed over a 24 h period or in patients with comorbidities including CHF, renal dysfunction and pre-existing electrolyte disturbances.
Division of Gastroenterology, University of Calgary, Calgary, Alberta
Here, we report a 57-year-old female who developed severe, symptomatic hypokalemia (K+<1.5 mmol/L) after undergoing colonic preparation with oral phosphate solutions. Her past history was unremarkable except for minor electrolyte disturbances and a six-year period of resistant hypertension. She was admitted to hospital, where she was treated and subsequently diagnosed with primary aldosteronism (PAL), a condition where the body's aldosterone production exceeds it's natural requirements.
Although once considered rare, recent reviews have suggested that up to 32% of patients with resistant hypertension may be afflicted with PAL. These patients may be more susceptible to the development of hypokalemias, which in turn may be exacerbated by oral phosphate colonic preparations. Measurement and correction of their baseline electrolytes, before and after colonic preparation, should be strongly considered.