Sodium phosphate enemas do not worsen renal function among hospitalized patients with mild to moderate renal failure: A matched, case-control study

Background: Sodium phosphate enemas (SPEs) are widely used among hospitalized patients despite their potential to worsen renal failure. Aim: We decided to assess the extent to which this side effect is clinically relevant. Design: We conducted a matched case-control, retrospective study in a cohort of hospitalized patients. Methods: Patients treated and untreated with SPEs were matched for age, gender, baseline creatinine, usage of certain medications and several background diagnoses. Three groups of matched patients (whole study cohort, patients with baseline creatinine > 1.5 mg/dl and those with baseline creatinine > 2 mg/dl) were compared with regards to their creatinine and blood electrolyte concentrations during 3 consecutive hospitalization days after SPE application. Results: Four hundred and twelve patients were included in this study of which 206 were treated by single SPEs. Exact matching was done for the whole study cohort, for 108 patients with baseline creatinine > 1.5mg/dl and for 58 patients with baseline creatinine > 2mg/dl. During 3 consecutive days after SPEs, the maximal blood concentrations of creatinine, phosphor and potassium did not differ significantly between treated patients andmatched controls, in all three patients' groups. Conclusion: Application of SPEs neither seem to worsen mild to moderate renal failure, nor are associated with hyperphosphatemia or hyperkalemia in patients hospitalized in internal medicine departments.