INTRAVENOUS PHOSPHATE REPLETION REGIMEN FOR CRITICALLY ILL PATIENTS WITH MODERATE HYPOPHOSPHATEMIA

Objective: To document the safety and efficacy of an intravenous phosp hate repletion regimen that is more aggressive than recommended by pre viously published guidelines, in intensive care unit (ICU) patients wi th hypophosphatemia. Design: Prospective evaluation of rapid, intraven ous phosphate repletion in eligible patients. Setting: Surgical ICU in a teaching hospital. Patients: Patients with a serum phosphorus conce ntration of <2 mg/dL (<0.65 mmol/L) while in the ICU. Interventions: E nrolled patients received 15 mmol of sodium phosphate in 100 mt of 0.9 % sodium chloride, infused intravenously over a period of 2 hrs. Patie nts with a serum potassium concentration of <3.5 mmol/L received potas sium phosphate, if no other potassium supplementation was ordered. The same dose could be repeated to a maximum of 45 mmol in a 24-hr period if either the 6-hr or follow-up (18- to 24-hr) postinfusion serum pho sphorus remained <2 mg/dL (<0.65 mmol). Serum electrolytes, renal func tion, vital signs, and reflexes were closely monitored. Measurements a nd Main Results: Eleven patients enrolled had baseline serum phosphoru s values of 1.6 to 1.9 mg/dL (0.51 to 0.61 mmol/L). The serum phosphor us value immediately postinfusion was 2.3 to 5.3 mg/dL (0.74 to 1.7 mm ol/L). Only one patient had a 6-hr postinfusion serum phosphorus of <2 mg/dL (<0.65 mmol/L), requiring two additional doses. Two other patie nts each required a second dose. Serum phosphorus was corrected in oth er patients with a single dose. No significant changes were noted in s erum calcium, magnesium, or potassium concentrations, urine output, vi tal signs, or reflexes throughout the repletion period. Conclusions: A ll patients were successfully repleted using the described protocol wi thout any significant adverse effects. This repletion regimen may have widespread applicability in the ICU setting.