Hypophosphatemia on the intensive care unit: individualized phosphate replacement based on serum levels and distribution volume.

BACKGROUND: Hypophosphatemia occurs in about 25% of patients admitted to the intensive care unit. To date, a safe and validated phosphate replacement protocol is not available. OBJECTIVE: To evaluate an individualized phosphate replacement regimen. DESIGN: Fifty consecutive intensive care unit patients with a serum phosphate level<0.6 mmol/L were treated with sodium-potassium-phosphate intravenously at a rate of 10 mmol/h. The dose was calculated according to the following equation: Phosphate dose in mmol=0.5xBody Weightx(1.25-[serum Phosphate]). Phosphate levels were measured immediately upon completion of the infusion, as well as the next morning at 8 am. RESULTS: Post-infusion phosphate levels were >0.6 mmol/L in 98% of the patients. Hyperphosphatemia, hyperkalemia or a decrease in serum calcium were not observed. In about a third of patients serum phosphate decreased to