Prevention of hypophosphatemia after burn injury with a protocol for continuous, preemptive repletion

Severe burn injury has been shown to result in hypophosphatemia. Hypophosphatemia can cause cardiac, hematologic, immunologic, and neuromuscular dysfunction. This study compares serum phosphate levels and outcomes in patients who were administered a continuous, preemptive phosphate repletion protocol vs those who only received phosphate supplementation after they developed hypophosphatemia. Records of patients with greater than 19% TBSA burn admitted to the intensive care unit from 2006 to 2010 were reviewed. Patients were divided into two groups: historical controls who received responsive repletion when serum phosphate levels were less than 2.5 mg/dl (2006-2008) and the experimental group that received 30 mmol intravenous every 6 hours starting at approximately 24 hours after injury as long as serum phosphate levels were less than 4 mg/dl (2008-2010). Patients with chronic kidney disease or acute kidney injury were excluded. Data collected included age, weight, burn size, age, all serum phosphate levels, and total amount of phosphate administered. Differences in groups were compared with Mann-Whitney U test and Fisher's exact test. A total of 30 patients were included in the study, 20 in the responsive repletion group and 10 in the continuous repletion group. No significant difference was detected in age, sex, burn size, or full thickness burn size between groups. The continuous group had a statistically lower percentage of hypophosphatemic lab values compared with the responsive group, 13 ± 14% vs 45 ± 21% (P < .0001). No difference was found in percent of observations reflecting hyperphosphatemia (median of 2% in each group, P = .7). Four patients in the continuous group suffered cardiac and/or infectious complications compared with 16 in the responsive group (P = .04). Continuous, pre-emptive repletion of phosphate prevents hypophosphatemia after severe burn injury when compared with responsive repletion in historical controls. The protocol resulted in less hypophosphatemia without increasing the risk of hyperphosphatemia. This study also suggests that continuous repletion may result in fewer complications, but this needs to be confirmed in larger, prospective studies.