Pamidronate Dose Response for Hypercalcemia in Burn-Injured Patients

BACKGROUND: Hypercalcemia after a burn injury is attributed to bone resorption secondary to muscle inactivity and prolonged immobilization. Evidence to guide treatment is extremely limited. The purpose of this study was to assess the effect of pamidronate on hypercalcemia in burn-injured patients. METHODS: This retrospective, observational study was conducted at a regional burn center. Adult patients admitted to the burn surgery service who received IV pamidronate for hypercalcemia during hospitalization were included. The primary outcome was the change in ionized calcium (iCa) at day 7 and 14 after pamidronate treatment. Secondary outcomes included hypocalcemia and the requirement for calcium replacement. Descriptive statistics were used to evaluate the outcomes. Mixed-effects regression analyses were performed to estimate the direction and magnitude of clinical factors on change in iCa. RESULTS: Twenty-seven patients and thirty-seven courses of therapy were included for analysis. The mean age was 44.4 ± 16.0 years; 85% were male, and the mean total body surface area (TBSA) burned was 60.2 ± 22.2%. The majority of IV pamidronate doses were 30 mg (96.2%). The mean peak iCa was 1.45 ± 0.11 mmol/L. The absolute decrease in iCa was -0.26 ± 0.12 mmol/L (-17.1± 7.3%) and -0.26 ± 0.13 mmol/L (-17.0 ± 7.5%) at day 7 and day 14, respectively. Hypocalcemia occurred after 5 pamidronate administrations (13.5%). CONCLUSION: The use of IV pamidronate for the management of hypercalcemia post-burn injury appeared effective in decreasing ionized calcium levels. Future studies are needed to further evaluate the clinical implications of these findings.