Decrease in Total Leukocyte Count is Associated with Acute Kidney Injury After Severe Burn

Leukocytosis is common after burn injury from profound systemic inflammatory response. Total leukocyte count (TLC) often decreases 72-96 h post-injury. The incidence of early (<72 h) leukopenia has not been previously described; this analysis sought to determine if early and extreme decreases in TLC were associated with increased fluid requirements or resuscitation-related outcomes in patients after burn injury. The burn navigator (BN) database is composed of 300 patients with >20% TBSA and >40 kg that were resuscitated utilizing the BN clinical decision support system. Patients were split into 2 groups based on a decrease in TLC from admission of greater than versus less than 15 000 cells per microliter. Demographics, resuscitation volumes, resuscitation-related complications, and 7-day survival were collected. Of the 295 patients in the analysis, patients with greater than the 15-point decrease in WBC from admission had more full-thickness burns (14.2 [2, 36]) and greater TBSA (41 [30.2, 57.4]) than those with less than a 15-point decrease (7.7 [0.3, 14.8], P < .001), 27.5 [23, 36], P < .001. Patients with greater than a 15-point WBC drop had a significantly higher incidence of admission myoglobinuria and AKI in the first 48 h even after adjusting for TBSA. Survival at 7 days did not differ (66.7% vs. 83.7%, P > .05) when adjusting for TBSA. A decrease in WBC of at least 15 points after admission was associated with early AKI and a significantly higher incidence of admission myoglobinuria. Future studies need to investigate the mechanism behind this association and possible early interventions.