Microalbuminuria: A marker of systemic endothelial dysfunction during burn excision

IntroductionSystemic endothelial dysfunction characterises both burn injury and surgery and can be monitored by serial immunoassay of urine albumin (microalbuminuria). The aim of this study was to assess microalbuminuria before and during burn excision and identify factors that may influence it.MethodsSerial half-hourly urine albumin/creatinine ratio (ACR, normal <2.3 mg/mmol) was measured in 25 adult patients during 44 burn-excision procedures, at a median of 5 days post-injury. Median total body surface area (TBSA) excised was 12%.ResultsPre-operative median ACR was normal rising to 3.25 mg/mmol at 1.5 h of surgery (p < 0.05). Per-operative ACR at 0.5, 1, 2 and 2.5 h were all associated with % TBSA burn excised (p < 0.04). Median intraoperative ACR at 1 h was 2.3 mg/mmol for surgery within 48 h post-injury, 1.6 for surgery at 2–7 days and 25.5 during excisions later than 1 month after injury (p < 0.05). ACR at 1 h was associated with CRP at 48 h post-surgery (p = 0.04). Per-operative ACR was also significantly correlated with post-operative complications.ConclusionSystemic endothelial dysfunction of acute thermal injury assessed by microalbuminuria recurs with surgery, is minimal at 2–7 days post-burn and affected by % TBSA burn excised and post-operative complications.