Femoral nailing during serum bicarbonate-defined hypo-perfusion predicts pulmonary organ dysfunction in multi-system trauma patients

Abstract

Objective: To assess the value of venous serum bicarbonate as an endpoint of resuscitation and guide to timing of femoral nailing in multi-system trauma patients.

Design: Retrospective cohort study.

Setting: Academic Level 1 Trauma Centre.

Patients: Seventy-two consecutive adult multi-system trauma patients (Injury Severity Score≥15) with femoral shaft fracture (Orthopaedic Trauma Association Class 32-A to 32-C) treated with reamed medullary nail fixation.

Intervention: Femoral nailing in the setting of hypo-perfusion defined by venous serum bicarbonate (SB). Threshold values of SB were determined first by correlating SB and simultaneously drawn arterial base deficit (BD). Then, corresponding values of SB to previously defined thresholds of hypo-perfusion based on BD were identified using regression analysis.

Main outcome measurement: Pulmonary organ dysfunction (POD) component of the Denver Multiple Organ Failure scoring system.

Results: Simultaneous admission SB and BD values were correlated (r=-0.43, p=0.001). Adjusting for age, ISS and baseline POD, patients with SB<24.7 mequiv./L within 6 h of treatment had a 12-fold increase in POD (OR 12.2, 95% CI 1.5-98.6, p=0.019). This association was diminished, but still significant with hypo-perfusion present within 12 h prior to treatment (OR 5.6, 95% CI 1.0-29.1, p=0.042) and 24 h prior to treatment (OR 5.9, 95% CI 1.1-30.7, p=0.037).

Conclusions: Medullary fixation of femoral shaft fracture in the setting of serum bicarbonate-defined hypo-perfusion is associated with increased morbidity. Appropriate damage-control measures and aggressive resuscitation prior to definitive fracture care are advised and physiologic markers such as serum bicarbonate should guide clinical decision making rather than temporal distinctions.