Predictive factors for nephrectomy in renal trauma; assessment of a 6-point score

To evaluate predictive and associated risk factors for nephrectomy in renal trauma and assess a 6-point score for surgical decision-making.

This multicenter, retrospective, and observational study assessed 247 subjects with blunt or penetrating kidney trauma. Kidney injuries were classified according to the American Association for the Surgery of Trauma (AAST) Injury Scoring Scale. Renal trauma was classified as "low-grade" (Grades I-III), Grade IV, and Grade V. Subjects were compared according to conservative treatment (CTrt.) or nephrectomy. Predictive factors were evaluated with a multiple regression model. A 6-point score was evaluated with a ROC analysis.

Patients requiring nephrectomy had a lower mean arterial pressure MAP compared to CTrt, 64.71 mmHg (SD ± 10.26) and 73.86 (SD ± 12.42), respectively (p =  < 0.001). A response to IV solutions was observed in 90.2% of patients undergoing CTrt. (p =  < 0.001, OR = 0.211, 95%CI = 0.101-0.442). Blood lactate ≥ 4 mmol/L was associated with nephrectomy (p =  < 0.001). A hematoma ≥ 25 mm was observed in 41.5% of patients undergoing nephrectomy compared to 20.1% of CTrt. (p = 0.004, OR = 9.29, 95% CI = 1.37-5.58). A logistic regression analysis (p =  < 0.001) showed that blood lactate ≥ 4 mmol/L (p = 0.043), an inadequate response to IV solutions (p = 0.041) and renal trauma grade IV-V (p =  < 0.001), predicted nephrectomy. A 6-point score with a cut-off value ≥ 3 points showed 83% sensitivity and 87% specificity for nephrectomy with an AUC of 89.9% (p =  < 0.001).

An inadequate response to IV solutions, a lactate level ≥ 4 mmol/L, and grade IV-V renal trauma predict nephrectomy. A score ≥ 3 points showed a good performance in this population.