American Association for the Surgery of Trauma organ injury scale for kidney injuries predicts nephrectomy, dialysis, and death in patients with blunt injury and nephrectomy for penetrating injuries

Background: Despite broad clinical use of the American Association of the Surgery of Trauma (AAST) injury scale for kidney, it has only been found to predict the need for renal surgery in single institution series. We sought to validate this scheme for morbidity and mortality in a national cohort of patients with renal injury. Methods: A retrospective cohort design was used to determine the association between increasing AAST scores and nephrectomy, dialysis, and mortality. The cohort included all patients with a renal injury in the National Trauma Data Bank (NTDB) from 1994 and 2003. Univariate and multivariate prediction models were used for analysis of data. Results: At the time of review, a total of 742,774 patient records were registered in the NTDB. Renal injury occurred in 8465 patients (1.2%). Increasing injury grade was associated with a greater nephrectomy (RR 12-127), dialysis (RR 1.3-4.7), and mortality (RR 1.3-1.9) rate for blunt kidney injury. For penetrating injury, nephrectomy was the only outcome that was associated with higher grades of renal injury with a RR of 7.7 to 31 for grades III to V injuries. Conclusion: The AAST injury scale for kidney predicts for morbidity in blunt and penetrating renal injury and for mortality in blunt injury. Thus, we continue to support its use as a clinical and research tool.