title: Blunt renal trauma and the predictors of failure of non-operative management.
abstract: OBJECTIVE
  While non-operative management of renal trauma in selected patients is now an accepted management option, predictors of failure of this treatment strategy are still unclear.
  
  
  METHODS
  Five-year retrospective study of all patients with blunt renal injuries managed non-operatively at a Level I Trauma Center. Abstracted data included patient demographics, initial vital signs, base deficit, associated injuries, use of blood transfusion, management, and outcomes. Patients with successful non-operative management (S-NOM) and failure of non-operative management (F-NOM) were compared with two-tailed Student's t test, Fisher's exact test, or chi-square analysis as appropriate.
  
  
  RESULTS
  Over five years, 271 patients out of 12,252 trauma cases (2.2%) had blunt renal injury; 239 (88%) were initially managed non-operatively, and ten (4.1%) of these patients later requiring operation or intervention. No differences in age, sex, initial vitals, or GCS were found between S-NOM and F-NOM. The F-NOM patients were more seriously injured than the S-NOM patients (ISS 31 vs. 21, p < 0.001); had worse acidosis (ABG base deficit of-9.1 vs. -4.5, p < 0.001); required more blood products (12 units PRBC vs. 2.6 units PRBC, p < 0.001); and had significantly longer hospital lengths of stay (37 days vs. 12 days, p < 0.001). Angiography was used more frequently in the F-NOM patients (40% vs. 8.7%, p < 0.02). In the F-NOM only 3 (30%) required direct kidney intervention: 1 nephrectomy, 1 open urinoma drainage and 1 open nephrostomy tube placement. All of these patients had grade V renal injuries. The rest of the F-NOM patients had operative interventions not directly related to their renal injuries: 1 splenectomy and 6 missed bowel injuries.
  
  
  CONCLUSIONS
  Non-operative management of blunt renal injuries is successful in most cases. Patients with a high base deficit, ongoing transfusion requirements, and greater Injury Severity Scores have a higher likelihood of requiring operation, but these procedures most often are to address non-renal abdominal injuries. High-grade blunt renal injuries that are hemodynamically stable can be treated expectantly on an individual basis with close follow-up. Any patient with hemodynamic instability, renal pedicle injury, renal artery thrombosis, or urinary extravasation will likely require operative intervention.
authors.affiliation: Division of Trauma & Surgical Critical Care, University of Mississippi Medical Center, 2500 N State Street, Jackson, MS 39216, USA. jdsimmons@surgery.umsmed.edu
authors.forename: Jon D
authors.initials: JD
authors.lastname: Simmons
authors.forename: A Neal
authors.initials: AN
authors.lastname: Haraway
authors.forename: Robert E
authors.initials: RE
authors.lastname: Schmieg
authors.forename: Juan D
authors.initials: JD
authors.lastname: Duchesne
mesh_terms: D006801:Humans; D015601:Injury Severity Score; D007668:Kidney / Q000293:injuries*; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012959:Socioeconomic Factors; D014193:Trauma Centers; D014949:Wounds, Nonpenetrating / Q000503:physiopathology / Q000628:therapy*