Blunt splenic injury and severe brain injury: a decision analysis and implications for care

Abstract

Background: The initial nonoperative management (NOM) of blunt splenic injuries in hemodynamically stable patients is common. In soldiers who experience blunt splenic injuries with concomitant severe brain injury while on deployment, however, NOM may put the injured soldier at risk for secondary brain injury from prolonged hypotension.

Methods: We conducted a decision analysis using a Markov process to evaluate 2 strategies for managing hemodynamically stable patients with blunt splenic injuries and severe brain injury--immediate splenectomy and NOM--in the setting of a field hospital with surgical capability but no angiography capabilities. We considered the base case of a 40-year-old man with a life expectancy of 78 years who experienced blunt trauma resulting in a severe traumatic brain injury and an isolated splenic injury with an estimated failure rate of NOM of 19.6%. The primary outcome measured was life expectancy. We assumed that failure of NOM would occur in the setting of a prolonged casualty evacuation, where surgical capability was not present.

Results: Immediate splenectomy was the slightly more effective strategy, resulting in a very modest increase in overall survival compared with NOM. Immediate splenectomy yielded a survival benefit of only 0.4 years over NOM.

Conclusion: In terms of overall survival, we would not recommend splenectomy unless the estimated failure rate of NOM exceeded 20%, which corresponds to an American Association for the Surgery of Trauma grade III splenic injury. For military patients for whom angiography may not be available at the field hospital and who require prolonged evacuation, immediate splenectomy should be considered for grade III-V injuries in the presence of severe brain injury.

Fig. 1

Decision model for management of blunt splenic injury. HV = hepatitis virus; TBI = traumatic brain injury.

Fig. 2

Transition states for (A) neurological morbidity, (B) transfusion diseases and (C) surgical complications. Cirr = cirrhosis.

Fig. 3

Survival curves for NOM versus immediate splenectomy.

Fig. 4

(A) One-way sensitivity analysis on probability of nonoperative management failure. (B) Two-way sensitivity analysis on hypotension from immediate splenectomy and on the mortality effect of hypotension on traumatic brain injury (TBI). (C) Two-way sensitivity analysis on probability of asplenic sepsis mortality and probability of fatal surgical complication. EV = expected value; P = probability.