Various injury severity scores exist for trauma; it is known that they do not correlate accurately to military injuries. A promising anatomical scoring system for blast pelvic and perineal injury led to the development of an improved scoring system using machine-learning techniques. An unbiased genetic algorithm selected optimal anatomical and physiological parameters from 118 military cases. A Naïve Bayesian (NB) model was built using the proposed parameters to predict the probability of survival. Ten-fold cross validation was employed to evaluate its performance. Our model significantly out-performed Injury Severity Score (ISS), Trauma ISS, New ISS and the Revised Trauma Score in virtually all areas; Positive Predictive Value 0.8941, Specificity 0.9027, Accuracy 0.9056 and Area Under Curve 0.9059. A two-sample t-test showed that the predictive performance of the proposed scoring system was significantly better than the other systems (p<0.001). With limited resources and the simplest of Bayesian methodologies we have demonstrated that the Naïve Bayesian model performed significantly better in virtually all areas assessed by current scoring systems used for trauma. This is encouraging and highlights that more can be done to improve trauma systems not only for the military, but also in civilian trauma.

This study defines the patterns of perineal injury due to blast currently seen on operations. It refines our team-based surgical strategies of surgical resuscitation provides an evidence base for a perineal debridement - colonic diversion didactic on the Military Operational Surgical Training (MOST) course.

The Joint Theatre Trauma Registry (JTTR) held at RCDM was examined from 1 January 2003 to 31 December 2010. Data abstracted included patient demographics, mechanism of injury, injury severity score (ISS), treatment, management, length of stay (LOS) and outcomes.

Of 4807 military trauma patients, 118 (2.5%) had a recorded perineal injury, 56 died (48% all IED). Pelvic fractures were identified in 63 (53%) of which 17 (27%) survived. Mortality rates were significantly different between the combined perineal & pelvic fracture group compared to pelvic fracture & perineal injuries alone (41% & 18% respectively, p = 0.0001). Mean ISS for all patients was 41.03. Those with a pelvic fracture had a significantly higher ISS than those with perineal injuries alone (29.53 vs. 51.06, p = 0.0001). Recorded early antibiotic use was significantly more frequent in survivors (p = 0.0119). A literature review demonstrated the benefits of early feeding, emergent diversion, antibiotics, daily washouts and radical early debridement.

Combined perineal injuries & pelvic fractures have the highest rate of mortality. Early aggressive management is essential to survival in this cohort. Our recommendations are immediate faecal diversion, aggressive initial debridement & early enteral feeding (in the deployed ITU after first surgery). These findings will enable the rapid provision of an evidence based training schedule to be incorporated into our pre-deployment surgical training program (MOST) to improve surgical team preparation and patient outcomes.