Can we predict failure of non-operative management of blunt splenic injuries on arrival? A comparison of predictors of immediate splenectomy versus splenectomy secondary to non-operative management failure

Aims and Background The spleen is the most frequently injured solid organ after blunt trauma and a trial non-operative management (NOM) has become the standard of care in hemodynamically stable patients. It remains uncertain which patients are at increased risk of non-operative management failure (NOMF) at initial presentation. We explored whether clinical variables including the contemporary rotational thromboelastography (ROTEM) parameters are predictive of NOMF. Materials and Methods Data for all adult patients with a blunt splenic injury was collected retrospectively at St. Michael's Hospital in Toronto, Canada between 2005 and 2021. Those who underwent a splenectomy within 4 hours of presentation were classified as direct operative management (OM), while those who had a splenectomy after 4 hours of observation were classified as NOM failure. Vital signs on arrival and injury characteristics were collected. Logistic regression was used to identify predictors of OM and predictors of NOM failure. Results Seven hundred and seventeen patients were identified with splenic injury during our study period. The median Injury Severity Score (ISS) was 27 (IQR 17-36), and 19% (n = 134) had a shock index of 1 or more. One hundred and eleven (15.5%) underwent direct operative management. A shock index above 1 and increasing spleen injury severity were strong predictors of patients undergoing direct OM. The remaining 606 patients underwent NOM of which 59% (n = 357) of these were admitted to the ICU. NOM failure occurred in 7.4% (n = 45) with a median time to NOM failure of 23 (IQR 8-72) hours. The American Association for the Surgery of Trauma (AAST) spleen injury severity was the major factor significantly associated with NOM failure. Conclusions The only major predictor of NOMF available on arrival is increased spleen injury grade. Other clinical variables such as age, vital signs on arrival, and bloodwork were not significantly able to predict NOM failure. Additional investigation is required to identify novel predictors of NOM failure.