Injury severity in polytrauma patients is underestimated using the injury severity score: a single-center correlation study in air rescue.

purposePrehospital estimation of injury severity is essential for prehospital therapy, deciding on the destination hospital and the associated emergency room care. The aim of this study was to compare prehospital estimates of the abbreviated injury scale (AIS) and the Injury Severity Score (ISS) by emergency physicians with the values of AIS and ISS of injury severity determined at the conclusion of diagnostics.

methodsIn this prospective study, the ISS was determined prehospital by emergency physicians. The validated AIS and ISS were analyzed based on final diagnoses. A Bland-Altman plot was used in analyzing the agreement between two different assays as well as sensitivity and specificity were determined. Confidence intervals were calculated for a Wilson score. Significance level was set at p ≤ 0.05.

resultsThe prehospital ISS was estimated at 26.0 ± 13.0 and was 34.7 ± 16.3 (p < 0.001) after in-hospital validation. In addition, most of the AIS subgroups were significantly higher in the final calculation than preclinically estimated (p < 0.05). When analyzing subgroups of trauma patients (ISS < 16 vs. ISS ≥ 16), we were able to demonstrate a sensitivity of > 90% to identify a multiple-trauma patient. Diagnosing a higher injury severity group (ISS ≥ 25), sensitivity dropped to 61.1%. The Bland-Altman plot demonstrates that injury severity is underestimated in higher injury levels.

conclusionMultiple-trauma patients can be identified using the ISS. Anatomic scores might be used for transport decisions; however, an accurate estimation of the injury severity should also be based on other criteria such as patient status, mechanism of injury, and other triage criteria.