COMBAT-C: COntrol of Major Bleeding by Application of Tourniquets over Clothing.

INTRODUCTION: External bleeding is the leading cause of preventable trauma-related death. In certain circumstances, tourniquet application over clothing may be necessary. Therefore, the aim of this study was to assess the effectiveness of tourniquets over different clothing setups. METHODS: Three windlass tourniquets (CAT, SAMXT, SOFTT-W) were applied over nine different clothing setups and without clothing on the Hapmed™ Tourniquet Trainer. We compared each tourniquet in each clothing setup to the tourniquet trainer that was not dressed, and we compared the three tourniquets within each clothing setup concerning blood loss, applied pressure and application time. Regression analysis of the effect of thickness, mean weight, mean deformation, application time, and applied pressure on blood loss was performed. RESULTS: Although blood loss was significantly greater in the CAT and SAMXT tourniquets when they were applied over leather motorcycle trousers, the overall findings showed that the clothing setups significantly reduced or did not affect blood loss. The mean blood loss was the lowest with CAT and the highest with SOFTT-W. The measured mean pressures were lower than 180 mmHg in four out of nine clothing setups with SOFTT-W, but CAT and SAMXT always exceeded this threshold. CAT had the fastest application time. Blood loss was significantly influenced by applied pressure and application time but was influenced to a far lesser degree by clothing parameters. CONCLUSION: The effects of the clothing setups were of little clinical relevance, except for leather motorcycle trousers. The effects of rugged protective equipment, e.g., hazard suits, are conceivable and need to be tested for specific garments with the tourniquet intended for use. No clothing parameter for predicting tourniquet effectiveness could be identified.

Impact of "hypotension on arrival" on required surgical disciplines and usage of damage control protocols in severely injured patients.

BACKGROUND: For trauma patients with subsequent immediate surgery, it is unclear which surgical disciplines are most commonly required for treatment, and whether and to what extend this might depend on or change with "hypotension on arrival". It is also not known how frequently damage control protocols are used in daily practice and whether this might also be related to "hypotension on arrival". METHODS: A retrospective analysis of trauma patients from a German level 1 trauma centre and subsequent "immediate surgery" between 01/2017 and 09/2022 was performed. Patients with systolic blood pressure > 90 mmHg (group 1, no-shock) and < 90 mmHg (group 2, shock) on arrival were compared with regard to (a) most frequently required surgical disciplines, (b) usage of damage control protocols, and (c) outcome. A descriptive analysis was performed, and Fisher's exact test and the Mann‒Whitney U test were used to calculate differences between groups where appropriate. RESULTS: In total, 98 trauma patients with "immediate surgery" were included in our study. Of these, 61 (62%; group 1) were normotensive, and 37 (38%, group 2) were hypotensive on arrival. Hypotension on arrival was associated with a significant increase in the need for abdominal surgery procedures (group 1: 37.1 vs. group 2: 54.5%; p = 0.009), more frequent usage of damage control protocols (group 1: 59.0 vs. group 2: 75.6%; p = 0.019) and higher mortality (group 1: 5.5 vs. group 2: 24.3%; p 0.027). CONCLUSION: Our data from a German level 1 trauma centre proof that abdominal surgeons are most frequently required for the treatment of trauma patients with hypotension on arrival among all surgical disciplines (> thoracic surgery > vascular surgery > neurosurgery). Therefore, surgeons from these specialties must be available without delay to provide optimal trauma care.