Association between prehospital intravenous fluid administration with oxygen supplementation and the delta shock index for trauma-suspected shock without hypoxia

Background: This study aimed to examine the associations between prehospital intravenous (IV) fluid administration with oxygen (O2) supplementation and the shock index in trauma patients suspected of having shock without hypoxia. Methods: This study analyzed data from an international multicenter trauma database from 2015 to 2020. We analyzed adult trauma patients transported by emergency medical service (EMS) personnel with an initial shock index more than or equal to 1.0. A delta shock index (DSI) of 0.1 or less was the primary outcome. Study participants were categorized into 3 groups: IV fluid with O2, IV fluid only and no IV fluid. After adjusting for confounders, adjusted odds ratios (AORs) and 95% confidence intervals (CIs) were computed using multivariate logistic regression. Results: Among 2019 patients, 1370 were not receiving IV fluid, 157 were receiving IV fluid only, and 492 received IV fluid with O2. IV fluid with O2 patients had a greater proportion of males (76.4%), and DSI was −0.27 for IV fluid and O2, −0.26 for IV fluid only, and −0.21 for no IV fluid (p < 0.01). Compared to no IV fluid, there was no significant association between IV fluid with O2 group and a DSI equal to or less than 0.1. AOR (95% CI) was 1.38 (0.85–2.23) for IV fluid with O2 and 0.94 (0.65–1.35) for IV fluid only. Conclusions: No significant association was found between IV fluid administration and DSI in trauma patients with suspected shock without hypoxia at the scene, even when oxygen supplementation was added.