Background The administration of intravenous fluid (IV fluid) during prehospital setting for trauma patients is the traditional procedure in emergency medical service (EMS) system. We believed that intravenous fluid would maintain intravascular volume and organ perfusion. Conversely, the prehospital IV fluid access procedure increased the on scene time and missed the concept scoop and run for definite treatment and in one theory IV fluid was cause of rebleeding from elevation of blood pressure. This study aimed to identify the effect of prehospital IV fluid administration on survival to discharge of trauma patients in Khon Kaen hospital.

Methods This was retrospective cohort study. Trauma patients who arrived by EMS system and admited in Khon Kaen hospital during 1^st January 2014–31^th December 2014 were enrolled. The effect of prehospital IV fluid and other important variables on survival to discharge were analysed by multiple logistic regression.

Results There were 2,610 patients who arrived by EMS system and all of them were admited. 4.4% of patients received IV fluid from prehospital setting. Survival was higher in patients who not received prehospital IV fluid (98.2% vs. 81.9%). From univariate analysis, patients receiving prehospital IV fluid were less likely to survive (OR 0.08; 95% CI: 0.05–0.14 p-value < 0.00001) after adjusted for other variables (age, sex, mechanism of injury, Glasgow Coma Scale, initial blood pressure and Injury Severity Score), prehospital IV fluid did not decrease survival (OR 0.85; 95% CI: 0.35–2.07 p-value=0.735). However subgroup analysis in patients with hypotension at scene, prehospital IV fluid significantly decreased survival to discharge (OR 0.16; 95% CI: 0.04–0.76 p-value = 0.021).

Conclusions Prehospital IV fluid did not increase survival in trauma victims and it may be harmful in hypotensive patients. The routine use of prehospital IV fluid administration for all trauma patients should be considered.