Abstract: Six trials involving a total of 2128 people were included in this review. We did not combine the results quantitatively because the interventions and patient populations were so diverse. Early versus delayed fluid administration  Three trials reported mortality and two reported coagulation data. In the first trial (n = 598) the relative risk (RR) for death with early fluid administration was 1.26 (95% confidence interval (CI) 1.00 to 1.58). The weighted mean differences (WMD) for prothrombin time and partial thromboplastin time were 2.7 (95% CI 0.9 to 4.5) and 4.3 (95% CI 1.74 to 6.9) seconds, respectively. In the second trial (n = 50) the RR for death with early blood transfusion was 5.4 (95% CI 0.3 to 107.1). The WMD for partial thromboplastin time was 7.0 (95% CI 6.0 to 8.0) seconds. In the third trial (n = 1309) the RR for death with early fluid administration was 1.06 (95% CI 0.77 to 1.47). Larger versus smaller volume of fluid administration Three trials reported mortality and one reported coagulation data. In the first trial (n = 36) the RR for death with a larger volume of fluid resuscitation was 0.80 (95% CI 0.28 to 22.29). Prothrombin time and partial thromboplastin time were 14.8 and 47.3 seconds in those who received a larger volume of fluid, as compared to 13.9 and 35.1 seconds in the comparison group. In the second trial (n = 110) the RR for death with a high systolic blood pressure resuscitation target (100 mm Hg) maintained with a larger volume of fluid as compared to a low systolic blood pressure resuscitation target (70 mm Hg) maintained with a smaller volume of fluid was 1.00 (95% CI 0.26 to 3.81). In the third trial (n = 25) there were no deaths. We found no evidence from randomised controlled trials for or against early or larger volume of intravenous fluid administration in uncontrolled haemorrhage. There is continuing uncertainty about the best fluid administration strategy in bleeding trauma patients. Further randomised controlled trials are needed to establish the most effective fluid resuscitation strategy.

Plain-language summary: The authors searched for relevant medical research reports and found six randomised controlled trials involving a total of 2128 people. In each study, people with uncontrolled bleeding were randomly assigned to receive one treatment or another. Three studies were about the amount of fluid given (more or less), and three studies were about giving fluid at different times following injury (sooner or later). The authors were interested in finding out which treatments were better, to reduce deaths and to enable blood clotting. Blood clotting was measured by prothrombin time and partial thromboplastin time during fluid administration. The review of trials found that there is uncertainty about the best time to give fluid and what volume of fluid should be given. While increasing fluids will maintain blood pressure, it may also worsen bleeding by diluting clotting factors in the blood. The first version of this review was published in 2000 and included these six trials. The authors searched for new, relevant studies in 2003, 2008 and 2014 but none were found. The authors will look for studies in 2020, and any new information will be incorporated into the review.