Effect of a fixed-ratio (1:1:1) transfusion protocol versus laboratory-results-guided transfusion in patients with severe trauma: a randomized feasibility trial

Abstract

Background: Hemorrhage coupled with coagulopathy remains the leading cause of preventable in-hospital deaths among trauma patients. Use of a transfusion protocol with a predefined ratio of 1:1:1 (1 each of red blood cells [RBC], frozen plasma [FP] and platelets) has been associated with improved survival in retrospective studies in military and civilian settings, but such a protocol has its challenges and may increase the risk of respiratory complications. We conducted a randomized controlled trial to assess the feasibility of a 1:1:1 transfusion protocol and its effect on mortality and complications among patients with severe trauma.

Methods: We included 78 patients seen in a tertiary trauma centre between July 2009 and October 2011 who had hypotension and bleeding and were expected to need massive transfusion (≥ 10 RBC units in 24 h). We randomly assigned them to either the fixed-ratio (1:1:1) transfusion protocol (n = 40) or to a laboratory-results-guided transfusion protocol (control; n = 38). The primary outcome, feasibility, was assessed in terms of blood product ratios and plasma wastage. Safety was measured based on 28-day mortality and survival free of acute respiratory distress syndrome.

Results: Overall, a transfusion ratio of 1:1:1 was achieved in 57% (21/37) of patients in the fixed-ratio group, as compared with 6% (2/32) in the control group. A ratio of 1:1 (RBC:FP) was achieved in 73% (27/37) in the fixed-ratio group and 22% (7/32) in the control group. Plasma wastage was higher with the intervention protocol (22% [86/390] of FP units v. 10% [30/289] in the control group). The 28-day mortality and number of days free of acute respiratory distress syndrome were statistically similar between the groups.

Interpretation: The fixed-ratio transfusion protocol was feasible in our study, but it was associated with increased plasma wastage. Larger randomized trials are needed to evaluate the efficacy of such a protocol in trauma care.

Trial registration: ClinicalTrials.gov, no. NCT00945542.

Figure 1:

Flow of patients through the trial. *The intention-to-treat (ITT) analysis of all-cause 28-day mortality included the patients who were excluded after randomization.

Figure 2:

Kaplan–Meier curves for event-free survival (free of acute respiratory distress syndrome [ARDS] or death) within 28 days after enrolment.