Introducing the CanadiEM MVP Series
Evidence-based practice is critical for delivering quality emergency care, but with such a broad specialty identifying and recalling high-yield studies can be challenging. This is especially true for new EM learners, who are tasked with becoming evidence-informed while transitioning to practice.
To make this process easier, CJEM recently published a survey-based study aimed at compiling “must know” papers for emergency medicine trainees.1
The study, conducted by Bazak et al, created a list of important papers based on the input of experts from specialty EM programs across the country.1 Participants were asked to generate a list of EM papers they considered to be the most influential, then rank the papers based on which they thought were the most important to include. Their final list contained 29 studies, 10 of which were supported by 100% of participants surveyed.
The CanadiEM MVP series will summarize these consensus papers using infographics, each of which will detail a different study’s objectives, methods and results.
The end goal of the series is to create an effective resource for recalling key papers, and to act as a primer for new trainees orienting themselves to EM evidence.
Transfusion of Plasma, Platelets, and Red Blood Cells in a 1:1:1 vs a 1:1:2 Ratio: The PROPPR Randomized Clinical Trial2
20-40% of trauma deaths after hospital admission involve massive hemorrhage, a devastating outcome potentially avoided with good rapid hemorrhage control. Rapid hemorrhage control is best achieved by the timely delivery of plasma, platelets, and packed red blood cells in a balanced ratio, to replace ongoing losses without encouraging coagulopathy. This is most often seen in the context of a massive transfusion protocol activation.3
For a quick refresher on MTP check out Blood and Clots here.
In 2013 the Prospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study demonstrated that clinicians were generally transfusing their trauma patients with a blood product ratio of 1:1:1 or 1:1:2, but there was no evidence to suggest which ratio was better.4 The Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial was a follow-up to PROMMTT designed to address the differences between 1:1:1 1:1:2 transfusion ratios by assessing their safety and efficacy.
PROPPR was designed as a phase 3 randomized control trial conducted in 12 level 1 trauma centers across North America, where trauma patients expected to require massive transfusion were randomized to receive one of the two ratios. By the study’s completion 680 patients were randomized to the two treatment arms, with no statistically significant difference in their all-cause mortality. However, patients who received blood products in a 1:1:1 ratio had fewer deaths from exsanguination in the first 24 hours (9.2% vs 14.6%, P=0.03), and achieved anatomic hemostasis more often (86.7% vs 78.1%, P=0.006).2
Due to a lower percentage of deaths from exsanguination without a change in safety, PROPPR encouraged clinicians to consider use of a 1:1:1 transfusion protocol for trauma patients requiring rapid hemorrhage control.
However, it is important to note that PROPPR was powered to detect differences >10% between groups and could not definitely establish benefit below this threshold. The study was also unable to completely exclude patients with an unsurvivable brain injury, who made up a significant proportion of deaths (23% of deaths at 24 hrs and 38% of deaths at 30 days).
This post was peer reviewed by Alvin Chin and uploaded by Lauren Beals.
- 1.Bazak S, Sherbino J, Upadhye S, Chan T. Ascertaining top evidence in emergency medicine: A modified Delphi study. CJEM. 2019;21(2):291-295. https://www.ncbi.nlm.nih.gov/pubmed/29925456.
- 2.Holcomb J, Tilley B, Baraniuk S, et al. Transfusion of plasma, platelets, and red blood cells in a 1:1:1 vs a 1:1:2 ratio and mortality in patients with severe trauma: the PROPPR randomized clinical trial. JAMA. 2015;313(5):471-482. https://www.ncbi.nlm.nih.gov/pubmed/25647203.
- 3.Tisherman S, Schmicker R, Brasel K, et al. Detailed description of all deaths in both the shock and traumatic brain injury hypertonic saline trials of the Resuscitation Outcomes Consortium. Ann Surg. 2015;261(3):586-590. https://www.ncbi.nlm.nih.gov/pubmed/25072443.
- 4.Holcomb J, del J, Fox E, et al. The prospective, observational, multicenter, major trauma transfusion (PROMMTT) study: comparative effectiveness of a time-varying treatment with competing risks. JAMA Surg. 2013;148(2):127-136. https://www.ncbi.nlm.nih.gov/pubmed/23560283.