Equal Ratio of Plasma, RBCs Appears Best for Hemorrhaging Trauma Patients

By Scott Baltic

December 27, 2019

NEW YORK (Reuters Health) - A 1:1 ratio of fresh frozen plasma to packed red blood cells (FFP:pRBC) is associated with the lowest 24-hour mortality in trauma patients needing massive transfusion, according to a study of data from a nationwide cohort.

Lower FFP:pRBC ratios, such as 1:2 or 1:3, were associated with mortality increases, researchers report in the Journal of the American College of Surgeons.

"Until a larger randomized controlled study is performed, we suggest the use of a 1:1 FFP:pRBC ratio rather than a 1:2 ratio in the massively transfused trauma patient," Dr. Haytham Kaafarani of Massachusetts General Hospital, in Boston, and colleagues write.

Theirs is the largest national study of massively transfused hemorrhaging trauma patients, and the largest to show a statistically significant mortality benefit of the 1:1 FFP:pRBC ratio versus lower ratios, they note.

Dr. Jeremy W. Cannon, an associate professor of surgery at the University of Pennsylvania's Perelman School of Medicine, in Philadelphia, who was not involved in the study, called the work "very important" and highlighted its sound methodology in a phone interview with Reuters Health. He also said the authors had "zeroed in on the patients who have the highest risk of dying of hemorrhage."

The findings contrast with those of the 2015 randomized PROPPR study, which found no significant difference in 24-hour or 30-day survival between patients who received 1:1:1 versus 1:1:2 ratios of FFP:platelets:pRBC. However, exsanguination, the predominant cause of death in the first 24 hours, was significantly less likely in the 1:1:1 group.

The new results suggest that "the correct interpretation of the well-known PROPPR trial is perhaps that the 1:1:1 ratio is indeed superior" and that PROPPR's failure to show that might have been due to a type-II error (a false negative) and a smaller patient sample than was needed.

Drawing from the American College of Surgeons Trauma Quality Improvement Program 2013-2016 database, Dr. Kaafarani's team identified all trauma patients age 18 and older who needed at least 10 units (3,000 cc) of pRBC and at least one unit (300 cc) of FFP within 24 hours of admission.

They included 4,427 patients with a mean age of 41 (79% male), most of whom received transfusions with a 1:1 (31%), 1:2 (41%) or 1:3 (11%) FFP:pRBC ratio.

The 1:1 subgroup had the highest mean injury-severity-scale score and the highest proportions of pelvic and gastrointestinal injuries. Patients in higher-ratio subgroups spent significantly more time in the emergency department and required laparotomy and embolization significantly more often than those in other cohorts.

When compared with the 1:1 ratio subgroup, the odds of mortality increased to 1.23 for a 1:2 ratio, 2.11 for 1:4 and as high as 4.11 for 1:5 (all P<0.05).

In the study's most important finding, Dr. Kaafarani told Reuters Health by email, "we showed that 1:1 is statistically better than 1:2, which the PROPPR trial failed to do, likely because of insufficient number of patients."

Dr. John B. Holcomb, a professor of surgery at the University of Alabama at Birmingham and lead author of the PROPPR report, told Reuters Health by email, "It is disconcerting that a substantial portion of massively transfused patients still receive less than optimal transfusion ratios."

He noted the difficulty in reaching a balanced ratio of plasma, platelets and RBCs quickly in bleeding patients and pointed to the authors' mention of a trend in recent studies suggesting whole blood transfusion. Whole blood, Dr. Holcomb said, "always delivers a perfectly balanced ratio, includes platelets and fibrinogen in addition to plasma and RBCs, and is cheaper than individual components."

SOURCE: https://bit.ly/36cDESu Journal of the American College of Surgeons, online November 20, 2019.