An evaluation of the impact of apheresis platelets used in the setting of massively transfused trauma patients.
BACKGROUND
Trauma is a major cause of morbidity and mortality worldwide. Of patients arriving to trauma centers, patients requiring massive transfusion (MT, >or=10 units in 24 hours) are a small patient subset but are at the highest risk of mortality. Transfusion of appropriate ratios of blood products to such patients has recently been an area of interest to both the civilian and military medical community. Plasma is increasingly recognized as a critical component, though less is known about appropriate ratios of platelets. Combat casualties managed at the busiest combat hospital in Iraq provided an opportunity to examine this question.


METHODS
In-patient records for 8,618 trauma casualties treated at the military hospital in Baghdad more than a 3-year interval between January 2004 and December 2006 were retrospectively reviewed and patients requiring MT (n = 694) were identified. Patients who required MT in the first 24 hours and did not receive fresh whole blood were divided into study groups defined by source of platelets: (1) patient receiving a low ratio of platelets (<1:16 apheresis platelets per stored red cell unit, aPLT:RBC) (n = 214), (2) patients receiving a medium ratio of platelets (1:16 to <1:8 aPLT:RBC) (n = 154), and (3) patients receiving a high ratio of platelets (>or=1:8 aPLT:RBC) (n = 96). The primary endpoint was survival at 24 hours and at 30 days.


RESULTS
At 24 hours, patients receiving a high ratio of platelets had higher survival (95%) as compared with patients receiving a medium ratio (87%) and patients receiving the lowest ratio of platelets (64%) (log-rank p = 0.04 and p < 0.001, respectively). The survival benefit for the high and medium ratio groups remained at 30 days as compared with those receiving the lowest ratio of platelets (75% and 60% vs. 43%, p < 0.001 for both comparisons). On multivariate regression, plasma:RBC ratios and aPLT:RBC were both independently associated with improved survival at 24 hours and at 30 days.


CONCLUSIONS
Transfusion of a ratio of >or=1:8 aPLT:RBC is associated with improved survival at 24 hours and at 30 days in combat casualties requiring a MT within 24 hours of injury. Although prospective study is needed to confirm this finding, MT protocols outside of investigational research should consider incorporation of appropriate ratios of both plasma and platelets.
Walter Reed Army Medical Center, Washington, DC 20307, USA. Jeremy.perkins1@us.army.mil
Jeremy G
JG
Perkins
Andrew P
AP
Cap
Cap P
CP
Andrew
Philip C
PC
Spinella
Lorne H
LH
Blackbourne
Kurt W
KW
Grathwohl
Thomas B
TB
Repine
Lloyd
L
Ketchum
Paige
P
Waterman
Ruth E
RE
Lee
Alec C
AC
Beekley
James A
JA
Sebesta
Andrew F
AF
Shorr
Charles E
CE
Wade
John B
JB
Holcomb
D000328:Adult; D017707:Erythrocyte Transfusion; D005260:Female; D006772:Hospitals, Military; D006801:Humans; D054542:Iraq War, 2003-2011; D053208:Kaplan-Meier Estimate; D008297:Male; D008889:Military Personnel; D017713:Platelet Transfusion; D012189:Retrospective Studies; D012771:Shock, Hemorrhagic / Q000209:etiology / Q000628:therapy*; D014193:Trauma Centers; D014950:Wounds, Penetrating / Q000150:complications; D055815:Young Adult