Platelet-to-red blood cell ratio and mortality in bleeding trauma patients: A systematic review and meta-analysis
Transfusion. 2021;61 Suppl 1:S243-s251
BACKGROUND In traumatic bleeding, transfusion practice has shifted toward higher doses of platelets and plasma transfusion. The aim of this systematic review was to investigate whether a higher platelet-to-red blood cell (RBC) transfusion ratio improves mortality without worsening organ failure when compared with a lower ratio of platelet-to-RBC. METHODS Pubmed, Medline, and Embase were screened for randomized controlled trials (RCTs) in bleeding trauma patients (age ≥16 years) receiving platelet transfusion between 1946 until October 2020. High platelet:RBC ratio was defined as being the highest ratio within an included study. Primary outcome was 24 hour mortality. Secondary outcomes were 30-day mortality, thromboembolic events, organ failure, and correction of coagulopathy. RESULTS In total five RCTs (n = 1757 patients) were included. A high platelet:RBC compared with a low platelet:RBC ratio significantly improved 24 hour mortality (odds ratio [OR] 0.69 [0.53-0.89]) and 30- day mortality (OR 0.78 [0.63-0.98]). There was no difference between platelet:RBC ratio groups in thromboembolic events and organ failure. Correction of coagulopathy was reported in five studies, in which platelet dose had no impact on trauma-induced coagulopathy. CONCLUSIONS In traumatic bleeding, a high platelet:RBC improves mortality as compared to low platelet:RBC ratio. The high platelet:RBC ratio does not influence thromboembolic or organ failure event rates.
Bleeding trauma patients receiving platelet transfusion (5 studies, n= 1,757).
Higher platelet-to-red blood cell (RBC) transfusion ratio.
Lower ratio of platelet-to-RBC.
A high platelet:RBC compared with a low platelet:RBC ratio significantly improved 24 hour mortality (odds ratio (OR) 0.69 (0.53-0.89)) and 30- day mortality (OR 0.78 (0.63-0.98)). There was no difference between platelet:RBC ratio groups in thromboembolic events and organ failure. Correction of coagulopathy was reported in five studies, in which platelet dose had no impact on trauma-induced coagulopathy.
Dynamics of Platelet Counts in Major Trauma: The Impact of Haemostatic Resuscitation and Effects of Platelet Transfusion-A Sub-Study of the Randomized Controlled RETIC Trial
J Clin Med. 2020;9(8)
Although platelets play a central role in haemostasis, the dynamics of platelet counts during haemostatic resuscitation, the response to platelet transfusion, and effects on clinical outcome are poorly described for trauma patients. As a sub-study of the already published randomized controlled RETIC Study "Reversal of Trauma-induced Coagulopathy using First-line Coagulation Factor Concentrates or Fresh-Frozen Plasma" trial, we here analysed whether the type of first-line haemostatic resuscitation influences the frequency of platelet transfusion and determined the effects of platelet transfusion in coagulopathic patients with major trauma. Patients randomly received first-line plasma (FFP) or coagulation factor concentrates (CFC), mainly fibrinogen concentrate. In both groups, platelets were transfused to maintain platelet counts between 50 and 100 × 10(9) /L. Transfusion rates were significantly higher in the FFP (n = 44) vs. CFC (n = 50) group (FFP 47.7% vs. CFC 26%); p = 0.0335. Logistic regression analysis adjusted for the stratification variables injury severity score (ISS) and brain injury confirmed that first-line FFP therapy increases the odds for platelet transfusion (odds ratio (OR) 5.79 (1.89 to 20.62), p = 0.0036) and this effect was larger than a 16-point increase in ISS (OR 4.33 (2.17 to 9.74), p =0.0001). In conclusion, early fibrinogen supplementation exerted a platelet-saving effect while platelet transfusions did not substantially improve platelet count and might contribute to poor clinical outcome.
Trauma patients with trauma-induced coagulopathy (TIC) enrolled in the RETIC trial (n= 94).
First-line plasma (FFP), (n= 44).
Coagulation factor concentrates (CFC), (n= 50).
Transfusion rates were significantly higher for FFP 47.7% than CFC 26%. Logistic regression analysis adjusted for the stratification variables injury severity score and brain injury confirmed that first-line FFP therapy increases the odds for platelet transfusion.
Outcomes after concomitant traumatic brain injury and hemorrhagic shock: a secondary analysis from the Pragmatic, Randomized Optimal Platelets and Plasma Ratios trial
The Journal of Trauma and Acute Care Surgery. 2017;83((4)):668-674.
BACKGROUND Often the clinician is faced with a diagnostic and therapeutic dilemma in patients with concomitant traumatic brain injury (TBI) and hemorrhagic shock (HS), as rapid deterioration from either can be fatal. Knowledge about outcomes after concomitant TBI and HS may help prioritize the emergent management of these patients. We hypothesized that patients with concomitant TBI and HS (TBI + HS) had worse outcomes and required more intensive care compared with patients with only one of these injuries. METHODS This is a post hoc analysis of the Pragmatic, Randomized Optimal Platelets and Plasma Ratios (PROPPR) trial. TBI was defined by a head Abbreviated Injury Scale score greater than 2. HS was defined as a base excess of -4 or less and/or shock index of 0.9 or greater. The primary outcome for this analysis was mortality at 30 days. Logistic regression, using generalized estimating equations, was used to model categorical outcomes. RESULTS Six hundred seventy patients were included. Patients with TBI + HS had significantly higher lactate (median, 6.3; interquartile range, 4.7-9.2) compared with the TBI group (median, 3.3; interquartile range, 2.3-4). TBI + HS patients had higher activated prothrombin times and lower platelet counts. Unadjusted mortality was higher in the TBI + HS (51.6%) and TBI (50%) groups compared with the HS (17.5%) and neither group (7.7%). Adjusted odds of death in the TBI and TBI + HS groups were 8.2 (95% confidence interval, 3.4-19.5) and 10.6 (95% confidence interval, 4.8-23.2) times higher, respectively. Ventilator, intensive care unit-free and hospital-free days were lower in the TBI and TBI + HS groups compared with the other groups. Patients with TBI + HS or TBI had significantly greater odds of developing a respiratory complication compared with the neither group. CONCLUSION The addition of TBI to HS is associated with worse coagulopathy before resuscitation and increased mortality. When controlling for multiple known confounders, the diagnosis of TBI alone or TBI+HS was associated with significantly greater odds of developing respiratory complications. LEVEL OF EVIDENCE Prognostic study, level II.
The use of higher platelet: RBC transfusion ratio in the acute phase of trauma resuscitation: a systematic review
Critical Care Medicine. 2013;41((12):):2800-11.
OBJECTIVE With the recognition of early coagulopathy, trauma resuscitation has shifted toward liberal platelet transfusions. The overall benefit of this strategy remains controversial. Our objective was to compare the effects of a liberal use of platelet (higher platelet:RBC ratios) with a conservative approach (lower ratios) in trauma resuscitation. DATA SOURCES We systematically searched Medline, Embase, Web of Science, Biosis, Cochrane Central, and Scopus. STUDY SELECTION Two independent reviewers selected randomized controlled trials and observational studies comparing two or more platelet:RBC ratios in trauma resuscitation. We excluded studies investigating the use of whole blood or hemostatic products. DATA EXTRACTION Two independent reviewers extracted data and assessed the risk of bias. Primary outcomes were early (in ICU or within 30 d) and late (in hospital or after 30 d) mortality. Secondary outcomes were multiple organ failure, lung injury, and sepsis. DATA SYNTHESIS From 6,123 citations, no randomized controlled trials were identified. We included seven observational studies (4,230 patients) addressing confounders through multivariable regression or propensity scores. Heterogeneity of studies precluded meta-analysis. Among the five studies including exclusively patients requiring massive transfusions, four observed a lower mortality with higher ratios. Two studies considering nonmassively bleeding patients observed no benefit of using higher ratios. Two studies evaluated the implementation of a massive transfusion protocol; only one study observed a decrease in mortality with higher ratios. Of the two studies at low risk of survival bias, one study observed a survival benefit. Three studies assessed secondary outcomes. One study observed an increase in multiple organ failure with higher ratios, whereas no study demonstrated an increased risk in lung injury or sepsis. CONCLUSIONS There is insufficient evidence to strongly support the use of a precise platelet:RBC ratio for trauma resuscitation, especially in nonmassively bleeding patients. Randomized controlled trials evaluating both the safety and efficacy of liberal platelet transfusions are warranted.
Utility of platelet transfusion in adult patients with traumatic intracranial hemorrhage and preinjury antiplatelet use: A systematic review
The Journal of Trauma and Acute Care Surgery. 2012;72((6):):1658-63.
BACKGROUND Preinjury use of antiplatelet agents (e.g., clopidogrel and aspirin) is a risk factor for increased morbidity and mortality for patients with traumatic intracranial hemorrhage (tICH). Some investigators have recommended platelet transfusion to reverse the antiplatelet effects in tICH. This evidence-based medicine review examines the evidence regarding the impact of platelet transfusion on emergency department (ED) patients with preinjury antiplatelet use and tICH on patient-oriented outcomes. METHODS The MEDLINE, EMBASE, Cochrane Library, and other databases were searched. Studies were selected for inclusion if they compared platelet transfusion with no-platelet transfusion in the treatment of adult ED patients with preinjury antiplatelet use and tICH and reported rates of mortality, neurocognitive function, or adverse effects. We assessed the quality of the included studies using standard criteria. RESULTS Five retrospective, registry-based studies were identified, which enrolled 635 patients cumulatively. Based on standard criteria, three studies were of low-quality evidence, and two studies were of very low-quality evidence. One study reported higher in-hospital mortality for patients with platelet transfusion (relative risk, 2.42; 95% confidence interval, 1.2-4.9); another showed a lower mortality rate for patients receiving platelet transfusion (relative risk, 0.21; 95% confidence interval, 0.05-0.95). Three studies did not show any statistical difference in comparing mortality rates between the groups. No studies reported intermediate or long-term neurocognitive outcomes or adverse events. CONCLUSION Five retrospective registry studies with suboptimal methodologies provide inadequate evidence to support the routine use of platelet transfusion in adult ED patients with preinjury antiplatelet use and tICH. (J Trauma Acute Care Surg. 2012;72: 1658-1663. Copyright Copyright 2012 by Lippincott Williams & Wilkins). LEVEL OF EVIDENCE Systematic review, level III.
Prophylactic platelet administration during massive transfusion. A prospective, randomized, double-blind clinical study
Annals of Surgery. 1986;203((1):):40-8.
Prior studies at Harborview Medical Center have suggested that dilutional thrombocytopenia is a major etiology of microvascular, nonmechanical bleeding (MVB). We undertook a prospective randomized double-blind clinical study to compare the prophylactic effects of 6 units of platelet concentrates (PLT) versus 2 units of fresh frozen plasma (FFP) administered with every 12 units of modified whole blood in patients undergoing massive transfusion (12 or more units in 12 hours). After exclusions, three of 17 patients who received PLT and three of 16 patients who received FFP developed MVB, an incidence no different from our previous findings. Regression lines of platelet counts during transfusion were no different between groups, and both groups had higher platelet counts than predicted from a standard washout equation. Only one patient had evidence of dilutional thrombocytopenia as a cause for MVB. Prophylactic platelet administration is not warranted as a routine measure to prevent MVB.