Transfusing whole blood before patients with severe haemorrhage reach hospital does not improve survival or other key outcomes compared to standard component therapy, new studies have shown.
A US study found that 30-day mortality was similar for patients at risk of haemorrhagic shock whether they were treated with prehospital whole blood or blood components.
Whole blood also failed to improve secondary outcomes, such as the amount of blood transfused at the hospital, and mortality was unaffected by the length of time the whole blood was stored for.
“These results have important implications for both civilian prehospital resuscitation and military blood-supply planning,” wrote the authors, led by Professor Jason Sperry of the University of Pittsburgh, in the NEJM [link here].
The results support the findings of an earlier UK study, also published in the NEJM [link here], which found that prehospital transfusion of whole blood did not reduce the risk of death following life-threatening haemorrhage, compared to standard care.
The US study analysed outcomes of patients at risk of haemorrhagic shock who were treated prior to hospital at 44 medical bases in the USA with either type O whole blood (n=695) or as-indicated blood components (plasma, red cells, or both, n=298).
Patients who were given whole blood had similar rates of mortality to those given components (26% vs 21%, p=0.24), with similar rates seen in subgroups including head or neck AIS score (>2), severe hypotension (≤70 mm Hg), age, or sex.
Rates of mortality at 3, 6 and 24 hours, and in-hospital mortality, were also all comparable between both treatment groups, as were the number of units of blood products transfused within 24 hours and the incidence of multiple organ failure, nosocomial infection, or acute respiratory distress syndrome.
Safety, including rates of severe adverse events, was also similar in both groups.
The data also showed similar 30-day mortality among patients who received whole blood with a storage age of 15 to 21 days (32%) and those given whole blood with a storage age of 1 to 14 days (68%) had also had similar rates of 30-day mortality (27% vs 26%).
In the UK study, patients attended to by an air ambulance service received either a whole-blood transfusion of up to two units (n=314) or standard care with up to two units each of red cells and plasma (n=302).
Death from any cause or massive transfusion occurred at similar rates in both the whole blood and blood components group (49% vs 48%, p=0.84).
The incidence of death from any cause, at all time points, massive transfusion, and other secondary outcomes was also similar.
“This trial provides key evidence to inform the use of whole blood within civilian prehospital trauma systems,” wrote the authors, led by Professor Jason Smith, Emeritus Defence Professor of Emergency Medicine at the Royal Centre for Defence Medicine.
“Decisions about adopting the use of whole blood must balance logistic advantages against supply constraints, cost, and the overall availability of blood,” they concluded.