Liberal vs. Restrictive Blood Transfusion Strategies Show Similar Outcomes in Subarachnoid Hemorrhage Patients: JAMA

In this study, a liberal transfusion strategy considered compulsory transfusion at a hemoglobin cutoff of ≤10 g/dL, while a restrictive strategy allowed optional transfusion at a hemoglobin level of ≤8 g/dl. At 12 months, unfavorable neurological outcomes, as defined by a modified Rankin scale score of ≥4, were found in 33.5% of the liberal group and 37.7% of the restrictive group (relative risk [RR]=0.88, 95% confidence interval [CI] 0.72-1.09).

Blood transfusion thresholds and guidelines seem contentious in different situations among critically ill patients, with guidelines presenting rather vague recommendations. Liberal transfusions offer the promise of improved oxygen delivery, which would leave behind a poorly perfused, hypoxic brain tissue, but carry additional risks for complications and mortality. Cumulative previous studies, including HEMOTION and TRAIN trials, yielded conflicting results on appropriate transfusion thresholds in critically ill people. The SAHARA trial was designed to confront this ignorance by focusing on patients with acute aneurysmal subarachnoid hemorrhage and anemia.

SAHARA trial by 23 centers in Canada, Australia, and the US recruited a total of 742 critically ill adults, almost 82% of whom are women, with a mean age of 59.4 years. The major findings are:

• Neurological outcomes: Unfavorable outcomes occurred in 33.5% of the liberal group and 37.7% of the restrictive group (RR 0.88, 95% CI 0.72-1.09). Mortality rates: Similar between groups at 27.2% for the liberal group and 27.1% for the restrictive group (RR 0.99, 95% CI 0.77-1.28).

• Functional independence: Functional Independence Measure scores were 82.8 points in the liberal group versus 79.8 points in the restrictive group.

• Quality of life (QoL): EuroQol utility index scores were 0.5 in both groups, and visual analog scale scores were 52.1 against 50 points, respectively.

• Transfusion specifics: Median red cell units transfused as 2 in liberal group and 0 in the restrictive group, with median pretransfusion hemoglobin levels of 9.6 g/dL and 7.6 g/dl, respectively.

The findings indicate that neither the liberal transfusion strategy nor the restrictive transfusion strategy offers a clear neurological benefit to patients with aneurysmal subarachnoid hemorrhage with anemia.

Reference:

English SW, Delaney A, Fergusson DA, Chassé M, Turgeon AF, Lauzier F, Tuttle A, Sadan O, Griesdale DE, Redekop G, Chapman M, Hannouche M, Kramer A, Seppelt I, Udy A, Kutsogiannis DJ, Zarychanski R, D'Aragon F, Boyd JG, Salt G, Bellapart J, Wood G, Cava L, Pickett G, Koffman L, Watpool I, Bass F, Hammond N, Ramsay T, Mallick R, Scales DC, Andersen CR, Fitzgerald E, Talbot P, Dowlatshahi D, Sinclair J, Acker J, Marshall SC, McIntyre L; SAHARA Trial Investigators on behalf of the Canadian Critical Care Trials Group. Liberal or Restrictive Transfusion Strategy in Aneurysmal Subarachnoid Hemorrhage. N Engl J Med. 2024 Dec 9. doi: 10.1056/NEJMoa2410962. Epub ahead of print. PMID: 39655786.