Mortality in Critically Ill Patients with Liberal Versus Restrictive Transfusion Thresholds: A Systematic Review and...

Area of Science:

• Critical Care Medicine
• Hematology
• Evidence-Based Medicine

Background:

• Anemia is prevalent in critically ill patients, with red blood cell (RBC) transfusion practices debated due to inconsistent outcomes and potential risks.
• Current guidelines vary, with some advocating restrictive transfusion thresholds (e.g., 7 g/dL) over liberal ones (e.g., 9 g/dL).

Purpose of the Study:

• To systematically review and meta-analyze randomized controlled trials comparing restrictive versus liberal red blood cell transfusion strategies in critically ill adults.
• To assess the impact of different transfusion thresholds on mortality and other clinical outcomes.

Main Methods:

• Systematic review and meta-analysis adhering to PRISMA guidelines, searching PubMed, EMBASE, and LILACS (January 1995 - October 2024).
• Inclusion of 13 randomized controlled trials with 13,705 critically ill adults.
• Risk of bias assessed using Cochrane Risk of Bias Tool 2; pooled effects estimated via random-effects model; protocol registered in PROSPERO.

Main Results:

• No statistically significant difference in 30-day mortality between restrictive and liberal RBC transfusion strategies (OR 1.02; 95% CI, 0.83-1.25).
• Similar non-significant findings for 90-day/180-day mortality, hospital/ICU length of stay, dialysis, and ARDS incidence.
• Restrictive strategy resulted in significantly fewer RBC units transfused; Trial Sequential Analysis indicated insufficient evidence to confirm or exclude an effect on 30-day mortality.

Conclusions:

• The meta-analysis found no statistically significant difference in short-term mortality between restrictive and liberal transfusion strategies in critically ill patients.
• Larger clinical trials are necessary to definitively establish any clinically meaningful differences in outcomes for this population.