Transfusion Thresholds Should Be Conservative for Patients with Septic Shock

Authors: Holst LB et al., N Engl J Med 2014 Oct 9; 371:1381

Transfusion thresholds of 7 g/dL or 9 g/dL yielded similar outcomes.

Patients with septic shock are treated with early antibiotics, rapid fluid resuscitation, vasopressor/inotrope support, and blood transfusions. The Surviving Sepsis guidelines’recommendation for a transfusion hemoglobin target of 7 to 9 g/dL reflects the lack of evidence on an optimal threshold value for such patients.

Scandinavian investigators randomized 998 adults with septic shock in 32 intensive care units (ICUs) to a transfusion hemoglobin threshold of 7 g/dL (conservative) or 9 g/dL (liberal). The cohort included patients with chronic cardiovascular disease (53%), chronic lung disease (21%), and hematologic malignancy (7%) but excluded those with acute coronary syndrome or life-threatening bleeding. About half the patients had undergone surgery, and most (69%) were supported with mechanical ventilation. Median time to randomization was ≈24 hours after ICU admission.

Red cell transfusions were given during the ICU stay to 63.9% of the conservative group and 98.8% of the liberal group; median transfused units were 1 and 4, respectively. Ischemic events, requisite life support (i.e., mechanical ventilation, vasopressor/inotrope administration, or renal replacement therapy), and 90-day mortality (44%) were similar between groups. No between-group differences were exposed in prespecified analyses of older patients (age, ≥70), sicker patients (Simplified Acute Physiology Score, >53) and patients with chronic cardiovascular disease.

Comment
Although these researchers didn’t look at the very early resuscitation time frame (i.e., first 6 hours), their results provide strong support for a more-conservative transfusion threshold. The time has come to include septic patients with other critically ill patients and set the transfusion threshold at 7 g/dL.