Anesthesia Management: 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, greater than 70), sicker patients (Simplified Acute Physiology Score, greater than 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.