Anemia in septic shock: which transfusion thresholds?

Abstract

Anemia is a frequent condition in intensive care units (ICU), most especially in septic patients. The hemoglobin level is a major determinant of oxygen transport. Red blood cell transfusion represents the main therapeutic of anemia in the ICU, and the only one able to rapidly increase the hemoglobin level in critical care. Overall, about half of septic patients will require red blood cell transfusion in the ICU and after discharge. Interventional randomized studies have demonstrated the safety and possibly a benefit of restrictive transfusion strategies in the ICU. Hence national and international guidelines consistently recommend such restrictive transfusion strategy by using a hemoglobin transfusion threshold of 7 g/dL to maintain a hemoglobin level between 7 and 9 g/dL in critically ill patients including septic patients. However, septic shock exhibits several features likely to modulate the transfusion indications, including the high prevalence of cardiovascular and onco-hematological comorbid conditions, as well as the defining tissue dysoxia. Transfusion indications in septic shock should certainly be based on the current guidelines, but most importantly should urge a personalized decision-making process taking into account an individual assessment of expected benefits and risks of transfusion.