Updated guidelines on red blood cell transfusions for critically ill patients recommend a mainly restrictive approach, intended to improve patient outcomes and manage resources, according to lead author Angel Coz Yataco, MD, a pulmonology and critical care specialist at the Cleveland Clinic, Ohio, who presented the guidelines at the CHEST 2025 annual meeting. 

Recent research shows that approximately 25% of critically ill patients in the United States receive red blood cell transfusions, which are often life-saving but not without significant risk for adverse events, including infection risk, transfusion-related acute lung injury, and circulatory overload, the authors wrote. Recent evidence shows a lack of complications and death with a restrictive threshold for red blood cell transfusions; and minimizing unnecessary transfusions not only reduces unnecessary risk but also preserves red blood cell (RBC) resources for patients who derive the greatest benefit, they said.

The guidelines, also published in CHEST, were developed by the American College of Chest Physicians for two main reasons: to respond to the lack of guidance on transfusions of blood products for critically ill patients specifically, and to address the variability in thresholds of practice, Coz Yataco said in an interview. 

The goal of the guidelines is to promote greater consistency in practice, and by doing so, reduce patient side effects and use resources judiciously, Coz Yataco told Medscape Medical News.

However, challenges to implementing the guidelines in practice include clinicians’ ability to step outside their comfort zones in regard to low hemoglobin and to implement a strategy in which one unit of RBCs is transfused at a time, followed by rechecking hemoglobin levels before deciding to transfuse an additional unit, he said.

The recommendations were based on comprehensive reviews of current evidence on RBC transfusions, including 22 randomized controlled trials and one cohort study. 

The resulting two strong and four conditional recommendations mainly favored a restrictive strategy for RBC transfusions for most patients, which reduces RBC use without increasing risk. A restrictive threshold is generally defined as a hemoglobin level of 7 g/dL to 8 g/dL, compared to a permissive threshold, generally defined as a hemoglobin level ranging from 8.5 g/dL to 10 g/dL. 

Overall, the new guidelines recommend a restrictive strategy for RBC transfusion over a permissive threshold in critically ill patients, excluding those with hemodynamic instability after acute hemorrhage or those with neurologic injuries or trauma. 

Restrictive thresholds also are recommended for postoperative treatment of critically ill patients undergoing cardiac surgery, those with acute gastrointestinal bleeding, and those with isolated elevation of serum troponin without other evidence of cardiac ischemia. 

For patients with septic shock and end-organ hypoperfusion, the guidelines do not recommend restrictive thresholds but suggest against adding permissive RBC transfusion thresholds to usual care. 

“The only recommendation against a restrictive approach is in patients with acute coronary syndrome, so there is a need to raise clinician awareness to what a restrictive approach entails,” Coz Yataco told Medscape Medical News. “Results regarding restrictive transfusion in ACS have been mixed, and the recommendations were largely influenced by a single study, the MINT trial, which showed that patients with ACS who were transfused more restrictively could have more mortality from cardiac causes, and future studies might identify the most effective threshold,” he noted.

As for additional research to inform practice, studies of transfusions comparing critically ill and non-critically ill patients could reinforce the current evidence and make it stronger, Coz Yataco said.

Sparing Patients, Preserving Resources 

Variability in transfusion practices persists across ICUs in the United States, despite substantial new evidence supporting restrictive transfusion strategies, said Daniel A. Salerno, MD, a professor of clinical thoracic medicine and surgery at the Lewis Katz School of Medicine at Temple University, Philadelphia, in an interview. 

“Approximately 25% of critically ill patients in the US receive RBC transfusions, often at hemoglobin thresholds above 7 g/dL, and transfusion carries significant risks and resource implications,” said Salerno, who was not involved in writing the guidelines. 

“The most significant update is the strong recommendation for a restrictive transfusion strategy of 7 g/dL-8 g/dL in most critically ill adults, including those with gastrointestinal bleeding and post-cardiac surgery,” Salerno told Medscape Medical News. However, the guidelines recognize that a restrictive approach may increase adverse outcomes in patients with acute coronary syndrome, he said. 

“The guidelines also emphasize single-unit transfusion with reassessment, and provide nuanced recommendations for subgroups, such as those with isolated troponin elevation or septic shock,” Salerno told Medscape Medical News. As the authors noted, adoption of these recommendations could potentially spare hundreds of thousands of patients unnecessary transfusions annually, without increasing mortality or major complications, he said.

Potential Challenges in the Clinic

Barriers to implementing the guidelines in the clinical setting include entrenched local practices, clinician discomfort with lower hemoglobin thresholds, and logistical challenges in protocol adoption, Salerno said. “The guidelines recommend several implementation strategies: academic detailing, audit and feedback, standardized order sets, computerized decision support, and ongoing education, and institutional leadership and resource allocation are critical for success,” he said. “The guidelines also highlight the importance of patient-centered discussions, especially for those with transfusion refusal based on personal or religious beliefs,” Salerno added.

The guideline received no outside funding. 

Coz Yataco and coauthors reported no financial conflicts of interest. 

Salerno reported no financial conflicts of interest.