Published in Anesthesiology 2015 Jan 122:29
Authors: Pinheiro de Almeida J et al.
A hemoglobin level of 9 g/dL was superior to 7 g/dL as a trigger for transfusion.
Randomized trials have shown favorable outcomes with a restrictive red-cell transfusion strategy — that is, not transfusing until hemoglobin levels are <7 g/dL in general critical-care patients (NEJM JW Gen Med Feb 12 1999), patients with noncatastrophic gastrointestinal bleeding (NEJM JW Hosp Med Feb 15 2013), and patients with septic shock (N Engl J Med 2014; 371:1381) and <8 g/dL in patients undergoing cardiac surgery (NEJM JW Cardiol Nov 3 2010) and hip-fracture surgery (NEJM JW Gen Med Jan 19 2012). Now, in another patient population, investigators have reached a different conclusion.
Researchers in Brazil enrolled 198 patients who underwent surgery for abdominal cancer (mostly gastrointestinal, pancreatic, or urogenital) and who required postoperative intensive care unit (ICU) stays. Patients were randomized to a transfusion threshold of 7 g/dL (restrictive) or 9 g/dL (liberal) during their ICU stay; 21% and 42% of patients, respectively, were transfused in the two groups.
The primary endpoint (death or severe complication at 30 days) occurred significantly more often in the restrictive group than in the liberal group (36% vs. 20%). Several individual adverse outcomes also occurred significantly more frequently with the restrictive strategy: 30-day mortality (23% vs. 8%), 60-day mortality (24% vs. 11%), cardiovascular complications (14% vs. 5%), and abdominal infection (15% vs. 5%).
Why researchers got different results in surgical patients with abdominal cancer than those obtained in other patient cohorts is unclear. The authors discuss several theoretical possibilities, including adverse physiological effects of major abdominal surgery and their institution’s use of leukoreduced blood with relatively short storage time (which might improve transfusion outcomes). Whatever the explanation, this study suggests that a one-size-fits-all transfusion threshold is not necessarily applicable universally.