A restrictive transfusion strategy did not reduce mortality among ICU patients with septic shock and cancer, a recent trial found.
The single-center trial randomized adult cancer patients with septic shock to either a liberal red blood cell transfusion strategy (hemoglobin threshold of <9 g/dL) or a restrictive strategy (hemoglobin threshold of <7 g/dL) during their ICU stays. The primary outcome was 28-day mortality. Results were published by Critical Care Medicine on Feb. 24.
There were 149 patients in the liberal group, and they received an average of one unit of blood (range, 0 to 3 units), while the 151 patients in the restrictive group received an average of zero units (range, 0 to 2 units) (P<0.001). After 28 days, there was a trend toward lower mortality in the liberal group compared to the restrictive group (45% vs. 56%; hazard ratio, 0.74; 95% CI, 0.53 to 1.04; P=0.08). At 90 days, the mortality difference was even greater (59% vs. 70%; hazard ratio, 0.72; 95% CI, 0.53 to 0.97; P=0.03). The groups had similar lengths of stay in the hospital and the ICU.
The study authors concluded that the survival trend favored the liberal transfusion strategy. “These results went in the opposite direction of our a priori hypothesis, of existing guidelines and of other trials in the field and should be considered of limited external generalizability and only hypothesis generating,” they wrote. The study focused on cancer patients because they make up 15% of ICU admissions due to septic shock, they are at high risk of anemia, and they have not been well represented in previous randomized trials on this question. The researchers had hypothesized that lowering the risk of transfusion-related complications would result in lower mortality.
Although the results should be interpreted with caution, they do “create concern regarding the safety of a restrictive strategy of [red blood cell] transfusion in cancer patients with septic shock,” the authors said. They noted that while current guidelines support restrictive strategies generally, liberal strategies might be found to provide better outcomes for certain subsets of patients, such as oncology and perioperative patients.
