Clinical Question: Are there particular groups of patients in which lower transfusion thresholds (transfusion only at lower hemoglobin levels) may be harmful?
Background: Previously published meta-analyses have examined transfusion thresholds for critically ill, surgical, and medical patients. By combining these patients, previous meta-analyses are limited in the identification of intervention effects. A more refined understanding of how transfusion thresholds impact outcomes for a variety of patients in different clinical settings is needed.
Study Design: Context-specific systematic review and meta-analysis of randomized clinical trials.
Setting: Adult patients in perioperative, emergency, or intensive-care settings.
Synopsis: Patient information was extracted from 31 randomized clinical trials. The authors found that among 3,465 elderly patients undergoing orthopedic surgery, those given restrictive transfusion strategies had significantly more events reflecting inadequate oxygen supply (relative risk, 1.41; 95% CI, 1.03–1.92). No statistically significant effect from restrictive transfusions was seen in 3,322 patients with cardiovascular disease undergoing cardiac or vascular procedures; 3,590 mixed medical-surgical patients in emergency and intensive-care settings; and 823 patients in a combined group of postpartum women, hematologic malignancy patients, and younger patients with neurologic injury.
The authors argue that even statistically nonsignificant differences in morbidity and mortality should encourage more liberal transfusion; apart from orthopedic surgery patients, this argument is not well-supported by the available data.
Bottom Line: It remains unclear whether restrictive transfusion strategies have a negative impact on certain types of patients, although the authors argue that there may be a trend in that direction. Further study is needed for specific patient populations.
Citation: Hovaguimian F, Myles PS. Restrictive versus liberal transfusion strategy in the perioperative and acute care settings: a context-specific systematic review and meta-analysis of randomized clinical trials. Anesthesiology. 2016;125(1):46-61.