How low should we go: A systematic review and meta-analysis of the impact of red blood cell transfusion in oncology.

摘要

Background: Blood is a scarce and expensive resource that is utilized with wide variation in clinical practice. Most non-oncologic clinical practice guidelines recommend restrictive allogeneic blood transfusion practices, however there is a lack of consensus regarding the best transfusion practices in oncology.;Objectives: To compare the efficacy and safety of restrictive versus liberal transfusion strategy in patients with cancer.;Methods: We conducted a systematic literature review. We searched MEDLINE (Ovid), PUBMED (National Library of Medicine), EMBASE (Ovid) up to March 2015. Citations included in analysis were searched in Scopus (Elsevier) to determine if any unique studies were missed by the database searches. Bibliographies of highly significant articles were also examined for potential relevant citations otherwise not found. All controlled studies comparing the use of restrictive transfusion with liberal transfusion in adult oncology participants were included. Studies were limited to English language publications. Two review authors (LP and JT) independently assessed studies for inclusion, extracted data and appraised the quality of the included studies. The primary outcome of interest was all-cause mortality. Secondary outcomes included perioperative morbidity, transfusion-specific adverse events, and proportion of patients transfused. We pooled risk ratios and mean differences independently using fixed-effect models except where heterogeneity existed. In cases of heterogeneity, we utilized a random effects model.;Results: We screened 3262 studies. Six studies (3 randomized and 3 non-randomized) involving a total of 983 patients were included in the final review. The clinical context of the studies varied with 3 chemotherapy and 3 surgical studies. There was significant heterogeneity in the definition of a restrictive and liberal transfusion strategy with overlap between studies. Restrictive transfusion strategies were associated with a 36% reduced risk of receiving a perioperative transfusion (RR 0.64, 95% CI 0.49 to 0.83). There was no difference in mortality between the strategies (RR 1.00, 95% CI 0.32 to 3.18). There was no difference in surgical site infections, venous thromboembolism, or urinary tract infections between the two strategies. We were unable to pool the majority of outcomes of the chemotherapy studies due to heterogeneity in reporting. There were no differences in adverse events reported between the restrictive and liberal transfusion strategies in the individual studies. The risk of bias in all studies was moderate to high.;Conclusion: Restrictive strategy appears to decrease blood utilization without increasing morbidity or mortality in oncologic patients. The quality of studies investigating the efficacy and safety of restrictive verses liberal transfusion strategy are poor and better studies are warranted.