Comparative evaluation of efficacy and safety of automated versus manual red cell exchange in sickle cell disease: A systematic review and meta-analysis
Vox sanguinis. 2022
BACKGROUND AND OBJECTIVES Exchange transfusion is a valuable treatment option in sickle cell disease (SCD) and is preferred over simple transfusion as it removes abnormal haemoglobin S (HbS) levels and reduces complications. This meta-analysis aims to evaluate the efficacy and safety profile of automated red cell exchange (aRBX) procedure over manual red cell exchange transfusion (MET) in SCD patients. MATERIALS AND METHODS A standard meta-analysis protocol was developed, and after performing a comprehensive literature search in PubMed/MEDLINE, Cochrane and International Clinical Trial Registry Platform (ICTRP), reviewers assessed eligibility and extracted data from nine relevant studies. A random effects model was used to estimate the pooled effect size calculated from the mean difference in HbS percentage, serum ferritin level and risk ratio for the adverse events. Quality assessment was done using the risk-of-bias assessment tool, and a summary of observations was prepared using standard Cochrane methodology with GradePro GDT. RESULTS The random-model analysis revealed a mean difference of 4.10 (95% CI: -3.29-11.49; Z = 1.09; p = 0.28) for HbS percentage, mean difference of 435.29 (95% CI: -73.74-944.32; Z = 1.68; p = 0.09) for serum ferritin and pooled risk ratio of 1.35 (95% CI: 0.63-2.87; Z = 0.77; p = 0.44) for adverse events. CONCLUSION This meta-analysis did not reveal any significant benefit of aRBX in reducing HbS percentage and attenuating the serum ferritin level when compared with MET. There was also no significant increased risk of adverse events detected in association with aRBX.
Preoperative transfusion in patients with sickle cell disease to prevent perioperative complications: A systematic review and meta-analysis
Background Sickle cell disease (SCD) is associated with perioperative vascular (SCD-related) and non-vascular complications. To minimize perioperative complications during elective surgery, either exchange blood transfusion or simple blood transfusion can be used. We systematically reviewed the literature and meta-analyzed randomized and observational trials comparing exchange transfusion to simple transfusion, as well as studies comparing preoperative transfusion to no transfusion to assess the relative risk (RR) and benefit of each strategy in sickle cell patients undergoing surgery. Methods Medline, Embase, and the Cochrane-controlled trial register were searched to identify studies that evaluated exchange transfusion to simple transfusion, as well as studies comparing any form of blood transfusion with no transfusion. Studies were evaluated according to a priori inclusion criteria and critically appraised using established internal validity criteria. Pooled RR was estimated using a random effects model. Results Three randomized trials and seven observational studies were included. We found there was no difference between exchange transfusion and simple transfusion for perioperative mortality, vascular, or non-vascular perioperative complications. However, transfusion-related complications (RR 2.41, 95% confidence interval (CI): 1.49-3.91) and the amount of blood transfused (mean difference 2.03, 95% CI: 1.23-2.83) were higher in those treated with exchange transfusion versus simple transfusion. Similarly, there was no difference in perioperative mortality, vascular, or non-vascular perioperative complications between those treated with preoperative transfusion strategy and no transfusion strategy. Conclusion Based on the current literature, neither preoperative exchange transfusion nor simple transfusion reduces perioperative complications in patients with SCD who are undergoing surgery; however, available studies were underpowered to detect a treatment effect.