The effect of neuraxial blocks on surgical blood loss and blood transfusion requirements: a meta-analysis

PurposeThe aim of this study was to evaluate the effect of neuraxial blocks on surgical blood losses and on the number of patients requiring blood transfusion.MethodsA search of the American National Library of Medicine's PubMed up to November 12, 2004, was performed. Twenty-four studies could be kept for analysis.ResultsRegional anesthesia reduced the number of transfused patients for total hip replacement (P = 0.0009) and spinal fusion (P = 0.04). A reduction of measured blood loss that did not lead to a reduction in the number of transfused patients was also found for fractured hip surgery (P < 0.0001), lumbar disk surgery (P = 0.01), peripheral vascular surgery (P = 0.03), retropubic prostatectomy (P = 0.02), cesarean section (P < 0.0001), and bowel surgery (P = 0.0008).In summary neuraxial blocks have a clear and definite effect on surgical blood loss, but this effect do not usually lead to a reduction in the number of transfused patients except for patients undergoing total hip replacement and spinal fusion.