Noninvasive continuous hemoglobin monitoring of blood transfusion in obstetric procedures

Background Non-invasive Hb (SpHb) may allow for a faster detection of clinically important blood loss, improve perioperative transfusion practices significantly and enable a faster evaluation of a patient's condition and a better blood treatment and may even reduce needless transfusions. This study determined the accuracy of continuous SpHb monitoring as a guide for fluid and blood transfusion practice using Masimo pulse co-oximetry in comparison with invasive Hb during elective cesarean section (CS).Methods This prospective cohort study was carried out on 60 pregnant women candidates for elective CS under general anesthesia. Participants were multigravida, aged between 18 and 45 years and carry a singleton fetus with ASA I–II. All had antepartum hemorrhage and were candidates for blood transfusion. Pre-induction of anesthesia (basal), pre-transfusion and post-transfusion SpHb and invasive Hb were assessed. The primary outcome parameter was the correlation between SpHb and invasive hemoglobin (Hb).Results There was a significant positive correlation between SpHb and Invasive Hb in baseline, pretransfusion and posttransfusion (r = 0.946, 0.902 and 0.698, respectively). Bland–Altman analysis between SpHb and invasive Hb reported low bias with moderate limits of agreement at baseline, pre-transfusion and post-transfusion [mean bias (limits of agreement): 0.348 (−0.584 and 1.280) g/dl, 0.314 (−0.561 and 1.188) g/dl and 0.348 (−0.584 and 1.280) g/dl, respectively]Conclusions In patients undergoing CS with antepartum hemorrhage, continuous SpHb through Masimo pulse co–oximetry demonstrated clinically acceptable accuracy of Hb measurement compared with Invasive Hb, even at low hemoglobin levels.