Impact of SpHb Monitoring on Transfusion

Continuous and Noninvasive Hemoglobin Monitoring Reduces Red Blood Cell Transfusion During Neurosurgery: A Prospective Cohort Study

Continuous and noninvasive hemoglobin (SpHb) monitoring provides clinicians with real-time trending of changes or lack of changes in hemoglobin, which has the potential to alter red blood cell (RBC) transfusion decision making. The objective of this study was to evaluate the impact of SpHb monitoring on RBC transfusions in high blood loss surgery. The investigators hypothesize that SpHb will improve blood transfusion practice in the for of change the number of blood unit per patient and improve the outcome regards the time to take decision of transfusion trigger.

Eligible patients scheduled for neurosurgeries were enrolled into either a standard care group (Control Group) or an intervention group (SpHb Group). The Control Group received typical anesthesia care including estimated blood loss (EBL) assessment and intraoperative hemoglobin measurements from the central laboratory (Hb). Blood samples were taken when EBL was ≥15% of total blood volume. RBC transfusion was initiated if Hb was ≤10 g/dL and continued until the EBL was replaced and Hb >10g/dL was confirmed. The SpHb Group followed the same transfusion practice as the Control Group except the anesthesiologist was guided by the addition of SpHb monitoring with blood samples still taken pre- and post-transfusion. Additionally, the absolute and trend accuracy of SpHb compared to Hb was evaluated. Potential cost savings from reduced RBC utilization will be calculated if occured.

Control Group received standard anesthesia care including intraoperative blood sampling when estimated blood loss was ≥15% of total blood volume and transfusion when hemoglobin was ≤10 g/dL.

Continuous non-invasive hemoglobin monitoring (SpHb monitoring) was provided to the anesthesiologist to influence administration of care

Anesthesiologist is provided with real-time continuous non-invasive hemoglobin monitoring to influence care provided to patient

Determine whether using SpHb can affect the quantity of RBC transfused, per patient receiving a transfusion.

To assess absolute accuracy, or single point comparison, paired SpHb and Hb measurements were compared pre- and post- transfusion and bias and standard deviation were calculated. A Bland Altman graph with limits of agreement (1.96 x standard deviation, adjusted for the bias) was plotted to show agreement across the range of values. To assess trending, a regression plot of changes in Hb and corresponding changes in SpHb was plotted and a coefficient of determination (R2) was calculated

Potential cost saving resulting from reduced RBC utilization was estimated using activity-based cost estimates established by Shander et al.(8) which determined from both U.S. and European hospitals the total cost of transfusing one RBC unit to be between $522 and $1,183 with a mean and standard deviation of $761 ± $294.

Inclusion Criteria: ASA 1,2 patients from 15 to 60 years old scheduled for neurosurgical procedure Exclusion Criteria: Exclusion criteria included significant liver or renal disease, coagulopathy, pregnancy, anemia, and patients scheduled for procedures with excepted low blood loss.