Validation of a non-invasive pulse CO-oximetry based hemoglobin estimation in normal blood donors

Introduction: Non-invasive hemoglobin estimation may increase the recruitment of blood donors. CO-oximetry hemoglobin estimation is a non-invasive method used to estimate the hemoglobin level. The primary objective of this study is to validate the pulse CO-oximetry based hemoglobin estimation in normal blood donors. Methods: We conducted a prospective observational study on 106 in a tertiary care hospital blood bank over a period of 4. weeks. We performed a Spot Hemoglobin concentration (Sp Hb) using Masimo Pronto-7 Pulse CO-oximetry, and compared it to a venous sample Hb concentration (Reference Hemoglobin; Ref Hb) measured using Abbott CELL-DYN Sapphire hematology analyzer. Age, gender, weight, height, blood pressure and reference hemoglobin were used in the multivariable linear regression model of the difference in measurement. Results: Total of 106 donors (98 males, 8 females) were enrolled with a mean age and Ref Hb of 27years (SD 6.2; 18-49) and 14.2g/dL (SD 1.2; 11.5-17) respectively. The mean Sp Hb was 14.4g/dL (SD 1.2;11.3-16.7). The mean difference between the Sp Hb and Ref Hb was 0.2g/dL (SD 1.2;-4.5 to 3) with a correlation coefficient of 0.46 (R²=21%). In the multivariable model, height (p=0.015) and Hb level (p<0.001) were statistically significant predictors. A strong correlation was found between the two CO-oximetry Hb measurements (coefficient 0.78, R²=60%). Conclusions: Our study validated the use of the CO-oximetry in blood donors. Larger prospective studies are needed to confirm our results.