Evaluation of Noninvasive Hemoglobin Measurements in Trauma Patients: A Repeat Study

Abstract

Introduction: Reliable, accurate, and non-invasive hemoglobin measurements would be useful in the trauma setting. The aim of this study was to re-examine the ability of the Masimo Radical 7 in this setting after recent hardware and software improvements.

Methods: Level 1 Trauma patients were prospectively enrolled in the study over a 9-mo period with the goal of obtaining 3 paired data points from 150 patients admitted to the ICU or IMU. Hospital laboratory hemoglobin values were compared with cyanomethemoglobin (HiCN) and Masimo device hemoglobin (SpHb) values using comparison plots and Bland-Altman analysis.

Results: A total of 380 patients were enrolled in the study with 150 of those being admitted to the ICU or IMU. Comparison of hospital lab hemoglobin and HiCN (n = 494) found a correlation of R2 = 0.92. Comparison of hospital lab hemoglobin and Masimo device hemoglobin (n = 218) found a correlation of R2 = 0.27. Bland-Altman analysis of the 218 of the comparable hospital hemoglobin and Masimo device hemoglobin values had a bias of 0.505 g/dL with 95% of values within the limits of agreement of 4.06 g/dL to -3.60 g/dL.

Conclusions: The Masimo Radical 7 device has the potential to provide timely, useful clinical information, but it is not currently able to serve as an initial noninvasive diagnostic tool for trauma patients. There was poor correlation between clinical Hgb and SpHb, and because of that, SpHb should not be used to evaluate hemoglobin levels in trauma patients.

Keywords: Hemoglobin; Masimo; Non-invasive; Radical 7; Trauma.