Evaluation of multiwave pulse total-hemoglobinometer during general anesthesia.

Area of Science:

• Anesthesiology
• Medical Devices
• Clinical Chemistry

Background:

• Accurate hemoglobin monitoring is crucial for surgical patient management.
• Noninvasive methods offer potential advantages over traditional blood sampling.
• Evaluating new technologies for hemoglobin measurement is essential.

Purpose of the Study:

• To assess the accuracy and trending capability of a novel four-wavelength pulse-total hemoglobinometer.
• To compare noninvasive spectrophotometric hemoglobin (SpHb) measurements with CO-oximeter-derived hemoglobin.
• To determine the clinical utility of the device for transfusion decisions.

Main Methods:

• Prospective study involving 56 surgical patients.
• Continuous, noninvasive SpHb measurement using a pulse-total hemoglobinometer.
• Comparison with invasive CO-oximeter measurements on 225 samples.
• Statistical analysis including Bland-Altman, error grid, and Cohen kappa.

Main Results:

• Bias ± precision was 0.0 ± 1.4 g/dL (total) and -0.2 ± 1.3 g/dL (Hb 8-11 g/dL).
• 17% of samples fell into the intermediate risk category for therapeutic error.
• Concordance rate for trending was 77%, with a Cohen kappa of 0.38 for Hb < 10 g/dL.

Conclusions:

• The pulse-total hemoglobinometer demonstrated wide limits of agreement with CO-oximeter.
• Agreement was less than moderate, particularly at critical hemoglobin levels.
• The device is not recommended as a decision-making tool for transfusions.