Chest
Bias and Precision of Pulse Oximeters and Arterial Oximeters
Section snippets
MATERIAL AND METHODS
The Human Subjects Review Board of Children's Hospital of Oakland gave approval for this study. Five 31- to 34-year-old nonsmoking men free from lung, heart, or blood disease gave informed consent. All completed the test and none complained of excessive discomfort during the procedure.
After local anesthesia, a 20-gauge radial arterial catheter was placed in the nondominant wrist for collection of arterial blood samples. Four different pulse oximeters (Biox/Omeda 3700, Boulder, CO, designated as
RESULTS
We obtained 165 arterial samples and simultaneous pulse oximetry measurements. The mean and standard deviation of pH measurements were 7.40 ± 0.03 and of the PaCO2 were 41.3 ± 5.50. The mean carboxyhemoglobin was 2.0 percent and the mean methemoglobin was 0.3 percent. Thus, an oximeter with a bias of –2.3 relative to the sum of oxy-, carboxy- and methemoglobin would closely approximate the oxyhemoglobin saturation reading of the IL282 device. In no case was the carboxyhemoglobin greater than
DISCUSSION
Before accepting a new device in clinical practice, clinicians should be aware of the bias, precision, reproducibility, and limitations. This study confirms that noninvasive pulse oximeters perform adequately for clinical decision-making over the range of saturations likely to be encountered. Indeed, their performance compared favorably with that of conventional oximeters which use arterial blood samples. We found that caution should be exercised in interpreting pulse oximeter readings of less
ACKNOWLEDGMENT
The authors thank Drs. Marshall Klaus, Herman W. Lipow, Gabriella E. Molnar, Lily C. Kao and David Durand for their suggestions, and Joy Childers and Ceres C. Larkrith for preparation of the manuscript.
REFERENCES (11)
- et al.
Pulse oximetry in pediatric intensive care: Comparison with measured saturations and transcutaneous oxygen tension.
J Pediatr
(1985) - et al.
Pulse oximetry for continuous oxygen monitoring in sick newborn infants.
J Pediatr
(1986) - et al.
Spectrophotometric monitoring of arterial oxygen saturation in the fingertip.
Med Biol Eng Comput
(1980) - et al.
Evaluation of pulse oximetry.
Anesthesiology
(1983) - et al.
Effects of multiple scattering and peripheral circulation on arterial oxygen saturation measured with a pulse-type oximeter.
Med Biol Eng Comput
(1984)
Cited by (0)
Supported by grants from the Novametrix Corporation, the Fund for Pediatric Care and Research, and the Northern California Sudden Infant Death Syndrome Foundation.
Presented in part at the Annual Meeting, American Thoracic Society, New Orleans, May, 1987.
Manuscript received May 22; revision accepted August 11.