Operation Everest II: Comparison of Four Instruments for Measuring Blood O2 Saturation
Abstract
The bias and precision of four different methods for determining O2 saturation (So2) were evaluated during a study of hypobaric hypoxia conducted with seven male subjects exposed progressively over a 40-day period to simulated altitudes from sea level (760 Torr) to 8,840 m (240 Torr). So2 of arterial and mixed venous blood samples were measured with the Instrumentation Laboratory 282 CO-oximeter (CO-OX), the Radiometer ABL-300 (ABL), and the Lex-O2-Con-K (LEX). Noninvasive measurements of arterial So2 were made with a Hewlett-Packard 47201A ear oximeter (EAR-OX). The CO-OX method was used as a secondary standard for comparison with the other methods because it has been validated against the classical Van Slyke method over a wide physiological range. The LEX results most closely approximated but consistently underestimated those of the CO-OX:LEX = 0. 93 CO-OX -0.86, standard error of the estimate (SEE) = 5.17, r = 0.98, n = 670. The ABL method appeared to combine two linear trends: for So2>75%, ABL = 0.84 CO-OX +14.4, SEE = 1.77, r = 0.97, n = 369;<75%, ABL = 0.98 CO-OX +5.9, SEE = 4. 44, r = 0.97, n = 486. The EAR-OX results were found to approximate those of the CO-OX at So2 values only >65%: EAR-OX = 1.07 CO-OX -6.12, SEE = 7.71, r = 0.98, n = 326. Hypobaric hypoxia; Tonometry; Reprints; Mixed venous saturation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1989
- Accession Number
- ADA219731
Entities
People
- Allen Cymerman
- Bruce A. Ruscio
- Charles S. Houston
- John R. Sutton
- Laurie A. Trad
- Mark K. Malconian
- Patricia M. Young
- Paul B. Rock
- Richard L. Burse
- Vincent A. Forte Jr.
Organizations
- United States Army Research Institute of Environmental Medicine