Diagnostic room-air pulse oximetry: effects of smoking, race, and sex☆☆☆
Received 7 February 2007; received in revised form 29 March 2007; accepted 3 April 2007.
Abstract
Objective
We sought to determine the distribution of oximetry (Spo2) values in awake, asymptomatic adults and the effect of personal characteristics on these values.
Methods
Using a cross-sectional design, we sampled oximetry readings in awake, asymptomatic adults in an emergency department setting. Personal characteristics were analyzed using logistic regression, with lower oximetry readings, defined by the 20th percentile, as the dependent variable.
Results
Of 871 eligible subjects, 50 (5.7%) had an Spo2 value less than 97%, and 13 (1.5%) had an Spo2 value less than 96%. Lower readings were associated with the following characteristics (odds ratio with 95% confidence interval): male sex, 3.8 (2.5-5.6); age ≥60 years, 2.4 (1.3-4.5); white race, 5.3 (3.6-7.8); obesity, 3.2 (2.1-4.8); history of asthma, 3.2 (1.6-6.2). Smoking was not associated with lower Spo2 values.
Conclusion
Room-air Spo2 values less than 97% are rare in asymptomatic, awake adults. White race and male sex are associated with lower Spo2 readings.
aDepartment of Emergency Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
bDivision of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
ABSTRACT