Study objectives: To determine whether pulse oximetry
accurately estimates arterial blood gas measurements during exercise in
the assessment of chronic beryllium disease (CBD) and beryllium
underwent maximal exercise physiology testing in a clinical-practice
setting. Oxygen saturation in the blood was measured through an
indwelling arterial line and by pulse oximetry.
Setting: All exercise physiology tests were performed in
the pulmonary physiology unit of the National Jewish Medical and
Research Center (NJMRC) between December 1985 and November 1998.
Patients: We analyzed the exercise physiology data for 168
individuals who were referred to NJMRC for evaluation of possible CBD
and underwent exercise testing. On evaluation, they subsequently
received diagnoses of either CBD or BeS.
BeS subjects, the percentage of oxygen saturation as measured by pulse
oximetry (Spo2) often underestimated the
percentage of arterial oxygen saturation
(Sao2) (mean [± SD] underestimation,
0.88 ± 4.6%) at maximum exercise and showed no significant
correlation (r = −0.13; p = 0.3). The use of
Spo2 misclassified 14.9% of BeS subjects as
having abnormal gas exchange levels (< 90%) that were normal by
arterial blood gas measurement. In contrast,
Spo2 and Sao2 values
correlated at maximum exercise in CBD subjects
(r = −0.55; p = 0.0001) without exhibiting
Spo2 underestimation of
Sao2, and misclassification occurred in only
Conclusions: These data suggest that pulse
oximetry cannot be used reliably to distinguish between CBD and BeS
and, thus, is not an adequate substitute for arterial blood gas
analysis with exercise.