1998 OPEN FORUM Abstracts
PULSE OXIMETRY DURING WALKING AND BICYCLE EXERCISE.
Douglas MacIntyre, Barbara McMullen, RRT Rebecca Crouch, RRT, Neil MacIntyre, MD. Duke University Medical Center, Durham NC
Exercise training in pulmonary patients during pulmonary rehabilitation requires careful assessment and monitoring of oxygenation as ventilation-perfusion relationships can change markedly with exercise. This is often assessed by pulse oximetry using probes on various skin surfaces. We reasoned that the different types of exercise might have different effects on oxygenation and that the oximeter probe site might have its measurements affected by local perfusion changes as well as limb motion changes that occur with exercise. Accordingly, we undertook a study of pulse oximetry during exercise training in a group of chronic lung disease patients undergoing pulmonary rehabilitation. Our null hypothesis was that oximetry readings not be affected by probe location or type of exercise performed at a given exercise heart rate. METHODS. All patients with chronic lung disease undergoing exercise training were eligible for study. These patients exercised daily for 15 minutes on a bicycle ergometer (BIKE) and 15 minutes of track walking (WALK). On the day of testing, pulse oximetry readings were performed using either a Nellcor or a Novametrix device at the end of each exercise period. Readings were taken with the probe on the finger (FIN) or on the temple (TEM). Exercise heart rate (HR) was also recorded. Analysis of variance was performed with significance taken as P < 0.05.
RESULTS. Sixty two patients were studied. Group data is given in the table:
Exercise HR SpO2 (FIN) SpO2 (TEM)
BIKE 110+/-19 94.4+/-3.5* 96.5+/-2.9*
WALK 112+/-17 93.0+/-4.2* 94.6+/-4.4*
* P < 0.05 for BIKE vs WALK (both probe sites) and FIN vs TEM (both exercises)
CONCLUSIONS. For a given HR, bicycle exercise is associated with higher pulse oximetry readings than walking exercise. This may reflect different central cardiorespiratory responses or different peripheral perfusion responses during the different exercises. In addition, temporal probes read higher than finger probes during both forms of exercise. This probably reflects different scalp vs. digit perfusion changes during exercise.
The 44th International Respiratory Congress Abstracts-On-Disk®, November 7 - 10, 1998, Atlanta, Georgia.