Pulse oximetry in family practice: indications and clinical observations in patients with COPD

Purpose. To establish situations in which family physicians (FPs) consider pulse oximetry a valuable addition to their clinical patient assessment; to explore pulse oximetry results (SpO2) when used by FPs in patients with chronic obstructive pulmonary disease (COPD); to explore associations between SpO2 and other markers of COPD severity. Methods. We performed three separate studies: (i) interviews plus a Delphi consensus procedure with FPs experienced in using pulse oximetry to elucidate indications for pulse oximetry; (ii) analysis of SpO2 and clinical data in COPD patients who presented to FPs with deteriorating symptoms and (iii) analysis of SpO2, spirometry and clinical data in patients with stable COPD. Results. Interviewed FPs (n = 11) used their pulse oximeter for a range of acute (14) and non-acute (11) indications but valued it highest in acute (worsening of) dyspnoea, in suspected respiratory insufficiency/failure and in patients with COPD. In 88 patients with deteriorating COPD, 22% showed SpO2 ≤92%. Correlation between baseline forced expiratory volume in 1 second % predicted and SpO2 in patients presenting with acute COPD exacerbations was r = 0.55 (P = 0.001). In 207 patients with stable COPD, 6.3% showed SpO2 values ≤92%. SpO2 values were associated with Medical Research Council dyspnoea scores (P = 0.019). Conclusions. FPs report a wide range of indications for pulse oximetry in acute as well as non-acute situations. In COPD, pulse oximetry appears to be especially useful in patients with severe disease and worsening of symptoms. Pulse oximetry may have a role in the monitoring of patients with COPD with exercise-related dyspnoea.