Utilization of the walking oximetry test to allow safe ambulation after pulmonary resection

Supplemental oxygen therapy after pulmonary resection can generally be tapered according to arterial blood gases at rest or pulse oximetry (SpO2). However, detecting exercise-induced oxygen desaturation can be difficult. We developed the walking oximetry test (WOT) so that thoracotomy patients could be rehabilitated without the risk of undetected ambulatory hypoxemia. The subjects were 58 patients who had undergone pulmonary resection and could walk at the bedside, with oxygen at 3 l/min via a nasal cannula. Patients with a value of more than 100 torr were allowed to walk with assistance for 6 min in the corridor. The oxygen flow rate was kept at 3 l/min and the walking pace was less than 50 m/min. SpO2 was determined using a wristwatch pulse oximeter. The test was stopped if the SpO2 fell below 90% or there was a score of 5 or more on the Borg scale (range 1-10). Oxygen desaturation occurred in six patients (10%) during the WOT. These patients underwent ambulatory training with sufficient oxygen supplementation and were then tested again. Patients whose SpO2 values remained higher than 90% and who showed no more than 5% desaturation were permitted to walk in the corridor with oxygen at 3 l/min via a nasal cannula. All these patients had a Borg score of 4 or lower. The WOT is a reliable, nonvasive method for detecting exercise-induced oxygen desaturation during ambulation after pulmonary resection.