Association between values of preoperative 6-min walk test and surgical outcomes in lung cancer patients with decreased predicted postoperative pulmonary function.

Abstract

We retrospectively investigated the possibility that the 6-min walk test (6MWT) could predict surgical outcomes in lung cancer patients with decreased predicted postoperative (ppo) lung function. Patients were enrolled based on their preoperative spirometry: <60% of the ppo forced expiratory volume in 1s (FEV1.0) or < 60% of the ppo lung carbon monoxide diffusion capacity (DLco). Morbidity, oxygen inhalation required > 10days, home oxygen therapy (HOT) requirement, unexpected readmission within 90days, and 90-day mortality were included as surgical outcomes. The correlations with walking distance and the minimum SpO2 (SpO2min) and maximum decrease in SpO2 (ΔSpO2) during the 6MWT were analyzed using logistic regression analysis, adjusting for age, sex, and surgical procedure. Altogether, 121 patients were analyzed. Logistic regression analysis revealed that higher ΔSpO2 and lower SpO2min were significantly correlated with a higher risk of prolonged need for oxygen inhalation and HOT, surgical morbidity, and 90-day mortality. Cut-off values of > 4% for ΔSpO2 were significant for prolonged oxygen inhalation and surgical morbidity. Cut-off values of < 89-91% for SpO2min were also significant for the need for prolonged oxygen inhalation, surgical morbidity, and HOT requirement. There were no significant correlations between walking distance and each surgical outcome. Oxygen desaturation during 6MWT was a good predictor for poor surgical outcomes in lung cancer patients with decreased ppo pulmonary function.