Evaluation of predictive factors related to the presence or absence of supplemental oxygen therapy and comparison of physical functions after video-assisted thoracic surgery

We performed a retrospective study of 102 individuals to evaluate predictive factors for needing supplemental oxygen therapy following video-assisted thoracic surgery (VATS) and to compare patients’ physical functions before and after surgery. Prior to surgery, we evaluated quadriceps torque, 6-minute walk distance (6MWD), timed up and go test, and grip strength. During the 6MWD, patients’ oxygen saturation was recorded every minute. Quadriceps torque and 6MWD were evaluated again following surgery. The indication for supplemental oxygen therapy was determined based on desaturation (<85%) during the 6MWD in room air. A total of 14 patients needed oxygen therapy at discharge (group A), while 88 patients did not need oxygen therapy (group B). In group A, the postoperative 6MWD was repeated with supplemental oxygen. Compared with the same parameters in group B, in group A the percentage diffusing capacity for carbon monoxide was significantly lower (p=0.011), while a history of smoking (p=0.016), exercise-induced hypoxemia (EIH, p<0.001), chronic obstructive pulmonary disease (p<0.001), and interstitial pneumonia (p=0.008) were significantly higher. Logistic regression analysis showed that EIH was an independent risk factor for requiring supplemental oxygen therapy following surgery (odds ratio: 46.2, 95% CI: 9–237.1; p<0.001). In group A, patients’ minimum oxygen saturation was significantly improved by oxygen administration (83.4±3.4 vs. 87.7±3.3, p=0.002), but there was no difference in walking distance (359.5±64.2 vs. 353.6±41.6, p=0.482). Our data indicate that patients should be preoperatively evaluated to predict postoperative hypoxemia and that this evaluation could complement the prediction of postoperative need for oxygen therapy.