Abstract
Aim: To compare symptoms, peak heart rate (HR) and nadir arterial oxygen saturation (SpO2) during a 6-minute walk test (6MWT) in people following lobectomy for non-small cell lung cancer (NSCLC) with those elicited during a maximal symptom-limited cardiopulmonary exercise test (CPET).
Methods: People 6 to 10 weeks following lobectomy for primary NSCLC completed two 6MWTs (data were taken from the best) and one symptom-limited ramp CPET, over two days. Peak HR, nadir SpO2 and symptoms of dyspnoea (BORGd) and leg fatigue (BORGf) at the end of the tests were compared.
Results: Data were available on 19 participants (13 females, age 68±9yr [mean±SD]; BMI 26±6kg·m-2). Peak rate of oxygen uptake [VO2peak] was 15±3ml·kg-1·min-1 (64±15%predicted) and 6-minute walk distance [6MWD] was 501±72m [82±10%predicted]). Three participants reached a VO2peak >80%predicted during the CPET, whereas 10 participants had a 6MWD >80%predicted. Peak HR and symptoms were higher during the CPET than the 6MWT (HR 127±18 vs 118±15bpm; BORGd 7±3 vs 3±2; BORGf 7±3 vs 2±2, respectively; p < 0.04 for all). The peak HR elicited during the 6MWT was equivalent to 93±12% of that elicited during the CPET. Nadir SpO2 was lower during the 6MWT (93±3% vs 95±3%; p = 0.01). VO2peak and 6MWD were moderately correlated (r = 0.6; p = 0.007).
Conclusions: Although eliciting a lower SpO2, the 6MWT elicited less symptoms and a submaximal HR in people following lobectomy for NSCLC compared with the CPET. Studies investigating ventilatory and metabolic responses during the 6MWT are needed. More detailed analysis is required to determine responsiveness as well as usefulness of the 6MWT in this population.
- © 2014 ERS