PT - JOURNAL ARTICLE AU - Polkey, Michael I AU - Hawkins, Peter AU - Kyroussis, Dimitris AU - Ellum, Sheric G AU - Sherwood, Roy AU - Moxham, John TI - Inspiratory pressure support prolongs exercise induced lactataemia in severe COPD AID - 10.1136/thorax.55.7.547 DP - 2000 Jul 01 TA - Thorax PG - 547--549 VI - 55 IP - 7 4099 - http://thorax.bmj.com/content/55/7/547.short 4100 - http://thorax.bmj.com/content/55/7/547.full SO - Thorax2000 Jul 01; 55 AB - BACKGROUND A physiological benefit from pulmonary rehabilitation in chronic obstructive pulmonary disease (COPD) is more probable if exercise is performed above the lactate threshold. This study was undertaken to investigate whether it was possible to extend the lactataemia of exercise using non-invasive inspiratory pressure support (IPS).METHODS Plasma lactate levels were measured in eight men with severe COPD who performed two treadmill walks at an identical constant work rate to a condition of severe dyspnoea; the second walk was supported by IPS.RESULTS Mean plasma lactate levels before the free and IPS assisted walks were 1.65 mmol/l and 1.53 mmol/l, respectively (p = NS). Lactate levels increased during both walks to 2.96 mmol/l and 2.42 mmol/l, respectively (p = 0.01 for each) but the duration of the IPS assisted walk was significantly greater than the free walk (13.6 minutes versus 5.5 minutes, p = 0.01).CONCLUSIONS Patients with severe COPD can sustain exercise induced lactataemia for longer if assisted with IPS. This technique may prove to be a useful adjunct in pulmonary rehabilitation.