Skip to main content
Thorax logoLink to Thorax
. 2000 Jul;55(7):547–549. doi: 10.1136/thorax.55.7.547

Inspiratory pressure support prolongs exercise induced lactataemia in severe COPD

M Polkey 1, P Hawkins 1, D Kyroussis 1, S Ellum 1, R Sherwood 1, J Moxham 1
PMCID: PMC1745811  PMID: 10856312

Abstract

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.



Full Text

The Full Text of this article is available as a PDF (88.6 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bianchi L., Foglio K., Pagani M., Vitacca M., Rossi A., Ambrosino N. Effects of proportional assist ventilation on exercise tolerance in COPD patients with chronic hypercapnia. Eur Respir J. 1998 Feb;11(2):422–427. doi: 10.1183/09031936.98.11020422. [DOI] [PubMed] [Google Scholar]
  2. Casaburi R., Patessio A., Ioli F., Zanaboni S., Donner C. F., Wasserman K. Reductions in exercise lactic acidosis and ventilation as a result of exercise training in patients with obstructive lung disease. Am Rev Respir Dis. 1991 Jan;143(1):9–18. doi: 10.1164/ajrccm/143.1.9. [DOI] [PubMed] [Google Scholar]
  3. Casaburi R., Porszasz J., Burns M. R., Carithers E. R., Chang R. S., Cooper C. B. Physiologic benefits of exercise training in rehabilitation of patients with severe chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1997 May;155(5):1541–1551. doi: 10.1164/ajrccm.155.5.9154855. [DOI] [PubMed] [Google Scholar]
  4. Cooke N. T., Wilson S. H., Freedman S. Blood lactate and respiratory muscle fatigue in patients with chronic airways obstruction. Thorax. 1983 Mar;38(3):184–187. doi: 10.1136/thx.38.3.184. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Engelen M. P., Casaburi R., Rucker R., Carithers E. Contribution of the respiratory muscles to the lactic acidosis of heavy exercise in COPD. Chest. 1995 Nov;108(5):1246–1251. doi: 10.1378/chest.108.5.1246. [DOI] [PubMed] [Google Scholar]
  6. Keilty S. E., Ponte J., Fleming T. A., Moxham J. Effect of inspiratory pressure support on exercise tolerance and breathlessness in patients with severe stable chronic obstructive pulmonary disease. Thorax. 1994 Oct;49(10):990–994. doi: 10.1136/thx.49.10.990. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Polkey M. I., Kyroussis D., Mills G. H., Hamnegard C. H., Keilty S. E., Green M., Moxham J. Inspiratory pressure support reduces slowing of inspiratory muscle relaxation rate during exhaustive treadmill walking in severe COPD. Am J Respir Crit Care Med. 1996 Oct;154(4 Pt 1):1146–1150. doi: 10.1164/ajrccm.154.4.8887619. [DOI] [PubMed] [Google Scholar]

Articles from Thorax are provided here courtesy of BMJ Publishing Group

RESOURCES