Abstract
Background: The effects of providing ventilatory assistance to patients with severe chronic obstructive pulmonary disease (COPD) during a high intensity outpatient cycle exercise programme were examined.
Methods: Nineteen patients (17 men) with severe COPD (mean (SD) forced expiratory volume in 1 second (FEV1) 27 (7)% predicted) underwent a 6 week supervised outpatient cycle exercise programme. Ten patients were randomised to exercise with ventilatory assistance using proportional assist ventilation (PAV) and nine (two women) to exercise unaided. Before and after training patients performed a maximal symptom limited incremental cycle test to determine peak work rate (Wpeak) followed by a constant work rate (CWR) test at 70% of Wpeak achieved in the baseline incremental test. Minute ventilation (VE), heart rate, and arterialised venous plasma lactate concentration [La+] were measured before and after each test.
Results: Mean training intensity (Wt/Wpeak) at 6 weeks was 15.2% (95% CI 3.2 to 27.1) higher in the group that used ventilatory assistance (p=0.016). Peak work rate after training was 18.4% (95% CI 6.4 to 30.5) higher (p=0.005) in the assisted group (p=0.09). [La+] at an identical workload after training was reduced by 30% (95% CI 16 to 44) in the assisted group (p=0.002 compared with baseline) and by 11% (95% CI –7 to 31) (p=0.08 compared with baseline) in the unassisted group (mean difference 18.4% (95% CI 3.3 to 40), p=0.09). A significant inverse relationship was found between reduction in plasma lactate concentration (ΔL) at an equivalent workload after training during the CWR test and Wt/Wpeak achieved during the last week of training (r=–0.7, p=0.0006).
Conclusions: PAV enables a higher intensity of training in patients with severe COPD, leading to greater improvements in maximum exercise capacity with evidence of true physiological adaptation.
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Selected References
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- 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]
- Borg G. A. Psychophysical bases of perceived exertion. Med Sci Sports Exerc. 1982;14(5):377–381. [PubMed] [Google Scholar]
- 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]
- 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]
- Clark T. J., Freedman S., Campbell E. J., Winn R. R. The ventilatory capacity of patients with chronic airways obstruction. Clin Sci. 1969 Apr;36(2):307–316. [PubMed] [Google Scholar]
- Dolmage T. E., Goldstein R. S. Proportional assist ventilation and exercise tolerance in subjects with COPD. Chest. 1997 Apr;111(4):948–954. doi: 10.1378/chest.111.4.948. [DOI] [PubMed] [Google Scholar]
- Forster H. V., Dempsey J. A., Thomson J., Vidruk E., DoPico G. A. Estimation of arterial PO2, PCO2, pH, and lactate from arterialized venous blood. J Appl Physiol. 1972 Jan;32(1):134–137. doi: 10.1152/jappl.1972.32.1.134. [DOI] [PubMed] [Google Scholar]
- Goldstein R. S., Gort E. H., Stubbing D., Avendano M. A., Guyatt G. H. Randomised controlled trial of respiratory rehabilitation. Lancet. 1994 Nov 19;344(8934):1394–1397. doi: 10.1016/s0140-6736(94)90568-1. [DOI] [PubMed] [Google Scholar]
- Griffiths T. L., Burr M. L., Campbell I. A., Lewis-Jenkins V., Mullins J., Shiels K., Turner-Lawlor P. J., Payne N., Newcombe R. G., Ionescu A. A. Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: a randomised controlled trial. Lancet. 2000 Jan 29;355(9201):362–368. doi: 10.1016/s0140-6736(99)07042-7. [DOI] [PubMed] [Google Scholar]
- Harms C. A., Babcock M. A., McClaran S. R., Pegelow D. F., Nickele G. A., Nelson W. B., Dempsey J. A. Respiratory muscle work compromises leg blood flow during maximal exercise. J Appl Physiol (1985) 1997 May;82(5):1573–1583. doi: 10.1152/jappl.1997.82.5.1573. [DOI] [PubMed] [Google Scholar]
- Hernandez P., Maltais F., Gursahaney A., Leblanc P., Gottfried S. B. Proportional assist ventilation may improve exercise performance in severe chronic obstructive pulmonary disease. J Cardiopulm Rehabil. 2001 May-Jun;21(3):135–142. doi: 10.1097/00008483-200105000-00003. [DOI] [PubMed] [Google Scholar]
- 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]
- Killian K. J., Leblanc P., Martin D. H., Summers E., Jones N. L., Campbell E. J. Exercise capacity and ventilatory, circulatory, and symptom limitation in patients with chronic airflow limitation. Am Rev Respir Dis. 1992 Oct;146(4):935–940. doi: 10.1164/ajrccm/146.4.935. [DOI] [PubMed] [Google Scholar]
- Maltais F., Jobin J., Sullivan M. J., Bernard S., Whittom F., Killian K. J., Desmeules M., Bélanger M., LeBlanc P. Metabolic and hemodynamic responses of lower limb during exercise in patients with COPD. J Appl Physiol (1985) 1998 May;84(5):1573–1580. doi: 10.1152/jappl.1998.84.5.1573. [DOI] [PubMed] [Google Scholar]
- Maltais F., LeBlanc P., Jobin J., Bérubé C., Bruneau J., Carrier L., Breton M. J., Falardeau G., Belleau R. Intensity of training and physiologic adaptation in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1997 Feb;155(2):555–561. doi: 10.1164/ajrccm.155.2.9032194. [DOI] [PubMed] [Google Scholar]
- Maltais F., LeBlanc P., Simard C., Jobin J., Bérubé C., Bruneau J., Carrier L., Belleau R. Skeletal muscle adaptation to endurance training in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1996 Aug;154(2 Pt 1):442–447. doi: 10.1164/ajrccm.154.2.8756820. [DOI] [PubMed] [Google Scholar]
- Maltais F., Reissmann H., Gottfried S. B. Pressure support reduces inspiratory effort and dyspnea during exercise in chronic airflow obstruction. Am J Respir Crit Care Med. 1995 Apr;151(4):1027–1033. doi: 10.1164/ajrccm/151.4.1027. [DOI] [PubMed] [Google Scholar]
- Maltais F., Simard A. A., Simard C., Jobin J., Desgagnés P., LeBlanc P. Oxidative capacity of the skeletal muscle and lactic acid kinetics during exercise in normal subjects and in patients with COPD. Am J Respir Crit Care Med. 1996 Jan;153(1):288–293. doi: 10.1164/ajrccm.153.1.8542131. [DOI] [PubMed] [Google Scholar]
- Maltais F., Sullivan M. J., LeBlanc P., Duscha B. D., Schachat F. H., Simard C., Blank J. M., Jobin J. Altered expression of myosin heavy chain in the vastus lateralis muscle in patients with COPD. Eur Respir J. 1999 Apr;13(4):850–854. doi: 10.1034/j.1399-3003.1999.13d26.x. [DOI] [PubMed] [Google Scholar]
- Nishimura M., Taniguchi A., Imanaka H., Taenaka N. Hypoplastic left heart syndrome associated with congenital right-sided diaphragmatic hernia and omphalocele. Chest. 1992 Jan;101(1):263–264. doi: 10.1378/chest.101.1.263. [DOI] [PubMed] [Google Scholar]
- Polese G., Vitacca M., Bianchi L., Rossi A., Ambrosino N. Nasal proportional assist ventilation unloads the inspiratory muscles of stable patients with hypercapnia due to COPD. Eur Respir J. 2000 Sep;16(3):491–498. doi: 10.1034/j.1399-3003.2000.016003491.x. [DOI] [PubMed] [Google Scholar]
- Polkey M. I., Hawkins P., Kyroussis D., Ellum S. G., Sherwood R., Moxham J. Inspiratory pressure support prolongs exercise induced lactataemia in severe COPD. Thorax. 2000 Jul;55(7):547–549. doi: 10.1136/thorax.55.7.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Richardson R. S., Sheldon J., Poole D. C., Hopkins S. R., Ries A. L., Wagner P. D. Evidence of skeletal muscle metabolic reserve during whole body exercise in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1999 Mar;159(3):881–885. doi: 10.1164/ajrccm.159.3.9803049. [DOI] [PubMed] [Google Scholar]
- Sala E., Roca J., Marrades R. M., Alonso J., Gonzalez De Suso J. M., Moreno A., Barberá J. A., Nadal J., de Jover L., Rodriguez-Roisin R. Effects of endurance training on skeletal muscle bioenergetics in chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1999 Jun;159(6):1726–1734. doi: 10.1164/ajrccm.159.6.9804136. [DOI] [PubMed] [Google Scholar]
- Younes M. Proportional assist ventilation, a new approach to ventilatory support. Theory. Am Rev Respir Dis. 1992 Jan;145(1):114–120. doi: 10.1164/ajrccm/145.1.114. [DOI] [PubMed] [Google Scholar]