Non-pharmacological management of chronic obstructive pulmonary disease
Issue: BCMJ,
vol. 50 , No. 2 , March 2008 ,
Pages 90-96 Clinical Articles
Chronic obstructive pulmonary disease (COPD) is a complex condition with many aspects that are amenable to therapy. A better understanding of the physiology of COPD and better tools to evaluate outcomes have led to advances in our ability to treat this disease. Pharmacological approaches can improve patients’ quality of life considerably by reducing dyspnea and limiting exacerbations. Nonpharmacological approaches can also improve quality of life and prolong survival for patients. Education on a number of topics (including the importance of smoking cessation), oxygen therapy, pulmonary rehabilitation, and surgery can all have an impact on the course of COPD. Although the nonpharmacological interventions at our disposal are not yet consistently available throughout BC, these interventions do promise to change the course of this disabling disease.
Education in self-management strategies, oxygen therapy, pulmonary rehabilitation, and surgical interventions all contribute to long-term survival for COPD patients.
Chronic obstructive pulmonary disease (COPD) is a complex condition. The nonpharmacological component of COPD management is at least as important as the pharmacological management. Nonpharmacological interventions can be applied to patients with stable COPD and acute COPD exacerbations.
These nonpharmacological measures, which can improve both long- and short-term survival, include patient education and oxygen therapy, as well as pulmonary rehabilitation, noninvasive positive pressure ventilation, and surgical interventions such as lung volume reduction surgery and lung transplantation. The recently updated Canadian Thoracic Society recommendations for management of COPD refers to all of these nonpharmacological approaches (www.copdguidelines.ca). [1]
Education
Specific educational interventions provided by the family practitioner, respirologist, and respiratory health care team, such as teaching effective inhaler technique, have been shown to improve lung function and exercise performance.[1,2] Education is the key to any self-management program. Topics for education include the following:
• The importance of smoking cessation—the single most effective intervention to reduce the risk of developing COPD and to slow its progression.
• The pathogenesis of COPD and the rationale for medical therapy.
• Effective inhaler technique.
• How to self-manage with case manager participation.
• How to recognize and treat acute exacerbations of COPD by following an “Action Plan.”
• Strategies to alleviate dyspnea.
• Advanced directives and/or end-of-life preparation.
• Educational resources.
COPD patients with an understanding of the disease process can become more active and effective participants in disease management. Education can reduce health care utilization by itself and by managing acute exacerbations.
The Action Plan referred to above helps patients to recognize an exacerbation and seek appropriate interventions. (A COPD exacerbation is a sustained worsening of dyspnea that lasts for at least 48 hours and requires an increase in medication.) When a patient with moderate to severe COPD is expectorating purulent sputum during an exacerbation, the Action Plan directs the patient to take an antibiotic and a course of prednisone, an approach that has been shown to reduce ER visits and hospitalizations.[3]
Oxygen therapy
Long-term oxygen therapy is essential for hypoxemic COPD patients as it has been shown to significantly improve survival.[4,5] Indications for long-term oxygen therapy in COPD for BC (consistent with national guidelines) include significant hypoxemia with either a Pao2 of equal to or less than 55 mm Hg, or a Pao2 less than 60 mm Hg in the presence of cor pulmonale, pulmonary hypertension, clinically significant congestive heart failure, or polycythemia (hematocrit of greater than 56%).
Patients who meet these criteria are provided with oxygen by the Home Oxygen Program. Oxygen should be applied for at least 15 hours per day, the longer the better, to maintain an oxygen saturation of greater than 90%.[4,5] Long-term oxygen therapy has been shown to improve pulmonary artery pressure and to lower the pulmonary vascular resistance in edematous patients.[6,7]
Continuous oxygen therapy reverses polycythemia and improves cardiac output, exercise tolerance, and quality of life.[8-13]
Oxygen desaturation during sleep is common in COPD and is associated with a poor sleep quality and increased mortality.[14-16] Nocturnal oxygen therapy alone reverses nocturnal hypoxemia in these patients if no other sleep-related disorder, such as obstructive sleep apnea, is present.
However, nocturnal oxygen therapy has not been shown to improve survival or quality of sleep in patients who experience hypoxemia only during sleep.[17-19] Nocturnal oxygen is, however, recommended to those who desaturate to less than 88% for more than 30% (minimum 4-hour oximetry study) of the night.
Oxygen therapy during exercise improves dyspnea and exercise tolerance.20 Oxygen therapy may increase exercise endurance by reducing dynamic hyperinflation and improving breathing pattern.[21,22] To qualify for short-term oxygen therapy for ambulation in BC, patients should have a sustained Spo2 (oxygen saturation as measured by pulse oximetry) of less than 88% for 1 minute during a 6-minute walk test.
To qualify for long-term oxygen therapy for ambulation, the patient must meet the following additional criteria:
• A measured improvement in a 6-minute walk test of 25% and at least 30 m with oxygen therapy and
• A 3-point reduction in the dyspnea score on the 7-point Borg Scale; or an SpO2 less than 80% with ambulation as in the BC Home Oxygen Program medical criteria (www.vch.ca/programs/hop.htm).
The Borg Scale allows subjects to grade the severity of shortness of breath they are experiencing during exercise. In BC 6-minute walk testing is best done at one of the many Category 3 lung function laboratories located in all major centres through the Home Oxygen Program.
Pulmonary rehabilitation
Pulmonary rehabilitation is a multidisciplinary program of care designed to optimize physical and social performance and autonomy.[23] It is tailored to the individual patient. Components of pulmonary rehabilitation include exercise training, psychosocial and behavioral interventions, and nutritional therapy.
A typical exercise program involves strength and endurance training. Exercise programs are individualized to increase exercise capacity and strength; they mainly focus on the lower limbs, but upper extremity exercises are also often part of the routine. Benefits of pulmonary rehabilitation include the following:
• Relief of dyspnea: Pulmonary rehabilitation improves exertional dyspnea and dyspnea associated with daily activities.[24-34]
• Improvement in exercise capacity: Pulmonary rehabilitation improves exercise tolerance, peak oxygen uptake, endurance time, functional walking distance, and peripheral and respiratory muscle strength.[25,29-33,35]
• Improvement in health status: Pulmonary rehabilitation is associated with an improvement in disease-specific and general aspects of health.[25,26,29,31,36] This occurs by alleviating symptoms such as dyspnea and fatigue, and by improving emotional function, activity level, and quality of life.
• Prevention of complications and exacerbations: Although pulmonary rehabilitation may not influence the frequency of hospitalization, it has been shown to reduce the duration of hospital stay (10.4 versus 21.0 days).[32] Other trials have concluded that pulmonary rehabilitation is associated with fewer exacerbations and more efficient primary care utilization.[37-40]
• Long-term benefits: The effects of pulmonary rehabilitation on symptoms, activity, and quality of life are usually sustained for several months after the program ends.[37-44] If program activities are not continued there is progressive loss of the acquired benefits. Although pulmonary rehabilitation has not been shown to improve FEV1 (forced expiratory volume in 1 second), one clinical trial has shown that the nutritional intervention component of pulmonary rehabilitation improves survival.[45]
Indications for pulmonary rehabilitation
COPD patients with all of the following criteria should be considered for referral for pulmonary rehabilitation:
• Patient is clinically stable but symptomatic.
• Patient has experienced a reduction in activity level and an increase in dyspnea despite pharmacological therapy.
• Patient has no evidence of active ischemic heart, musculoskeletal, psychiatric, or other systemic disease.
• Patient is sufficiently motivated to participate.
Most regions in BC have pulmonary rehabilitation programs. However, access is not optimal and there is a need here and elsewhere to increase the availability of these programs. Increased availability could lead to starting this intervention at an earlier stage of the disease rather than as a last resort and could also allow pulmonary rehabilitation to be offered more economically. A strong argument can be made for increasing pulmonary rehabilitation programs based on their favorable cost-effectiveness profile.
Noninvasive positive pressure ventilation
Noninvasive positive pressure ventilation (NIPPV) is superior to medical therapy alone in the setting of a severe exacerbation of COPD.[46-56] One-year mortality was reported to be lower in patients receiving NIPPV for exacerbations of COPD than patients receiving either optimal medical therapy alone[57] or conventional mechanical ventilation.[58] A full face mask is shown to be more comfortable than a nasal or oral mask.[59] Patients with advanced COPD who are not candidates for active resuscitation or ICU admission may still benefit from NIPPV in the general ward with up to 60% hospital survival.[60-62]
Indications, precautions, and contraindications for NIPPV
NIPPV in the form of bilevel positive airway pressure therapy should be offered to COPD patients with severe exacerbations (pH less than 7.3) or those who remain excessively dyspneic despite appropriate therapy and oxygenation. Although NIPPV may be initiated safely for most patients in the respiratory ward, subgroups with more severe symptoms should be closely monitored while on NIPPV (i.e., in an intensive care setting) in case an emergency intervention is needed.55 NIPPV should be avoided in patients with the following:
• Respiratory arrest.
• Hemodynamic instability.
• High risk for aspiration.
• Impaired mental status or recent craniofacial trauma.
• Surgery or burns.
Modest sedation is accepted, but excessive sedation may predispose to aspiration. Finally, NIPPV is not indicated in stable patients with chronic hypercapnea.[63]
Lung volume reduction surgery
Patients with advanced upper lobe predominant emphysema should be considered for lung volume reduction surgery (LVRS). In BC, patients being considered for LVRS must be assessed for specific indications and contraindications (Table). There is increasing evidence for the benefits of LVRS,[64-69] which has been shown to improve health-related quality of life, exercise capacity, FEV1 and lung volumes at 2 years.[70-72]
Additionally, LVRS is associated with a significant reduction in mortality, especially in patients with upper lobe predominant emphysema and greatly reduced exercise capacity (less than 40 watts). Patients with upper lobe predominant emphysema with high exercise capacity had no survival benefits but showed sustained improvement in exercise capacity and health-related quality of life.
Patients with an FEV1 of less than 20% together with a DLco (diffusing capacity of the lung for carbon monoxide) of less than 20% or homogeneous distribution of emphysema were found to receive no benefit from LVRS.[73]
Recently, endobronchial lung volume reduction using a fibreoptic bronchoscopy and unidirectional endobronchial valves has been introduced as a possible future replacement for the more invasive and expensive LVRS.[74] More data from trials are needed before any recommendations can be made regarding this new technique.
Lung transplantation
Lung transplantation is indicated in patients with very advanced COPD who meet at least one of the following criteria:
• FEV1 less than 25% of predicted.
• Paco2 greater than 55 mmHg.
• Elevated pulmonary artery pressure with progressive deterioration.
COPD patients represent 60% of all single lung transplant recipients and 30% of bilateral lung transplant recipients.[75] COPD patients usually have a better outcome following a lung transplant than those with other conditions. The transplant-related complication responsible for long-term morbidity and mortality is bronchiolitis obliterans, which causes chronic graft dysfunction.
Conclusions
Nonpharmacological management of COPD improves quality of life and prolongs survival. Access to some promising interventions, however, is not province-wide. Oxygen therapy is available in BC to all who meet the Home Oxygen Program criteria.
Pulmonary rehabilitation and COPD education are not as readily available, particularly in rural parts of BC and even in some larger centres. Smoking cessation programs are readily available everywhere by different delivery methods (e.g., by telephone).
LVRS is a costly elective surgical procedure that is available in BC but is subject to significant wait times. Lung transplantation is also available, but is limited by donor lung availability. In spite of these limitations, COPD treatment has improved and the outlook for patients suffering with this disabling condition is indeed more positive than it was as recently as 5 years ago.
Competing interests
None declared.
References
1. O’Donnell DE, Aaron S, Bourbeau J, et al. Canadian Thoracic Society recommendations for management of chronic obstructive pulmonary disease—2007 update. Can Respir J 2007;14(suppl B):5B-32B.
2. Anthonisen NR, Connett JE, Murray RP; for the Lung Health Study Research Group. Smoking and lung function of Lung Health Study participants after 11 years. Am J Respir Crit Care Med 2002;166:675-679.
3. Bourbeau J, Julien M, Maltais F, et al. Reduction of hospital utilization in patients with chronic obstructive pulmonary disease: A disease-specific self-management intervention. Arch Intern Med 2003;163:585-591.
4. Berry D, Fry J, Hindley C, et al. Exacerbations of chronic bronchitis treatment with oxytetracycline. Lancet 1960;1:137-139.
5. Maltais F, Leblanc P, Jobin J, et al. Intensity of training and physiologic adaptation in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1997;155:555-561.
6. Weitzenblum E, Sautegeau A, Ehrhart M, et al. Long-term oxygen therapy can reverse the progression of pulmonary hypertension in patients with chronic obstructive pulmonary disease. Am Rev Respir Dis 1985;131:493-498.
7. MacNee W, Wathen CG, Flenley DC, et al. The effects of controlled oxygen therapy on ventricular function in patients with stable and decompensated cor pulmonale. Am Rev Respir Dis 1988;137:1289-1295.
8. Balter MS, Daniak N, Chapman KR, et al. Erythropoietin response to acute hypoxemia in patients with chronic pulmonary disease. Chest 1992;102:482-485.
9. Zielinski J. Effects of long-term oxygen therapy in patients with chronic obstructive pulmonary disease. Curr Opin Pulm Med 1999;5:81-87.
10. Mannix ET, Manfredi F, Palange P, et al. Oxygen may lower the O2 cost of breathing in chronic obstructive lung disease. Chest 1992;101:910-915.
11. Dean NC, Brown JK, Himelman RB, et al. Oxygen may improve dyspnea and endurance in patients with chronic obstructive pulmonary disease and only mild hypoxemia. Am Rev Respir Dis 1992;146:941-945.
12. Somfay A, Porszasz J, Lee SM, et al. Dose-response effect of oxygen on hypertension and exercise endurance in nonhypoxaemic COPD patients. Eur Respir J 2001;18:77-84.
13. Eaton T, Garrett JE, Young P, et al. Ambulatory oxygen improves quality of life of COPD patients: A randomised controlled study. Eur Respir J 2002;20:306-312.
14. Fletcher EC, Luckett RA, Goodnight-White S, et al. A double-blind trial of nocturnal supplemental oxygen for sleep desaturation in patients with chronic obstructive pulmonary disease and a daytime PaO2 above 60 mm Hg. Am Rev Respir Dis 1992;145:1070-1076.
15. Chaouat A, Weitzenblum E, Kessler R, et al. A randomized trial of nocturnal oxygen therapy in chronic obstructive pulmonary disease patients. Eur Respir J 1999;14:1002-1008.
16. Cormick W, Olson LG, Hensley MJ, et al. Nocturnal hypoxaemia and quality of sleep in patients with chronic obstructive lung disease. Thorax 1986;41:846-854.
17. Fleetham J, West P, Mezon B, et al. Sleep, arousals, and oxygen desaturation in chronic obstructive pulmonary disease. The effect of oxygen therapy. Am Rev Respir Dis 1982;126:429-433.
18. McKeon JL, Murree-Allen K, Saunders NA. Supplemental oxygen and quality of sleep in patients with chronic obstructive pulmonary disease. Thorax 1989;44:184-188.
19. Folgering H. Supplemental oxygen for COPD patients with nocturnal desaturations. Eur Respir J 1999;14:997-999.
20. Liker ES, Karnick A, Lerner L. Portable oxygen in chronic obstructive lung disease with hypoxemia and cor pulmonale. Chest 1975;68:236.
21. Somfay A, Porszasz J, Lee SM, et al. Dose-response effect of oxygen on hypertension and exercise endurance in nonhypoxaemic COPD patients. Eur Respir J 2001;18:77-84.
22. Rooyackers JM, Dekhuijzen PN, Van Herwaarden CL, et al. Training with supplemental oxygen in patients with COPD and hypoxaemia at peak exercise. Eur Respir J 1997;10:1278-1284.
23. Pulmonary rehabilitation: Official statement of the American Thoracic Society. Am J Respir Crit Care Med 1999;159:1666-1682.
24. Goldstein RS, Gort EH, Stubbing D, et al. Randomised controlled trial of respiratory rehabilitation. Lancet 1994;344:1394-1397.
25. Ries AL, Kaplan RM, Limberg TM, et al. Effects of pulmonary rehabilitation on physiologic and psychosocial outcomes in patients with chronic obstructive pulmonary disease. Ann Intern Med 1995;122:823-832.
26. Lacasse Y, Wong E, Guyatt GH, et al. Meta-analysis of respiratory rehabilitation in chronic obstructive pulmonary disease. Lancet 1996;348:1115-1119.
27. Wijkstra PJ, van der Mark TW, Kraan J, et al. Effects of home rehabilitation on physical performance in patients with chronic obstructive pulmonary disease (COPD). Eur Respir J 1996;9:104-110.
28. Reardon J, Awad E, Normandin E, et al. The effect of comprehensive outpatient pulmonary rehabilitation on dyspnea. Chest 1994;105:1046-1052.
29. Strijbos JH, Postma DS, van Altena R, et al. A comparison between an outpatient hospital-based pulmonary rehabilitation program and a home-care pulmonary rehabilitation program in patients with COPD. A follow-up of 18 months. Chest 1996;109:366-372.
30. Wedzicha JA, Bestall JC, Garrod R, et al. Randomized controlled trial of pulmonary rehabilitation in severe chronic obstructive pulmonary disease patients, stratified with the MRC dyspnoea scale. Eur Respir J 1998;12:363-369.
31. Griffiths TL, Burr ML, Campbell IA, et al. Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: A randomized clinical trial. Lancet 2000;355:362-368.
32. Finnerty JP, Keeping I, Bullough I, et al. The effectiveness of outpatient pulmonary rehabilitation in chronic lung disease. A randomized controlled trial. Chest 2001;119:1705-1710.
33. Troosters T, Gosselink R, Decramer M. Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: A randomized trial. Am J Med 2000;109:207-212.
34. O’Donnell DE, McGuire M, Samis L, et al. The impact of exercise reconditioning on breathlessness in severe chronic airflow limitation. Am J Respir Crit Care Med 1995;152:2005-2013.
35. Bendstrup KE, Ingemann Jensen J, Holm S, et al. Out-patient rehabilitation improves activities of daily living, quality of life and exercise tolerance in chronic obstructive pulmonary disease. Eur Respir J 1997;10:2801-2806.
36. Boueri FMV, Bucher-Bartelson BL, Glenn KA, et al. Quality of life measured with a generic instrument (Short Form-36) improves following pulmonary rehabilitation in patients with COPD. Chest 2001;119:77-84.
37. Ries AL, Kaplan RM, Limberg TM, et al. Effects of pulmonary rehabilitation on physiologic and psychosocial outcomes in patients with chronic obstructive pulmonary disease. Ann Intern Med 1995;122:823-832.
38. Griffiths TL, Burr ML, Campbell IA, et al. Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: A randomized controlled trial. Lancet 2000; 355:362-368.
39. Guell R, Casan P, Belda J, et al. Long-term effects of outpatient rehabilitation of COPD. A randomized trial. Chest 2000;117:976-983.
40. Troosters T, Gosselink R, Decramer M. Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: A randomized trial. Am J Med 2000;109:207-212.
41. Strijbos JH, Postma DS, van Altena R, et al. A comparison between an outpatient hospital-based pulmonary rehabilitation program and a home-care pulmonary rehabilitation in patients with COPD. Chest 1996;109:366-372.
42. Ketelaars CA, Abu-Saad HH, Schlosser MA, et al. Long-term outcome of pulmonary rehabilitation in patients with COPD. Chest 1997;112:363-369.
43. Engström CP, Persson LO, Larsson S, et al. Long-term effects of a pulmonary rehabilitation programme in outpatients with chronic obstructive pulmonary disease: A randomized controlled study. Scand J Rehabil Med 1999;1:207-213.
44. Foglio K, Bianchi L, Bruletti G, et al. Long-term effectiveness of pulmonary rehabilitation in patients with chronic airway obstruction. Eur Respir J 1999;13:125-132.
45. Schols AM, Slangen J, Volovics L, et al. Weight loss is a reversible factor in the prognosis of chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1998;157:1791-1797.
46. Bott J, Carroll MP, Conway JH, et al. Randomized controlled trial of nasal ventilation in acute ventilatory failure due to chronic obstructive airways disease. Lancet 1993;41:1555-1557.
47. Brochard L, Mancebo J, Wysocki M, et al. Noninvasive ventilation for acute exacerbations of chronic obstructive pulmonary disease. N Engl J Med 1995;333:817-822.
48. Kramer N, Meyer TJ, Meharg J, et al. Randomized, prospective trial of noninvasive positive pressure ventilation in acute respiratory failure. Am J Respir Crit Care Med 1995;151:1799-1806.
49. Angus RM, Ahmed AA, Fenwick LJ, et al. Comparison of the acute effects on gas exchange of nasal ventilation and doxapram in exacerbations of chronic obstructive pulmonary disease. Thorax 1996;51:1048-1050.
50. Barbe F, Togores B, Rubi M, et al. Noninvasive ventilatory support does not facilitate recovery from acute respiratory failure in chronic obstructive pulmonary disease. Eur Respir J 1996;9:1240-1245.
51. Ceikel T, Sungur M, Ceyhan B, et al. Comparison of noninvasive positive pressure ventilation with standard medical therapy in hypercapnic acute respiratory failure. Chest 1998;114:1636-1642.
52. Andeev SN, Tret’iakov AV, Grigor’iants RA, et al. Study of the use of noninvasive ventilation of the lungs in acute respiratory insufficiency due to exacerbation of chronic obstructive pulmonary disease. Anesteziol Reanimatol 1998;3:45-51.
53. Confaloniere M, Potena A, Carbone G, et al. Acute respiratory failure in patients with severe community-acquired pneumonia: A prospective randomized evaluation of noninvasive ventilation. Am Respir Crit Care Med 1999;160:1585-1591.
54. Martin TJ, Hovis JD, Costantino JP, et al. A randomized, prospective evaluation of noninvasive ventilation for acute respiratory failure. Am J Respir Crit Care Med 2000;161:807-813.
55. Plant PK, Owen JL, Elliott MW. Early use of non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease on general respiratory wards: A multicentre randomized controlled trial. Lancet 2000;355:1931-1935.
56. Wijkstra PJ, Lacasse Y, Guyatt GH, et al. Nocturnal non-invasive positive pressure ventilation for stable chronic obstructive pulmonary disease. Cochrane Database Syst Rev 2002;(3):CD002878.
57. Plant PK, Owen JL, Elliott MW. Non-invasive ventilation in acute exacerbations of chronic obstructive pulmonary disease: Long term survival and predictors of in-hospital outcome. Thorax 2001;56:708-712.
58. Conti G, Antonelli M, Navalesi P, et al. Noninvaisve vs. conventional mechanical ventilation in patients with chronic obstructive pulmonary disease after failure of medical treatment in the ward: A randomized trial. Intensive Care Med 2002;28:1701-1707.
59. Kwok H, McCormack J, Cece R, et al. Controlled trial of oronasal versus nasal mask ventilation in the treatment of acute respiratory failure. Crit Care Med 2003;31:468-473.
60. Levy M, Tanios MA, Nelson D, et al. Outcomes of patients with do-not-intubate orders treated with noninvasive ventilation. Crit Care Med 2004;32:2002-2007.
61. Schettino G, Altobelli N, Kacmarek RM. Noninvasive positive pressure ventilation reverses acute respiratory failure in select “do-not-intubate” patients. Crit Care Med 2005;33:1976-1982.
62. Benhamou D, Girault C, Faure C, et al. Nasal mask ventilation in acute respiratory failure. Experience in elderly patients. Chest 1992;102:912-917.
63. Chu CM, Chan VL, Wong IW, et al. Noninvasive ventilation in patients with acute hypercapnic exacerbation of chronic obstructive pulmonary disease who refused endotracheal intubation. Crit Care Med 2004;32:372-377.
64. Criner GJ, Cordova FC, Furukawa S, et al. Prospective randomized trial comparing bilateral lung volume reduction surgery to pulmonary rehabilitation in severe chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1999;160:2021-2027.
65. Goodnight-White S, Jones WJ, Baaklini J, et al. Prospective randomized controlled trial comparing bilateral lung volume reduction surgery (LVRS) to medical therapy alone in patients with severe emphysema. Chest 2000;118(suppl 4):102S.
66. Hillerdal G, Lofdahl CG, Strom K, et al.; the Swedish VOLREM Group. Comparison of lung volume reduction surgery and physical training on health status and physiologic outcomes: A randomized controlled clinical trial. Chest 2005;128:3489-3499.
67. Geddes D, Davies M, Koyama H, et al. Effects of lung volume reduction surgery in patients with severe emphysema. N Engl J Med 2000;343:239-245.
68. Pompeo E, Marino M, Nofroni I, et al. Reduction pneumoplasty versus respiratory rehabilitation in severe emphysema: A randomized study. Ann Thorac Surg 2000;70:948-954.
69. Goldstein RS, Todd TR, Guyatt G, et al. Influence of lung volume reduction surgery (LVRS) on health related quality of life in patients with chronic obstructive pulmonary disease. Thorax 2003;58:405-410.
70. Fishman A, Martinez F, Naunheim K, et al.; the National Emphysema Treatment Trial Research Group. A randomized trial comparing lung-volume-reduction surgery with medical therapy for severe emphysema. N Engl J Med 2003;348:2059-2073.
71. Miller JD, Berger RL, Malthaner RA, et al. Lung volume reduction surgery vs medical treatment for patents with advanced emphysema. Chest 2005;127:1166-1177.
72. Miller JD, Malthaner RA, Goldsmith CH, et al.; The Canadian Lung Volume Reduction Surgery Study. A randomized trial of lung volume reduction surgery versus best medical care for patients with advanced emphysema: A two-year study from Canada. Ann Thorac Surg 2006;81:314-320.
73. National Emphysema Treatment Trial Research Group. Patients at high risk of death after lung-volume-reduction surgery. N Engl J Med 2001;345:1075-1083.
74. Hopkinson NS, Toma TP, Hansell DM, et al. Effect of bronchoscopic lung volume reduction on dynamic hyperinflation and exercise in emphysema. Am J Respir Crit Care Med 2005;171:453-460.
75. Hosenpud JD, Bennett LE, Keck BM, et al. The Registry of the International Society for Heart and Lung Transplantation: Eighteenth Official Report—2001. J Heart Lung Transplant 2001;20:805-815.
Dr Ali Al Talag is a fellow in the Division of Respiratory Medicine at the University of British Columbia.
Dr Road is a respirologist with Vancouver Coastal Health, director of the COPD Clinic at the Lung Health Centre, and a professor in the Department of Medicine at UBC (www.thelungcentre.ca).
