Mechanisms of relief of exertional breathlessness following unilateral bullectomy and lung volume reduction surgery in emphysema.

STUDY OBJECTIVE To explore mechanisms of relief of exertional breathlessness following surgery to reduce thoracic gas volume in patients with emphysema. MATERIALS AND METHODS We studied 8 patients with emphysema (FEV1 = 39 +/- 3% predicted; residual volume [RV] = 234 +/- 12% predicted; mean +/- SEM) who were severely breathless despite optimal pharmacotherapy and who underwent unilateral bullectomy for giant bullae (greater than one third hemithorax); 4 of these also had ipsilateral lung reduction (pneumectomy). Pulmonary function and cycle exercise performance (n = 6) were evaluated before and 13 +/- 3 weeks after surgery. Chronic breathlessness was measured with the Baseline Dyspnea Index and the Medical Research Council dyspnea scale. Exertional breathlessness was measured using Borg ratings at a standardized work rate (BorgSTD). RESULTS FEV1, FVC, and maximal inspiratory pressures increased postsurgery by 29 +/- 7% (p < 0.05), 24 +/- 10% (p = 0.06), and 39 +/- 12% (p < 0.01), respectively. Plethysmographic total lung capacity, RV, and functional residual capacity fell by 14 +/- 2%, 30 +/- 4%, and 18 +/- 3%, respectively (p < 0.001). All measures of chronic breathlessness improved significantly (p < 0.05). During exercise at a standardized work rate, BorgSTD fell 45% (p < 0.05), end-expiratory lung volume (EELV) fell 22% (p < 0.01), and breathing frequency (F) fell 25% (p = 0.08). By multiple stepwise regression analysis, 99% (p = 0.007) of the variance in symptom relief (delta BorgSTD) was explained by the combination of decreased ratio of the end-expiratory lung volume to total lung capacity, decreased F, and diminished mechanical constraints on tidal volume (tidal volume to vital capacity ratio). CONCLUSION Reduced exertional breathlessness at a given workload after volume reduction surgery was attributed to a combination of reduced thoracic hyperinflation, reduced F, and reduced mechanical constraints on lung volume expansion.

[1]  D. O’Donnell,et al.  The impact of exercise reconditioning on breathlessness in severe chronic airflow limitation. , 1995, American journal of respiratory and critical care medicine.

[2]  G. Criner,et al.  Effect of bullectomy on diaphragm strength. , 1995, American journal of respiratory and critical care medicine.

[3]  B. Make,et al.  Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease. American Thoracic Society. , 1995, American journal of respiratory and critical care medicine.

[4]  J. Cooper,et al.  Bilateral pneumectomy (volume reduction) for chronic obstructive pulmonary disease. , 1995, The Journal of thoracic and cardiovascular surgery.

[5]  D. O’Donnell,et al.  Breathlessness in patients with chronic airflow limitation. Mechanisms and management. , 1994, Chest.

[6]  J. Cooper.  Technique to reduce air leaks after resection of emphysematous lung. , 1994, The Annals of thoracic surgery.

[7]  D. O’Donnell,et al.  Exertional breathlessness in patients with chronic airflow limitation. The role of lung hyperinflation. , 1993, The American review of respiratory disease.

[8]  S. Teramoto,et al.  Quantitative assessment of dyspnea during exercise before and after bullectomy for giant bulla. , 1992, Chest.

[9]  F. Eldridge,et al.  Respiratory-associated thalamic activity is related to level of respiratory drive. , 1992, Respiration physiology.

[10]  N. Jones,et al.  Exercise capacity and ventilatory, circulatory, and symptom limitation in patients with chronic airflow limitation. , 1992, The American review of respiratory disease.

[11]  K. Nakahara,et al.  Prediction of postoperative performance status in patients with giant bulla. , 1992, Chest.

[12]  P. Leblanc,et al.  Effects of lung resection on pulmonary function and exercise capacity. , 1990, Thorax.

[13]  A. Wilson,et al.  The current status of surgery for bullous emphysema. , 1989, The Journal of thoracic and cardiovascular surgery.

[14]  H. Feldman,et al.  Families of lines: random effects in linear regression analysis. , 1988, Journal of applied physiology.

[15]  S. Gandevia,et al.  Neural mechanisms underlying the sensation of breathlessness: kinesthetic parallels between respiratory and limb muscles. , 1988, Australian and New Zealand journal of medicine.

[16]  P. Davenport,et al.  Respiratory-related cortical potentials evoked by inspiratory occlusion in humans. , 1986, Journal of applied physiology.

[17]  C. Westermann,et al.  Bullectomy for giant bullae in emphysema. , 1986, The Journal of thoracic and cardiovascular surgery.

[18]  C. Wells,et al.  The measurement of dyspnea. Contents, interobserver agreement, and physiologic correlates of two new clinical indexes. , 1984, Chest.

[19]  D. Cugell,et al.  Surgical management of emphysema. , 1983, Clinics in chest medicine.

[20]  M. Pearson,et al.  Surgical treatment of emphysematous bullae: late outcome. , 1983, Thorax.

[21]  D. Rodenstein,et al.  Frequency dependence of plethysmographic volume in healthy and asthmatic subjects. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[22]  W A Zin,et al.  A simple method for assessing the validity of the esophageal balloon technique. , 2015, The American review of respiratory disease.

[23]  A. Grassino,et al.  Effect of pressure and timing of contraction on human diaphragm fatigue. , 1982, Journal of applied physiology: respiratory, environmental and exercise physiology.

[24]  N. Jones.  Clinical Exercise Testing , 1982 .

[25]  G. Borg.  Psychophysical bases of perceived exertion. , 1982, Medicine and science in sports and exercise.

[26]  N. Jones,et al.  Pulmonary mechanics during exercise in subjects with chronic airflow obstruction. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[27]  M. Artvinli,et al.  Dyspnoea, disability, and distance walked: comparison of estimates of exercise performance in respiratory disease. , 1978, British medical journal.

[28]  D. Cugell,et al.  Long-term results of surgery for bullous emphysema. , 1974, The Journal of thoracic and cardiovascular surgery.

[29]  E. Gaensler,et al.  Evaluation of respiratory impairment. , 1966, Archives of environmental health.

[30]  J. Growdon,et al.  Physical properties of the lungs in giant cysts. Report of a case treated surgically. , 1962, New England Journal of Medicine.

[31]  Goldman Hi,et al.  Respiratory function tests; normal values at median altitudes and the prediction of normal results. , 1959 .

[32]  A. B. Dubois,et al.  The relationship between airway resistance, airway conductance and lung volume in subjects of different age and body size. , 1958, The Journal of clinical investigation.