REVIEW ASOK DAS GUPTA, MD, MRCP JANET MAURER, MD Department of Pulmonary and Critical Care Medicine, Head, Section of Lung Transplantation, Kelsey-Seybold Clinic, Houston, Texas Department of Pulmonary and Critical Care Medicine, Cleveland Clinic Late-stage emphysema: When medical therapy fails ABSTRACT OST PATIENTS with chronic obstructive pulmonary disease (COPD) are man- Although most patients with emphysema are managed aged medically, but a small subset of patients medically, a small subset of severely disabled patients may who experience a progressive and accelerated become candidates for surgery. This paper discusses for the decline in lung function, increasing symp- internist who works with emphysema patients the risks, toms, and severe disability1 may be candidates benefits, patient selection criteria, and outcome data for for one of three surgical treatments: three procedures in current use: bullectomy, lung • Bullectomy transplantation, and a new procedure which provides an • Lung transplantation alternative to transplantation—lung volume reduction. • Lung volume reduction. This article will briefly touch on medical management of emphysema, and then review KEY POINTS the rationale, indications, patient selection, All patients with emphysema require maximal maintenance and outcome data for each surgical approach. medical therapy for functional relief and also as a • ELEMENTS OF MAXIMAL MEDICAL THERAPY prerequisite for surgical intervention. Smoking cessation and oxygen therapy are the Patient selection for bullectomy is based on symptoms, cornerstones of management for all patients comorbid states, pulmonary function tests, imaging studies, with severe airflow obstruction and functional and, above all, the size of the bullae. limitation. All patients require maximal main- tenance medical therapy—not only for func- Studies fail to show any statistical advantage of double tional relief, but also as a prerequisite for any lung vs single lung transplantation as late as 5 years after surgical intervention. surgery; thus, since donor lungs are scarce, double lung Specific components of medical therapy transplantation should be reserved for select cases. include pharmacotherapy, pulmonary rehabil- itation, preventive vaccination, smoking ces- In lung volume reduction, abnormal and nearly functionless sation, and long-term oxygen therapy. When these treatments do not provide enough relief emphysematous lung tissue comprising 20% of the lung is and the patient is able to undergo surgery, con- resected, thus reducing the hyperinflated lungs closer to sideration of bullectomy, lung transplantation, normal lung volume. or lung volume reduction is appropriate. Drug therapy Pharmacologic interventions aim to relieve symptoms and include short-acting and long- acting beta-2 agonists (albuterol, salmeterol), anticholinergic agents (antimuscarinics), methylxanthines, and steroids.2-3-7 The role of CLEVELAND CLINIC JOURNAL OF MEDICINE VOLUME 66 • NUMBER 7 JULY / AUGUST 1999 415 Downloaded from www.ccjm.org on September 27, 2021. For personal use only. All other uses require permission. LATE-STAGE EMPHYSEMA DASGUPTA AND MAURER TABLE 5 Only smoking cessation and long-term oxygen therapy improve survival Indications for long-term The above interventions are associated with oxygen therapy* symptomatic improvement, but survival bene- fits have been demonstrated only with smok- Partial pressure of oxygen (Pa02) < 55 mm Hg or oxygen saturation < 88% ing cessation and long-term oxygen therapy. Smoking cessation. Although smoking Pa02 56 to 59 mm Hg or oxygen saturation 89%, if cessation fails to regain lost FEVj, it reduces Electrocardiographic evidence of cor pulmonale, or the accelerated annual rate of decline in FEVi Edema due to congestive heart failure, or seen in smokers, and may even reduce the Hematocrit > 56% decline to levels seen in lifetime nonsmokers Medicare-reimbursable to correct hypoxemia during if stopped at an early stage. Exercise, if Pa02 < 55 mm Hg or oxygen saturation < 88% Oxygen therapy. Both the Medical Sleep, if Pa02 < 55 mm Hg or oxygen saturation < 88% Council Research trial and the Nocturnal Drop in Pa02 > 10 mm Hg or oxygen saturation > 5% with Oxygen Therapy Trial demonstrated a survival signs or symptoms of hypoxia benefit from continuous oxygen therapy, with survival directly related to the total number of 15 16 "Medicare requires recertification and retesting in 60 to 90 days if Pa02 hours of oxygen used. - In patients in whom > 55 mm Hg, or oxygen saturation > 88% when oxygen was prescribed; conventional oxygen delivery systems may be recertification in all patients required after 1 year problematic or fail to achieve adequate oxy- genation, a transtracheal oxygen system may be a more effective alternative to achieve steroids in slowing the rate of decline in FEVj therapeutic blood oxygen levels with lower is still unclear; results from ongoing long-term flow rates.17 Physiologic improvement from studies (ISOLDE, EUROSCOP) are expected long-term oxygen therapy includes reduction shortly. Steroids seem to offer clear-cut benefit in dyspnea, maximal voluntary ventilation, when used during acute exacerbations.8 polycythemia, pulmonary hypertension, Smoking Similar benefits during an acute exacerbation hypoxia associated with rapid eye movement cessation and have also been shown with the use of antibi- during sleep, and nocturnal arrhythmias. It otics compared with placebo.9 also results in improved arterial oxygenation, oxygen therapy neuropsychiatric function, and exercise toler- are still the Vaccination ance (table 1). Preventive vaccination against pneumococcus cornerstone of and annual vaccination against influenza are • BULLECTOMY management advised. A bulla is an airspace greater than 1 cm in Pulmonary rehabilitation diameter formed as a result of pulmonary tis- All patients with emphysema should under- sue destruction.18 It maintains direct commu- take a pulmonary rehabilitation program and nication with bronchioles, but its walls lack should continue a home-based exercise pro- vascularity. Thus, the bulla does not partici- gram for life.10-12 An 8-week comprehensive pate in gas exchange and acts more like a rehabilitation program has been shown to space-occupying lesion with compressive result in a greater increase in maximal exercise effects on surrounding parenchyma. tolerance, oxygen uptake, and exercise endurance, with improvement in perceived Patient selection for bullectomy breathlessness and muscle fatigue when com- Patient selection for bullectomy should be pared to a similar period of education alone.13 based on symptoms, comorbid states, pul- Similar improvement in exercise tolerance monary function tests, imaging studies, and, and quality of life (for parameters of dyspnea, above all, the size of the bullae. Bullae in fatigue, emotion, and mastery) has been patients with emphysema are generally from 1 observed with home rehabilitation compared cm to 4 cm in diameter, but are sometimes to controls.14 much larger, occupying more than one third of 416 CLEVELAND CLINIC JOURNAL OF MEDICINE VOLUME 66 • NUMBER 7 JULY / AUGUST 1999 Downloaded from www.ccjm.org on September 27, 2021. For personal use only. All other uses require permission. the hemithorax.19 The larger the bulla, the TABLE 2 stronger the indication for surgery. Bullae predispose patients to pneumo- Selection criteria thorax. In one series of patients with bullous for lung transplantation 20 emphysema, the incidence of pneumotho- Between 70% and 130% of ideal body weight rax was 15.7% among patients followed with- Taking only a minimal dose of steroids (< 20 mg of prednisone) out surgery. In the same series, pneumothorax Approximate maximum age (years): was the indication for bullectomy in 19% of 65 (single lung recipients) cases. 60 (double lung recipients) Asymptomatic patients, irrespective of 55 (heart-lung recipients) the size of the bulla, generally are not operat- No substance abuse for more than 6 months ed on unless they work at a job that puts them Creatinine clearance > 50 mg/mL/min at high risk for pneumothorax (eg, commer- Chronic obstructive pulmonary disease 21 cial airline pilots). FEV| < 25% of predicted (without reversibility) Significant dyspnea remains the most Hypercapnia (PaC02 > 55 mm Hg) common indication for bullectomy. Pulmonary hypertension The bullae should be the likely cause of Progressive disease (eg, cor pulmonale) symptoms. If dyspnea and reduced pulmonary function are caused by widespread emphysema rather than by a giant bulla, then bullectomy may have no effect on symptoms or lung func- decrease in total lung volume may improve tion. For example, if a bulla is not a giant bulla diaphragmatic contour. Reduction in physio- (ie, it occupies less than 30% of the hemitho- logic dead space is unlikely, as bullae normal- rax) but the patient has a severely reduced ly do not participate in gas exchange. FEVi, a reduced diffusing capacity, hypoxia, Long-term results in properly selected hypercarbia, and disabling dyspnea, then patients have been good. The best outcome symptoms are likely due to the underlying has been seen in patients with giant bullae emphysema rather than to the bulla. occupying more than 50% of the hemitho- Bullectomy is 25 On the other hand, in a symptomatic rax and near-normal underlying lung func- generally for patient with a giant bulla and normal sur- tions. Subjective improvement in symptoms is rounding lung tissue, significant improvement often greater than objective increases