Comparison of lung volume reduction surgery and physical training on health status and physiologic outcomes: a randomized controlled clinical trial

The effects of lung volume reduction treatment on diffusing capacity and gas exchange

Lung volume reduction (LVR) treatment in patients with severe emphysema has been shown to have a positive effect on hyperinflation, expiratory flow, exercise capacity and quality of life. However, the effects on diffusing capacity of the lungs and gas exchange are less clear. In this review, the possible mechanisms by which LVR treatment can affect diffusing capacity of the lung for carbon monoxide (D _LCO) and arterial gas parameters are discussed, the use of D _LCO in LVR treatment is evaluated and other diagnostic techniques reflecting diffusing capacity and regional ventilation (V')/perfusion (Q') mismatch are considered.A systematic review of the literature was performed for studies reporting on D _LCO and arterial blood gas parameters before and after LVR surgery or endoscopic LVR with endobronchial valves (EBV). D _LCO after these LVR treatments improved (40 studies, n=1855) and the mean absolute change from baseline in % predicted D _LCO was +5.7% (range -4.6% to +29%), with no real change in blood gas parameters. Improvement in V' inhomogeneity and V'/Q' mismatch are plausible explanations for the improvement in D _LCO after LVR treatment.

Chronic Obstructive Pulmonary Disease: A Palliative Medicine Review of the Disease, Its Therapies, and Drug Interactions

Despite significant advances in treatment, chronic obstructive pulmonary disease (COPD) remains a chronic and progressive disease that frequently leads to premature mortality. COPD is associated with a constellation of significant symptoms, including dyspnea, cough, wheezing, pain, fatigue, anxiety, depression, and insomnia, and is associated with increased morbidity. Palliative care is appropriate to support these patients. However, historically, palliative care has focused on supporting patients with malignant disease, rather than progressive chronic diseases such as COPD. Therapies for COPD often result in functional and symptomatic improvements, including health-related quality of life (HRQL), and palliative care may further improve symptoms and HRQL. Provision of usual palliative care therapies for this patient population requires understanding the pathogenesis of COPD and common disease-targeted pharmacotherapies, as well as an approach to balancing life-prolonging and HRQL care strategies. This review describes COPD and current targeted therapies and their effects on symptoms, exercise tolerance, HRQL, and survival. It is important to note that medications commonly used for symptom management in palliative care can interact with COPD medications resulting in increased risk of adverse effects, enhanced toxicity, or changes in clearance of medications. To address this, we review pharmacologic interactions with and precautions related to use of COPD therapies in conjunction with commonly used palliative care medications.

Improving Lung Function in Severe Heterogenous Emphysema with the Spiration Valve System (EMPROVE). A Multicenter, Open-Label Randomized Controlled Clinical Trial

Rationale: Less invasive, nonsurgical approaches are needed to treat severe emphysema.

Objectives: To evaluate the effectiveness and safety of the Spiration Valve System (SVS) versus optimal medical management.

Methods: In this multicenter, open-label, randomized, controlled trial, subjects aged 40 years or older with severe, heterogeneous emphysema were randomized 2:1 to SVS with medical management (treatment) or medical management alone (control).

Measurements and Main Results: The primary efficacy outcome was the difference in mean FEV₁ from baseline to 6 months. Secondary effectiveness outcomes included: difference in FEV₁ responder rates, target lobe volume reduction, hyperinflation, health status, dyspnea, and exercise capacity. The primary safety outcome was the incidence of composite thoracic serious adverse events. All analyses were conducted by determining the 95% Bayesian credible intervals (BCIs) for the difference between treatment and control arms. Between October 2013 and May 2017, 172 participants (53.5% male; mean age, 67.4 yr) were randomized to treatment (n = 113) or control (n = 59). Mean FEV₁ showed statistically significant improvements between the treatment and control groups—between-group difference at 6 and 12 months, respectively, of 0.101 L (95% BCI, 0.060–0.141) and 0.099 L (95% BCI, 0.048–0.151). At 6 months, the treatment group had statistically significant improvements in all secondary endpoints except 6-minute-walk distance. Composite thoracic serious adverse event incidence through 6 months was greater in the treatment group (31.0% vs. 11.9%), primarily due to a 12.4% incidence of serious pneumothorax.

Conclusions: In patients with severe heterogeneous emphysema, the SVS shows significant improvement in multiple efficacy outcomes, with an acceptable safety profile.

Clinical trial registered with www.clinicaltrials.gov (NCT01812447).

Surgical and endoscopic interventions that reduce lung volume for emphysema: a systemic review and meta-analysis

BACKGROUND

Severe emphysema is a debilitating condition with few treatment options. Lung volume reduction procedures in the treatment of severe emphysema have shown excellent results in selected patients but their exact role remains unclear with studies reporting a wide variation in outcomes. We therefore aimed to evaluate the effects of volume reduction.

METHODS

We did a systematic review and meta-analysis. We searched MEDLINE on Sept 29, 2016, for trials of lung volume reduction in patients with emphysema, and we did an updated search on Embase and PubMed on June 18, 2018. We only included randomised controlled studies published in English evaluating the intervention with either sham or standard of care. Inclusion was limited to trials of techniques in which there was sustainable volume reduction. Primary outcomes were residual volume, FEV₁, St George's Respiratory Questionnaire (SGRQ), and 6-min walk distance (6MWT). Secondary outcomes were severe adverse events (including mortality), short-term mortality, and overall mortality. We extracted summary level data from the trial publications and where necessary we obtained unpublished data. A random-effects model with the I² statistic was used to determine heterogeneity and trial weight in each analysis. The study is registered with the PROSPERO database, number CRD42016045705.

FINDINGS

We identified 4747 references in the search, and included 20 randomised controlled trials of lung volume reduction involving 2794 participants with emphysema. Following lung volume reduction from any of the interventions in pooled analyses (ie, surgery, endobronchial valve, endobronchial coil, or sclerosing agents), the mean differences compared with the control were reduction in residual volume of 0·58 L (95% CI -0·80 to -0·37), increase in FEV₁ of 15·87% (95% CI 12·27 to 19·47), improvement in 6MWT of 43·28 m (31·36 to 55·21), and reduction in the SGRQ of 9·39 points (-10·92 to -7·86). The odds ratio for a severe adverse event, which included mortality, was 6·21 (95% CI 4·02 to 9·58) following intervention. Regression analysis showed improvements relative to the degree of volume reduction: FEV₁ (r²=0·86; p<0·0001), 6MWT (r²=0·77; p<0·0001), and SGRQ (r²=0·70; p<0·0001). Most studies were at high risk of bias for lack of blinding, and heterogeneity was high for some outcomes when pooled across all interventions, but was generally lower in the subgroups by intervention type.

INTERPRETATION

Despite limitations of high risk of bias and heterogeneity for some analyses, our results provide support that lung volume reduction in patients with severe emphysema on maximal medical treatment has clinically meaningful benefits. These benefits should be considered alongside potential adverse events.

FUNDING

None.

Reference equation for the incremental shuttle walk test in Japanese adults

BACKGROUND

The incremental shuttle walk test (ISWT) is widely used in clinical and research settings. However, there are no reference equations to predict the walk distance achieved in the ISWT (ISWD) for healthy Japanese adults. We aimed to establish a reference equation for the ISWD prediction in Japanese adults.

METHODS

The sample comprised 590 healthy Japanese subjects (237 male). All subjects performed the ISWT twice, and their anthropometric and demographic data were collected, including gender, age, height, weight, and body mass index (BMI).

RESULTS

Subjects walked 640 [490-793] m in the ISWT. The ISWD correlated (p < 0.001 for all) with age (r = - 0.51), gender (r = 0.56), weight (r = 0.39), and height (r = 0.62), but not with BMI (r = - 0.01, p = 0.74). The stepwise multiple regression model showed that age, gender, and height were independent contributors to the ISWT in healthy subjects, explaining 50% of the variability. The reference equation for the ISWD was: ISWD(m) = - 4.894 - 4.107 × Age (years) + 131.115 × Gender + 4.895 × Height (cm), where male gender = 1.

CONCLUSION

We have established a reference equation for the ISWD prediction in Japanese adults. The prediction accuracy was high (R² = 50%), and a reference equation was established using anthropometric and demographic variables that can be easily assessed in clinical settings. The reference equation developed in this study will be useful for evaluating the magnitude of exercise intolerance in Japanese adults.

History of lung volume reduction procedures

Lung volume reduction (LVR) procedures for emphysematous patients were firstly introduced in the second half of the twentieth century. Over time, from the first invasive surgical procedures, new less invasive techniques have been conceived. In regards to the surgical approach, the adoption of VATS and the execution, in selected centers, of a non-resectional approach, with folding of less functional lung tissue, reduced mortality and adverse events risks. As regards to the bronchoscopic approach, endobronchial valves (EBV) and intrabronchial valves (IBV) were initially proposed in the early 2000s to obtain segmental or lobar atelectasis of the more compromised lung parenchyma. Despite showing promising results with respect to improvement of pulmonary function tests, particularly forced expiratory volume in 1st second (FEV₁), and quality of life, and a good safety profile, valves showed disappointing results in presence of collateral ventilation, such as in cases of incomplete fissures. To overcome this technical issue, in the last 10 years, endobronchial coils have been designed and used. Having a compressive effect on the lung parenchyma where they are located, they are not affected by collateral ventilation. Randomized control trials (RCTs) on endobronchial coils showed a significant improvement in FEV₁ and quality of life, however this technique was not immune to side effects, particularly low respiratory tract infections and pneumothoraces. Besides bronchial valves (BV) and coils, airway by-pass stents have also been evaluated in a RCT but without reaching the desired endpoints. Other innovative procedures recently considered and delivered through bronchoscopy regards thermal energy, with vapour therapy, to achieve a scarring reaction of the emphysematous lung parenchyma, and polymeric foams used as lung sealants to achieve absorptive atelectasis. In conclusion, LVR procedures may be considered in carefully selected patients with symptomatic emphysema and severe lung hyperinflation, and might be personalized according to the anatomical characteristics of emphysematous area.

Surgical and endoscopic treatment for COPD: patients selection, techniques and results

Chronic obstructive pulmonary disease (COPD) is a very heterogeneous disease characterised by an obstructive lung pattern that constitutes worldwide a major cause of high morbidity and mortality. In the last decades, lung volume reduction surgery (LVRS) has demonstrated to be a potential good alternative to transplantation in patients affected by COPD. The trend toward minimally invasive techniques resulted not only in surgical procedures better tolerated by the patients but also in several endoscopic treatments modality that are rapidly gaining ground.

Lung volume reduction surgery in hypercapnic patients: a single-center experience from China

Background

Lung volume reduction surgery (LVRS) has shown early promise as a palliative therapy in severe emphysema, but with a controversy over its indications. The aim of this study was to evaluate whether patients with hypercapnia should be excluded from LVRS.

Methods

Total 15 cases of severe emphysema with the level of PaCO₂ exceeding 50 mmHg were retrospectively studied. Their basic characteristics, pulmonary function, preoperative and postoperative PaCO₂ level as well as postoperative complications were calculated statistically.

Results

All of the 15 patients received video-assisted thoracoscopic LVRS and finally discharged uneventfully from hospital after the surgical procedures. Nine cases were supported by mechanical ventilation after surgery with the median duration of 44 hours. One of them was treated by extracorporeal membrane oxygenation (ECMO) both during surgery and the first 4 days after surgery. The result of blood gas analysis on 3 months after hospital discharge decreased than that before surgery (60.07 vs. 55.61 mmHg, P=0.076), but without statistical significance.

Conclusions

The emphysematous patients with hypercapnia should not be excluded from the benefits of LVRS.

Lung volume reduction surgery for diffuse emphysema

BACKGROUND

Lung volume reduction surgery (LVRS) performed to treat patients with severe diffuse emphysema was reintroduced in the nineties. Lung volume reduction surgery aims to resect damaged emphysematous lung tissue, thereby increasing elastic properties of the lung. This treatment is hypothesised to improve long-term daily functioning and quality of life, although it may be costly and may be associated with risks of morbidity and mortality. Ten years have passed since the last version of this review was prepared, prompting us to perform an update.

OBJECTIVES

The objective of this review was to gather all available evidence from randomised controlled trials comparing the effectiveness of lung volume reduction surgery (LVRS) versus non-surgical standard therapy in improving health outcomes for patients with severe diffuse emphysema. Secondary objectives included determining which subgroup of patients benefit from LVRS and for which patients LVRS is contraindicated, to establish the postoperative complications of LVRS and its morbidity and mortality, to determine which surgical approaches for LVRS are most effective and to calculate the cost-effectiveness of LVRS.

SEARCH METHODS

We identified RCTs by using the Cochrane Airways Group Chronic Obstructive Pulmonary Disease (COPD) register, in addition to the online clinical trials registers. Searches are current to April 2016.

SELECTION CRITERIA

We included RCTs that studied the safety and efficacy of LVRS in participants with diffuse emphysema. We excluded studies that investigated giant or bullous emphysema.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed trials for inclusion and extracted data. When possible, we combined data from more than one study in a meta-analysis using RevMan 5 software.

MAIN RESULTS

We identified two new studies (89 participants) in this updated review. A total of 11 studies (1760 participants) met the entry criteria of the review, one of which accounted for 68% of recruited participants. The quality of evidence ranged from low to moderate owing to an unclear risk of bias across many studies, lack of blinding and low participant numbers for some outcomes. Eight of the studies compared LVRS versus standard medical care, one compared two closure techniques (stapling vs laser ablation), one looked at the effect of buttressing the staple line on the effectiveness of LVRS and one compared traditional 'resectional' LVRS with a non-resectional surgical approach. Participants completed a mandatory course of pulmonary rehabilitation/physical training before the procedure commenced. Short-term mortality was higher for LVRS (odds ratio (OR) 6.16, 95% confidence interval (CI) 3.22 to 11.79; 1489 participants; five studies; moderate-quality evidence) than for control, but long-term mortality favoured LVRS (OR 0.76, 95% CI 0.61 to 0.95; 1280 participants; two studies; moderate-quality evidence). Participants identified post hoc as being at high risk of death from surgery were those with particularly impaired lung function, poor diffusing capacity and/or homogenous emphysema. Participants with upper lobe-predominant emphysema and low baseline exercise capacity showed the most favourable outcomes related to mortality, as investigators reported no significant differences in early mortality between participants treated with LVRS and those in the control group (OR 0.87, 95% CI 0.23 to 3.29; 290 participants; one study), as well as significantly lower mortality at the end of follow-up for LVRS compared with control (OR 0.45, 95% CI 0.26 to 0.78; 290 participants; one study). Trials in this review furthermore provided evidence of low to moderate quality showing that improvements in lung function parameters other than forced expiratory volume in one second (FEV1), quality of life and exercise capacity were more likely with LVRS than with usual follow-up. Adverse events were more common with LVRS than with control, specifically the occurrence of (persistent) air leaks, pulmonary morbidity (e.g. pneumonia) and cardiovascular morbidity. Although LVRS leads to an increase in quality-adjusted life-years (QALYs), the procedure is relatively costly overall.

AUTHORS' CONCLUSIONS

Lung volume reduction surgery, an effective treatment for selected patients with severe emphysema, may lead to better health status and lung function outcomes, specifically for patients who have upper lobe-predominant emphysema with low exercise capacity, but the procedure is associated with risks of early mortality and adverse events.

Lung volume reduction for emphysema

Advanced emphysema is a lung disease in which alveolar capillary units are destroyed and supporting tissue is lost. The combined effect of reduced gas exchange and changes in airway dynamics impairs expiratory airflow and leads to progressive air trapping. Pharmacological therapies have limited effects. Surgical resection of the most destroyed sections of the lung can improve pulmonary function and exercise capacity but its benefit is tempered by significant morbidity. This issue stimulated a search for novel approaches to lung volume reduction. Alternative minimally invasive approaches using bronchoscopic techniques including valves, coils, vapour thermal ablation, and sclerosant agents have been at the forefront of these developments. Insertion of endobronchial valves in selected patients could have benefits that are comparable with lung volume reduction surgery. Endobronchial coils might have a role in the treatment of patients with emphysema with severe hyperinflation and less parenchymal destruction. Use of vapour thermal energy or a sclerosant might allow focal treatment but the unpredictability of the inflammatory response limits their current use. In this Review, we aim to summarise clinical trial evidence on lung volume reduction and provide guidance on patient selection for available therapies.

Lung volume reduction surgery since the National Emphysema Treatment Trial: study of Society of Thoracic Surgeons Database

OBJECTIVES

The National Emphysema Treatment Trial demonstrated that lung volume reduction surgery is an effective treatment for emphysema in select patients. With chronic lower respiratory disease being the third leading cause of death in the United States, this study sought to assess practice patterns and outcomes for lung volume reduction surgery on a national level since the National Emphysema Treatment Trial.

METHODS

Aggregate statistics on lung volume reduction surgery reported in the Society of Thoracic Surgeons Database from January 2003 to June 2011 were analyzed to assess procedure volume, preoperative and operative characteristics, and outcomes. Comparisons with published data from the National Emphysema Treatment Trial were made using chi-square and 2-sided t tests.

RESULTS

In 8.5 years, 538 patients underwent lung volume reduction surgery, with 20 to 118 cases reported in the Society of Thoracic Surgeons Database per year. When compared with subjects in the National Emphysema Treatment Trial, subjects in the Society of Thoracic Surgeons Database were younger (P < .001), a larger proportion underwent the procedure thoracoscopically (P < .001), and forced expiratory volume in 1 second was 31% versus 28% of predicted (P < .001). When mortality was compared between subjects in the Society of Thoracic Surgeons Database and all subjects in the National Emphysema Treatment Trial randomized to surgery, there were no significant differences. However, mortality was 3% higher in subjects in the Society of Thoracic Surgeons Database when compared with the non-high-risk National Emphysema Treatment Trial subset (P = .005).

CONCLUSIONS

This study demonstrates the importance of patient selection and the need to develop consensus on appropriate benchmarks for mortality rates after lung volume reduction surgery. It underscores the need for dedicated centers to increasingly address the heavy burden of chronic lower respiratory disease in the United States in a multidisciplinary fashion, particularly for preoperative evaluation and postoperative management of emphysema.

[Lung volume reduction surgery for emphysema and bullous pulmonary emphysema]

The improvement of respiratory symptoms for emphysematous patients by surgery is a concept that has evolved over time. Initially used for giant bullae, this surgery was then applied to patients with diffuse microbullous emphysema. The physiological and pathological concepts underlying these surgical procedures are the same in both cases: improve respiratory performance by reducing the high intrapleural pressure. The functional benefit of lung volume reduction surgery (LVRS) in the severe diffuse emphysema has been validated by the National Emphysema Treatment Trial (NETT) and the later studies which allowed to identify prognostic factors. The quality of the clinical, morphological and functional data made it possible to develop recommendations now widely used in current practice. Surgery for giant bullae occurring on little or moderately emphysematous lung is often a simpler approach but also requires specialised support to optimize its results.

Several clinical interests regarding lung volume reduction surgery for severe emphysema: meta-analysis and systematic review of randomized controlled trials

Objectives

We aim to address several clinical interests regarding lung volume reduction surgery (LVRS) for severe emphysema using meta-analysis and systematic review of randomized controlled trials (RCTs).

Methods

Eight RCTs published from 1999 to 2010 were identified and synthesized to compare the efficacy and safety of LVRS vs conservative medical therapy. One RCT was obtained regarding comparison of median sternotomy (MS) and video-assisted thoracoscopic surgery (VATS). And three RCTs were available evaluating clinical efficacy of using bovine pericardium for buttressing, autologous fibrin sealant and BioGlue, respectively.

Results

Odds ratio (95%CI), expressed as the mortality of group A (the group underwent LVRS) versus group B (conservative medical therapies), was 5.16(2.84, 9.35) in 3 months, 3(0.94, 9.57) in 6 months, 1.05(0.82, 1.33) in 12 months, respectively. On the 3^rd, 6^th and 12^th month, all lung function indices of group A were improved more significantly as compared with group B. PaO2 and PaCO2 on the 6^th and 12^th month showed the same trend. 6MWD of group A on the 6^th month and 12^th month were improved significantly than of group B, despite no difference on the 3^rd month. Quality of life (QOL) of group A was better than of group B in 6 and 12 months. VATS is preferred to MS, due to the earlier recovery and lower cost. And autologous fibrin sealant and BioGlue seems to be the efficacious methods to reduce air leak following LVRS.

Conclusions

LVRS offers the more benefits regarding survival, lung function, gas exchange, exercise capacity and QOL, despite the higher mortality in initial three postoperative months. LVRS, with the optimization of surgical approach and material for reinforcement of the staple lines, should be recommended to patients suffering from severe heterogeneous emphysema.

[Surgical management of COPD distension]

INTRODUCTION

The impressive results seen when giant and compressing lung bullae are resected has inspired pneumonologists and thoracic surgeons to consider the possibility of applying a similar approach to the treatment of respiratory failure due to chronic obstructive pulmonary disease (COPD).

STATE OF THE ART

The major problem with this surgical indication lies in our ability to understand fully the pathophysiology of lesions and thus identify which emphysematous patients will have a response most similar to that achieved in purely bullous disease.

PERSPECTIVES

At the present time consideration should be given as to whether surgery is the only means of reducing pulmonary distension. Indeed, as endoscopic alternatives develop could they reproduce its beneficial effects and what would be their place compared to the surgery?

CONCLUSIONS

While waiting the development of these innovations, if the selection of the candidates is correct, the surgical treatment of lung hyperinflation can temporarily improve the quality of life of these patients by decreasing their dyspnea and increasing their exercise tolerance.

Taking a chance: the experience of lung volume reduction procedures for chronic obstructive pulmonary disease

OBJECTIVES

Lung Volume Reduction Surgery and Endo-Bronchial Valve(TM) insertion have expanded the therapeutic choices for chronic obstructive pulmonary disease (COPD). Controversy over efficacy, costs and risks limits access to these therapies. There are no published findings to guide our understanding of the patient's experience of surgery. The aim of this study is to understand the experience of palliative surgery for COPD.

METHODS

Merleau-Ponty's philosophy provided a framework for this Heideggerian phenomenological inquiry. Fifty-eight semi-structured interviews were conducted with 15 patients undergoing lung volume reduction procedures and 14 family members.

RESULTS

Patients and families felt they had no option but to 'take a chance' on surgery. Interventions frequently led to regaining lost tasks or easier completion of existing tasks. Where patients did not perceive an increase in things they could 'do', surgery allowed some to reclaim their sense of self. Regardless of the outcome, most did not regret their decision for surgery.

DISCUSSION

Meanings of surgery are not always tied to the visible, objective measurements of outsiders but may relate to regaining of self. Despite the concerns of some clinicians, patients and families are more likely to accept the risk of morbidity and mortality from surgery than has previously been realized.

Changes in arterial oxygenation and self-reported oxygen use after lung volume reduction surgery

RATIONALE

Lung volume reduction surgery (LVRS) is inconsistently reported to improve arterial oxygenation in patients with chronic obstructive pulmonary disease.

OBJECTIVES

We studied the effects of surgery on oxygenation in a large cohort and identified predictors of postoperative oxygenation improvement.

METHODS

We evaluated oxygenation in 1,078 subjects with chronic obstructive pulmonary disease enrolled in the National Emphysema Treatment Trial after LVRS compared with medical control subjects, including arterial blood gases, use of supplemental oxygen during treadmill walking, and self-reported use of oxygen during rest, exertion, and sleep.

MEASUREMENTS AND MAIN RESULTS

Pa(O(2)) breathing room air was equal in medical and surgical subjects at baseline (64.8 vs. 65.0 mm Hg, P = not significant), but lower in medical subjects at 6 months (63.6 vs. 70.0 mm Hg, P < 0.001), 12 months (63.9 vs. 68.7 mm Hg, P < 0.001), and 24 months (62.4 vs. 68.0 mm Hg, P < 0.001). Fewer medical subjects required oxygen for treadmill walking at baseline compared with surgical subjects (46 vs. 53%, P = 0.02). However, more medical subjects required oxygen for this activity at 6 months (49 vs. 33%, P < 0.001), 12 months (50 vs. 36%, P < 0.001), and 24 months (52 vs. 42%, P = 0.02). Self-reported oxygen use was greater in medical than in surgical subjects at 6, 12, and 24 months. Multivariate modeling of preoperative characteristics showed baseline oxygenation status was the best predictor of postoperative oxygenation.

CONCLUSIONS

LVRS increases Pa(O(2)), and decreases treadmill and self-reported use of oxygen for up to 24 months post-procedure. Clinical trial registered with www.clinicaltrials.gov (NCT 00000606).

Update in Surgical Therapy for Chronic Obstructive Pulmonary Disease

Bullectomy for giant bullae, lung volume reduction surgery, and lung transplantation are three surgical therapies that may benefit highly selected patients with advanced chronic obstructive pulmonary disease. In this article, each procedure is reviewed, with an emphasis on guidelines for patient selection and clinical outcomes for the practicing pulmonologist. Recent results from the National Emphysema Treatment Trial, updated International Society for Heart and Lung Transplantation Registry data, and revised guidelines for patient selection for lung transplantation are discussed.

Canadian Thoracic Society recommendations for management of chronic obstructive pulmonary disease - 2007 update

Chronic obstructive pulmonary disease (COPD) is a major respiratory illness in Canada that is both preventable and treatable. Our understanding of the pathophysiology of this complex condition continues to grow and our ability to offer effective treatment to those who suffer from it has improved considerably. The purpose of the present educational initiative of the Canadian Thoracic Society (CTS) is to provide up to date information on new developments in the field so that patients with this condition will receive optimal care that is firmly based on scientific evidence. Since the previous CTS management recommendations were published in 2003, a wealth of new scientific information has become available. The implications of this new knowledge with respect to optimal clinical care have been carefully considered by the CTS Panel and the conclusions are presented in the current document. Highlights of this update include new epidemiological information on mortality and prevalence of COPD, which charts its emergence as a major health problem for women; a new section on common comorbidities in COPD; an increased emphasis on the meaningful benefits of combined pharmacological and nonpharmacological therapies; and a new discussion on the prevention of acute exacerbations. A revised stratification system for severity of airway obstruction is proposed, together with other suggestions on how best to clinically evaluate individual patients with this complex disease. The results of the largest randomized clinical trial ever undertaken in COPD have recently been published, enabling the Panel to make evidence-based recommendations on the role of modern pharmacotherapy. The Panel hopes that these new practice guidelines, which reflect a rigorous analysis of the recent literature, will assist caregivers in the diagnosis and management of this common condition.

Computerized estimation of the lung volume removed during lung volume reduction surgery

RATIONALE AND OBJECTIVES

This study was designed to develop an automated method for estimating lung volume removed during lung volume reduction surgery (LVRS) using computed tomography (CT).

MATERIALS AND METHODS

The CT examinations of six patients who underwent bilateral LVRS were analyzed in this study. The resected lung tissue (right and left) was weighed during pathologic examination. An automated computer scheme was developed to estimate the lung volume removed using the CT voxel values and lung specimen weight. The computed fraction of lung volume removed was evaluated across a range of simulated surgical planes (ie, other than parallel to the CT image plane) and CT reconstruction kernels, and it was compared with the surgeons' postsurgical estimates.

RESULTS

The computed fraction of the lung volume removed during LVRS was linearly correlated with the resected lung tissue weight (Pearson correlation = 0.697, P = .012). The computed fraction of lung volume removed ranged from 12.9% to 51.7% of the total lung volume. The surgeons' postsurgical estimates of lung volume removed ranged from 30% to 33%. The percent difference between the surgeons' estimates and the computed lung volume removed as a percentage of the surgeons' estimates ranged from -72.3% to 57.0% with mean absolute difference of 29.7% (+/-20.7).

CONCLUSION

The preliminary findings of this study suggest that the proposed quantitative model should provide an objective measure of lung volume removed during LVRS that may be used to investigate the relationship between lung volume removed and outcome.

Lung volume reduction surgery for diffuse emphysema

BACKGROUND

Lung volume reduction surgery (LVRS) has been re-introduced for treating patients with severe diffuse emphysema. It is a procedure that aims to improve long-term daily functioning, although it is costly and may also be associated with a high risk of mortality.

OBJECTIVES

To assemble evidence from randomised controlled trials for the effectiveness of LVRS, and identify optimal surgical techniques.

SEARCH STRATEGY

Randomised controlled trials were identified using the Cochrane Airways Group Chronic Obstructive Pulmonary Disease (COPD) register. Searches are current to September 2005.

SELECTION CRITERIA

Randomised controlled trials that studied the safety and efficacy of LVRS in patients with diffuse emphysema were included. Studies were excluded if they investigated giant or bullous emphysema.

DATA COLLECTION AND ANALYSIS

Two independent review authors assessed trials for inclusion and extracted data. Where possible, data from more than one study were combined using RevMan 4.2 software.

MAIN RESULTS

Eight studies (1663 participants) met the entry criteria of the review. One study accounted for 73% of the participants recruited. Study quality was high, although blinding in studies was not possible. Ninety day mortality was significantly greater in all those who underwent LVRS (odds ratio 6.57 (95% CI 3.34 to 12.95), four studies, N = 1415). A subgroup analysis by risk status suggested that there was a subgroup of participants who were consistently at a significant risk of death, although this was only measured in one large study. The ninety day mortality data indicated that death was more likely with LVRS irrespective of risk status identified in one large study. Improvements in lung function, quality of life and exercise capacity were more likely with LVRS than with usual follow-up.

AUTHORS' CONCLUSIONS

The evidence summarised in this review is drawn from one large study, and several smaller trials. The findings from the large study indicated that in patients who survive up to three months post-surgery, there were significantly better health status and lung function outcomes in favour of surgery compared with usual medical care. Patients identified post hoc as being of high risk of death from surgery were those with particularly impaired lung function and poor diffusing capacity and/or homogenous emphysema. Further research should address the effect of this intervention on exacerbations and rate of decline in lung function and health status.

Is there any treatment other than drugs to alleviate dyspnea in COPD patients?

Patients with chronic obstructive pulmonary disease (COPD) are often limited in their activities by breathlessness. In these patients, exercise training may result in significant improvements in dyspnea, exercise tolerance, and health related quality of life (HRQoL). Further possibilities are to reduce ventilatory demand by decreasing the central respiratory drive or to lessen the perceived breathing effort by increasing respiratory muscle strength through specific respiratory muscle training. Upper limb training may also improve exercise capacity and symptoms in these patients through the modulation of dynamic hyperinflation. Ventilatory assistance during exercise reduces dyspnea and work of breathing and enhances exercise tolerance, although further studies should be required to define their applicability in the routine pulmonary rehabilitation programs. Lung volume resection surgery and lung transplantation in selected patients may control symptoms and improve HRQoL.