Background: This NCI funded program project (P01) is an interdisciplinary research project focused on palliative care, quality of life (QOL), and symptom control in lung cancer. The purpose of this study is to test usual care versus integration of palliative care encompassing four dimensions of QOL.

Collective experience with pulmonary rehabilitation and disease management has shown that patients with lung diseases including COPD and restrictive lung diseases live a longer and more productive quality of life if they can remain active. Patients who require oxygen supplementation but can otherwise be active should have the most portable and non-encumbering systems possible. Oxygen conserving devices have made a high level of portability possible. Small gas, liquid and even some concentrators have replaced the 20 pound E cylinder with 4 and 5 pound systems. In a parallel physiological development, exercise plus oxygen increases the physiological benefits of exercise and thereby enhances the patient's ability to function in life. This paper examines available options and their mechanical and physiological foundations.

Objective: To develop regression equations for estimating peak oxygen consumption (Vo(2)) for men and women with moderate to severe chronic obstructive pulmonary disease (COPD) from the 6-minute walk test (6MWT).Design: Multivariate analysis of patient pulmonary function and exercise gas exchange indices to 2 outcomes for the 6MWT (distance ambulated, calculated work [6M(WORK)]).Setting: A university hospital and clinics.Participants: A total of 124 patients (90 men 34 women; age range, 45-81y), from the community, with moderate to very severe COPD. Forced expiratory volume in 1 second (FEV1) ranged from .70 to 2.79 L/min, forced vital capacity (FVC) ranged from 1.73 to 5.77 L, and FEV1/FVC ranged from 24% to 69%. All patients were in stable condition at the time of testing and were on a stable drug regimen.Interventions: Not applicable.Main Outcome Measures: Pulmonary function testing was completed according to American Thoracic Society criteria. Cycle ergometry with gas exchange, by using a ramp protocol, was completed. The 6MWT was done in the hospital corridor, with distances recorded after each minute. Work capacity by each method was reduced from the normal predicted.Results: Peak oxygen uptake (Vo(2)) averaged 1184+/-302 mL/min for men and 860+/-256 mL/min for women (58%, 68% of predicted, respectively). Ventilatory reserve was limited at an achieved peak ventilation (VE) of 79.9%+/-19.1% of predicted. Borg scores for dyspnea and leg fatigue were equivalent for each test modality, with leg fatigue being slightly higher for each gender. 6M(WORK) for the 6MWT was the strongest independent predictor of peak Vo(2) (r=.81, P<.0001), whereas that for distance ambulated was correlated at r equal to.54 (P<.0001). This is a 36% improvement in the variance accounted for by the application of 6MWORK as the outcome for the 6MWT. Generalized regression modeling was then used to develop equations for the estimation of peak Vo(2) for the 6MWT. Additional variables included in the model were diffusing capacity of lung for carbon dioxide, FVC, maximal inspiratory pressure, weight (in kilograms), and age, with their appropriate interactions. This derived regression model accounted for 79% on the variance for estimation of peak Vo(2) in the patients studied.Conclusion: Peak Vo(2) can be estimated for men and for women by using the generalized equations presented. The calculation of 6M(WORK) is an improvement over distance ambulated as the 6MWT outcome. These data build on the existing body of knowledge for the 6MWT and extend its application for patients with COPD. Knowledge of the peak Vo(2) can be used for patient assessment, serial monitoring, evaluating disability, and as a common index of function across modalities. The calculation of 6M(WORK) outperformed distance ambulated and is easily converted to other indices of caloric expenditure that are commonly used in the laboratory and clinical settings. (C) 2003 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.

UNLABELLED The 6-min walk (6MW) test is commonly used to assess exercise capacity in patients with COPD and to track functional change resulting from disease progression or therapeutic intervention. Not surprisingly, distance covered has been the preferred outcome for this test. However, distance walked does not account for differences in body weight that are known to influence exercise capacity. OBJECTIVE The aim of this study was to evaluate the 6-min distance x body weight product (6MWORK) as an improved outcome measure with a solid physiologic foundation. PATIENTS AND METHODS One hundred twenty-four men and women with moderate-to-severe COPD volunteered and completed the testing sequence, which included pulmonary function, a peak effort ramp cardiopulmonary exercise study with gas exchange, and the 6MW. Means and SD were generated for the variables of interest. Differences were analyzed using analysis of variance techniques. Correlation coefficients and receiver operating characteristic (ROC) curves were calculated for the 6-min walk distance (6MWD) and 6MWORK with indexes of pulmonary function, work performance, and Borg scores for dyspnea and effort. RESULTS Men and women presented with a significant smoking history that also differed by gender (48 vs 66 pack-years, respectively; p < 0.01). The mean (+/- SD) FEV(1) values were 45 +/- 12.6% and 48 +/- 12.1%, respectively (not significant), while the diffusing capacity of the lung for carbon monoxide (DLCO) was 14.7 +/- 6.1 vs 10.3 +/- 3.9 mL/min/mm Hg, respectively (p < 0.001), for men and women. The 6MWD averaged 416.8 +/- 79.0 m for men and 367.8 +/- 78.6 m for women, and these differences were significant (p < 0.002). When 6MWD was compared as the percent predicted of normal values, each gender presented with a similar reduction of 78.6 +/- 14.5% vs 79.9 +/- 17.5% (p > 0.05), respectively. 6MWORK averaged 35,370 +/- 9,482 kg/m and 25,643 +/- 9,080 kg/m (p < 0.0001) for men and women, respectively. 6MWORK yielded higher correlation coefficients than did 6MWD when correlated with DLCO, lung diffusion for alveolar ventilation, FEV(1), FEV(1)/FVC ratio, watts, peak oxygen uptake, peak minute ventilation, and peak tidal volume. The ROC curve demonstrated that 6MWORK had a significantly larger calculated area under the curve (p < 0.05) [plot of 100-sensitivity to specificity for each variable of interest for all subjects] than 6MWD when differentiating an objectively selected definition of low work capacity vs high work capacity (bike ergometry work, < 55 vs > 55 W, respectively). CONCLUSIONS We conclude that work calculated as the product of distance x body weight is an improved outcome measure for the 6MW. 6MWORK can be used whenever the 6MW is required to estimate a patient's functional capacity. This measure is also a common measure, which can be converted to indexes of caloric expenditure for direct cross-modality comparisons.

SUMMARY OF APPROACH The approach to surgery in the patient with COPD is summa-rized below. Surgery Definitely indicated Lung resection. Pulmonary function studies should be performedbefore lung resection. Simple spirometry has the greatest utilityin documenting physiologic operability. FEV, > 2 L in an adultman or > 60% of predicted is acceptable for pneumonectomy.Values below this suggest that further studies, such as split func-tion assessment by quantitative lung scintigraphy and exercisetesting, are warranted.FEV, predicted after lung resection to be less than 40 to 50%of normal for the patient’s sex, age, and height suggests highermorbidity and mortality. An exercise 90, of less than 10 to 15ml/min per kg of body weight is associated with higher mor-bidity and mortality after lung resection.All elective surgery Prophylaxis against deep venous throm-bosis should be given before most procedures that will requirepostoperative bed rest or significantly reduce mobility. Heparinin low doses seems well accepted for most procedures. Externalpneumatic compression of the lower legs can be used when anti-coagulants are contraindicated.

There is much recent evidence that patients with chronic pulmonary disease who are hypoxemic benefit from continuous therapy with oxygen. These benefits include reduction in symptoms of cor pulmonale, reduction in mortality, and improvement in quality of life. Oxygen therapy is very expensive, and steady-flow delivery of oxygen is wasteful, since almost the entire benefit of the oxygen presented to the patient occurs at the very beginning of inspiration. We previously described a conserver nasal cannula (CNC) which stores oxygen during exhalation for delivery during subsequent inspirations. The CNC achieves adequate arterial oxygen saturation (SaO2) at one fourth to one half of the flow in liters of steady-flow oxygen delivery. Because some patients found the mustache configuration objectionable, a pendant nasal cannula (PNC) was designed, displacing the reservoir off of the face and onto the anterior wall of the chest. While both cannulas require some breathing by nose to function, the PNC is more esthetically acceptable. No studies with exercise have been reported using the PNC. We evaluated the PNC during treadmill exercise in ten subjects with chronic obstructive pulmonary disease and hypoxemia on exercise. We compared the PNC with steady-flow oxygen during steady level treadmill walking sufficient to cause oxygen desaturation while breathing room air at oxygen presentations of 0.5 through 3.0 L/min. At comparable workloads the SaO2 achieved by PNC required one third of the oxygen flow required by steady-flow oxygen to achieve an equivalent SaO2. These differences were statistically significant (p less than 0.01). We conclude that the PNC provides effective delivery of oxygen during exercise, as well as at rest, while minimizing oxygen flow rate and thus substantially reducing the economic burden normally associated with supplemental oxygen delivery.

Departments of Respiratory Disease and Rehabilitation, City of Hope National Medical Center, Duarte, CA 91010