A 74-year-old man with an enlarging pleural-based mass that was not a mesothelioma.

Soft tissue sarcomas of the chest wall, also known as primary malignant mesenchymal tumors, may be mistaken for a malignant mesothelioma because of their histologic similarities. Reports of primary pleural sarcomas are exceedingly uncommon. We present an unusual case of a primary pleural sarcoma with unique clinical and histological features not previously seen in any other subtype of pulmonary sarcoma.

Correlation of changes in quality of life after lung volume reduction surgery with changes in lung function, exercise, and gas exchange.

STUDY OBJECTIVES: To evaluate correlations between improvement in quality of life (QOL) in patients with severe COPD before and after they undergo lung volume reduction surgery (LVRS) with changes in pulmonary function tests, gas exchange, exercise performance, and alterations in medical management. DESIGN: Case-series analysis. SETTING: University hospital. PATIENTS: Forty-two patients (mean [+/- SD] age, 56+/-8 years; 53% women) with severe airflow obstruction (FEV(1), 0.62+/-0.2 L), and moderate to severe hyperinflation (total lung capacity [TLC], 6.9+/-1.7 L). INTERVENTION AND MEASUREMENTS: All patients underwent bilateral LVRS via median sternotomy. Measurements of lung function, symptom-limited cardiopulmonary exercise testing, the total distance the patient was able to walk in 6 min in a corridor, and sickness impact profile (SIP) scores were made before and 3 months after LVRS. SIP scores are inversely proportional to the level of function and QOL. RESULTS: Compared to baseline, FEV(1) increased (0.87+/-0.3 vs. 0.62+/-0.2 L, respectively; p<0.01) while residual volume significantly decreased (3.2+/-1.8 vs. 6.3+/-1.2 L, respectively; p<0.004) at 3 months post-LVRS. On cardiopulmonary exercise testing, values increased from baseline to post-LVRS for total exercise time (9.0+/-2.2 vs. 6.0+/-1.5 min, respectively; p = 0.045), maximum oxygen uptake (VO(2)) (16+/-3 vs. 11+/-2 mL/kg/min, respectively; p = 0.01), and maximum minute ventilation (VE) (33+/-9 vs. 28+/-5 L/min, respectively; p = 0.03). The percentage change in the oxygen cost of breathing (VO2/VE ratio) from low to high workloads during exercise was significantly lower after LVRS (p = 0.002). There was no significant change in oxygenation after LVRS (PaO(2)/fraction of inspired oxygen, 331+/-27 vs. 337+/-39, respectively; p = 0.76), but PaCO(2) tended to be lower (41+/-9 vs. 48+/-6 mm Hg, respectively; p = 0.07). Overall SIP scores were significantly lower after LVRS than before (8+/-4 vs. 15+/-2, respectively; p = 0.002). Changes in SIP scores correlated with the change in VO2/VE ratio from low to high workloads, with patients having the smallest changes in VO2/VE ratio having the smallest changes in SIP scores after LVRS (r = 0.6; p = 0.01). Improved or lower SIP scores also tended to correlate with a reduction in residual volume/TLC ratio (r = 0.45; p = 0.09), and there was a linear correlation with a statistically significant Pearson r value with decreased steroid requirements (r = 0.7; p = 0.001). Moreover, changes in psychological SIP subscore tended to correlate with diminished oxygen requirements post-LVRS (r = 0.45; p = 0.09). However, there was no significant correlation between changes in SIP scores and routine measurements of lung function, exercise performance, or gas exchange. CONCLUSION: There is an association between an improvement in QOL and reduced hyperinflation after LVRS. Reduced hyperinflation may lead to more efficient work of breathing during exercise and, therefore, to an increased ability to perform daily activities. Changes in QOL scores correlate best with behaviorally based variables that directly affect the patient's well-being, such as systemic steroid administration.

Prospective randomized trial comparing bilateral lung volume reduction surgery to pulmonary rehabilitation in severe chronic obstructive pulmonary disease.

Several uncontrolled studies report improvement in lung function, gas exchange, and exercise capacity after bilateral lung volume reduction surgery (LVRS). We recruited 200 patients with severe chronic obstructive pulmonary disease (COPD) for a prospective randomized trial of pulmonary rehabilitation versus bilateral LVRS with stapling resection of 20 to 40% of each lung. Pulmonary function tests, gas exchange, 6-min walk distance, and symptom-limited maximal exercise testing were done in all patients at baseline and after 8 wk of rehabilitation. Patients were then randomized to either 3 additional months of rehabilitation or LVRS. Thirty-seven patients met study criteria and were enrolled into the trial. Eighteen patients were in the medical arm; 15 of 18 patients completed 3 mo of additional pulmonary rehabilitation. Thirty-two patients underwent LVRS (19 in the surgical arm, 13 crossover from the medical arm). After 8 wk of pulmonary rehabilitation, pulmonary function tests remained unchanged compared with baseline data. However, there was a trend toward a higher 6-min walk distance (285 +/- 96 versus 269 +/- 91 m, p = 0.14) and total exercise time on maximal exercise test was significantly longer compared with baseline values (7.4 +/- 2.1 versus 5.8 +/- 1.7 min, p < 0.001). In 15 patients who completed 3 mo of additional rehabilitation, there was a trend to a higher maximal oxygen consumption (V O(2)max) (13.3 +/- 3.0 versus 12.6 +/- 3.3, p < 0.08). In contrast, at 3 mo post-LVRS, FVC (2.79 +/- 0.59 versus 2.36 +/- 0.55 L, p < 0.001) and FEV(1) (0.85 +/- 0.3 versus 0.65 +/- 0.16 L, p < 0.005) increased whereas TLC (6.53 +/- 1.3 versus 7.65 +/- 2.1 L, p < 0.001) and residual volume (RV) (3.7 +/- 1.2 versus 4.9 +/- 1.1 L, p < 0.001) decreased when compared with 8 wk postrehabilitation data. In addition, Pa(CO(2)) decreased significantly 3 mo post-LVRS compared with 8 wk postrehabilitation. Six-minute walk distance (6MWD), total exercise time, and V O(2)max were higher after LVRS but did not reach statistical significance. However, when 13 patients who crossed over from the medical to the surgical arm were included in the analysis, the increases in 6MWD (337 +/- 99 versus 282 +/- 100 m, p < 0.001) and V O(2)max (13.8 +/- 4 versus 12.0 +/- 3 ml/kg/min, p < 0.01) 3 mo post-LVRS were highly significant when compared with postrehabilitation data. The Sickness Impact Profile (SIP), a generalized measure of quality of life (QOL), was significantly improved after 8 wk of rehabilitation and was maintained after 3 mo of additional rehabilitation. A further improvement in QOL was observed 3 mo after LVRS compared with the initial improvement gained after 8 wk of rehabilitation. There were 3 (9.4%) postoperative deaths, and one patient died before surgery (2.7%). We conclude that bilateral LVRS, in addition to pulmonary rehabilitation, improves static lung function, gas exchange, and QOL compared with pulmonary rehabilitation alone. Further studies need to evaluate the risks, benefits, and durability of LVRS over time.

Effect of lung volume reduction surgery on diaphragm strength.

Since lung volume reduction surgery (LVRS) reduces end-expiratory lung volume, we hypothesized that it may improve diaphragm strength. We evaluated 37 patients for pulmonary rehabilitation and LVRS. Before and 8 wk after pulmonary rehabilitation, 24 patients had spirometry, lung volumes, diffusion capacity, incremental symptom limited maximum exercise test, 6-min walk test, maximal static inspiratory and expiratory mouth pressures, and transdiaphragmatic pressures during maximum static inspiratory efforts and bilateral supramaximal electrophrenic twitch stimulation measured. Twenty patients (including 7 patients who crossed over after completing pulmonary rehabilitation) had baseline measurements postrehabilitation, and 3 mo post-LVRS. Patients were 58 +/- 8 yr of age, with severe COPD and hyperinflation (FEV1, 0.69 +/- 0.21 L; RV, 4.7 +/- 1.4 L). Nineteen patients had bilateral LVRS performed via median sternotomy and stapling, and 1 patient had unilateral LVRS via thorascopy with stapling. After rehabilitation, spirometry and DL(CO)/VA were not different, and lung volumes showed a slight worsening in hyperinflation. Gas exchange, 6-min walk distance, maximum oxygen uptake (VO2max), and breathing pattern during maximum exercise did not change after rehabilitation, but total exercise time was significantly longer. Inspiratory muscle strength (PImax, Pdi(max combined), Pdi(max sniff), Pdi(max), Pdi(twitch)), was unchanged after rehabilitation. In contrast, after LVRS, FVC increased 21%, FEV1 increased 34%, TLC decreased 13%, FRC decreased 23%, and FRC(trapped gas) and RV decreased by 57 and 28%, respectively. PCO2 was lower (44 +/- 6 versus 48 +/- 6 mm Hg, p < 0.003) and 6-min walk distance increased (343 +/- 79 versus 250 +/- 89 m, p < 0.001), as did total exercise time during maximum exercise (9.2 +/- 1.9 versus 6.9 +/- 2.7 min, p < 0.01). Minute ventilation (29 +/- 8 versus 21 +/- 6 L/min, p < 0.001) and tidal volume (1.0 +/- 0.33 versus 0.84 +/- 0.25 L, p < 0.001) during maximum exercise increased whereas respiratory rate was lower (28 +/- 6 versus 32 +/- 7 breaths/min, p < 0.02). Measurements of respiratory muscle strength (PImax, 74 +/- 28 versus 50 +/- 18 cm H2O, p < 0.002; Pdi(max combined), 80 +/- 25 versus 56 +/- 29 cm H2O, p < 0.01; Pdi(max sniff), 71 +/- 7 versus 46 +/- 27 cm H2O, p < 0.01; Pdi(twitch), 15 +/- 5 versus 7 +/- 5 cm H2O, p < 0.01) were all greater post-LVRS. Inspiratory muscle workload as measured by Pdi TTI was lower following LVRS (0.07 +/- 0.02 versus 0.09 +/- 0.03, p < 0.03). On multiple regression analysis, increases in PImax correlated significantly with decreases in RV and FRC(trapped gas) after LVRS (r = 0.67, p < 0.03). We conclude that LVRS significantly improves diaphragm strength that is associated with a reduction in lung volumes and an improvement in exercise performance. Future studies are needed to determine the relationship and stability of these changes over time.

Effect of N-acetylcysteine on human diaphragm strength and fatigability.

Free radical injury is believed to be important in diaphragm dysfunction. N-Acetylcysteine (NAC) is a potent free radical scavenger shown in animal models to attenuate diaphragm fatigue; however, its effects on human diaphragm function are unknown. We assessed diaphragm function by electrophrenic twitch stimulation (PdiT) and twitch occlusion (to yield Pdimax) in four healthy subjects 35 +/- 3 yr of age (mean +/- SD). We intravenously administered NAC (150 mg/kg in 250 ml D5W) or placebo (CON) (250 ml D5W) in a randomized manner after subjects were premedicated with antihistamines. There were no significant side effects with the infusion. After infusion, we measured baseline Pdimax and PdiT at FRC. Diaphragm fatigue was then induced by subjects breathing through an inspiratory resistive load. Pdimax and PdiT were then measured at 15 to 30 min and 1, 2, 3, 4, and 20-25 h after fatigue. Times to fatigue were 13 +/- 4 min (CON) and 21 +/- 6 min (NAC) (p = 0.04). At 15 min after fatigue, PdiT was reduced to 40% (CON) compared with 30% (NAC) initial PdiT value (p = 0.05). Other twitch characteristics (maximal rate of relaxation and maximal contraction rate) were reduced to a greater degree after placebo compared with NAC. There were no significant differences in the rate of recovery between CON and NAC. Pdimax at 30 min after fatigue was significantly greater with NAC; however, at 1 h after fatigue, Pdimax for CON and NAC were not different, suggesting similar rates of recovery in high-frequency fatigue. These data suggest that NAC may attenuate low-frequency human diaphragm fatigue.