Comparison of the ATS versus EU Mini Wright peak flow meter in normal volunteers.

OBJECTIVES: The American Thoracic Society (ATS) and European Union (EU) have precise and accurate Mini Wright peak flow meters. The purpose of this investigation was to compare both 1) for accuracy using a pneumotachometer, 2) in volunteers to determine whether they are interchangeable, and 3) to spirometrically predicted peak flows. METHODS: Lab testing: A pneumotachometer was connected in series with each peak flow meter and varying flows pushed through both meters for comparison. Human subjects: Nonsmoking adult volunteers did three standing peak flows. The order of peak flow meter used was random. The best of three efforts was used for analysis. The t-test, concordance correlation coefficient (CCC), Deming regression, and Bland-Altman plot were the analytic strategies used to determine agreement. Peak flow results were compared to spirometrically predicted values. RESULTS: Fifty-seven volunteers, average age 37 ± 12 years and mean BMI 24.9 ± 2.5 years, were included. The average peak flows were different at 541 ± 114 and 526 ± 112 L/min for the ATS and EU meters, respectively (p < .01). Both peak flow meter values were significantly different than spirometrically predicted values of 483 ± 86 L/min (p < .01). The CCC was 0.98 (0.97-0.99) and regression revealed a slope and y-intercept consistent with 1 and 0, respectively. The Bland-Altman plot revealed no increase in scatter of values over the range of peak flows versus the difference with a mean bias of 15 ± 15 L/min. Laboratory testing revealed that the ATS and EU peak flow meters read 3.0 ± 2.1% above and -2.0 ± 1.5% below the comparison pneumotachometer, respectively. The pneumotachometer comparison was significantly different for both meters at p < .01, paired t-test. CONCLUSIONS: The ATS peak flow meter reads 2.8% higher than the EU peak flow meter across a range of flows. Both meters have similar accuracy with a different bias compared with a pneumotachometer. Finally, both peak flow meters read slightly and significantly higher than spirometrically derived peak flows. Therefore, the peak flow meters are not interchangeable and both may obtain slightly higher values than those determined using current spirometrically derived prediction equations.

Peak expiratory flow in normals: comparison of the mini Wright versus spirometric predicted peak flows.

OBJECTIVES: U.S. prediction equation estimated peak flows were obtained spirometrically and may not correctly predict actual peak flows that are obtained using a peak flow meter. The purpose of this investigation was to compare actual Mini Wright peak flows in normal volunteers as compared with spirometric predicted values to determine whether they are similar. METHODS: Nonsmoking, nonobese adult volunteers with no history of lung disease underwent peak flow testing with an American Thoracic Society (ATS) Mini Wright peak flow meter. All subjects did three peak flows by taking a maximal deep breath and expiring as hard and fast as possible while in the standing position. The best of three efforts was taken as the peak flow value for analysis and compared with prediction equation estimates. The paired t test compared differences between actual and predicted values. The concordance correlation coefficient evaluated whether the actual peak flows were interchangeable with predicted. RESULTS: Seventy-two volunteers, average age 44 +/- 10 years and mean BMI 25.2 +/- 2.9, were included. The Mini Wright peak flow values of 508 +/- 113 L/min were significantly different than the predicted values of 471 +/- 84 (p < 0.01). The predicted values were reduced on average by 7.3 percent compared to actual values. The concordance correlation coefficient was 0.72 (95% C.I.; 0.60 - 0.80) suggesting the actual and predicted values are not interchangeable. CONCLUSIONS: The ATS Mini Wright peak flow values are slightly higher than spirometrically derived predicted peak flow values in subjects without lung disease. This suggests that predicted peak flow values should be generated by a peak flow meter and would be higher than current spirometrically predicted values.

Combined video-assisted thoracoscopic lung volume reduction surgery and lobectomy in a high-risk patient.

Nonsmall cell lung cancer often occurs in patients with severe emphysema. Lobectomy in these patients is often contraindicated due to extensive parenchymal destruction and subsequent pulmonary insufficiency. Video-assisted thoracoscopic lobectomy has been described as a less morbid procedure in high-risk patients. Lung volume reduction surgery has been shown to improve pulmonary function in selected patients with emphysema. We describe the successful combination of lobectomy and lung volume reduction surgery (LVRS) with a video-assisted thoracoscopic (VATS) approach in a high-risk patient with Stage I nonsmall cell lung cancer.