Pulmonary Function Testing in Patients with Tracheostomies: Feasibility and Technical Considerations.

PURPOSE: Pulmonary function testing (PFT) in patients with tracheostomies has been perceived as difficult to perform and clinically unreliable. We studied the feasibility, quality, repeatability and clinical significance of PFT. METHODS: Patients with tracheostomies that underwent PFT from January 1, 2010 to February 29, 2012 were identified. Clinical history and PFT data were reviewed retrospectively. RESULTS: Fifty patients (88% men) were identified. Forty-seven (94%) patients were able to perform PFT. Acceptable repeatability was obtained for FVC in 39 (83%) and for FEV1 in 41 (87%). Patients with tracheostomies showed difficulty in meeting ATS end-of-test criteria; only 9 (19%) met plateau criteria and 25 (53%) had exhalation times of greater than 6 s. Obstructive pattern was observed in 30 (64%) and restrictive pattern in 9 (19%). DLCO measurements were attempted in 43 patients and satisfactorily obtained in 34 (79%). CONCLUSIONS: PFT can be performed with reliability in patients with tracheostomies, and they are useful for detecting and classifying types of lung dysfunction.

Using quantitative breath sound measurements to predict lung function following resection.

BACKGROUND: Predicting postoperative lung function is important for estimating the risk of complications and long-term disability after pulmonary resection. We investigated the capability of vibration response imaging (VRI) as an alternative to lung scintigraphy for prediction of postoperative lung function in patients with intrathoracic malignancies. METHODS: Eighty-five patients with intrathoracic malignancies, considered candidates for lung resection, were prospectively studied. The projected postoperative (ppo) lung function was calculated using: perfusion scintigraphy, ventilation scintigraphy, and VRI. Two sets of assessments made: one for lobectomy and one for pneumonectomy. Clinical concordance was defined as both methods agreeing that either a patient was or was not a surgical candidate based on a ppoFEV1% and ppoDLCO% > 40%. RESULTS: Limits of agreement between scintigraphy and VRI for ppo following lobectomy were -16.47% to 15.08% (mean difference = -0.70%;95%CI = -2.51% to 1.12%) and for pneumonectomy were -23.79% to 19.04% (mean difference = -2.38%;95%CI = -4.69% to -0.07%). Clinical concordance between VRI and scintigraphy was 73% for pneumonectomy and 98% for lobectomy. For patients who had surgery and postoperative lung function testing (n = 31), ppoFEV1% using scintigraphic methods correlated with measured postoperative values better than projections using VRI, (adjusted R2 = 0.32 scintigraphy; 0.20 VRI), however the difference between methods failed to reach statistical significance. Limits of agreement between measured FEV1% postoperatively and ppoFEV1% based on perfusion scintigraphy were -16.86% to 23.73% (mean difference = 3.44%;95%CI = -0.29% to 7.16%); based on VRI were -19.56% to 28.99% (mean difference = 4.72%;95%CI = 0.27% to 9.17%). CONCLUSIONS: Further investigation of VRI as an alternative to lung scintigraphy for prediction of postoperative lung function is warranted.

Effects of body position on resting lung volume in overweight and mildly to moderately obese subjects.

INTRODUCTION: A partial sitting position has been reported to increase functional residual capacity (FRC) in lean subjects, whereas FRC does not change with position in the morbidly obese. The effects of positioning in the subgroup of overweight and mildly to moderately obese subjects have not been examined. We hypothesized that a change in FRC may be related to adipose tissue distribution. METHODS: We investigated the hypotheses that a 30 degrees Fowler's position would increase the FRC and decrease the closing-capacity-to-FRC ratio in subjects with a body mass index in the 25.0-39.9 kg/m(2) range. We tested whether body fat distribution, measured by waist circumference and waist-to-hip ratio, correlated with the lung-volume changes. RESULTS: The 30 degrees Fowler's position did not improve the FRC, when compared to the supine position (n = 32). The closing-capacity-to-FRC ratio was > 1 in 5 of 7 subjects while sitting, and in all 7 subjects while supine or in the 30 degrees Fowler's position. The waist-to-hip ratio was correlated with closing capacity in all positions, and correlated with closing-capacity-to-FRC ratio in the supine position. CONCLUSIONS: Standard position changes purported to increase FRC are ineffective in the overweight and mildly to moderately obese, a subpopulation represented by almost 67% of Americans. Bedside caregivers may need to modify current practices when the clinical goal is to improve resting lung volumes in sedentary patients.

Pulmonary dysfunction as a major cause of inoperability among patients with non-small-cell lung cancer.

PURPOSE: We wanted to assess the prevalence of pulmonary dysfunction as the underlying reason for inoperability among patients with non-small-cell lung cancer (NSCLC) who were considered for surgical treatment at the time of diagnosis. PATIENTS AND METHODS: This is a retrospective analysis of all patients with NSCLC referred to our pulmonary function laboratory for preoperative evaluation between January 2001 and November 2001. Pulmonary function testing consisted of measurement of spirometric indices (forced expiratory volume in 1 second [FEV1]), lung volumes and diffusing capacity for carbon monoxide, Xenon-133 quantitative ventilation and perfusion studies, and exercise testing when indicated. Patient demographics and clinical characteristics at the time of the evaluation were reviewed. RESULTS: The group comprised 206 consecutive potential surgical candidates (mean age, 64.7 years +/- 10.1 years) with NSCLC. Nearly half (45.6%) of the patients had early-stage (I/II) disease, and the remainder had late-stage disease at the time of pulmonary evaluation. The average predicted FEV1 among all patients was 70.3% +/- 19.6% (range, 25%-123%). One hundred eight patients (52.4%) were deemed surgically inoperable after the preoperative assessment. Severe pulmonary function impairment was identified as the reason for surgical inoperability in more than one third of these patients (40 of 108). CONCLUSION: A substantial number of patients with anatomically resectable NSCLC are deemed surgically ineligible based on poor lung function. Recognition of the magnitude of this problem is fundamental to the development of effective treatment options, which might include preoperative management strategies that could better prepare patients for surgery or, alternatively, aggressive nonsurgical approaches.