Journal article
Inspiratory lung impedance in COPD: effects of PEEP and immediate impact of lung volume reduction surgery
Journal of applied physiology (1985), Vol.90(5), pp.1833-1841
05/01/2001
DOI: 10.1152/jappl.2001.90.5.1833
PMID: 11299274
Abstract
Frequency-dependent characteristics of lung resistance (Rl) and elastance (El) are sensitive to different patterns of airway obstruction. We used an enhanced ventilator waveform (EVW) to measure inspiratory Rl and El spectra in ventilated patients during thoracic surgery. The EVW delivers an inspiratory flow waveform with enhanced spectral excitation from 0.156 to 8.1 Hz. Estimates of the coefficients in a trigonometric approximation of the EVW flow and transpulmonary pressure inspirations yielded inspiratory Rl and Elspectra. We applied the EVW in a group with mild obstruction undergoing various thoracoscopic procedures ( n = 6), and another group with severe chronic obstructive pulmonary disease undergoing lung volume reduction surgery ( n = 8). Measurements were made at positive end-expiratory pressure (PEEP) of 0, 3, and 6 cmH2O. Inspiratory Rl was similar in both groups despite marked differences in spirometry. The chronic obstructive pulmonary disease patients demonstrated a pronounced frequency-dependent increase in inspiratory El consistent with severe heterogeneous peripheral airway obstruction. PEEP appears to have beneficial effects by reducing peripheral airway resistance. Lung volume reduction surgery resulted in increased inspiratory Rl and El at all frequencies and PEEPs, possibly due to loss of diseased lung tissue, pulmonary edema, increased mechanical heterogeneity, and/or an improvement in airway tethering.
Details
- Title: Subtitle
- Inspiratory lung impedance in COPD: effects of PEEP and immediate impact of lung volume reduction surgery
- Creators
- David W Kaczka - Department of Biomedical Engineering, Boston University, Boston 02215; andEdward P Ingenito - Pulmonary DivisionSimon C Body - Department of Anesthesia, Perioperative and Pain Medicine, andSabine E Duffy - Department of Anesthesia, Perioperative and Pain Medicine, andSteven J Mentzer - Division of Thoracic Surgery, Brigham and Women's Hospital, Boston, Massachusetts 02115Malcolm M DeCamp - Division of Thoracic Surgery, Brigham and Women's Hospital, Boston, Massachusetts 02115Kenneth R Lutchen - Department of Biomedical Engineering, Boston University, Boston 02215; and
- Resource Type
- Journal article
- Publication Details
- Journal of applied physiology (1985), Vol.90(5), pp.1833-1841
- DOI
- 10.1152/jappl.2001.90.5.1833
- PMID
- 11299274
- ISSN
- 8750-7587
- eISSN
- 1522-1601
- Language
- English
- Date published
- 05/01/2001
- Academic Unit
- Roy J. Carver Department of Biomedical Engineering; Radiology; Anesthesia
- Record Identifier
- 9984007192702771
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