| Respiratory restriction and elevated pleural and esophageal pressures in morbid obesity. | |
| | |
MedLine Citation:
|
PMID: 19910329 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
To explore mechanisms of restrictive respiratory physiology and high pleural pressure (P(Pl)) in severe obesity, we studied 51 obese subjects (body mass index = 38-80.7 kg/m(2)) and 10 nonobese subjects, both groups without lung disease, anesthetized, and paralyzed for surgery. We measured esophageal and gastric pressures (P(Es), P(Ga)) using a balloon-catheter, airway pressure (P(AO)), flow, and volume. We compared P(Es) to another estimate of P(Pl) based on P(AO) and flow. Reasoning that the lungs would not inflate until P(AO) exceeded alveolar and pleural pressures (P(AO) > P(Alv) > P(Pl)), we disconnected subjects from the ventilator for 10-15 s to allow them to reach relaxation volume (V(Rel)) and then slowly raised P(AO) until lung volume increased by 10 ml, indicating the "threshold P(AO)" (P(AO-Thr)) for inflation, which we took to be an estimate of the lowest P(Alv) or P(Pl) to be found in the chest at V(Rel). P(AO-Thr) ranged from 0.6 to 14.0 cmH2O in obese and 0.2 to 0.9 cmH2O in control subjects. P(Es) at V(Rel) was higher in obese than control subjects (12.5 +/- 3.9 vs. 6.9 +/- 3.1 cmH2O, means +/- SD; P = 0.0002) and correlated with P(AO-Thr) (R(2) = 0.16, P = 0.0015). Respiratory system compliance (C(RS)) was lower in obese than control (0.032 +/- 0.008 vs. 0.053 +/- 0.007 l/cmH2O) due principally to lower lung compliance (0.043 +/- 0.016 vs. 0.084 +/- 0.029 l/cmH2O) rather than chest wall compliance (obese 0.195 +/- 0.109, control 0.223 +/- 0.132 l/cmH2O). We conclude that many severely obese supine subjects at relaxation volume have positive P(pl) throughout the chest. High P(Es) suggests high P(Pl) in such individuals. Lung and respiratory system compliances are low because of breathing at abnormally low lung volumes. |
| | |
Authors:
|
Negin Behazin; Stephanie B Jones; Robert I Cohen; Stephen H Loring |
Related Documents
:
|
3733599 - Analysis of bronchial mechanics and density dependence of maximal expiratory flow. 670009 - Effect of parenchymal shear modulus and lung volume on bronchial pressure-diameter beha... 2588209 - Decreased pulmonary distensibility in fibrosing alveolitis and its relation to decrease... 17130889 - Maximal static mouth respiratory pressure in spinal cord injured patients: correlation ... 9014949 - Clinical implications of maximal respiratory pressure determinations for individuals wi... 8926239 - Regional lung volume trajectories during expiratory flow in dogs. 2333099 - Different muscarinic receptors mediate autoinhibition of acetylcholine release and vaga... 11414089 - Adenoviral-mediated gene transfer in human and animal vein grafts using clinically rele... 8747899 - Clinical performance of a high-efficiency rapid flow leucocyte removal filter for leuco... |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural Date: 2009-11-12 |
Journal Detail:
|
Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 108 ISSN: 1522-1601 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2010 Jan |
Date Detail:
|
Created Date: 2010-01-07 Completed Date: 2010-03-17 Revised Date: 2011-07-19 |
Medline Journal Info:
|
Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
|
Languages: eng Pagination: 212-8 Citation Subset: IM |
Affiliation:
|
Dept. of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Aged Esophagus / physiopathology* Female Humans Lung / physiopathology* Lung Compliance Male Middle Aged Obesity, Morbid / physiopathology* Pleural Cavity / physiopathology* Pressure Pulmonary Gas Exchange* Respiratory Mechanics* Young Adult |
| Grant Support | |
ID/Acronym/Agency:
|
HL-52586/HL/NHLBI NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Factors and outcomes associated with physicians' adherence to recommendations of infectious disease ...
Next Document: Elevations in ostensibly anabolic hormones with resistance exercise enhance neither training-induced...