Document Detail


The role of hypoventilation and ventilation-perfusion redistribution in oxygen-induced hypercapnia during acute exacerbations of chronic obstructive pulmonary disease.
MedLine Citation:
PMID:  10806149     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The detailed mechanisms of oxygen-induced hypercapnia were examined in 22 patients during an acute exacerbation of chronic obstructive pulmonary disease. Ventilation, cardiac output, and the distribution of ventilation-perfusion (V A/Q ) ratios were measured using the multiple inert gas elimination technique breathing air and then 100% oxygen through a nose mask. Twelve patients were classified as retainers (R) when Pa(CO(2)) rose by more than 3 mm Hg (8.3 +/- 5.6; mean +/- SD) after breathing 100% oxygen for at least 20 min. The other 10 patients showed a change in Pa(CO(2)) of -1.3 +/- 2.2 mm Hg breathing oxygen and were classified as nonretainers (NR). Ventilation fell significantly from 9.0 +/- 1.5 to 7.2 +/- 1.2 L/min in the R group breathing oxygen (p = 0.007), whereas there was no change in ventilation in the NR group (9.8 +/- 1.8 to 9.9 +/- 1.8 L/min). The dispersion of V A/Q ratios as measured by log SD of blood flow (log SD Q) increased significantly in both R (0.96 +/- 0. 17 to 1.13 +/- 0.17) and NR (0.77 +/- 0.20 to 1.04 +/- 0.23, p < 0.05) groups breathing oxygen, whereas log SD of ventilation (log SD Q ) increased only in the R group (0.97 +/- 0.24 to 1.20 +/- 0.46, p < 0.05). This study suggests that an overall reduction in ventilation characterizes oxygen-induced hypercapnia, as an increased dispersion of blood flow from release of hypoxic vasoconstriction occurred to a significant and similar degree in both groups. The significant increase in wasted ventilation (alveolar dead space) in the R group only may be secondary to the higher carbon dioxide tension, perhaps related to bronchodilatation.
Authors:
T D Robinson; D B Freiberg; J A Regnis; I H Young
Related Documents :
8981849 - Pressure controlled-inverse ratio ventilation.
17334259 - Patient-ventilator interaction and sleep in mechanically ventilated patients: pressure ...
339649 - High-frequency positive-pressure ventilation (hfppv) in neonates and infants during neu...
6946729 - High-frequency jet ventilation in major airway or pulmonary disruption.
786639 - Unusual response to continuous positive pressure ventilation.
1464129 - Pressure controlled-inverse ratio ventilation and pulmonary gas exchange during lower a...
11967609 - Comparison of different methods for measuring intra-abdominal pressure.
2346959 - Beneficial effect of adenosine during reperfusion following prolonged cardioplegic arrest.
14500139 - Perioperative assessment of left ventricular function by pressure-volume loops using th...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of respiratory and critical care medicine     Volume:  161     ISSN:  1073-449X     ISO Abbreviation:  Am. J. Respir. Crit. Care Med.     Publication Date:  2000 May 
Date Detail:
Created Date:  2000-06-21     Completed Date:  2000-06-21     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  9421642     Medline TA:  Am J Respir Crit Care Med     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1524-9     Citation Subset:  AIM; IM; S    
Affiliation:
Department of Respiratory Medicine, Royal Prince Alfred Hospital, Sydney; and the University of Sydney, Sydney, Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acute Disease
Aged
Air
Female
Humans
Hypercapnia / etiology*,  physiopathology
Lung Diseases, Obstructive / physiopathology*,  therapy
Male
Middle Aged
Oxygen Inhalation Therapy / adverse effects*
Pulmonary Gas Exchange
Ventilation-Perfusion Ratio*
Comments/Corrections
Comment In:
Am J Respir Crit Care Med. 2001 Jun;163(7):1755   [PMID:  11401898 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Monocyte IL-10 production during respiratory syncytial virus bronchiolitis is associated with recurr...
Next Document:  Implications of extubation delay in brain-injured patients meeting standard weaning criteria.