|
|
||||||||
1 Dept of Pulmonology Dekkerswald, University of Nijmegen, Groesbeek, and 2 Dept of Physiology, Faculty of Medical Sciences, University of Nijmegen, Nijmegen, The Netherlands
CORRESPONDENCE: M.J.T. Van de Ven, Dept of Pulmonology Dekkerswald, University of Nijmegen, PO Box 9001, 6560 GB Groesbeek, The Netherlands. Fax: 31 246859290
Keywords: cerebral blood volume, chemoresponsiveness, chronic obstructive pulmonary disease, control of breathing, mouth occlusion pressure, near infrared spectroscopy
Received: October 6, 2000
Accepted February 15, 2001
This study was supported by the Dutch Asthma Foundation (96.09).
This study investigated the hypothesis that hypercapnia in some chronic obstructive pulmonary disease (COPD) patients may be related to a high cerebrovascular response to carbon dioxide (CO2).
The relationship between responses of ventilation and of cerebral blood volume (CBV) to acute changes in carbon dioxide tension in arterial blood (Pa,CO2) was measured in 17 chronic hypercapnic (Pa,CO2 >6.0 kPa) and 16 normocapnic (Pa,CO2
During normocapnia, CBV (mL·100 g1) was 2.41±0.66 and 2.90±0.60 (mean±sd) in the normocapnic and chronic hypercapnic patients, respectively, which was significantly lower compared to healthy subjects (3.53±0.77). All slopes of CO2 responsiveness (
The findings do not support the hypothesis of abnormal cerebrovascular responses to carbon dioxide in hypercapnic chronic obstructive pulmonary disease patients.
6.0 kPa) COPD patients, who were matched for degree of airway obstruction (forced expiratory volume in one second 27% predicted). Results were compared with 15 age-matched healthy subjects. CBV was measered using near infrared spectroscopy during normo- and hypercapnia and related to inspired minute ventilation (V'I) and mouth occlusion pressure (P0.1). Hypercapnia (end-tidal pressure of carbon dioxide (
PET,CO2) >1 kPa) was induced by giving adequate amounts of CO2 in the inspired air.
CBV/
Pa,CO2,
V'I/
Pa,CO2,
P0.1/
Pa,CO2) were significantly lower in both COPD groups relative to healthy subjects, but were not significantly different between the COPD groups. A poor but positive correlation between ventilatory and cerebrovascular CO2 responsiveness (
CBV/
Pa,CO2 and
V'I/
Pa,CO2) was found in COPD patients and healthy subjects.
This article has been cited by other articles:
![]() |
T. A. C. Nizet, F. J. J. van den Elshout, Y. F. Heijdra, M. J. T. van de Ven, P. G. H. Mulder, and H. Th. M. Folgering Survival of Chronic Hypercapnic COPD Patients Is Predicted by Smoking Habits, Comorbidity, and Hypoxemia Chest, June 1, 2005; 127(6): 1904 - 1910. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |