0
Abstract: Poster Presentations |

EFFECT OF DOPAMINE AND SUPPLEMENTAL OXYGEN ON EXERCISE VENTILATORY RESPONSE AND ENDURANCE IN COPD PATIENTS FREE TO VIEW

Michelle Cao, DO*; Hideki Tsurugaya, MD; Janos Porszasz, MD, PhD; Brian J. Whipp, PhD; Richard Casaburi, MD, PhD
Author and Funding Information

Harbor/UCLA Medical Center, Torrance, CA



Chest. 2006;130(4_MeetingAbstracts):176S-d-177S. doi:10.1378/chest.130.4_MeetingAbstracts.176S-d
Text Size: A A A
Published online

Abstract

PURPOSE: To determine, by means of a randomized, double-blind, placebo controlled study, whether intravenous dopamine, a carotid body inhibitor, depresses exercise ventilation and improves exercise endurance –in a manner similar to supplemental oxygen.

METHODS: Seventeen COPD patients (7 men) with forced expiratory volume in one second of 41±12% predicted who did not demonstrate severe exercise desaturation (SPO2>85%) were enrolled. Each performed 4 constant work rate tests at 85% of the peak value achieved in ramp testing (62±23 watts). Breath-holding time (BHT) was assessed before each test. In randomized order, patients received: intravenous saline infusion+air breathing (saline-air), intravenous dopamine infusion(5μg/kg/min)+air (dopamine-air), saline+50% oxygen (saline-oxygen), or dopamine+50% oxygen (dopamine-oxygen). Ventilation (VE) and heart rate (HR) at the time of the shortest of these tests (isotime (Iso)) and time constant of phase II VE kinetics (&#964VE) were determined. As results were not normally distributed, median values are reported.

RESULTS: Compared to saline-air, oxygen (with or without dopamine) prolonged BHT and &#964VE, reduced isotime VE and increased exercise endurance, but did not alter isotime HR. Compared to saline-air, dopamine also prolonged BHT and reduced isotime VE, but did not alter &#964VE or exercise endurance; isotime HR was increased. (see Table).

CONCLUSION: In COPD patients, the carotid body inhibitor dopamine was similar to supplemental oxygen in that it prolonged breath holding time and diminished the ventilatory response to exercise. However, we failed to demonstrate that dopamine increased exercise tolerance. We speculate that this may be related to dopamine’s cardio-stimulatory effects.

CLINICAL IMPLICATIONS: Carotid body inhibitors without such cardio-excitatory effects might prove more beneficial in improving exercise tolerance in COPD patients.

DISCLOSURE: Michelle Cao, None.

Wednesday, October 25, 2006

12:30 PM - 2:00 PM


Figures

Tables

References

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543