Clinical Trial: Impact of NaHCO3- on Exercise Hyperpnea

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Effect of Induced Metabolic Alkalosis by Sodium Bicarbonate Administration on the Ventilatory Response to Exercise in Healthy Adults

Brief Summary: An abnormally high V̇E/V̇CO2 response to exercise is a key pathophysiological feature of patients with chronic cardiopulmonary disease that is associated with adverse health outcomes. It follows that any intervention capable of decreasing the V̇E/V̇CO2 response to exercise has the potential to improve clinical and/or patient-reported outcomes. The investigators of this trial will compare the effects of orally administered sodium chloride (4 g, placebo) and sodium bicarbonate (0.3 g/kg of body mass) on ventilation, breathing pattern, dynamic operating lung volume, gas exhange, cardiovascular, metabolic and symptom parameters during symptom-limited, high-intensity, constant-work-rate cycle exercise testing in healthy adults aged 20-40 years.

Detailed Summary:

The ventilatory response (V̇E) to exercise-induced increases in the rate of CO2 production (V̇CO2) depends on the regulated level of arterial PCO2 (PaCO2) and the dead space to tidal volume ratio (VD/VT).

An abnormally high V̇E/V̇CO2 response to exercise, reflecting a high VD/VT and/or low PaCO2 equilibrium point, is a key pathophysiological feature of patients with chronic cardiopulmonary disease, including heart failure, pulmonary arterial hypertension, interstitial lung disease and chronic obstructive pulmonary disease. In these patient groups, exercise ventilatory inefficiency is associated with: disease severity and progression; exercise intolerance; exertional breathlessness; and increased risk of hospitalization, major cardiac events and mortality. It follows that any intervention capable of decreasing the V̇E/V̇CO2 response to exercise has the potential to improve clinical and/or patient-reported outcomes. Unfortunately, our ability to enhance exercise ventilatory efficiency is limited by the fact that, with the possible exception of lung volume reduction surgery in chronic obstructive pulmonary disease and pulmonary vasodilator therapy in pulmonary arterial hypertension and heart failure, ventilation-perfusion abnormalities reflecting a high VD/VT are often irreversible.

A largely unexplored approach to decreasing the V̇E/V̇CO2 response to exercise is increasing the PaCO2 equilibrium point by inducing a metabolic alkalosis via administration of an alkalizing agent such as sodium bicarbonate (NaHCO3). Thus, the primary objective of this randomized, double blind, placebo controlled, crossover study was to test the hypothesis that increasing the PaCO2 equilibrium point via induced acute metabolic alkalosis by single-dose oral administration of NaHCO3 would decrease in the VM
Sponsor: McGill University

Current Primary Outcome: Ventilatory equivalent to carbon dioxide (V̇E/V̇CO2) at its lowest point ("nadir") during exercise [ Time Frame: Participants will be followed until all study visits are complete, an expected average of 3 weeks ]

Original Primary Outcome: Same as current

Current Secondary Outcome: Partial pressure of carbon dioxide in the arterialized capillary blood (PacCO2) [ Time Frame: Time Frame: Participants will be followed until all study visits are complete, an expected average of 3 weeks ]

Original Secondary Outcome: Same as current

Information By: McGill University

Dates:
Date Received: February 10, 2017
Date Started: May 2015
Date Completion:
Last Updated: February 15, 2017
Last Verified: February 2017