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Biomedical subjects

D Grondin

Publications and source records attributed to D Grondin.

4 recordsLinked to original sources
PubMed1994

Effect of caffeine on the ventilatory response to inhaled carbon dioxide.

We investigated the effect of caffeine on the hypercapnic ventilatory response (HCVR) using steady state (SS) and rebreathing (RB) methods in 6 subjects. They received caffeine (5 mg/kg) or saline intravenously in a randomized, double-blind, crossover manner, with measurement of serum caffeine levels. PETCO2 and (VE), normalized for vital capacity (VC), were measured continually during RB and during the last 5 min of SS runs. The slope of the VE-PETCO2 response increased from 0.21 +/- 0.14 to 0.38 +/- 0.14 and from 0.23 +/- 0.12 to 0.59 +/- 0.45 VC.min-1.mmHg-1, measured by RB and SS respectively (P < 0.05). Plotting VT vs PETCO2 revealed a parallel shift (additive effect) in the response measured by RB after caffeine; but an increased slope (multiplicative effect) in the VT-PETCO2 relation measured in SS. We conclude that caffeine acts as a respiratory stimulant and increases the HCVR, but that assessment of the caffeine-CO2 interaction is dependent on the methodology employed.

Administration, Inhalation↗
PubMed1983

Effect of caffeine on control of breathing in infantile apnea.

Abnormalities in control of breathing have been associated with near-miss sudden infant death syndrome. Because caffeine is a respiratory stimulant, its effect on breathing pattern was evaluated in 12 infants with infantile apnea. Caffeine induced a significant increase in ventilation, tidal volume, and mean inspiratory flow. In contrast, no changes were noted in inspiratory time, expiratory time, or total cycle duration. These effects were observed with plasma concentrations of caffeine ranging from 8 to 20 mg/L. Caffeine increases ventilation mainly by increasing central inspiratory drive, and not be effective timing (T1/TTOT). This drug may be of value in near-miss SIDS.

Apnea↗
PubMed1981

Pharmacologic considerations in the therapy of neonatal apnea.

Theophylline and caffeine are both effective stimulants of the central nervous system for the therapy of neonatal apnea. Both drugs are slowly eliminated from the body, and doses should be adjusted to account for this slow elimination. Interconversion of theophylline and caffeine occurs in the newborn infant, with the methylation of theophylline to caffeine as the probable predominant pathway. Caffeine may offer advantages over theophylline: wider therapeutic index, case of administration, less need for therapeutic drug monitoring, less fluctuation in plasma concentrations, and fewer peripheral effects. A major disadvantage of caffeine is in the lack of a readily available commercial preparation. Both drugs exert many pharmacologic actions that require further evaluation in the newborn infant. Long-term effects of these drugs administered during a critical period in the developing human remains an area of concern.

Apnea↗