Direct Effect of Caffeine on Diaphragmatic Muscles

The mechanism of methylxanthines is thought to increase chemoreceptor responsiveness to CO2 in central nervous system. Besides, effect of methylxanthines on diaphragmatic contractility has also been found in experimental studies. A study of premature newborns has showed caffeine increase diaphragmatic activity and tidal volume. But, there is limited data about caffeine direct effect on diaphragma.

Objective: The investigators aimed to show the direct effect of caffeine on diphragmatic contractility.

Method: The babies under 32 weeks with respiratory support, are being enrolled in this study if caffeine treatment is decided to receive. Evaluation of muscle contraction is being made by ultrasound before and 30 minutes after caffeine loading dose. Right and left sides of diaphragm thickness are being measured by two clinicians on B mode ultrasound by anterior subcostal view. The velocity before and after caffeine administration will be calculated, dividing excursion frequency (parameter) for inspiratory time. Movement of the diaphragm at inspiratory and expiratory phases are also observed on M mode and the difference between the two phases are measured.