Why some neonates nee...( (July 20 2004) - Bethesda MD Every m...)

(July 20, 2004) - Bethesda, MD Every morning, millions of adults consume voluminous cups of coffee, seeking the jolting effect of caffeine. As these adults consume their coffee, they do so unaware that some of the youngest Americans are also getting a treatment of caffeine -- not to stay awake, but to assist in treating a major sleep disorder found in some neonates.

Background

Apnea, the absence of breathing, is the most frequently reported disorder of breathing control in premature infants, and neonatal care units habitually use methylxanthine derivatives such as caffeine to treat these patients who are less than a month old. Caffeine treatment for premature infants is supposed to increase breathing frequency, decrease the number of apneic spells, and reduce partial tension of carbon dioxide (PCO2) and the need for (and duration of) mechanical ventilation. Peripheral chemoreceptors, found in the carotid and aortic bodies and stimulated by chemical changes in blood composition, provide feed-forward control of respiration, which can thus terminate apnea and initiate normal breathing. These receptors are believed to be an important target for caffeine action in premature neonates.

Peripheral chemoreceptor activity is typically assessed by monitoring the rapid decline in minute ventilation (in the first minute) after inhalation of pure O2 . This drop in ventilation involves an acute reduction in peripheral chemoreceptor inputs (i.e., physiological chemodenervation) and thus reflects the strength of the peripheral chemoreceptor drive. The decrease is ultimately followed by an increase in ventilation that is centrally mediated.

However, the localization of caffeine's target site (central nervous system and/or peripheral chemoreceptors) is not well defined, especially for sleeping neonates whose sleep stages interact with respiratory control. The question of an increase in peripheral chemoreceptor responsiveness (associated or n
'"/>


20-Jul-2004

Page: 1 2 3 4
Related biology news :

1. Of 101 neonates at a New Jersey hospital, 40 percent test positive for drugs of abuse
2. Researchers study metabolic, cardiovascular effects of caffeine consumed with naringin
3. Why does caffeine delay exercise-induced fatigue?
4. The genetic basis for caffeine-induced anxiety discovered
5. UT Southwestern scientist explores caffeine-signaling activity in brain function
6. Findings conclude sustained caffeine intake negates the benefits of creatine supplements
7. Medicines, caffeine and antibacterial soap among contaminants found in American streams
8. Moderate caffeine use does not increase miscarriage risk but high caffeine use doubles risk