Central sleep apnea.

A central apnea is a disorder characterized by apneic events during sleep with no associated ventilatory effort. Central sleep apnea syndrome is characterized by repeated apneas during sleep resulting from loss of respiratory effort. Although the etiology of central apnea remains obscure in most cases, current investigations into breathing control system during sleep and association with certain diseases have pointed out possible mechanisms. Ventilation during sleep is highly dependent on the nonbehavioral control system. As a result, any diseases affecting this control system could influence the breathing patterns while the patient is asleep. As our results show, most patients with central sleep apnea and without congestive heart failure had quantifiable abnormalities like diminished carbon dioxide response curves. Neurological diseases affecting the brainstem are able to produce breathing pattern disorders in sleep. Well-known neurological diseases such as arteriosclerosis in the elderly, infarctions, tumors, hemorrhage, accidents with damage of this region, encephalitis, poliomyelitis or other infectious diseases may cause central apnea during sleep, even if in wakefulness no abnormalities of breathing patterns are present. Apneas cause hypoxemia, hypercapnia and increased sympathicotonia. This may result in development of pulmonary artery hypertension or systemic hypertension. Published results demonstrate that medical treatment is ineffective in these patients. Implantation of a diaphragm pacing device is an invasive measure, the efficacy of the diaphragm pacing has not been proven by long-term trials, however. Mechanical ventilation was shown to be the most efficient treatment. A therapeutic procedure using a timed n-BiPAP device is able to normalize blood gases during sleep. The n-BiPAP prevented the development of severe pulmonary artery hypertension during sleep.