While nasal mucosal stimulation in animals has been reported to produce central apneas and while nasal packing in humans is known to produce sleep-disordered breathing, it is controversial whether intranasal obstruction in humans produces predominantly central or obstructive apnea. To answer this question, we studied eight normal men by having them sleep in random order with their nose open or ...

Apneas and hypopneas during sleep occur more frequently in men than women. Disordered breathing is also reported to increase in hypogonadal men following testosterone administration. This suggests a hormonal influence on sleeping respiratory pattern. We therefore studied respiratory rhythm during sleep in 11 hypogonadal males both on and off testosterone-replacement therapy. In four subjects th...

The diagnosis of sleep apnea syndrome (SAS) requires expensive and complex instrumentation. The purpose of the present study was to determine the value of end-tidal CO2 (EtCO2) in screening for sleep apneas. Thirty-nine patients referred to our sleep laboratory because of suspected SAS and ten normal subjects were studied. The EtCO2 was measured using an infrared spectrometer (POET) designed fo...

Sleep-disordered breathing occurs in as many as 17% of adults and is associated with increased mortality.1 Characterized by the occurrence of repetitive episodes of apneas and hypopneas resulting in intermittent oxyhemoglobin desaturation and sleep disruption, it is a common comorbid condition in patients with heart disease, who may have both obstructive and central variants. Apneas and hypopne...

Current knowledge suggests that laryngeal chemoreflexes (LCR) are involved in the occurrence of certain neonatal apneas/bradycardias, especially in the preterm newborn. While caffeine and/or nasal continuous positive airway pressure (nCPAP) are the most frequent options used for treating apneas in preterm newborns, their effects on LCR-related apneas/bradycardias are virtually unknown. The aim ...

The effect of the diving response on alveolar gas exchange was investigated in 15 subjects. During steady-state exercise (80 W) on a cycle ergometer, the subjects performed 40-s apneas in air and 40-s apneas with face immersion in cold (10 degrees C) water. Heart rate decreased and blood pressure increased during apneas, and the responses were augmented by face immersion. Oxygen uptake from the...

There are few studies investigating the influence of vagally mediated reflexes on the cardiovascular response to apneas. In 12 sedated preinstrumented pigs, we studied the effects of vagotomy during apneas, controlling for apnea periodicity and thoracic mechanical effects. Nonobstructive apneas were produced by paralyzing and mechanically ventilating the animals, then turning the ventilator off...

conclusions our case showed that if the respiratory failure occurred due to substernal goiter and svcs, we would need to investigate the coexistence of osas and svcs. case presentation we presented the clinical course and treatment of acute respiratory failure (arf) developed in a patient with svcs and osas due to substernal goiter. after treatment of arf with invasive mechanical ventilation, w...

Obstructive sleep apnea (OSA) is defined by quantifying apneas and hypopneas along with symptoms suggesting sleep disruption. Subtler forms of sleep-disordered breathing can be missed when this criteria is used. Newer technologies allow for non-invasive detection of flow limitation, however consensus classification is needed. Subjects with flow limitation demonstrate electroencephalogram change...