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We investigated the coordination of swallowing and breathing in 11 unconscious patients with an endotracheal tube in place during the recovery period from general anesthesia. Swallows occurred during both the inspiratory and expiratory phases with no preponderant occurrence during either phase. When a swallow occurred during inspiration, the inspiration was(More)
We investigated the effects of increasing CO2 ventilatory drive on the coordination of respiration and reflex swallowing elicited by continuous infusion of distilled water into the pharynx (2.5 ml/min) in 11 normal subjects. Ventilation was monitored using a pneumotachograph and swallowing was recorded by submental electromyogram. The CO2 ventilatory drive(More)
The effect of intravenous dopamine on carotid body chemoreceptor activity was investigated in 6 anesthetized cats which were paralyzed and artificially ventilated. Studies were performed at 4 steady-state PaO2 levels at a constant PaCO2 and at 4 levels of PaCO2 during hyperoxia. Dopamine inhibited carotid chemoreceptors before and excited them after(More)
Effects of dopamine and of a dopaminergic blocker, haloperidol, on the responses of carotid body chemoreceptors to hypoxia and hypercapnia were investigated in 16 anesthetized cats. Intravenous infusion of dopamine (10-20 micrograms.min-1) decreased carotid body chemoreceptor responses to hypoxia and hypercapnia. The effect was greater at higher levels of(More)
We evaluated the sensation of dyspnea induced by hypercapnia alone and a combination of hypercapnia and flow-resistive loading by the use of visual analogue scale (VAS) and the use of 13 listed descriptors in 23 healthy subjects. Hypercapnia alone caused a modest degree of dyspnea characterized by both air hunger and work/effort sensations. An addition of(More)
Swallowing must interact with respiration so that a swallow causes minimal or no disturbance of continual respiration. In order to study the coordinate control of swallowing and respiration, we investigated the effects of spontaneous and water-induced swallows on the pattern of ongoing respiration in 8 adult human subjects. Swallows were identified by(More)
1. Immediately after breath-holding at end-expiratory level, there is a certain period of no particular respiratory sensation which is terminated by the onset of an unpleasant sensation and followed by progressive discomfort during breath-holding. This period, defined as the time from the start of voluntary breath-holding to the point where the onset of an(More)
The response of breathing patterns to increased expiratory resistance is not only of physiologic interest, with respect to the control of breathing, but also of clinical interest because of its clinical relevance to obstructive diseases such as asthma and emphysema. To elucidate the response of breathing patterns to increased expiratory resistance during(More)
Both human and animal studies show that irritation of airway mucosa elicits a variety of reflex responses such as coughing, apnoea, and laryngeal closure. Most of the information concerning these reflex responses were obtained in anesthetized conditions with little applicability to awake conditions. Various aspects of cough and other reflexes on irritation(More)
Breath-holding is one of the most powerful methods to induce the dyspneic sensation, and the breath-holding test gives us much information on the onset and endurance of dyspnea. In conscious subjects, immediately after the start of breath-holding at functional residual capacity (FRC), there is a certain period of no particular respiratory sensation lasting(More)