Cardiovascular responses to nonrespiratory and respiratory arousals in a porcine model

Spontaneous and provoked nonrespiratory arousals can be accompanied by a pa tterned hemodynamic response. To investigate whether a patterned response i s also elicited by respiratory arousals, we compared nonrespiratory arousal s (NRA) to respiratory arousals (RA) induced by airway occlusion during non -rapid eye movement sleep. We monitored mean arterial blood pressure (MAP), heart rate, iliac and renal blood flow, and sleep stage in 7 pigs during n atural sleep. Iliac and renal vascular resistance were calculated. Airway o cclusions were obtained by manually inflating a chronically implanted trach eal balloon during sleep. The balloon was quickly deflated as soon as elect roencephalogram arousal occurred. As previously reported, NRA generally eli cited iliac vasodilation, renal vasoconstriction, little change in MAP, and tachycardia. In contrast, RA generally elicited iliac and renal vasoconstr iction, an increase in MAP and tachycardia. The frequent occurrence of ilia c vasoconstriction and arterial pressure elevation following RA but not NRA suggests that sleep state change alone does not account for the hemodynami c response to airway occlusion during sleep.