OBJECTIVE Chemoreceptors play an important role in the autonomic modulation of circulatory and ventilatory responses to changes in arterial O(2) and/or CO(2). However, studies evaluating hemodynamic responses to hypoxia and hypercapnia in rats have shown inconsistent results. Our aim was to evaluate hemodynamic and respiratory responses to different levels of hypoxia and hypercapnia in consciou...

Specimens of Bufo marinus were exposed to aerial and aquatic hypercapnia (5% CO2) in a closed, water recirculation system to evaluate mechanisms involved in the compensation of a respiratory acidosis in these animals. Arterial PCO2 was elevated from about 9 mmHg (1 mmHg = 133.3 Pa) to 35 (1 h) and 37 mmHg (2 h), and gradually approached about 40 mmHg (24 h of hypercapnia). The typical hypercapn...

Citation: Puchwein-Schwepcke AF, Schottmayer K, Mormanová Z, Dreyhaupt J, Genzel-Boroviczeny O and Thome UH (2018) Permissive Hypercapnia Results in Decreased Functional Vessel Density in the Skin of Extremely Low Birth Weight Infants. Front. Pediatr. 6:52. doi: 10.3389/fped.2018.00052 Permissive Hypercapnia results in Decreased Functional Vessel Density in the Skin of Extremely low Birth Weigh...

OBJECTIVES To assess whether hypercapnia may predict the prognosis in chronic obstructive pulmonary disease (COPD). DESIGN Prospective cohort study comparing the survival of patients with COPD and normocapnia to those with chronic hypercapnia. SETTING Patients with consecutive COPD were enrolled between 1 May 1993 and 31 October 2006 at two medical centres. Follow-up was censored on 31 Octo...

Animal studies have demonstrated that activation of the baroreflex by increases in arterial pressure inhibits cardiovascular and ventilatory responses to activation of peripheral chemoreceptors (PC) with hypoxia. In this study, we examined the influences of baroreflex activation on the sympathetic response to stimulation of PC and central chemoreceptors in humans. PC were stimulated by hypoxia ...

BACKGROUND Carbon dioxide is an important vasodilator of cerebral blood vessels. Cerebral vasodilation mediated by adenosine triphosphate (ATP)-sensitive K+ channels has not been demonstrated in precapillary microvessel levels. Therefore, the current study was designed to examine whether ATP-sensitive K+ channels play a role in vasodilation induced by mild hypercapnia in precapillary arterioles...

RATIONALE Hypercapnia has similar hemodynamic effects to those of a dobutamine infusion and may have relevance in the management of septic shock. OBJECTIVES To compare the effects induced by hypercapnia with those of dobutamine in a clinically relevant model of septic shock. METHODS Fecal peritonitis was induced in 21 anesthetized, invasively monitored, mechanically ventilated female sheep....

BACKGROUND AND PURPOSE Oxygen supplementation is the treatment most commonly used to relieve dyspnea in chronic obstructive pulmonary disease (COPD). There is a lack of data, however, on the response of the respiratory drive to low flow oxygen in severe stable COPD. The purpose of this investigation was to evaluate the magnitude of chemoresponsiveness to low flow supplemental oxygen in patients...

BACKGROUND Hypercapnia abolishes cerebral autoregulation, but little is known about the interaction between hypercapnia and autoregulation during general anesthesia. With normocapnia, sevoflurane (up to 1.5 minimum alveolar concentration) and propofol do not impair cerebral autoregulation. This study aimed to document the level of hypercapnia required to impair cerebral autoregulation during pr...