The etiology of exercise hypocapnia is unknown. The contributions of exercise intensity (ExInt), lactic acid, environmental temperature, rectal temperature (Tre), and physical conditioning to the variance in arterial CO2 tension (PaCO2) in the exercising sheep were quantified. We hypothesized that thermal drive contributes to hyperventilation. Four unshorn sheep were exercised at approximately ...

INTRODUCTION Arterial concentrations of carbon dioxide (PaCO2) and oxygen (PaO2) during admission to the intensive care unit (ICU) may substantially affect organ perfusion and outcome after cardiac arrest. Our aim was to investigate the independent and synergistic effects of both parameters on hospital mortality. METHODS This was a cohort study using data from mechanically ventilated cardiac ...

BACKGROUND AND PURPOSE Concerning vasoreactivity of cerebellar blood flow (CeBF) in patients affected with crossed cerebellar diaschisis (CCD), several controversies have been reported. One is reduced asymmetry of CeBF after acetazolamide administration in 99mTc hexamethylpropyleneamine oxime single-photon emission-computed tomography, and the other is persistent asymmetry with alternation in P...

The effect of locally induced cerebral ischemia on regional cerebral blood flow before and during elevation of Paco2 was measured qualitatively in anesthetized dogs by a thermistor probe technique and a photographic method involving cerebral angiography. The flow response to changes in systemic arterial pressure was also noted in the ischemic zone. Increased Paco2 resulted in increased flow to ...

Dead space fraction (V d/V t) measurement performed using volumetric capnography requires arterial blood gas (ABG) sampling to estimate the partial pressure of carbon dioxide (PaCO2). In recent years, transcutaneous capnography (PtcCO2) has emerged as a noninvasive method of estimating PaCO2. We hypothesized that PtcCO2 can be used as a substitute for PaCO2 in the calculation of V d/V t. In thi...

Background. Transcutaneous measurement of carbon dioxide (TcCO2) provides a non-invasive estimation of arterial carbon dioxide (PaCO2). Nasal capnography (PE 0 CO2 ) is used to assess ventilation during monitored anaesthesia care (MAC) with sedation since it can readily detect apnoea. We compared the agreement between TcCO2 and PE 0 CO2 with PaCO2 and the ability to detect hypercarbia in patien...

BACKGROUND We have proved that hypercapnic acidosis (a PaCO2 of 80-100 mmHg) protects against ventilator-induced lung injury in rats. However, there remains uncertainty regarding the appropriate target PaCO2 or if greater CO2 "doses" (PaCO2 > 100 mmHg) demonstrate this effect. We wished to determine whether severe acute hypercapnic acidosis can reduce stretch-induced injury, as well as the role...

Nasal intermittent positive pressure ventilation (NIPPV) has been widely used in the treatment of chronic respiratory disease. Ventilators may be volume or pressure preset; each type has theoretical advantages, but to date there has been no formal comparison. We wanted to assess the efficacy on blood gas changes that may be achieved and overall acceptability of four nasal ventilators (two press...

1618 Communications to the Editor monectomy. He was discharged home but died on the 85th postoperative day. While the majority of studies examining preoperative risk have acknowledged that hypercarbia represents a relative contraindication to lung resection, a threshold value of 45 mm Hg has not been formally evaluated.3 Most studies have not listed PaCO2 values, although it is likely the major...

The effects of changes in PaCO2 and PaO2 on the swallowing reflex were studied in anaesthetized, vagotomized, paralysed and artificially ventilated cats. The swallowing reflex was induced by electrical stimulation of the superior laryngeal nerve (SLN). This initially suppressed activity in the phrenic nerve (PN). The swallowing reflex was then identified by a characteristic brief burst of PN ac...