The interest in measuring physiological parameters (especially arterial blood gases) has grown progressively in parallel to the development of new technologies. Physiological parameters were first measured invasively and at discrete time points; however, it was clearly desirable to measure them continuously and non-invasively. The development of intensive care units promoted the use of ventilat...

Most studies on global warming rely on global mean surface temperature, whose change is jointly determined by anthropogenic greenhouse gases (GHGs) and natural variability. This introduces a heated debate on whether there is a recent warming hiatus and what caused the hiatus. Here, we presented a novel method and applied it to a 5° × 5° grid of Northern Hemisphere land for the period 1900 to 20...

Pulmonary hypertension (PH) is a life-threatening, multifactorial pathophysiological haemodynamic condition, diagnosed when the mean pulmonary arterial pressure equals or exceeds 25 mmHg at rest during right heart catheterization. Cardiac MRI, in general, and MR phase-contrast (PC) imaging, in particular, have emerged as potential techniques for the standardized assessment of cardiovascular fun...

Pulmonary hypertension (PH) is a haemodynamic and pathophysiological condition defined as increase in mean pulmonary arterial pressure ≥ 25 mmHg at rest as assessed by right heart catheterization (RHC). It can be due to a primary elevation of pressure in the pulmonary arterial system alone (pulmonary arterial hypertension), or secondary to elevations of pressure in the pulmonary venous and capi...

The cardiorespiratory responses to an i.v. infusion of dobutamine hydrochloride were assessed in eight anaesthetized, mechanically ventilated dogs. As the rate of infusion of dobutamine was increased from 2 to 30 microgram kg-1 min-1, there was a progressive decrease in arterial pressure, pulmonary wedge pressure and arterial pH. There was a significant decrease in arterial oxygen tension at th...

HYPOTHESIS Central venous blood gas (VBG) measurements of pH, PCO2, and base excess can be substituted for the same values obtained from an arterial blood gas (ABG) analysis in mechanically ventilated trauma patients, obviating the need for arterial puncture. DESIGN AND SETTING Prospective comparison of 99 sets of VBGs and ABGs at a level 1 academic trauma center. PATIENTS A consecutive sam...

Effects of acute hypercapnia on the cardiovascular system (CYS) were studied in the anesthetized cat. After surgery the animal was exposed to a gas mixture of 12% CO2 and 25% O2 in nitrogen, and hypercapnia with low levels of arterial pH (pHa) was produced for 20 minutes. In the second run the same level of hypercapnia was induced by ventilating the same cat from the above gas mixture but ...

BACKGROUND Transcutaneous carbon dioxide (PtcCO2 ) monitoring is rarely used in the acute hospital setting, where serial samples of arterial blood are instead taken to measure carbon dioxide tension (PaCO2 ). In this pilot observational study, we assessed the potential of PtcCO2 monitoring to calculate pH and guide management of acute noninvasive ventilation (NIV). METHODS Ten subjects with a...

Balakrishnan S, Gopalakrishnan M, Alagesan M, Prakash ES. What is the ultimate goal in acid-base regulation? Adv Physiol Educ 31: 51–54, 2007; doi:10.1152/advan.00010.2006.—It is common to see chapters on acid-base physiology state that the goal of acid-base regulatory mechanisms is to maintain the pH of arterial plasma and not arterial PCO2 (PaCO2) or plasma HCO3. A hypothetical situation in w...

The purpose of this study was to determine the effect of twin-to-twin delivery interval on umbilical artery acid-base status of the second twin at birth. This was a retrospective cohort study of all live-born twins with measured acid-base status in umbilical arterial blood who were delivered after 34 weeks' gestation from June 2003 to February 2006. Twins with any maternal or fetal complication...