A non-invasive technique was developed for measuring alveolar carbon dioxide and oxygen tension during tidal breathing. This was achieved by solving the Bohr equations for mean alveolar carbon dioxide and oxygen tensions (PACO2, PAO2) from known values of the dead-space:tidal volume ratio measured by helium washout, and from the mixed expired partial pressure of carbon dioxide and oxygen. The d...

To the Editor: Ventilation (VE) is controlled by the arterial tension of carbon dioxide (PaCO2), but during exercise other mechanisms prevail. At low work rates, the moderate increase in VE represents “hypoventilation” as PaCO2 increases, whereas at 60–70% of work capacity and during intense exercise, the marked increase in VE restores to the resting value, or even lowers, PaCO2 (2). Also, duri...

BACKGROUND Extracorporeal membrane oxygenation (ECMO) is a technique widely used worldwide to improve gas exchange. Changes in ECMO settings affect both oxygen and carbon dioxide. The impact on oxygenation can be followed closely by continuous pulse oximeter. Conversely, carbon dioxide equilibrates much slower and is not usually monitored directly. METHODS We investigated the time to stabiliz...

BACKGROUND AND OBJECTIVES Tracheal gas insufflation (TGI) consists in injecting gas in the trachea (usually oxygen). is used in patients with acute respiratory distress syndrome (ARDS) to reduce capnometry. In Anesthesiology, the reduction in capnometry can be useful, but there are no studies on the reduction in capnometry using TGI. The objective of this study was to evaluate the changes cause...

We sought to clarify the effect of a short-acting benzodiazepine hypnotic on the relationship of arterial blood pressure and arterial partial pressure of carbon dioxide (Paco2) to regional cerebral blood flow (rCBF) during human non-rapid-eye-movement (REM) sleep. Nine young normal volunteers were treated in a randomized, crossover design with triazolam or placebo and underwent positron emissio...

introduction chronic obstructive pulmonary disease (copd) is a chronic disorder with many systematic complications and one of the most important reasons for patients to require mechanical ventilation, admission in intensive care unit and prolonged mechanical ventilation. although the first attempt in separation of mechanical ventilation is failed in half of chronic obstructive pulmonary disease...

BACKGROUND Diagnosis of brain death usually requires an arterial carbon dioxide partial pressure (Paco2) of 60 mmHg during the apnea test, but the increase in Paco2 is unpredictable. The authors evaluated whether transcutaneous carbon dioxide partial pressure (Ptcco2) monitoring during apnea test can predict that a Paco2 of 60 mmHg has been reached. METHODS The authors compared Ptcco2 measure...

To the Editor: Ventilation (VE) is controlled by the arterial tension of carbon dioxide (PaCO2), but during exercise other mechanisms prevail. At low work rates, the moderate increase in VE represents “hypoventilation” as PaCO2 increases, whereas at 60–70% of work capacity and during intense exercise, the marked increase in VE restores to the resting value, or even lowers, PaCO2 (2). Also, duri...

OBJECTIVE There are conflicting data regarding the use of end-tidal carbon dioxide (PetCO2) measurement in preterm infants. The aim of this study was to evaluate the effects of different dead space to tidal volume ratios (VD/VT) on the correlation between PetCO2 and arterial carbon dioxide pressure (PaCO2) in ventilated preterm infants with respiratory distress syndrome (RDS). METHODS We enro...

AIM The harmful effect of hypocapnia on the neonatal brain emphasizes the importance of monitoring arterial carbon dioxide tension (PaCO2). Transcutaneous monitoring of carbon dioxide (tcPCO2) reduces the need for arterial blood sampling. Drawbacks are high electrode temperature causing risks of skin burning. The aim was to determine the accuracy and precision of tcPCO2 at reduced electrode tem...