I determined whether prolonged inspiratory resistive loading (IRL) affects phrenic motoneuron discharge, independent of changes in chemical drive. In seven decerebrate spontaneously breathing cats, the discharge patterns of eight phrenic motoneurons from filaments of one phrenic nerve were monitored, along with the global activity of the contralateral phrenic nerve, transdiaphragmatic pressure,...

In this paper, a novel approach to control end-tidal CO2 in mechanically ventilated patients is presented. Assuming a homogeneous lung model, a regulation of arterial CO2 tension in blood can be achieved non-invasively using L1 adaptive control with the aid of an extremum seeking method to set the proper respiratory rate. Using these integrated approaches, not only is end-tidal CO2 regulated at...

INTRODUCTION End tidal CO2 (ETCO2) has been established as a standard for confirmation of an airway, but its role is expanding. In certain settings ETCO2 closely approximates the partial pressure of arterial CO2 (PaCO2) and has been described as a tool to optimize a patient's ventilatory status. ETCO2 monitors are increasingly being used by EMS personnel to guide ventilation in the prehospital ...

OBJECTIVES To determine the availability of end-tidal CO2 measurement in confirmation of endotracheal tube placement in the non-arrest patient, and to assess its use in academic and non-academic emergency departments. METHODS Emergency physicians in the USA were surveyed by mail in the beginning of the year 2000 regarding availability at their institution of both colorimetric/qualitative and ...

OBJECTIVE To compare two different supraglottic airway devices, the laryngeal mask airway (LMA) and the I-gel, regarding easiness of insertion of the device, leak pressure, gastric insufflation, end tidal CO2, oxygen saturation, hemodynamic and postoperative complications in anesthetized, spontaneously ventilated adult patients performing different non-emergency surgical procedures. MATERIALS...

OBJECTIVE To assess the safety and efficacy of combining extracorporeal CO2 removal with continuous renal replacement therapy in patients presenting with acute respiratory distress syndrome and acute kidney injury. DESIGN Prospective human observational study. SETTINGS Patients received volume-controlled mechanical ventilation according to the acute respiratory distress syndrome net protoco...

We hypothesized that reductions in arterial PCO2 (PaCO2) below the apnea threshold play a key role in the pathogenesis of idiopathic central sleep apnea syndrome (ICSAS). If so, we reasoned that raising PaCO2 would abolish apneas in these patients. Accordingly, patients with ICSAS were studied overnight on four occasions during which the fraction of end-tidal CO2 and transcutaneous PCO2 were me...

The ventilatory sensitivity to CO2, in hyperoxia, is increased after an 8-h exposure to hypoxia. The purpose of the present study was to determine whether this increase arises through an increase in peripheral or central chemosensitivity. Ten healthy volunteers each underwent 8-h exposures to 1) isocapnic hypoxia, with end-tidal PO2 (PET(O2)) = 55 Torr and end-tidal PCO2 (PET(CO2)) = eucapnia; ...

BACKGROUND Potent inhaled anesthetics degrade in the presence of the strong bases (sodium hydroxide or potassium hydroxide) in carbon dioxide (CO2) absorbents. A new absorbent, Amsorb (Armstrong Medical Ltd., Coleraine, Northern Ireland), does not employ these strong bases. This study compared the scavenging efficacy and compound A production of two commercially available absorbents (soda lime ...