The normal breathing pattern of the turtle, Chrysemys picta (Schneider), consists of periods of continuous breathing interspersed with periods of breath holding. During each ventilatory period respiratory frequency and tidal volume are controlled independently. There is a large variability in inspiratory and expiratory gas-flow rates yet tidal volumes are maintained within narrow limits by adju...

The respiratory effects of stimulation of adenosine A(1) receptors were studied in spontaneously breathing rats that were either (1) neurally intact and subsequently bilaterally vagotomized in the neck, or (2) neurally intact and subjected to supranodosal vagotomy or (3) midcervically vagotomized before and after pharmacological blockade of A(1) receptors. Before neural interventions an intrave...

In many centres, height is used as a determinant for calculating predicted body weight. This predicted body weight is then multiplied to generate the desired tidal volume. The approach exhibits some mathematical effects: (1) any errors in height measurement are multiplied by 5.5 when generating the tidal volume (assuming 6 ml/kg); (2) any errors in height measurement have a greater impact on sh...

During partial liquid ventilation perfluorocarbons are eliminated mainly by evaporation via the airways. The effects of intrapulmonary perfluorocarbon volume, respiratory rate, tidal volume, as well as the level of end-expiratory pressure on perfluorocarbon elimination from isolated lungs, were studied. Nonperfused rabbit lungs underwent partial liquid ventilation (2-15 mL x kg(-1) perfluorocar...

Subjective assessment of the respiratory rate and the adequacy of tidal ventilation are the oldest and most widely practiced forms of respiratory monitoring in critically ill patients. Surprisingly, this method of assessment has itself never been evaluated in patients. The estimation of tidal volume in nine patients was performed by full-time intensive care unit (ICU) personnel and compared to ...

ELDRIDGE, FREDERIC L. Relationshz) between phrenic nerve activity and ventdation. Am. J. Physiol. 221(Z) : 535-543. 197 1 .-Phrenic nerve discharges were recorded in anesthetized cats simultaneously with a range of tidal volumes. Nerve impulses were processed in a variety of ways. Total impulses per breath and peak impulse frequency correlated poorly with tidal volume. Integrated electrical act...

Background Acid base alterations occur during laparoscopy with carbon dioxide insufflation. The purpose of this study was to investigate the effects of low tidal volume ventilation on acid base status during pneumoperitonium. Materials and Methods 30 patients undergoing laparoscopic surgery under General Anaesthesia were ventilated with tidal volume of 6 ml/kg and respiratory rate of 12 breat...

BACKGROUND Oscillations of the arterial partial pressure of oxygen induced by varying shunt fractions occur during cyclic alveolar recruitment within the injured lung. Recently, these were proposed as a pathomechanism that may be relevant for remote organ injury following acute respiratory distress syndrome. This study examines the transmission of oxygen oscillations to the renal tissue and the...

SUBJECT OBJECTIVE To assess the hemodynamic effects of manual lung hyperinflation in mechanically ventilated patients and to measure the different inspiratory pressures and tidal volumes generated by different operators. DESIGN Measurements of aortic blood flow (by esophageal Doppler ultrasonography), systemic blood pressure, tidal volumes (by respirometry), and inspiratory pressures in the v...

BACKGROUND Diaphragmatic dysfunction found in the patients with acute lung injury required prolonged mechanical ventilation. Mechanical ventilation can induce production of inflammatory cytokines and excess deposition of extracellular matrix proteins via up-regulation of transforming growth factor (TGF)-β1. Lumican is known to participate in TGF-β1 signaling during wound healing. The mechanisms...