Background Preoxygenation and apneic ventilation prolong apnea time without desaturation. Aims The primary objective of this study is to compare arterial oxygenation during the periods of apnea following preoxygenation and apneic ventilation with tidal volume breathing for 3 min with continuous positive airway pressure (CPAP) versus with transnasal humidified rapid-insufflation ventilatory ex...

A simple two-pump model has served to describe the mechanics of ventilation in cartilaginous and bony fishes since the pioneering work of G. M. Hughes. A hallmark of this model is that water flow over the gills is continuous. Studies of feeding kinematics in the swellshark Cephaloscyllium ventriosum, however, suggested that a flow reversal occurred during prey capture and transport. Given that ...

Mungbean (Phaseolus aureus Roxb.) seedlings were grown hypobarically to assess the effects of low pressure (21-24 kilopascals) on growth and mitochondrial respiration. Control seedlings grown at ambient pressure (101 kilopascals) were provided amounts of O2 equivalent to those provided experimental seedlings at reduced pressure to factor out responses to O2 concentration and to total pressure....

Because cardiovascular disorders and stroke may induce Cheyne-Stokes respiration, our purpose was to study the interaction among cerebral activity, cerebral circulation, blood pressure, and blood gases during Cheyne-Stokes respiration. Ten patients with heart failure or a previous stroke were investigated during Cheyne-Stokes respiration with recordings of daytime polysomnography, cerebral bloo...

A 64-year-old man with severe COPD developed refractory nonperfusing sinus rhythm after intubation and positive-pressure ventilation. Fifteen minutes after resuscitative efforts were halted, the patient was noted to have spontaneous respirations and blood pressure, suggesting that dynamic hyperinflation was responsible for the observed electromechanical dissociation (EMD). We recommend a brief ...

In two cases with a well-defined pulmonary capillary venous pressure pulse, the lobular pulmonary artery was occluded with a balloon while the pulmonary capillary venous pressure was registered. There was no change in the tracing obtained. In two other cases positive pressure respiration almost completely damped out the pulmonary capillary venous pressure variations, but the mean pressure remai...