IT IS "WELL KNOWN that the pattern of mechanical ventilation can affect the efficiency of pulmonary gas exchange. Despite this, the optimum ventilatory wave form has yet to be defined. In the past, most research has pertained to the pattern of inspiration T M and relatively little attention has been directed to the expiratory phase of ventilation. The concept of a maintained expiratory pressure...

In patients with acute lung injury, high levels of positive end-expiratory pressure (PEEP) may be necessary to maintain or restore oxygenation, despite the fact that 'aggressive' mechanical ventilation can markedly affect cardiac function in a complex and often unpredictable fashion. As heart rate usually does not change with PEEP, the entire fall in cardiac output is a consequence of a reducti...

With interest we have read the paper by Carvalho and colleagues, in which the authors report the results of their elegant study on the role of positive end-expiratory pressure (PEEP) in acute lung injury [1]. Carvalho and colleagues demonstrated in an acute respiratory distress syndrome (ARDS) model that alveolar hyperinflation and nonaerated areas may coincide during a stepwise reduction of PE...

The aim of the study was to assess the impact of the intrinsic positive end-expiratory pressure (PEEPi) on pulmonary gas exchange in mechanically-ventilated patients, by comparing the effects of similar levels (0.8-0.9 kPa) of positive end-expiratory pressure (PEEP) and PEEPi. Ten patients with acute respiratory failure, without chronic airway disease, were studied with three ventilatory modes:...

provided the original work is properly cited. CC Positive-pressure ventilation during general anesthesia is a prerequisite for numerous surgical conditions. Mechanical ventilation is non-physiological and can induce lung injury, although ventilator-induced lung injury may be of minor clinical importance during anesthesia for most patients with healthy lungs. However, growing evidence suggests t...

Positive end-expiratory pressure (PEEP) is essential in the management of acute respiratory failure (ARF) and acute respiratory distress syndrome (ARDS) in children and adults. Several studies have addressed the pulmonary beneficial effect and cardiovascular impact of an elevated PEEP in adults. However, the impact of an elevated PEEP on the respiratory and cardiovascular systems has not been w...

geneity in ventilation be good’ [1] and the related article by Zhao and colleagues [2]. We agree with the comments that instead of incremental positive end-expiratory pressure (PEEP) levels, a decremented PEEP titration might be an attractive option for determining optimal PEEP [1,3]. However, we feel that physiological inhomogeneity in ventilation and perfusion related to the gravitational eff...

In reviewing the article “Methemoglobinemia: Sudden Dyspnea and Oxygen Desaturation After Esophagoduodenoscopy,” in the August 2004 issue of RESPIRATORY CARE,1 I found the article suggested that, during the esophagoduodenoscopy procedure the patient’s blood oxygen saturation (measured via pulse oximetry) began to drop rapidly, and a saturation of 54% registered on the pulse oximeter while the p...