BACKGROUND Elevated dead space fraction (the ratio of dead space to tidal volume [V(D)/V(T)]) is a feature of ARDS. PEEP can partially reverse atelectasis, prevent alveoli recollapse, and improve lung compliance and gas exchange in patients with ARDS. However, whether V(D)/V(T) variables have a close relationship with PEEP and collapse alveolar recruitment remains under recognized. Meanwhile, f...

No study has elucidated the minimum time taken for oxygen delivery to reach steady-state levels after an increase in positive end-expiratory pressure (PEEP). We therefore investigated ten ventilated patients who received a total of 27 increments in PEEP of 5 cm H2O. Cardiorespiratory parameters were measured at baseline, at 1 min, and thereafter at 5-min intervals until 2 consecutive measuremen...

PURPOSE OF REVIEW In the last 2 years, several reports have dealt with recruitment/positive end-expiratory pressure (PEEP) selection. Most of them confirm previous results and few add new information. RECENT FINDINGS It has been definitely confirmed that opening pressures are different throughout the acute respiratory distress syndrome lung parenchyma, ranging from 5-10 up to 30-40 cmH2O. The...

The effects of almitrine on pulmonary gas exchange and haemodynamics were compared to those of positive end-expiratory pressure (PEEP) in 10 patients with a severe adult respiratory distress syndrome (ARDS) who required continuous mechanical ventilation. Haemodynamic and gas exchange measurements were made before and after 30 min of PEEP at a level of 10 cmH2O, then 30 min later, before and at ...

Application of positive end-expiratory pressure (PEEP) will reduce cardiac output (CO). Humoral mediation of this event by circulating negative inotropic agents was examined using a rat papillary muscle bioassay. Twenty-seven dogs were anesthetized with an iv pentobarbital infusion. Plasma was obtained before and after 30 minutes of PEEP. The plasma was oxygenated in a small (4.5-ml) papillary ...

The factors regulating lung aeration and the initiation of pulmonary gas exchange at birth are largely unknown, particularly in infants born very preterm. As hydrostatic pressure gradients may play a role, we have examined the effect of a positive end-expiratory pressure (PEEP) on the spatial and temporal pattern of lung aeration in preterm rabbit pups mechanically ventilated from birth using s...

This study was designed to examine whether the oxygenation response in the prone position differs in magnitude depending on the level of positive end-expiratory pressure (PEEP) applied in the supine position, and whether cardiac output (CO) increases in the prone position. In seven supine dogs, acute lung injury was established by saline lavage (arterial oxygen tension (Pa,O2)/inspiratory oxyge...

Controversy exists whether positive end-expiratory pressure (PEEP) ventilation lowers cardiac output by reducing left ventricular preload, or by a combination of mechanisms. Sixteen open-chest dogs were instrumented for measurement of left and right ventricular pressure, aortic flow, and left ventricular dimensions. With the pericardium intact, PEEP caused the interventricular septum to bulge t...

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:...

Patients undergoing cardiac surgery remain on mechanical ventilation postoperatively until they regain consciousness. Positive end-expiratory pressure (PEEP) may influence the duration of mechanical ventilation after coronary artery bypass grafting (CABG). The aim of this study was to compare the effects of different levels of PEEP on the duration of mechanical ventilation after coronary artery...