BACKGROUND The accuracy of end-expiratory lung volume measurement by the modified nitrogen wash-out/wash-in method (EELV-N(2)) depends on the precise determination of carbon dioxide elimination (V(CO(2))), which is affected by alveolar dead space (V(D-alv)). The purpose of this study was to investigate the influence of V(D-alv) on EELV-N(2). METHODS Six piglets with lavage-induced acute lung ...

BACKGROUND For mechanically ventilated patients with acute respiratory distress syndrome (ARDS), suboptimal PEEP levels can cause ventilator induced lung injury (VILI). In particular, high PEEP and high peak inspiratory pressures (PIP) can cause over distension of alveoli that is associated with VILI. However, PEEP must also be sufficient to maintain recruitment in ARDS lungs. A lung model that...

OBJECTIVE Acute respiratory dysfunction frequently occurs following severe aneurysmal subarachnoid hemorrhage requiring positive end-expiratory pressure (PEEP) ventilation to maintain adequate oxygenation. High PEEP levels, however, may negatively affect cerebral perfusion. The goal of this study was, to examine the influence of various PEEP levels on intracranial pressure, brain tissue oxygen ...

OBJECTIVE To evaluate the respiratory and hemodynamic changes during lung recruitment maneuvering (LRM) through stepwise increases and decreases in PEEP level. DESIGN AND SETTING A retrospective study in a 17-bed ICU was carried out. PATIENTS Twenty-one patients with acute respiratory failure and bilateral pulmonary infiltration. INTERVENTION LRM was carried out, consisting of stepwise in...

INTRODUCTION Functional residual capacity (FRC) measurement is now available on new ventilators as an automated procedure. We compared FRC, static thoracopulmonary compliance (Crs) and PaO2 evolution in an experimental model of acute respiratory distress syndrome (ARDS) during a reversed, sequential ramp procedure of positive end-expiratory pressure (PEEP) changes to investigate the potential i...

BACKGROUND We assessed the potential of risk stratification of ARDS patients using SpO2/FiO2 and positive end-expiratory pressure (PEEP) at ARDS onset and after 24 h. METHODS We used data from a prospective observational study in patients admitted to a mixed medical-surgical intensive care unit of a university hospital in the Netherlands. Risk stratification was by cutoffs for SpO2/FiO2 and P...

BACKGROUND Positive end-expiratory pressure (PEEP) can increase intracranial pressure. Pneumoperitoneum and the Trendelenburg position are associated with an increased intracranial pressure. We investigated whether PEEP ventilation could additionally influence the sonographic optic nerve sheath diameter as a surrogate for intracranial pressure during pneumoperitoneum combined with the Trendelen...

Controlled mechanical ventilation (CMV) with positive end-expiratory pressure (PEEP) has been shown to be effective in improving oxygenation and diminishing intrapulmonary shunt in patients with severe pulmonary failure [l, 10, 161. However, cardiac output depression may occur at levels of PEEP above 10 cm Hz0 and limit its usefulness [lo, 141. Civetta et al. [2] and Kirby et al. [8] have succe...

BACKGROUND Optimizing intracranial pressure (ICP) and cerebral perfusion pressure (CPP) is important in the management of severe traumatic brain injury (TBI). In trauma patients with TBI and respiratory dysfunction, positive end-expiratory pressure (PEEP) is often required to support oxygenation. Increases in PEEP may lead to reduced CPP. We hypothesized that increases in PEEP are associated wi...

The roles of the carotid arterial baroreceptor reflex and of vagally mediated mechanisms during positive end-expiratory pressure (PEEP) were determined in pentobarbital-anesthetized dogs with isolated carotid sinuses. Spontaneously breathing dogs were placed on PEEP (5-10 cmH2O) with the carotid sinus pressure set to the systemic arterial pressure (with feedback) or to a constant pressure (no f...