Esophageal pressures in acute lung injury: do they represent artifact or useful information about transpulmonary pressure, chest wall mechanics, and lung stress?

Acute lung injury can be worsened by inappropriate mechanical ventilation, and numerous experimental studies suggest that ventilator-induced lung injury is increased by excessive lung inflation at end inspiration or inadequate lung inflation at end expiration. Lung inflation depends not only on airway pressures from the ventilator but, also, pleural pressure within the chest wall. Although esophageal pressure (Pes) measurements are often used to estimate pleural pressures in healthy subjects and patients, they are widely mistrusted and rarely used in critical illness.

Mechanical ventilation guided by esophageal pressure in acute lung injury.

Background: Survival of patients with acute lung injury or the acute respiratory distress syndrome (ARDS) has been improved by ventilation with small tidal volumes and the use of positive end-expiratory pressure (PEEP); however, the optimal level of PEEP has been difficult to determine. In this pilot study, we estimated transpulmonary pressure with the use of esophageal balloon catheters. We reasoned that the use of pleural-pressure measurements, despite the technical limitations to the accuracy of such measurements, would enable us to find a PEEP value that could maintain oxygenation while preventing lung injury due to repeated alveolar collapse or overdistention.

Oxygen supplies during a mass casualty situation.

Mass casualty and pandemic events pose a substantial challenge to the resources available in our current health care system. The ability to provide adequate oxygen therapy is one of the systems that could be out-stripped in certain conditions. Natural disasters can disrupt manufacturing or delivery, and pandemic events can increase consumption beyond the available supply.

Attitudes of respiratory therapists and nurses about measures to prevent ventilator-associated pneumonia: a multicenter, cross-sectional survey study.

Objective: To understand the reported practices of and adherence to evidence-based guidelines for the prevention of ventilator-associated pneumonia (VAP) among respiratory therapists (RTs) and registered nurses (RNs) in academic and nonacademic intensive care units.

Methods: We conducted a multicenter, cross-sectional survey. We first obtained demographic information about health care professionals in a nonidentifiable method.

Cytokine release following recruitment maneuvers.

Background: There are reports of rigors and/or clinical deterioration following recruitment maneuvers (RMs), leading us to question whether the use of sustained high-pressure inflation could lead to release of inflammatory mediators.

Methods: Prospective cohort study of 26 patients with ARDS receiving mechanical ventilation. A single RM was performed during which the mean airway pressure was increased to 40 cm H2O and held constant for a period of 30 s.

Esophageal and transpulmonary pressures in acute respiratory failure.

Objective: Pressure inflating the lung during mechanical ventilation is the difference between pressure applied at the airway opening (Pao) and pleural pressure (Ppl). Depending on the chest wall's contribution to respiratory mechanics, a given positive end-expiratory and/or end-inspiratory plateau pressure may be appropriate for one patient but inadequate or potentially injurious for another. Thus, failure to account for chest wall mechanics may affect results in clinical trials of mechanical ventilation strategies in acute respiratory distress syndrome.