A comparison of methods to identify open-lung PEEP.

Purpose: Many methods exist in the literature for identifying PEEP to set in ARDS patients following a lung recruitment maneuver (RM). We compared ten published parameters for setting PEEP following a RM.

Methods: Lung injury was induced by bilateral lung lavage in 14 female Dorset sheep, yielding a PaO(2) 100-150 mmHg at F(I)O(2) 1.

Gas exchange impairment induced by open suctioning in acute respiratory distress syndrome: impact of permissive hypercapnia.

Objective: To determine whether hypercarbia occurs following the use of open suctioning in lung lavage injured sheep and whether the baseline PaCO2 and duration of suctioning affect gas exchange.

Design: Prospective laboratory evaluation.

Setting: Animal laboratory in a university hospital.

Performance comparison of 15 transport ventilators.

Background: Numerous mechanical ventilators are designed and marketed for use in patient transport. The complexity of these ventilators differs considerably, but very few data exist to compare their operational capabilities.

Methods: Using bench and animal models, we studied 15 currently available transport ventilators with regard to their physical characteristics, gas consumption (duration of an E-size oxygen cylinder), battery life, ease of use, need for compressed gas, ability to deliver set ventilation parameters to a test lung under 3 test conditions, and ability to maintain ventilation and oxygenation in normal and lung-injured sheep.

Regional blood flow in respiratory muscles during partial ventilatory assistance in rabbits.

We tested the hypothesis that even partial ventilatory assistance would reduce respiratory muscle blood flow to levels similar to those found during control mechanical ventilation (CMV). Three levels of pressure support ventilation (PSV) and 2 CMV settings were compared in 10 rabbits. PSV 0, 6, and 12 cm H2O, under continuous positive airway pressure mode, were applied, and then pressure control ventilation (PCV) values of 6 (36 breaths/min) and 12 cm H2O (18 per breaths/min) were applied to each CMV setting with a muscle relaxant.

Effects of gas leak on triggering function, humidification, and inspiratory oxygen fraction during noninvasive positive airway pressure ventilation.

Objectives: During noninvasive positive pressure ventilation (NPPV), the gas leak that commonly occurs around the mask can render NPPV ineffective. We evaluated the effects of gas leak on inspiratory trigger function during NPPV with bilevel pressure and ICU ventilators. In addition, we evaluated the effects of gas leak on fraction of inspired oxygen (Fio(2)) and humidification.