Compliance and dead space fraction indicate an optimal level of positive end-expiratory pressure after recruitment in anesthetized patients.

Background: "Optimal" positive end-expiratory pressure (PEEP) can be defined as the PEEP that prevents recollapse after a recruitment maneuver, avoids over-distension, and, consequently, leads to optimal lung mechanics at minimal dead space ventilation. In this study, we analyzed the effects of PEEP and recruitment on functional residual capacity (FRC), compliance, arterial oxygen partial pressure (Pao2) and dead space fraction, and we determined the most suitable variables indicating optimal PEEP.

Methods: We studied 20 anesthetized patients with healthy lungs undergoing faciomaxillary surgery.

Determination of functional residual capacity by oxygen washin-washout: a validation study.

Objective: To validate a new system for functional residual capacity (FRC) measurements using oxygen washin/washout in spontaneously breathing humans. The system (LUFU, Drägerwerk AG, Lübeck, Germany) consists of an unmodified EVITA 4 ventilator, a side-stream paramagnetic oxygen sensor and a dedicated software.

Design: Laboratory study and measurements in spontaneously breathing volunteers.

Use of dynamic compliance for open lung positive end-expiratory pressure titration in an experimental study.

Objective: We tested whether the continuous monitoring of dynamic compliance could become a useful bedside tool for detecting the beginning of collapse of a fully recruited lung.

Design: Prospective laboratory animal investigation.

Setting: Clinical physiology research laboratory, University of Uppsala, Sweden.

Monitoring dead space during recruitment and PEEP titration in an experimental model.

Objective: To test the usefulness of dead space for determining open-lung PEEP, the lowest PEEP that prevents lung collapse after a lung recruitment maneuver.

Design: Prospective animal study.

Setting: Department of Clinical Physiology, University of Uppsala, Sweden.

Monitoring of functional residual capacity by an oxygen washin/washout; technical description and evaluation.

Objective: It was the goal of this study to develop and test an automated method for measuring functional residual capacity (FRC) by an oxygen washin/washout in intensive care settings. Such a method is required to work with conventional ventilator breathing systems and to use only medical grade sensors.

Methods: The oxygen setting on a standard intensive care ventilator is changed by at least 10%.

Reduction of anesthesia process times after the introduction of an internal transfer pricing system for anesthesia services.

To improve operating room workflow, an internal transfer pricing system (ITPS) for anesthesia services was introduced in our hospital in 2001. The basic principle of the ITPS is that the department of anesthesia receives reimbursement only for the surgically controlled time, not for anesthesia-controlled time (ACT). A reduction in anesthesia process times is therefore beneficial for the anesthesia department.

Suctioning through a double-lumen endotracheal tube helps to prevent alveolar collapse and to preserve ventilation.

Objective: Endotracheal suctioning can cause alveolar collapse and impede ventilation. One reason is the gas flow through a single-lumen endotracheal tube (ETT) provoking a gradient between airway opening and tracheal (P(tr)) pressures. Separately extending the patient tubing limbs of a suitable ventilator into the trachea via a double-lumen ETT should maintain P(tr).

Upper airway patency during ventilation with a new airway device-the glossopalatinal tube.

Introduction: We studied a new rescue breathing device consisting of a mouthcap and a "glossopalatinal" tube reaching between tongue and palate (the "GPT"), with a connector for a bag, ventilator or rescuers mouth. By tilting the connector in a cranial direction, the tongue can be "scooped" out of the hypopharynx. The study was to test the efficacy and the ease of application of the GPT in anaesthetised patients.

Ventilation performance of a mixed group of operators using a new rescue breathing device-the glossopalatinal tube.

Introduction: We studied how effectively a mixed group of helpers could ventilate a manikin with a new rescue breathing device after a short period of instruction. The device consists of a mouthcap, a "glossopalatinal tube" (GPT) reaching between tongue and palate and a connector for a bag, ventilator or the rescuers mouth. Rather than reaching behind the tongue like an oropharyngeal airway (OP), it is able to scoop the tongue off the posterior pharyngeal wall when tilted by the rescuer.