Objective: Intermittent oscillatory flow has been reported experimentally to improve axial dispersion of respiratory gases by manipulating the flow waveform of oscillatory flow. We clinically investigated the improvement of high-frequency intermittent oscillation (HFIO). Methods: Seven male rabbits were anesthetized and controlled with conventional ventilation. Arterial blood gas was sampled to...

The minority of healthy subjects can (without previous learning) breathe at exactly double of their resting tidal volume on demand. The aim of the present study was to find whether this estimate of tidal volume value can be learned and at what speed. Basic spirometric values were measured by Oxycon B in 20 healthy volunteers. They learned in one day to breathe at double of the resting tidal vol...

The effect of bronchoconstriction on airway resistance is known to be spatially heterogeneous and dependent on tidal volume. We present a model of a single terminal airway that explains these features. The model describes a feedback between flow and airway resistance mediated by parenchymal interdependence and the mechanics of activated smooth muscle. The pressure-tidal volume relationship for ...

THE publication of the seminal article by the Acute Respiratory Distress Syndrome Network (ARDSNet) on ventilation with lower tidal volumes in 2000 has changed the way we ventilate patients with ARDS. The use of low tidal volumes was the first therapy ever proven to improve survival of patients who were diagnosed with ARDS. Despite initial reluctance and even open criticism, clinicians across t...

In this special issue of the Journal of Pediatric Intensive Care, we have compiled a series of articles relating to mechanical ventilation. We have chosen to select articles that do not address the usual reviews on mechanical ventilation but rather topics that our readers may find unique and interesting. The title of my editorial, “Structure determines function”, relates to that first lecture i...

Ventilator-induced lung injury is a major outcome determinant of the acute respiratory distress syndrome (ARDS). Ventilatory strategies that limit ventilator-induced lung injury should improve outcome from ARDS. The ARDSnet trial showed improved survival in subjects ventilated with a lower tidal volume. Although this trial developed and tested a rigorous clinical protocol, it did not define the...

BACKGROUND Determination of regional lung air volume has several clinical applications. This study investigates the use of mid-tidal breathing CT scans to provide regional lung volume data. METHODS Low resolution CT scans of the thorax were obtained during tidal breathing in 11 healthy control male subjects, each on two separate occasions. A 3D map of air volume was derived, and total lung vo...

Single fibre and "integrated" phrenic nerve activity was recorded in anaesthetized spontaneously breathing rabbits, during experimentally induced lung oedema. Tidal volume, blood pressure, end-tidal CO2, were monitored. In oedema the number of impulses in each volley slightly decreased while the discharge frequency was increased relatively to control values. The latter effect was due to the inc...

A b s t r a c t 4 . Oxygen consumption. ventilation frequency and tidal volume were measured simultaneously in two lizards, Varanus pouldii and Sauronrabts hispidus, during rest and maximal activity. 2. Ventilation frequency m d tidal volume are almost identical in these species. The grcater oxygen consumption during activity of Varanus results from a grcater oxygen extraction from ventilated a...