Learn More
The purpose of this study was to evaluate the influence of velocity of shortening on the relationship between diaphragm activation and pressure generation in humans. This was achieved by relating the root mean square (RMS) of the diaphragm electromyogram to the transdiaphragmatic pressure (Pdi) generated during dynamic contractions at different inspiratory(More)
We compared crural diaphragm electrical activity (EAdi) with transdiaphragmatic pressure (Pdi) during varying levels of pressure support ventilation (PS) in 13 intubated patients. With changing PS, we found no evidence for changes in neuromechanical coupling of the diaphragm. From lowest to highest PS (2 cm H(2)O +/- 4 to 20 cm H(2)O +/- 7), tidal volume(More)
The use of esophageal recordings of the diaphragm electromyogram (EMG) signal strength to evaluate diaphragm activation during voluntary contractions in humans has recently been criticized because of a possible artifact created by changes in lung volume. Therefore, the first aim of this study was to evaluate whether there is an artifactual influence of lung(More)
Neurally adjusted ventilatory assist (NAVA), a mode of mechanical ventilation controlled by diaphragmatic electrical activity (EAdi), may improve patient-ventilator interaction. We examined patient-ventilator interaction by comparing EAdi to ventilator pressure during conventional ventilation (CV) and NAVA delivered invasively and non-invasively. Seven(More)
INTRODUCTION The aim of this study was to validate an automated, objective and standardized algorithm for quantifying and displaying patient-ventilator interaction. METHODS Using a new method to detect patient-ventilator synchrony, the present study re-analyzed previously acquired and published data from 24 mechanically ventilated adult patients (Colombo(More)
Intersubject comparison of the crural diaphragm electromyogram, as measured by an esophageal electrode, requires a reliable means for normalizing the signal. The present study set out 1) to evaluate which voluntary respiratory maneuvers provide high and reproducible diaphragm electromyogram root-mean-square (RMS) values and 2) to determine the relative(More)
Although it has been postulated that central inhibition of respiratory drive may prevent development of diaphragm fatigue in patients with chronic obstructive pulmonary disease (COPD) during exercise, this premise has not been validated. We evaluated diaphragm electrical activation (EAdi) relative to maximum in 10 patients with moderately severe COPD at(More)
OBJECTIVE Patient-ventilator synchrony during non-invasive pressure support ventilation with the helmet device is often compromised when conventional pneumatic triggering and cycling-off were used. A possible solution to this shortcoming is to replace the pneumatic triggering with neural triggering and cycling-off-using the diaphragm electrical activity(More)
OBJECTIVE To evaluate the influence of neurally adjusted ventilatory assist (NAVA) and positive end-expiratory pressure (PEEP) on the control of breathing in rabbits with acute lung injury. DESIGN Prospective animal study. SETTING Experimental laboratory in a university hospital. SUBJECTS Male White New Zealand rabbits (n = 18). INTERVENTION(More)