Exclusion criteria were mechanical ventilation mode different than ACV and agitation, and disadaptation to the ventilator that troubled superior vena cava pressure measurements.
However, in the clinical situation, sedation is frequently necessary to ensure patient/ventilator synchrony with the controlled mechanical ventilation mode.
Improved synchrony has been well documented during assisted mechanical ventilation modes that apply pressure support proportionally to the inspiratory effort, like Proportional Assist Ventilation and Neurally Adjusted Ventilator Assist [ 90, 91].
A growing body of laboratory evidence suggests that variable mechanical ventilation modes aiming at imitating physiological respiratory variability improve gas exchange and respiratory system mechanics, and reduce ventilator-associated lung injury [ 5, 6, 9].
International variation in aspects of the delivery of mechanical ventilation such as preferred ventilator mode, use of non-invasive ventilation (NIV), and adoption of protocols for weaning has been noted previously [ 12, 13].
The patients that failed the DSA test were characterised by signs of intercostal retraction in response to the added burden and were connected to the mechanical ventilator in assist-control mode for six hours.
During lavage, all piglets were ventilated by a conventional mechanical ventilator using the pressure control mode.
Ventilation was achieved with a Siemens Servo 900C mechanical ventilator in the pressure-control mode, and adjusted to maintain normocapnia (arterial carbon dioxide tension 4 5 kPa).
After that, the animals were ventilated using mechanical ventilator LTV-10000 ventilator; Care Fusion, San Diego, CA), implementing pressure control mode, at the following ventilator settings: fraction of inspired oxygen (FIO2) 1.0, PEEP of 2 cm H2O, inspiratory time of 0.5 second.
In the conventional ventilation group, the piglets were ventilated using a conventional mechanical ventilator (Servo-i) in the pressure control mode at the following ventilator settings: peak inspiratory pressure, 20 cm H2O; PEEP, 4 cm H2O; inspiratory-to-expiratory ratio, 1 : 2; and FIO2, 1.0.
