Effect of an automatic triggering and cycling system on comfort and patient-ventilator synchrony during pressure support ventilation.
BACKGROUND
The digital Auto-Trak™ system is a technology capable of automatically adjusting the triggering and cycling mechanisms during pressure support ventilation (PSV).


OBJECTIVE
To compare Auto-Trak with conventional settings in terms of patient-ventilator synchrony and discomfort.


METHODS
Twelve healthy volunteers underwent PSV via the mouth by breathing through an endotracheal tube. In the conventional setting, a pressure support of 8 cm H2O with flow cycling (25% peak inspiratory flow) and a sensitivity of 1 cm H2O was adjusted. In Auto-Trak the triggering and cycling were automatically set. Discomfort, effort of breathing, and the asynchrony index (AI) were assessed. In a complementary bench study, the inspiratory and expiratory time delays were quantified for both settings in three mechanical models: 'normal', obstructive (COPD), and restrictive (ARDS), using the ASL 5000 simulator.


RESULTS
In the volunteer study the AI and the discomfort scores did not differ statistically between the two settings. In the bench investigation the use of Auto-Trak was associated with a greater triggering delay in the COPD model and earlier expiratory cycling in the ARDS model but with no asynchronic events.


CONCLUSIONS
Use of the Auto-Trak system during PSV showed similar results in comparison to the conventional adjustments with respect to patient-ventilator synchrony and discomfort in simulated conditions of invasive mechanical ventilation.
Laboratory of Respiration, Department of Internal Medicine, Federal University of Ceará, Fortaleza, Brazil.
Renata dos S
Rdos S
Vasconcelos
Luíz Henrique de P
LH
Melo
Raquel P
RP
Sales
Liégina S
LS
Marinho
Flávio C
FC
Deulefeu
Ricardo C
RC
Reis
Mirizana
M
Alves-de-Almeida
Marcelo A
MA
Holanda
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011175:Positive-Pressure Respiration / Q000379:methods*; D015656:Respiratory Mechanics; D012494:Sampling Studies; D012815:Signal Processing, Computer-Assisted; D016037:Single-Blind Method; D012984:Software; D064232:Visual Analog Scale; D014939:Work of Breathing; D055815:Young Adult