Components of a mechanically delivered breath
Among the several modes of ventilation, there are several key features in how they determine when to deliver a mechanical breath (triggering) and how they deliver it (targeting and cycling).
- Time cycle
Gas flow rate (i.e. volume control)
Pressure (i.e. pressure control/support)
- Volume of gas delivered
- Decrease in inspiratory flow
Ventilator Basics 101
This excellent and practical tutorial is brought to by American Thoracic Society.
This scheme can be made even simpler. The TAG scheme or taxonomic attributes grouping helps break down every mode of ventilation into 3 attributes. See reference below for details.
Continuous mandatory ventilation
Intermittent mandatory ventilation
Continuous spontaneous ventilation
Set point(s): all targets set by operator
Dual (d) vent switches between PC and VC within a breath
Bio-variable (b) inspiratory pressures varies randomly
Servo (r) inspiratory pressure proportional to patient insp effort
Adaptive (a) vent adjusts pressures to meet Vt target
Optimal (o) adaptive target to minimize WOB
Inteliigent (i) uses tools of artificial intelligence
Below is an example of how this schema is broken down. The major benefit of this scheme is it is vendor agnostic!
The consequences of positive pressure ventilation
Mireles-Cabodevila E, Siuba MT, Chatburn RL. A Taxonomy for Patient-Ventilator Interactions and a Method to Read Ventilator Waveforms. Respiratory care. 2021;(July). doi:10.4187/respcare.09316