This tutorial is about Volume Guaranteed Pressure Controlled (VG-PC) Ventilation – otherwise known as PC-VG, PRVC, VC+ etc. It is a modern mode of ventilation that aims to deliver a desired tidal volume (volume control) using the pressure controlled paradigm (unlimited flow). As such it is a mode that is often labelled “dual controlled” although, in some ways, it is neither volume controlled, pressure controlled nor both.
Confused? Most are. I have labelled the mode VG-PC – because that is the best approximation – but volume is not necessarily guaranteed and it is certainly not limited. So why bother using this mode. Simply – it works! As a general use “unit default” mode of ventilation VG-PC has few peers: it is nimble enough to be used as the mode of ventilation of choice for patients admitted to ICU following intubation: postoperatively or with respiratory failure.
If the lungs deteriorate – then the mode is versatile enough to deal with it. Being time cycled – mean airway pressure can be easily altered. If compliance or resistance of position changes – then the tidal volume “guarantee” changes the inspiratory pressure from breath to breath to ensure that things remain stable. If the patient breaths spontaneously, using the assist control or SIMV paradigm, flow is increased to meet patient demands. As such it is a very forgiving mode of ventilation, ideal for novices, reassuring to the ICU clinicians. This tutorial explains VG-PC, demonstrates how it is set up in three different ventilators – Puritan Bennetts, Dragers Evitas, Servo I and GE (Aisys) anesthetic machines. I explain the operation of this mode and its strengths and weaknesses. I guarantee you’ll learn something. @ccmtutorials http://www.ccmtutorials.com