Tuesday, November 12, 2013

Incorporating Proportional Assist into Ventilator Protocols

Image 1: PAV+ Work of Breathing bar. 

PAV+ may be used for the initial mode of ventilation during the acute phase of mechanical ventilation. However, from my experience I have had the most success and efficiency with PAV+ utilizing the mode to rest patients after a failed spontaneous breathing trial. After reviewing the literature it is still unclear the best way to wean or liberate a patient from PAV+. However, a traditional T-piece trail has been supported by many peer reviewed journals, so at my institution we still use a 30 minute to one hour T-Piece trial to screen patients for extubation.
How to incorporate PAV+

After a patient meets liberation criteria a Spontaneous breathing trial is performed by T-piece trial. If the patient fails the trial the patient is placed on PAV+ with a 70%  support setting.  At night or during sleep the %Supp may be titrated up (never above 80%). The patient is rested on PAV+ until the next spontaneous breathing trial is performed ( the following day, if there are no contra-indications).
This was ideal for our patient population since 81% (of sampled patients) failed their spontaneous breathing trial due to ventilatory muscle fatigue. The Main goal/current indication for mechanical ventilation in these patients was reversing ventilatory muscle fatigue/unloading ventilatory muscles. So PAV+ was ideal in resting these patients without providing too much support.
Additionally, this is a great way to introduce the modality.


  1. Chatburn R, & Mireles-Cabodevila E, Closed-Loop Control of Mechanical Ventilation. Respiratory Care 2011; 56 (1): 90,91, & 97.
2. Georgopoulos D,Plataki M, Prinianakis G, et al. Current Status of Proportional Assist Ventilation. International J Intensive Care 2007; August: 19-26.