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Volume 3 Supplement 1


A case series of a pav+ weaning protocol in an acute care environment demonstrating an absence of weaning failure


Most patients undergoing mechanical ventilation (MV) in critical care units are liberated from the ventilator within a median of 7 days. Unfortunately, some patients experience difficulty in liberation from MV during their ICU stays and require extended time on MV. It has been estimated that 40% of the patient's duration on the ventilator is spent weaning.[1] Moreover, although patients requiring prolonged mechanical ventilation represent approximately 6% of all ventilated patients, they consume 37% of intensive care unit resources.[2] Therefore, accelerating the liberation of prolonged weaning patients from MV improves patient care and could yield significant economic benefits.


Which weaning strategy is “best” is controversial. Proportional Assist Ventilation (PAV+) has many aspects that are theoretically beneficial as part of a difficult weaning protocol.


Single center case series of patients undergoing a PAV+ protocolized wean from an 18 bed mixed medical/surgical/ trauma Canadian tertiary care ICU.


Over the 39 month (3.25 year) period 46 patients underwent a slow wean, 40 of whom spent greater than 70% of their time weaning in a PAV+ mode. During weaning from MV there were 4/40 (10%) deaths in the PAV+ group, despite a high admitting APACHE II score. All patients in the PAV+ group who survived were successfully weaned from MV over a median of 13.3 (9.2-20) days.


Although this study was conducted in an acute hospital context that is significantly different from Long Term Acute Care Hospitals, it raises the possibility that a PAV+ weaning protocol could be superior to PSV or t piece weaning strategies. Further studies are needed.

Grant Acknowledgment

Study funded by grant from Covidien.

Table 1 Clinical Parameters of Wean Group vs. Literature.


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Correspondence to E Rohrs.

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  • Mechanical Ventilation
  • Acute Care Hospital
  • Critical Care Unit
  • Assist Ventilation
  • Prolonged Mechanical Ventilation