Inpatient and long-term outcomes of individuals admitted for weaning from mechanical ventilation at a specialized ventilation weaning unit


Liam M. Hannan, Department of Respiratory & Sleep Medicine, Austin Hospital, Heidelberg, Vic. 3084, Australia. Email:


Background:  Weaning from invasive mechanical ventilation (IMV) in specialized weaning units has been demonstrated to be safe and cost-effective. Success rates and outcomes vary widely, probably relating to patient factors and unit expertise.

Methods:  An audit was undertaken of patients admitted for weaning from IMV at the Austin Hospital Ventilation Weaning Unit (VWU) between March 2002 and January 2008. Weaning success, complications and both in-hospital and long-term mortality were examined and regression analysis was undertaken to examine factors related to these outcomes.

Results:  Seventy-eight patients were admitted to the VWU after a median of 27 days of IMV at their referring centre. Weaning success rate (ventilator free or nocturnal non-invasive ventilation only) was 78.2% (n = 61). Inpatient mortality was 10.2% (n = 8) and serious complications were infrequent. Progressive neuromuscular disease (odds ratio 0.10) and sepsis during admission to the VWU (odds ratio 0.09) were predictive of weaning failure at discharge. Overall survival at 12 months following discharge from the VWU was 66.7% (n = 52) with most survivors residing in the community. Increasing age (hazard ratio 1.93), referral from rural or outer metropolitan centres (hazard ratio 3.57 and 2.37 respectively) and a diagnosis of chronic obstructive pulmonary disease were associated with increased long-term mortality.

Conclusion:  High rates of weaning success with infrequent complications and low mortality were achieved in this specialized non-intensive care unit-based weaning unit. The VWU may provide a useful template for the development of similar units elsewhere.