MacIntyre Neil
In this review article the author discusses the findings of a mulispeciality evidenced-based task force set up to determine guidelines for discontinuing mechanical ventilation. The guidelines recommend that patients undergo a daily ventilator weaning screen (or hourly wean screen for post-operative patients) which focuses on disease stability/recovery, gas exchange, haemodynamics and respiratory drive. Those patients passing this screen should then undergo a spontaneous breathing trial (SBT). The spontaneous breathing trial involves patient assessment during spontaneous breathing, or with little or no ventilator assistance for a period of 30 minutes to 120 minutes. Patients who successfully complete a SBT have a high likelihood of tolerating ventilator discontinuation permanently. Those cases where it is not clear if the patient is a SBT success at the 120 min mark should be considered an SBT failure.
Patients failing the SBT provide one of the biggest challenges facing ICU clinicians. It is recommended that stable, comfortable modes of assisted/supported ventilatory support should be provided between the daily weaning screen/SBT. New evidence suggests that early tracheostomy in patients who are likely to require mechanical ventilation for > 2 weeks, may facilitate the ventilator withdrawal process.
Chest 2007, 132: 1049-1056