ICU · Respiratory / ventilation

Weaning from Mechanical Ventilation — SBT, Protocols & Prolonged Weaning

Also known as Weaning · Liberation · Spontaneous breathing trial · SBT · T-piece trial · Rapid shallow breathing index · RSBI · ABC trial · Daily sedation interruption · Weaning protocol · Prolonged weaning

Weaning is the process of discontinuing mechanical ventilation: a daily readiness screen, a spontaneous breathing trial (SBT), and extubation if the trial is tolerated. In the WIND cohort, 57 per cent of ventilated patients wean within 24 hours (simple), 10 per cent are difficult (separation between one day and one week), and 9 per cent are prolonged (one week or more from the first separation attempt). The SBT uses minimal support — a T-piece or low pressure support — for 30 minutes to 2 hours; tolerance means a respiratory rate under 35, an SpO2 over 90 per cent, a heart rate under 140, no distress, and stable haemodynamics. The ABC trial (Girard, paired a daily sedation interruption (SAT) with the daily SBT and improved outcomes. The rapid shallow breathing index (RSBI = RR/Vt in litres), under 105, predicts success (Yang & Tobin). Before extubating, assess airway patency with a cuff leak test and the patient's ability to protect the airway (cough on suction, gag); anticipate post-extubation stridor (especially in females, prolonged intubation, and traumatic intubation) and have a low threshold for prophylactic steroids and post-extubation high-flow nasal cannula or NIV. Reintubation rates run 10-20 per cent; a failed extubation carries a markedly higher mortality. Protocolised, nurse- or therapist-driven weaning reduces the duration of mechanical ventilation versus physician-directed weaning (Ely 1996).

Checked against its sources on 14 Oct 2026