Wean
Formal Definition
The gradual reduction and eventual discontinuation of mechanical ventilatory support, sedation, vasopressors, or other life-sustaining interventions as a patient's clinical condition improves — a systematic process guided by defined criteria rather than arbitrary time-based protocols.
How It's Used on the Ward
"Weaning the vent" or "weaning pressors" — the daily question in the ICU: is this patient ready to do more on their own?
Example
""Day 3 post-cardiac surgery: hemodynamically stable, vasopressors weaned off overnight, now on pressure support 10/5 with FiO2 0.4. SAT passed this morning. Starting SBT now — if tolerates 30 minutes, extubate this afternoon.""
Clinical Context
Ventilator weaning readiness criteria (SBT screen): hemodynamically stable off or on minimal vasopressors, adequate oxygenation (FiO2 ≤0.4, PEEP ≤5–8), reversible cause of respiratory failure addressed, able to follow simple commands, adequate cough and airway protective reflexes. The SBT (spontaneous breathing trial) — patient breathes on minimal support for 30–120 minutes — is the gold-standard weaning assessment. Extubation failure rate 10–20% despite passing SBT. Predictors of failure: age, secretion burden, upper airway edema, reintubation carries 3–10× ICU mortality.