spontaneous breathing trial
A weaning assessment where patients breathe with minimal or no ventilator support to evaluate readiness for extubation.
Full Definition
A spontaneous breathing trial (SBT) is a structured assessment used to determine a patient's ability to breathe independently before extubation. During the trial, ventilator support is minimized or eliminated while the patient breathes through the ventilator circuit or T-piece system. Common methods include T-piece trials, CPAP at 5 cmH2O, or low-level pressure support (5-7 cmH2O). Success criteria typically include adequate oxygenation, stable hemodynamics, appropriate respiratory rate, and absence of respiratory distress. SBT duration ranges from 30 minutes to 2 hours depending on institutional protocols. Failed trials indicate continued ventilator dependence and need for further support.
Usage
Usage note: Commonly abbreviated as SBT; specify trial method and duration in documentation.
In Context
- "The patient successfully completed a 2-hour spontaneous breathing trial and was extubated." — Weaning assessment report
- "SBT was terminated after 20 minutes due to increased work of breathing and tachypnea." — Failed extubation trial note