SBT Parameters
NIF < -30, RSBI < 100
Respiratory rate RR >38 bpm for 5 minutes or <6bpm
SpO2 < 92%
Tidal volume (TV) < 325 mL
Heart rate: HR > 140 OR 25% above baseline OR HR<60
Blood pressure: SBP 40 mm Hg above baseline
Worsening agitation, anxiety or discomfort despite reassurance
Rapid shallow breathing index (RSBI) = RR/ TV
Most consistent and powerful predictor
RSBI > 105 min/L predicted failure well, but if used rigidly may slow the weaning process
Spontaneous breathing trials (SBT) are used to identify patients who are likely to fail liberation from mechanical ventilation










