Independent of cause for ventilatory support, a patient should meet the following criteria to be suitable for a spontaneous breathing trial:
Resolution of underlying etiology of respiratory failure
Adequate oxygenation: PaO2 over 150 to 200 mmHg while at minimal ventilator settings (FiO2 ≤ 50% with PEEP ≤ 8 cm H2O)
pH greater than 7.25; arterial carbon dioxide partial pressure (PaCO2) within baseline levels
Patient initiates inspiration
Hemodynamically stable:
No evidence of acute reversible myocardial ischemia
Heart rate ≤ 140 bpm
Blood pressure is adequate with minimal / no vasopressors
Hemoglobin ≥ 7 g/dL
Afebrile: core temperature ≤ 38°C to 38.5°C
Mental status awake and alert or easily arousable
