Considerations for assessing readiness to wean
| Clinical assessment | Adequate cough |
| Absence of excessive tracheobronchial secretion | |
| Resolution of disease acute phase for which the patient was intubated | |
| Objective measurements | Clinical stability |
| Stable cardiovascular status (i.e. fC ≤140 beats·min−1, systolic BP 90–160 mmHg, no or minimal vasopressors) | |
| Stable metabolic status | |
| Adequate oxygenation | |
| Sa,O2 >90% on ≤FI,O2 0.4 (or Pa,O2/FI,O2 ≥150 mmHg) | |
| PEEP ≤8 cmH2O | |
| Adequate pulmonary function | |
| fR ≤35 breaths·min−1 | |
| MIP ≤-20– -25 cmH2O | |
| VT >5 mL·kg−1 | |
| VC >10 mL·kg−1 | |
| fR/VT <105 breaths·min−1·L−1 | |
| No significant respiratory acidosis | |
| Adequate mentation | |
| No sedation or adequate mentation on sedation (or stable neurologic patient) |
Data taken from 5, 6, 13, 16–18, 22. fC: cardiac frequency; BP: blood pressure; Sa,O2: arterial oxygen saturation; FI,O2: inspiratory oxygen fraction; Pa,O2: arterial oxygen tension; PEEP: positive end-expiratory pressure; fR: respiratory frequency; MIP: maximal inspiratory pressure; VT: tidal volume; VC: vital capacity. 1 mmHg = 0.133 kPa.