Use of a daily wean screen and weaning protocol for mechanically ventilated patients in a multidisciplinary tertiary critical care unit

Introduction: Variability in the initiation of the weaning process, style of weaning and discontinuation of mechanical ventilation amongst multiple ICU services can potentially increase ventilator length of stay (VLOS). The current emphasis on protocols and guidelines suggests that weaning standardization will result in decreased VLOS. The purpose of this study was to assess whether the success with standardization demonstrated in small homogenous populations could be reproduced in a large tertiary care multi-disciplinary ICU. Methods: All ventilated patients were screened (daily) by a Respiratory Care Practitioner for entry into a 2 hour spontaneous breathing trial on continuous positive airway pressure (CPAP) or low levels of pressure support (PS) and CPAP. Successful screening required a PaO₂/FiO₂ >200, PEEP <5, RR/Vt <105, adequate cough, Ramsay sedation score ≤3 and no vasopressors. Termination of the 2 hour spontaneous breathing trial occurred if the RR ≥35/minute for 5 minutes, O₂ sat ≤90%, HR ≥140 or a sustained 20% change, 180 ≤BP ≤90, or the presence of anxiety/diaphoresis. Successful completion of the spontaneous breathing trial prompted a request for an extubation order. Results: Over 8 months, 537 consecutive patients were evaluated. 290/537 (54%) passed the screen, 264/275 (96%) passed the spontaneous breathing trial and 232/264 (88%) were extubated with 217/232 (94%) remaining extubated ≥72 hours. Compared to 221 consecutive patients weaned without the wean screen/protocol, VLOS remained unchanged (131 vs. 141 hours). Conclusion: Although the vast majority of patients passing the wean screen and the spontaneous breathing trial were successfully extubated, standardization of the weaning process did not result in a decreased VLOS compared to previous practice in a multi-disciplinary ICU.