Evaluation of a weaning protocol in an intensive care unit

Objective

Current evidence suggests that patients spend about 41% of their time in mechanical ventilation (MV) with weaning. The application of weaning protocols brings better results over the treatment based upon simple observation of the patient, reducing the time of MV and its associated complications. The goal of this study was to evaluate the results from the application of a weaning protocol executed by the Physical Therapy team, aiming to reduce the weaning length and the MV length.

Methods

Fifty-eight inpatients were prospectively studied at the Clinica São Vicente ICU, from June 2005 to February 2007. These patients were ventilated through an endotracheal tube and were in MV ≥48 hours. The ventilatory status of these patients was evaluated daily and after they fitted the protocol we started the weaning program, using pressure support ventilation (PSV). Patients that tolerated one spontaneous ventilation attempt were considered eligible for extubation, considering PSV of 7 cmH₂O and PEEP of 4 cmH₂O for 30 minutes. Higher levels of PSV and PEEP were accepted for patients with chronic obstructive pulmonary disease (COPD).

Measurements and results

The mean age of the patients was 66.25 years (SD ± 20.21), with 52.6% males and 47.4% females. The average time of MV was 6.44 days (SD ± 3.17) and weaning length was 1.52 days (SD ± 1.09). The indication for an artificial airway and MV was 15 postoperative patients (26.3%), 33 patients with acute respiratory distress (57.9%) and nine neurology affected patents (15.8%). At the extubation time the average PSV was 7.81 (SD ± 1.30) and the average PEEP was 4.54 (SD ± 1.00). Forty-seven patients were successful (82.5%), while 10 needed reintubation (17.5%). There was no correlation between nonsuccess and age, COPD, MV causes or the Tobin index, considered a predictive index of success in the literature. Regarding the maximal inspiratory pressure, there was a statistically significant correlation (P = 0.01).

Conclusion

The time spent to weaning in our study was shorter than the literature description, and the reintubation rate was compatible with anterior publishing. The study showed that the institution of protocols can minimize the weaning length and the MV length in ICUs.