Three studies were included in the review: one randomised controlled trial (RCT) and two cohort studies. The RCT had level of evidence of I, whilst the two cohort studies had level of evidence II-2b and II-2c. The total number of participants was not stated.
The single RCT found that weaning commenced earlier in the protocol group: the difference between the control versus protocol group was -18.7 hours (95% CI: -40.2, +2.8, p=0.016), but this difference was not significant. There was a significant difference in the duration of the mechanical ventilation in the respiratory therapists (RT) group, compared with physician care: the difference between the control versus respiratory therapist protocol was -32.6 hours (95% CI: -63.4, -1.8, p=0.079). There were no significant differences in reintubation rates, mortality or hospital stay, although the hospital costs were reduced in the respiratory therapist group.
The first of the cohort studies (n=284) reported that the total ventilation time and weaning duration were reduced in the protocol group, compared with a retrospective control. However, neither result was statistically significant (p=0.09 and p=0.77, respectively).
The second of the cohort studies compared patients before and after the introduction of the weaning protocol. The study found no significant difference between the two groups in terms of the duration of ventilation (p=0.39).
In summary, two studies showed a reduction in ventilation time without additional complications; the third study had the weakest evidence and showed no difference between the control and treatment groups.