RCT: More Frequent Screening with Pressure-Supported SBTs Delayed Extubation in Mechanically Ventilated Adults
13 Oct, 2024 | 13:15h | UTCBackground: Prompt liberation from mechanical ventilation is crucial to reduce complications associated with prolonged ventilator use. The optimal frequency of weaning readiness screening and the most effective spontaneous breathing trial (SBT) technique are not well established.
Objective: To evaluate whether the frequency of screening for weaning readiness (once-daily vs more frequent) and the SBT technique used (pressure-supported vs T-piece) affect the time to successful extubation in adults receiving invasive mechanical ventilation.
Methods: In a multicenter randomized clinical trial with a 2×2 factorial design, 797 critically ill adults who had been mechanically ventilated for at least 24 hours were enrolled. Participants were randomized to either once-daily or more frequent screening for weaning readiness and to undergo either pressure-supported SBTs (pressure support >0 to ≤8 cm H₂O with PEEP >0 to ≤5 cm H₂O) or T-piece SBTs, each lasting 30–120 minutes. The primary outcome was the time to successful extubation, defined as the time from starting unsupported spontaneous breathing that was sustained for at least 48 hours post-extubation.
Results: Among the 797 patients (mean age 62.4 years; 59.2% male), there was no significant difference in time to successful extubation when comparing screening frequencies (hazard ratio [HR] 0.88; 95% CI, 0.76–1.03; P = .12) or SBT techniques (HR 1.06; 95% CI, 0.91–1.23; P = .45) individually. However, a significant interaction between screening frequency and SBT technique was identified (P = .009). Specifically, in patients undergoing pressure-supported SBTs, more frequent screening *delayed* time to successful extubation compared to once-daily screening (HR 0.70; 95% CI, 0.50–0.96; P = .02). Conversely, when T-piece SBTs were used, the frequency of screening did not significantly affect extubation time. The median time to successful extubation was shortest in the once-daily screening with pressure-supported SBT group (2.0 days) and longest in the more frequent screening with pressure-supported SBT group (3.9 days).
Conclusions: More frequent screening combined with pressure-supported SBTs resulted in a *longer* time to successful extubation, suggesting this combination may delay weaning from mechanical ventilation. Once-daily screening with pressure-supported SBTs showed a trend toward faster extubation compared to other strategies, although this was not statistically significant.
Implications for Practice: Clinicians should be cautious about combining more frequent screening with pressure-supported SBTs, as this may unintentionally prolong mechanical ventilation. Adopting once-daily screening with pressure-supported SBTs might facilitate earlier extubation.
Study Strengths and Limitations: Strengths of the study include its large sample size, multicenter design, and high adherence to the intervention protocols. Limitations involve the unexpected significant interaction between interventions, which may limit the generalizability of the results.
Future Research: Additional studies are warranted to confirm the interaction between screening frequency and SBT technique and to explore the mechanisms underlying the delayed extubation with more frequent screening and pressure-supported SBTs.