Application of automated tube compensation/airway resistance compensation modes for liberation from prolonged mechanical ventilation in tracheostomized patients

ABSTRACT

RATIONALE The attempt at direct liberation from mechanical ventilation (MV) using open-circuit oxygen in the tracheostomized patients with prolonged MV might carry a substantial failure rate. Frequent switching between closed-circuit MV support and open-circuit oxygen, such as a T-piece during the liberation attempt, might also carry a risk of dispersing aerosol particles to the care environment, especially during the pandemic era. We aimed to analyze the feasibility and predictability of adding a screening test with automated tube compensation (ATC) or airway resistance compensation (ARC) mode before the attempt of an open-circuit oxygen trial. METHODS: We conducted a retrospective analysis of tracheostomized patients admitted to a medical center's dedicated weaning unit in Taiwan. Because of coronavirus's global pandemic, the unit implemented a universal process to apply ATC/ARC screening tests to patients since April 2020. Before starting the MV liberation trial with continuous spontaneous breathing via open-circuit oxygen (T-piece), the patients received a screening test consisting of 12 hours of ATC/ARC the first day followed by 72 hours of continuous ATC/ARC. Those who passed the test then proceeded to the open-circuit liberation trial. Those who failed the test would receive repeated ATC/ARC or open circuit trials. RESULTS: A total of 79 (51% of the admitted) patients, including 54 male, aged 69 [18-95] years, and averaged 32 days of MV before admission to the weaning unit, received the screening test (59 for ATC;20 for ARC) after MV settings reduction. Of the 79 patients, 48 (61%) succeeded in the test. Upon discharge from the unit, 49 (62%) were liberated from MV, and 43 (54%) were MV-free status 30 days after the ATC/ARC test. Of the 31 who failed ATC/ARC, 22 (71%) remained MV-dependent at 30 days after the ATC/ARC test. Therefore, the sensitivity, specificity, positive predictive value, and negative predictive values of the ATC/ARC test for outcomes of MV-liberation upon discharge from the unit were 90%, 87%, 92%, and 84%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive values of the ATC/ARC test for outcomes of MV-free status 30 days after the test were 93%, 78%, 83%, and 90%, respectively. CONCLUSION: Before proceeding with open-circuit oxygen, a screening test with ATC/ARC provides an optimal prediction for the 30-day outcomes of MV liberation.