Efficacy of Mechanical Insufflation-Exsufflation in Extubating Unweanable Subjects With Restrictive Pulmonary Disorders

BACKGROUND: Subjects who do not pass ventilator weaning parameters but whose ambient air oxyhemoglobin saturation can be normalized by mechanical insufflation-exsufflation (MIE) can be extubated to continuous noninvasive ventilatory support (CNVS) with MIE used to maintain extubation. Our aim was to study MIE-associated changes in breathing tolerance, pulse oximetry, and vital capacity (VC) for consecutive unweanable subjects.

METHODS: A retrospective chart review was performed for consecutively referred intubated subjects with single-organ (respiratory muscle) failure. At presentation, CO₂ was normalized by adjusting ventilator settings and VC was measured (point 1). Then, MIE was used via the tube up to every h until oximetry remained ≥ 95% on ambient air and VC was remeasured (point 2) immediately before extubation. Subjects who could not meet ventilator weaning criteria and had no ventilator-free breathing ability upon extubation to CNVS were enrolled. Post-extubation, the MIE was used to maintain oximetry ≥ 95% in room air. VC and breathing tolerance were remeasured within 3 weeks (point 3).

RESULTS: Ninety-seven of 98 subjects were successfully extubated despite 45 having been CNVS-dependent for 4 months to 18 y before being intubated. Sixty-nine of the 98 were intubated for 24.9 ± 22 (range 1–158) d and failed 0–6 (mean 1.7) extubation attempts before being transferred and successfully extubated in 2.24 ± 1.78 (range < 1–8) d to CNVS. VC increased by 270% (P < .001) from points 1 to 3. Weaning from CNVS to part-time NVS was achieved by all 52 subjects who had not been CNVS-dependent before intubation. One subject underwent tracheotomy.

CONCLUSIONS: Many unweanable subjects can be extubated to CNVS and MIE. The latter can normalize O₂ saturation, increase VC, and facilitate extubation.