Efficacy of mechanical insufflation-exsufflation in extubating unweanable subjects with restrictive pulmonary disorders

Abstract

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: Ninetyseven 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