Mechanical insufflation-exsufflation for clinical outcomes in mechanically ventilated critically ill patients: A systematic review and meta-analysis

Background This systematic review and meta-analysis aimed to evaluate the clinical efficacy of mechanical insufflation-exsufflation (MI-E) compared with usual care in mechanically ventilated critically ill adults. Methods We searched Embase, MEDLINE via PubMed, CINAHL, and the Cochrane Library for randomized controlled trials (RCTs) published up to April 2026 that compared MI-E with usual care in mechanically ventilated adults. The primary outcome was duration of mechanical ventilation. Secondary outcomes included the amount of aspirated airway secretions, respiratory system compliance, airway resistance, length of ICU stay, and mortality. Meta-analysis was performed when at least two studies provided clinically and methodologically comparable data. The certainty of evidence was assessed using the GRADE approach. Results Six RCTs involving 492 participants were included. For the primary outcome of mechanical ventilation duration, only one RCT contributed to the effect estimate (MD, −2.67 days; 95% CI, −6.91 to 1.57; very-low-certainty evidence). MI-E increased the amount of aspirated airway secretions compared with usual care (MD, 1.47 g; 95% CI, 0.74 to 2.19; very-low-certainty evidence). No statistically significant differences were observed in respiratory system compliance or airway resistance. ICU length of stay also showed no difference (2 RCTs; MD, −1.75 days; 95% CI, −4.61 to 1.10; very-low-certainty evidence). Mortality was evaluated by one RCT (risk ratio, 1.56; 95% CI, 0.44 to 5.50; very-low-certainty evidence). Conclusions The effects of MI-E on clinical outcomes in mechanically ventilated critically ill patients remain uncertain because the available evidence is of low to very low certainty. MI-E may improve airway secretion clearance; however, evidence regarding mechanical ventilation duration, ICU length of stay, and mortality remains very uncertain. Further high-quality randomized controlled trials are required.