The addition of mechanical insufflation/exsufflation shortens airway-clearance sessions in neuromuscular patients with chest infection

Abstract

Background: Mechanical insufflation/exsufflation (in-exsufflation) increases peak cough flow and may improve sputum clearance. No studies have compared current respiratory physiotherapy practice (manual percussion, shaking, and assisted cough) plus mechanical in-exsufflation to current physiotherapy practice without in-exsufflation in noninvasive-ventilation (NIV) dependent neuromuscular patients with an acute respiratory-tract infection. We hypothesized that airway clearance in these patients would be more effective with in-exsufflation, compared to without in-exsufflation.

Methods: Eight patients (6 male), median age 21.5 y (range 4-44 y). All had sputum retention, with an elevated C-reactive protein of 113 mg/L (range 13-231 mg/L) and a white-cell count of 14x10(9) cells/L (range 7-25x10(9) cells/L). Patients underwent a 2-day randomized crossover treatment program, with in-exsufflation for one session and without in-exsufflation for the second, with a reverse-crossover on the next day. Treatment time after 30 min (or earlier if sputum clearance was complete) was recorded. Outcome measures were heart rate, pulse oximetry (SpO2), transcutaneous carbon dioxide tension (PtcCO2), and independently assessed auscultation score. Patients rated effectiveness on a visual analog scale.

Results: Treatment time after 30 min was significantly shorter with in-exsufflation, versus without in-exsufflation session (30+0=30 min (range 0-26 min) vs 30+17=47 min (range 0-35 min) (P=.03). There was a significant improvement in auscultation score in both groups (with in-exsufflation 2.9+/-1.9 to 1.8+/-2.0, P=.02; without in-exsufflation 3.4+/-2.0 to 2.3+/-2.2, P=.007). Visual-analog-scale score for the amount of sputum cleared in both treatment groups showed a decline ( <.05). There was no difference in mean heart rate, SpO2, or PtcCO2 with either treatment.

Conclusions: This is a short-term study of the use of in-exsufflation as a supplement to standard NIV plus physiotherapy in a small group of patients with neuromuscular disease. The addition of mechanical in-exsufflation shortened airway-clearance sessions. The device appeared to be safe and well tolerated, and may provide additional benefit to patients with neuromuscular disease and upper-respiratory-tract infection; further studies are indicated.