Comparisons of Peak Cough Flow and Insufflation Volume Delivery and Accuracy on Mechanical Insufflation-Exsufflation Devices in a Pediatric Lung Model

Abstract

Background:

Long-term mechanical insufflation-exsufflation (MI-E) has been widely used to treat pediatric patients with ineffective cough from various conditions, such as neuromuscular diseases and chronic respiratory failure receiving mechanical ventilation. A previous bench study found the performance of MI-E devices extremely varied from manufacturers and even models of the same manufacturer and recommended individualized MI-E settings based on the specific machine utilized. We conducted a bench study to compare peak cough flow and insufflation volume delivery through two MI-E devices using a breathing simulator.

Methods:

A breathing simulator was set to simulate a pediatric patient (resistance of 50 L/min/s and compliance of 10 mL/cm H₂O) with spontaneous breathing efforts, connecting with two MI-E devices—CoughAssist T70 and Synclara. A flow analyzer Citrex H5 was connected between the MI-E devices and ASL 5000 to measure cough peak flow (CPF) and insufflation volume (Vi). Accuracies of the MI-E devices were calculated for CPF and Vi values. 10 consecutive CPF and Vi values measured by ASL 5000, MI-E devices, and the flow analyzer were recorded and analyzed.

Results:

The CPF values measured by CoughAssist T70 and Synclara were 97 [91-105] and 144 [121-157] L/min, respectively. The Vi values measured by CoughAssist T70 and Synclara were 344 [303-351] and 174 [165-187] mL, respectively. The median accuracy (%) of CPF for Cough Assist T70 and Synclara were -31 and -5%, respectively. The median accuracy (%) of Vi for CoughAssist T70 and Synclara were -38 and -56%, respectively. There were no significant differences on CPF and Vi delivery to the simulator (P = .21 and P = .98, respectively).

Conclusions:

Although the accuracy of parameters varied by MI-E devices, there were no significant differences on CPF and Vi delivery. Future research may be needed to evaluate movement of secretion in pediatric population among different MI-E devices.

Accuracy of Peak Cough Flow and Insufflation Volume Measurement on Mechanical Insufflation-Exsufflation Devices