Abdominal functional electrical stimulation to enhance mechanical insufflation-exsufflation

Abstract

ContextRespiratory complications, attributed to the build-up of secretions in the airway, are a leading cause of rehospitalisation for the tetraplegic population. Previously, we observed that the application of Abdominal Functional Electrical Stimulation (AFES) improved cough function and increased demand for secretion removal, suggesting AFES may aid secretion clearance. Clinically, secretion clearance is commonly achieved by using Mechanical insufflation-exsufflation (MI-E) to simulate a cough. In this study the feasibility of combining AFES with MI-E is evaluated.FindingsAFES was successfully combined with MI-E at eight fortnightly assessment sessions conducted with one sub-acute participant with tetraplegia. By using the signal from a pressure sensor, integrated with the MI-E device, AFES was correctly applied in synchrony with MI-E with an accuracy of 96.7%. Acute increases in exhaled volume and peak flow were observed during AFES assisted MI-E, compared to MI-E alone, at six of eight assessment sessions.ConclusionThe successful integration of AFES with MI-E at eight assessment sessions demonstrates the feasibility of this technique. The acute increases in respiratory function observed at the majority of assessment sessions generate the hypothesis that AFES assisted MI-E may be more effective for secretion clearance than MI-E alone.

Abdominal Functional Electrical Stimulation to Augment Respiratory Function in Spinal Cord Injury

“…16 This instantaneous improvement in CPF should reduce respiratory complications in tetraplegia. Hence, abdominal FES provides a directly applicable clinical tool that can be used in conjunction with established physiotherapy techniques such as manually assisted cough (MAC), mechanical insufflation-exsufflation (ie, Cough Assist machine), 19 and tracheal and bronchial suction and postural drainage. 20 While the best clinical indicator for cough efficacy in humans is not clear, 21 the gastric (P ga ) and esophageal pressure (P es ) generated during a cough have been identified as good laboratory parameters to indicate expiratory muscle strength, which is likely to correlate with cough efficacy in humans.…”

Effects of Mechanical Insufflation-Exsufflation on Airway Mucus Clearance Among Mechanically Ventilated ICU Subjects

“…8 The active cough maneuver is not essential when MI-E is used in the invasive interfaces (orotracheal tube or tracheostomy) because the device can create an artificial cough, even in patients who are sedated or unconscious. [9][10][11][12][13][14][15] Despite the promising results of MI-E use in neuromuscular subjects, 16,17 use of MI-E in patients who are acutely critical is uncommon, although it is a safe technique, given that the inspiratory positive pressure during the insufflation can provide ventilatory support. In this sense, our study aimed to evaluate the efficacy of MI-E on airway mucus clearance among general ICU subjects receiving mechanical ventilation.…”

Critical Care of Traumatic Cervical Spinal Cord Injuries: Preventing Secondary Injury

“…29 Taken further, a recent small clinical trial to show proof of principle of abdominal function electrical stimulation on 10 ventilator-dependent patients with cervical SCI showed a reduced time to wean 11 days faster than controls. 30 The hypothesis is that timed stimulation to exhalation increases abdomen muscle strength, allowing greater control of abdominal contents so that the diaphragm can again use them as a fulcrum to expand the lower rib cage. The trial was underpowered to show a statistically significant reduced time to wean, but further studies are underway.…”