NMES to Prevent Respiratory Muscle Atrophy in Mechanically Ventilated Patients

Breath Synchronized Electrical Stimulation of the Abdominal Wall Muscles to Prevent Respiratory Muscle Atrophy During the Acute Stages of Mechanical Ventilation Therapy

Patients requiring prolonged time on the ventilator are susceptible to a wide range of clinical complications and excess mortality. It is therefore imperative for them to wean at the earliest possible time. Respiratory muscle weakness due to disuse of these muscles is a major underlying factor for weaning failure. Surprisingly, there is not much known about the impact of critical illness and MV on the expiratory abdominal wall muscles.These muscles are immediately activated as ventilation demands increase and are important in supporting respiratory function in patients with diaphragm weakness. Weakness of expiratory abdominal wall muscles will result in a decreased cough function and reduced ventilatory capacity. These are considerable causes of weaning failure and (re)hospitalisation for respiratory complications such as pneumonia. Recent evidence shows that neuromuscular electrical stimulation (NMES) can be used as a safe therapy to maintain skeletal muscle function in critically ill patients. This study will be the first to test the hypothesis that breath-synchronized NMES of the abdominal wall muscles can prevent expiratory muscle atrophy during the acute stages of MV.

Approximately 30-40% of intubated patients at the intensive care unit (ICU) take more than one attempt to wean from mechanical ventilation (MV). 6-14% of intubated patients take longer than 7 days to wean from MV. Patients requiring prolonged time on the ventilator are susceptible to a wide range of clinical complications and excess mortality. It is therefore imperative for them to wean at the earliest possible time. Respiratory muscle weakness due to disuse of these muscles is a major underlying factor for weaning failure. It is known that diaphragm strength rapidly declines within a few days after the initiation of MV. Surprisingly, there is not much known about the impact of critical illness and MV on the expiratory abdominal wall muscles.These muscles are immediately activated as ventilation demands increase and are important in supporting respiratory function in patients with diaphragm weakness. Weakness of expiratory abdominal wall muscles will result in a decreased cough function and reduced ventilatory capacity. These are considerable causes of weaning failure and (re)hospitalisation for respiratory complications such as pneumonia. Recent evidence shows that neuromuscular electrical stimulation (NMES) can be used as a safe therapy to maintain skeletal muscle function in critically ill patients, e.g. by stimulating quadriceps muscles in patients receiving MV. This study will be the first to test the hypothesis that exhalation synchronized NMES of the abdominal wall muscles can prevent expiratory muscle atrophy during the acute stages of MV. The investigators hypothesize that this approach will improve respiratory function and thereby will reduce the amount of time it takes to wean patients from mechanical ventilation.

Expiratory muscles, Mechanically ventilated patients, Neuromuscular electrical stimulation, Respiratory function, Ventilator-acquired muscle atrophy

NMES applied to the abdominal wall muscles using the VentFree prototype (VF03-K). Stimulation is applied twice daily for 30 minutes, 5 days per week, for 6 weeks or until the patient is weaned from mechanical ventilation, whichever occurs sooner.

Sham stimulation applied to the abdominal wall muscles using the VentFree prototype (VF03-K). Sham stimulation is applied twice daily for 30 minutes, 5 days per week, for 6 weeks or until the patient is weaned from mechanical ventilation, whichever occurs sooner.

Abdominal wall muscle stimulation synchronised with mechanical ventilation. Stimulation frequency: 30 Hz, pulse width: 352us, max. intensity: 100mA (threshold intensity determined using ultrasound)

Abdominal wall muscle sham-stimulation synchronised with mechanical ventilation. Stimulation frequency: 10 Hz, pulse width: 352us, intensity: 15 mA.

Weaning failure defined as the failure to pass a spontaneous-breathing trial or the need for reintubation within 48 hours following extubation

Number of patients with development of pneumonia, and readmission to the ICU due to atelectasis or respiratory problems that require mechanical ventilation.

Inclusion Criteria: age > 18 year invasive mechanical ventilation less than 72 hours expected duration of MV after inclusion > 72 hours Exclusion Criteria: no clearly visible separate layers of the abdominal wall muscles (external oblique, internal oblique and transverse abdominal muscles), assessed with ultrasound during routine care cardiac pacemaker congenital myopathies and/or existing central or peripheral neuropathies refractory epilepsy recent abdominal surgery within four weeks prior to study inclusion body mass index (BMI) greater than 35 kg/m2 pregnancy

Jonkman AH, Frenzel T, McCaughey EJ, McLachlan AJ, Boswell-Ruys CL, Collins DW, Gandevia SC, Girbes ARJ, Hoiting O, Kox M, Oppersma E, Peters M, Pickkers P, Roesthuis LH, Schouten J, Shi ZH, Veltink PH, de Vries HJ, Shannon Weickert C, Wiedenbach C, Zhang Y, Tuinman PR, de Man AME, Butler JE, Heunks LMA. Breath-synchronized electrical stimulation of the expiratory muscles in mechanically ventilated patients: a randomized controlled feasibility study and pooled analysis. Crit Care. 2020 Oct 30;24(1):628. doi: 10.1186/s13054-020-03352-0.