Evaluation of Muscle Strength by Transcutaneous Electrical Stimulation

Evaluation of Muscle Strength by Transcutaneous Electrical Stimulation in Intensive Care Unit Patients

Acquired Neuromyopathy of Resuscitation (NMAR) is a common condition. Its diagnosis is difficult and often late because it is based on a clinical assessment of muscle strength (MRC score) requiring the patient to be awake and cooperative.

Transcutaneous electrical stimulation consists of applying electrical stimulation along the path of a motor nerve in order to generate contraction of the previously relaxed muscle. The mechanical response thus generated is recorded and allows the muscular strength developed to be assessed. Non-invasive and easily performed in the patient's bed, transcutaneous electrical stimulation could be an interesting alternative for early assessment of muscle strength in the still sedated resuscitation patient. However, this technique could be perceived as uncomfortable or painful in the awake patient so that magnetic stimulation, which is generally much better tolerated, should be preferred. However, magnetic stimulators have a limited maximum magnetic field which may prevent supramaximal stimulation especially in patients developing generalized edema (i.e., in the initial resuscitation phase).

We propose to conduct a reproducibility study of quadriceps force measurement in patients undergoing resuscitation by transcutaneous electrical and/or magnetic neurostimulation in the initial (i.e., < 96 h) and late (> 96 h) phases of resuscitation and then in the recovery phase. For each investigative technique (i.e., electrical vs. magnetic), we will perform 2 types of stimulation: single stimulation and high frequency doublet stimulation (100 Hz), repeated 3 times each.

Inclusion Criteria:

• Age ≥ 18 years
• admitted in intensive care unit B of ST-Etienne hospital
• Predictable duration of mechanical ventilation of more than 72 hours
• Patient whose family has given informed and written consent to the patient's participation in the study

Exclusion Criteria:

• Pregnant woman,
• Patients with peripheral nerve damage prior to or at the time of measurement
• Curarized patients (non-efficacy of neurostimulation)
• Fracture of limb or pelvis
• Presence of a catheter in the stimulation zone (femoral artery or vein)
• Patients suffering from psychiatric pathologies.
• Brain pathology leading the patient to intensive care.
• Patients with neuromuscular pathology.
• Patients carrying equipment subject to possible electrical and/or magnetic interference,
• Patient with spinal fracture(s) at risk of spinal cord injury