Neuromuscular Electrical Stimulation in a Patient on Invasive Mechanical Ventilation (MOVCARE)

Neuromuscular Electrical Stimulation of Lower Limbs in Patients Undergoing Invasive Mechanical Ventilation: Randomized Clinical Trial

This clinical study aims to compare the effects of conventional physical therapy alone versus conventional physical therapy combined with neuromuscular electrical stimulation (NMES) in patients admitted to the ICU and undergoing invasive mechanical ventilation. Participants will be randomly assigned to receive either conventional physical therapy or the same therapy plus NMES applied to the lower limbs. The protocol includes muscle-specific stimulation parameters and safety criteria to postpone sessions in cases of clinical instability. The primary goal is to assess whether NMES improves muscle function and recovery in critically ill patients.

This randomized clinical trial will investigate the effects of neuromuscular electrical stimulation (NMES) in critically ill patients undergoing invasive mechanical ventilation. Participants will be randomly assigned to two groups: a control group receiving conventional physical therapy alone and an intervention group receiving conventional physical therapy combined with NMES.

The control group will receive individualized conventional physical therapy, adjusted daily based on each patient's physiological status and following protocols supported by current literature. Interventions may include progressive mobility, such as bed exercises, rolling, sitting at the edge of the bed, standing, chair transfers, and ambulation, as well as respiratory physiotherapy techniques including bronchial hygiene, pulmonary re-expansion, and management of mechanical ventilation. Sessions will last approximately 20 minutes and continue throughout hospitalization, except in cases of clinical contraindications or refusal by the patient/family.

The NMES group will receive the same conventional physical therapy described above, plus NMES applied once or twice daily to both lower limbs for up to 14 consecutive days or until hospital discharge, whichever comes first.

Rectangular electrodes (90 × 50 mm) will be placed bilaterally on the vastus lateralis, vastus medialis, tibialis anterior, hamstrings, and gastrocnemius muscles. If hair interferes with electrode adhesion, the area will be shaved.

NMES will be delivered using the ReCARE® device (Visuri, MG, Brazil) with the following parameters:

Frequency: 60 Hz

Pulse duration: 500 µs

Intensity: adjusted to produce visible muscle contractions during the first two days and, from day three onward, contractions sufficient to generate movement against gravity.

Contraction (on) and relaxation (off) times and the number of contractions will be progressively adjusted according to the 14-day protocol:

Days 1-2: On = 9s, Off = 22s, 30 contractions, 1x/day

Days 3-6: On = 9s, Off = 20s, 40 contractions, 1x/day

Days 7-9: On = 9s, Off = 18s, 50 contractions, 1x/day

Days 10-14: On = 9s, Off = 15s, 60 contractions, 1x/day

NMES sessions will be postponed if the participant exhibits any of the following clinical findings within three hours prior to the session:

Acidosis (arterial pH < 7.25 or venous pH < 7.20)

Hypotension or hypertension (mean arterial pressure < 60 mmHg or > 140 mmHg)

Use of a single vasopressor at >50% of the ICU maximum dose (e.g., dopamine >12.5 µg/kg/min, phenylephrine >2 µg/kg/min, vasopressin ≥0.02 U/min, norepinephrine >1 µg/kg/min)

Use of two vasopressors at ≥40% of the ICU maximum dose

New diagnosis of pulmonary embolism or deep vein thrombosis without anticoagulation for more than 48 hours

Other signs of physiological instability, including temperature <34°C or >41°C, lactate >3.0 mmol/L, creatine kinase >400 U/L, platelet count <20,000/mm³, or suspected muscle inflammation (e.g., rhabdomyolysis, myositis, neuroleptic malignant syndrome, or serotonin syndrome).

This study aims to determine whether NMES, as an early adjunct therapy, can improve recovery and clinical outcomes in critically ill mechanically ventilated patients when combined with conventional physical therapy.

Protocol Amendment and Rationale The study protocol was amended following study initiation due to operational and feasibility constraints identified during the early recruitment phase (from the second enrolled participant onwards), particularly related to limited availability of research personnel required for intervention delivery as originally designed.

Amendments implemented:

1. Study duration and intervention schedule The intervention duration was reduced from 20 to 14 days. In addition, the original protocol of two daily sessions during the initial phase was modified to a single daily session throughout the intervention period. Stimulation parameters were also adjusted, including optimization of on/off time and number of contractions, resulting in a shorter and more feasible protocol while maintaining the intended neuromuscular stimulation dose.
2. Eligibility criteria modification The exclusion criterion related to baseline mobility was refined. The original criterion excluding patients unable to independently leave the bed was modified to exclude patients who were either unable to leave the bed independently or had pre-existing dependence for mobility prior to hospital admission, in order to improve baseline functional homogeneity and recruitment feasibility.
3. Blinding procedures Outcome assessor blinding was removed. Although initially planned, blinding was not feasible due to limited research personnel and logistical constraints associated with intervention delivery.

Rationale:

These amendments were introduced to ensure study feasibility under resource and staffing constraints while maintaining protocol integrity and alignment with the physiological objectives of the intervention.

Importantly, these changes were implemented early in the recruitment process and reflect an adaptation toward a more feasible and clinically applicable protocol.

Impact:

These modifications do not affect the study objectives, primary or secondary outcomes, or participant safety. The intervention remains within established safety parameters for neuromuscular electrical stimulation, and no additional risk to participants has been introduced.

Inclusion Criteria:

• Patients will be eligible if they are 18 years or older, are under invasive mechanical ventilation (IMV), and are expected to require IMV for more than 48 hours.

Exclusion Criteria:

• Body mass index (BMI) greater than or equal to 35 kg/m²;
• Length of ICU stay longer than 7 ICU-free days or more than 3 continuous days of invasive mechanical ventilation (IMV) before enrollment;
• Known intracranial process (e.g., stroke, intracranial hypertension);
• Neuromuscular disease (e.g., Guillain-Barré syndrome, myasthenia gravis) at ICU admission;
• Inability to speak Portuguese or pre-existing cognitive impairment prior to ICU admission;
• Any condition that prevents neuromuscular electrical stimulation (NMES) treatment or assessment of the primary outcome in both legs (e.g., skin lesions, fractures, or amputation);
• inability to transfer from bed to chair with or without assistance prior to hospital admission;
• Cardiac arrest as the cause of ICU admission or cardiac arrest before screening;
• Deep vein thrombosis (DVT) or pulmonary embolism (PE) treated for less than 48 hours;
• Pregnant patients;
• Known or suspected malignancy in the legs;
• Any care limitation including a do-not-resuscitate order.