Critical Illness, Intensive Care Unit Patients, Mechanical Ventilation, Muscle Weakness Condition, Neuromuscular Electrical Stimulation (NMES)
Conditions
Keywords
Neuromuscular Electrical Stimulation, Physiotherapy, Mechanical Ventilation, Muscle Strength, Randomized Controlled Trial, Critical Illness
Brief summary
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.
Detailed description
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.
Interventions
OTHERConventional Physical Therapy
Individualized physical therapy including progressive mobility (e.g., bed exercises, sitting on the edge of the bed, standing, transfers, and ambulation) and respiratory therapy tailored to the patient's clinical condition. Delivered daily by trained professionals.
DEVICENeuromuscular Electrical Stimulation (NMES)
NMES will be applied to both lower limbs once or twice daily for 20 consecutive days. Electrodes will be positioned on the vastus lateralis, vastus medialis, tibialis anterior, hamstrings, and gastrocnemius muscles. The stimulation protocol includes progressive parameters to induce visible and effective muscle contractions.
Sponsors
Hospital Moinhos de Vento
Federal University of Health Science of Porto Alegre
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Masking description
The outcomes assessor will be blinded to participant group assignment to minimize bias in outcome evaluation. Participants and care providers will be aware of group assignments.
Intervention model description
Participants will be randomly assigned to one of two groups in a parallel design: the control group receiving conventional physical therapy, and the intervention group receiving conventional physical therapy plus neuromuscular electrical stimulation. Both groups will be treated simultaneously during the study period.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Muscle strength assessed by the Medical Research Council (MRC) sum score at ICU discharge | Within 24 hours after ICU discharge | Muscle strength will be evaluated by trained physiotherapists using the Medical Research Council (MRC) scale, which grades muscle strength from 0 (no contraction) to 5 (normal strength) in key muscle groups, with a maximum total score of 60 points. Muscle weakness is defined as a score below 48 points. This scale provides a standardized method to evaluate muscular recovery during critical illness and hospitalization. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Rectus femoris muscle thickness measured by ultrasound at initiation of invasive mechanical ventilation | within 24 hours after enrollment | The thickness of the rectus femoris muscle will be measured in millimeters using ultrasound imaging performed by trained professionals, in order to assess muscle morphology. |
| Rectus femoris pennation angle measured by ultrasound at initiation of invasive mechanical ventilation | within 24 hours after enrollment | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. The pennation angle of the rectus femoris will be measured in degrees to assess muscle architecture. |
| Rectus femoris pennation angle measured by ultrasound at sedation awakening | Within 24 hours after awakening from sedation in the ICU | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. The pennation angle (in degrees) will be measured. Assessments will be performed when sedation is reduced or stopped to the point that the patient can respond to at least three motor commands (e.g., blink eyes, look at the examiner, stick out tongue, shake head, or raise eyebrows), in order to assess muscle architecture at sedation awakening. Unit of Measure: degrees (°) |
| Rectus femoris muscle thickness measured by ultrasound at sedation awakening | Within 24 hours after awakening from sedation in the ICU | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. Muscle thickness (in millimeters) will be measured. Assessments will be performed when sedation is reduced or stopped to the point that the patient can respond to at least three motor commands (e.g., blink eyes, look at the examiner, stick out tongue, shake head, or raise eyebrows), in order to assess muscle morphology at sedation awakening. Unit of Measure: millimeters (mm) |
| Rectus femoris pennation angle measured by ultrasound at ICU discharge | Within 24 hours after ICU discharge | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. The pennation angle (in degrees) will be measured to assess muscle architecture. Each value will be recorded individually at ICU discharge. Unit of Measure: degrees (°) |
| Rectus femoris muscle thickness measured by ultrasound at ICU discharge | Within 24 hours after ICU discharge | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. Muscle thickness (in millimeters) will be measured to assess muscle morphology. Each value will be recorded individually at ICU discharge. Unit of Measure: millimeters (mm) |
| Rectus femoris pennation angle measured by ultrasound at hospital discharge | From 48 hours to 0 hours before hospital discharge | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. The pennation angle (in degrees) will be measured to assess muscle architecture. Assessments will be performed at hospital discharge. Unit of Measure: degrees (°) |
| Rectus femoris muscle thickness measured by ultrasound at hospital discharge | From 48 hours to 0 hours before hospital discharge | The quadriceps muscle (specifically the rectus femoris) will be evaluated using ultrasound imaging by trained professionals. Muscle thickness (in millimeters) will be measured to assess muscle morphology. Assessments will be performed at hospital discharge. Unit of Measure: millimeters (mm) |
| Muscle strength assessed by the Medical Research Council (MRC) sum score at awakening from sedation | Within 24 hours after awakening from sedation in the ICU | Muscle strength will be evaluated by trained physiotherapists using the Medical Research Council (MRC) sum score, which grades muscle strength from 0 (no contraction) to 5 (normal strength) in key muscle groups, with a maximum total score of 60 points. Muscle weakness is defined as a score below 48 points. Assessments will be performed when sedation is reduced or stopped so that the patient can respond to at least three motor commands (e.g., blink eyes, look at examiner, stick out tongue, shake head, raise eyebrows) to assess muscle strength at sedation awakening. |
| Muscle strength assessed by the Medical Research Council (MRC) sum score at hospital discharge | From 48 hours to 0 hours before hospital discharge | Muscle strength will be evaluated by trained physiotherapists using the Medical Research Council (MRC) scale, which grades muscle strength from 0 (no contraction) to 5 (normal strength) in key muscle groups, with a maximum total score of 60 points. Muscle weakness is defined as a score below 48 points. Assessments will be performed at three time points: awakening from sedation, ICU discharge, and hospital discharge. This scale provides a standardized method to evaluate muscular recovery during critical illness and hospitalization. |
| Handgrip strength measured at awakening from sedation in the ICU | Within 24 hours after awakening from sedation in the ICU | Handgrip strength will be assessed using a handheld hydraulic dynamometer, which measures the maximum force the participant can apply by squeezing the device with their hand. The participant will remain seated with their feet flat on the floor and the arm positioned in a standardized manner to ensure measurement accuracy. Assessments will be performed when sedation is reduced or stopped so that the patient can respond to at least three motor commands (e.g., blink eyes, look at examiner, stick out tongue, shake head, raise eyebrows) to assess muscle. |
| Handgrip strength measured at ICU discharge | Within 24 hours after ICU discharge | Handgrip strength will be assessed using a handheld hydraulic dynamometer, which measures the maximum force the participant can apply by squeezing the device with their hand. The participant will remain seated with their feet flat on the floor and the arm positioned in a standardized manner to ensure measurement accuracy. |
| Handgrip strength measured at hospital discharge | From 48 hours to 0 hours before hospital discharge | Handgrip strength will be assessed using a handheld hydraulic dynamometer, which measures the maximum force the participant can apply by squeezing the device with their hand. The participant will remain seated with their feet flat on the floor and the arm positioned in a standardized manner to ensure measurement accuracy. |
| Isometric Knee Extension Strength Assessed at Awakening From Sedation in the ICU | Within 24 hours after awakening from sedation in the ICU | Isometric knee extension strength will be assessed using a portable dynamometer. Participants will be seated with the knee at a 60-degree angle of flexion and instructed to push the leg forward against the device without moving the joint. This test measures the force generated by the quadriceps while the joint remains still. Assessments will be conducted by trained professionals using standardized procedures. Measurements will be performed when sedation is reduced or stopped so that the patient can respond to at least three motor commands (e.g., blink eyes, look at examiner, stick out tongue, shake head, raise eyebrows) to assess muscle strength at sedation awakening. |
| Isometric Knee Extension Strength Assessed at ICU Discharge | Within 24 hours after ICU discharge | Isometric knee extension strength will be assessed using a portable dynamometer. The participant will be seated with the knee positioned at a 60 degree angle of flexion and instructed to push the leg forward against the device without moving the joint. This test measures the force the quadriceps can generate while the joint remains still. The assessment will be conducted by trained professionals using standardized procedures. |
| Isometric Knee Extension Strength Assessed at Hospital Discharge | From 48 hours to 0 hours before hospital discharge | Isometric knee extension strength will be assessed using a portable dynamometer. The participant will be seated with the knee positioned at a 60 degree angle of flexion and instructed to push the leg forward against the device without moving the joint. This test measures the force the quadriceps can generate while the joint remains still. The assessment will be conducted by trained professionals using standardized procedures. |
| Functional capacity assessed by the Six-Minute Walk Test (6MWT) | From 48 hours to 0 hours before hospital discharge | The six-minute walk test (6MWT) will be conducted by trained physiotherapists to assess functional exercise capacity. The total distance walked in six minutes will be recorded following standardized procedures. |
| Barthel Index Assessed at Study Enrollment | At baseline (study enrollment) | Functional independence will be evaluated using the Barthel Index, a questionnaire that measures a patient's ability to perform activities of daily living (ADLs). At study enrollment, the questionnaire will be answered by the patient's family member or primary caregiver to provide a baseline assessment of the patient's functional status prior to ICU admission. The Barthel Index assesses independence in areas such as personal care, mobility, locomotion, and elimination. Each activity is scored based on the patient's level of independence, assistance needed, or dependence. Scores range from 0 to 100 in increments of five, with higher scores indicating greater functional independence. |
| Barthel Index Assessed at Hospital Discharge | From 48 hours to 0 hours before hospital discharge | Functional independence will be evaluated using the Barthel Index, a questionnaire that measures a patient's ability to perform activities of daily living (ADLs). The questionnaire assesses independence in areas such as personal care, mobility, locomotion, and elimination. Each activity is scored based on the patient's level of independence, assistance needed, or dependence. Scores range from 0 to 100 in increments of five, with higher scores indicating greater functional independence. |
| Barthel Index Assessed at 6 Months Post Hospital Discharge | 6 months after hospital discharge | Functional independence will be evaluated using the Barthel Index, a questionnaire that measures a patient's ability to perform activities of daily living (ADLs). At 6 months post hospital discharge, the patient will be contacted by telephone to complete the questionnaire. The Barthel Index assesses independence in areas such as personal care, mobility, locomotion, and elimination. Each activity is scored based on the patient's level of independence, assistance needed, or dependence. Scores range from 0 to 100 in increments of five, with higher scores indicating greater functional independence. |
| Duration of invasive mechanical ventilation (IMV) | Within 24 hours after ICU discharge | The duration of invasive mechanical ventilation (IMV) will be measured from the initiation of IMV until the day of extubation. This duration will be verified and confirmed through review of the patient's medical records. |
| Ventilator-free days | Within 24 hours after ICU discharge | The number of days during which the patient was alive and free from invasive mechanical ventilation (IMV) during the ICU stay. This information will be collected from the patient's medical records at hospital discharge. |
| Length of stay in ICU and hospital | Within 24 hours after hospital discharge | The total number of days the patient remains admitted in the Intensive Care Unit (ICU) and the hospital during their treatment period. This includes the time from ICU admission until discharge from the hospital. This information will be collected from the patient's medical records at hospital discharge. |
| Mortality | From hospital admission until death or up to 180 days (6 months) after hospital discharge, whichever occurs first | The number of deaths occurring among study participants during the hospital stay and within six months after hospital discharge. |
Countries
Brazil
Contacts
CONTACTLarissa Carolina Brandão da Cunha, MSc
CONTACTCassiano Teixeira, Doctor
PRINCIPAL_INVESTIGATORCassiano TEIXEIRA, PhD
Hospital Moinhos de Vento
Outcome results
None listed