ICU Acquired Weakness
Conditions
Keywords
Biofeedback, Muscular disorders, Neuromuscular disorders, Rehabilitation
Brief summary
The goal of this study is to develop a non-invasive test to diagnose intensive care unit (ICU) acquired weakness that can be administered to both responsive and non-responsive patients. Study participation will involve the measurement of muscle fatigue during a single 30 minute session. Skeletal muscle will be stimulated with an FDA approved clinical electrical stimulator and accelerations will be passively recorded with an accelerometer.
Detailed description
The primary purpose of this study is to develop a procedure to identify intensive care unit (ICU) acquired weakness. This condition occurs in a subset of people admitted into the ICU, and is associated with a 30% increased risk of death before discharge from the ICU. There are currently major limitations in the ability to diagnose ICU acquired weakness, making it difficult to study. The goal is to develop a non-invasive test that can be administered to both responsive and non-responsive patients. The current proposal will focus on replicating the results of previous research using motion detecting accelerometers to measure fatigue in human skeletal muscles. This study is designed to test out the procedures in patients who have been transferred from the ICU to a lower level of care so that follow-on studies can be designed to help mitigate this condition in the ICU.
Interventions
DEVICEClinical Electrical Stimulator
Conductive electrodes will be on the skin at each end of the tested muscle(s). Each subject will have two target muscle groups tested (extensor carpi radialis longus, and tibialis anterior). Each muscle will be stimulated at three separate stimulation frequencies (2 Hz, 4 Hz, and 6Hz) over 3 minutes each, for a total of 9 minutes of stimulation per muscle. The clinical electrical stimulator will deliver mild electrical stimulations to the muscle (20-100 mA).
Sponsors
Emory University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Patients transferred from the ICU to a lower level of care within the past 7 days * Mechanical ventilation for greater than 7 days while in the ICU * Ability to understand English and provide written consent
Exclusion criteria
* Vulnerable populations including: patients who are pregnant or prisoners * Patients who are unable to understand English or provide written consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 | The highest acceleration over a single muscle twitch will be used as the peak acceleration. Peak acceleration will be measured in acceleration in number of times gravity (g). Higher twitch acceleration is a better response. |
| Peak Acceleration Measured in Tibialis Anterior | Day 1 | The highest acceleration over a single muscle twitch will be used as the peak acceleration. Peak acceleration will be measured in acceleration in number of times gravity (g). Higher twitch acceleration is a better response. |
| Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 2 Hz, Day 1 at 4 Hz, Day 1 at 6 Hz | The time, in seconds, until peak acceleration is reached will be assessed at 2, 4 and 6 Hz. There is not a reference range for the time to peak force and at this time it is unclear if a shorter or longer time to peak force indicates a more desirable state of health. |
| Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 | The time, in seconds, until peak acceleration is reached will be assessed. There is not a reference range for the time to peak force and at this time it is unclear if a shorter or longer time to peak force indicates a more desirable state of health. |
| End Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 | End acceleration is the twitch acceleration averaged over 5 twitches over the last second of stable twitches within the stimulation period. A reference range has not yet been established for this measurement. |
| End Acceleration Measured in Tibialis Anterior | Day 1 | End acceleration is the twitch acceleration averaged over 5 twitches over the last second of stable twitches within the stimulation period. A reference range has not yet been established for this measurement. |
| Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Day 1 | Fatigue ratio is the ending acceleration divided by peak acceleration during a given stimulation period. A reference range has not yet been established for this measurement. A higher ratio indicates less change from maximum. A lower score would indicate worse outcome. |
| Fatigue Ratio Measured in Tibialis Anterior | Day 1 | Fatigue ratio is the ending acceleration divided by peak acceleration during a given stimulation period. A reference range has not yet been established for this measurement. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| ICU Acquired Weakness Group Participants with a score less than 48 on the Medical Research Council (MRC) Scale will be classified as having ICU acquired weakness. All participants will have their skeletal muscles tested with a clinical electrical stimulator.
Clinical Electrical Stimulator: Conductive electrodes will be on the skin at each end of the tested muscle(s). Each subject will have two target muscle groups tested (extensor carpi radialis longus, and tibialis anterior). Each muscle will be stimulated at three separate stimulation frequencies (2 Hz, 4 Hz, and 6Hz) over 3 minutes each, for a total of 9 minutes of stimulation per muscle. The clinical electrical stimulator will deliver mild electrical stimulations to the muscle (20-100 mA). | 5 |
| No ICU Acquired Weakness Group Participants with a score of 48 or greater on the Medical Research Council (MRC) Scale will be classified as not having ICU acquired weakness. All participants will have their skeletal muscles tested with a clinical electrical stimulator.
Clinical Electrical Stimulator: Conductive electrodes will be on the skin at each end of the tested muscle(s). Each subject will have two target muscle groups tested (extensor carpi radialis longus, and tibialis anterior). Each muscle will be stimulated at three separate stimulation frequencies (2 Hz, 4 Hz, and 6Hz) over 3 minutes each, for a total of 9 minutes of stimulation per muscle. The clinical electrical stimulator will deliver mild electrical stimulations to the muscle (20-100 mA). | 17 |
| Total | 22 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Withdrawal by Subject | 0 | 1 |
Baseline characteristics
| Characteristic | ICU Acquired Weakness Group | No ICU Acquired Weakness Group | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 2 Participants | 3 Participants | 5 Participants |
| Age, Categorical Between 18 and 65 years | 3 Participants | 14 Participants | 17 Participants |
| Age, Continuous | 49.5 years STANDARD_DEVIATION 21.3 | 44.6 years STANDARD_DEVIATION 21.4 | 45.5 years STANDARD_DEVIATION 21 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 4 Participants | 4 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 5 Participants | 13 Participants | 18 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 5 Participants | 11 Participants | 16 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 4 Participants | 4 Participants |
| Race (NIH/OMB) White | 0 Participants | 2 Participants | 2 Participants |
| Region of Enrollment United States | 5 participants | 17 participants | 22 participants |
| Sex: Female, Male Female | 1 Participants | 2 Participants | 3 Participants |
| Sex: Female, Male Male | 4 Participants | 15 Participants | 19 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 5 | 0 / 17 |
| other Total, other adverse events | 0 / 5 | 0 / 17 |
| serious Total, serious adverse events | 0 / 5 | 0 / 17 |
Outcome results
Primary
End Acceleration Measured in Extensor Carpi Radialis Longus
End acceleration is the twitch acceleration averaged over 5 twitches over the last second of stable twitches within the stimulation period. A reference range has not yet been established for this measurement.
Time frame: Day 1
Population: 2 subjects data sets in the No ICU Acquired Weakness Group, were lost due to device malfunction. One additional subject had no data due to a malfunction with the accelerometer firmware The device manufacturer was contacted and were able to update the device, but no data was recorded during that trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | End Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 20 Hz | 0.289 Units of Gravity | Standard Deviation 0.328 |
| ICU Acquired Weakness Group | End Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 40 Hz | 0.147 Units of Gravity | Standard Deviation 0.161 |
| ICU Acquired Weakness Group | End Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 60 Hz | 0.239 Units of Gravity | Standard Deviation 0.263 |
| No ICU Acquired Weakness Group | End Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 20 Hz | 1.383 Units of Gravity | Standard Deviation 0.524 |
| No ICU Acquired Weakness Group | End Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 40 Hz | 1.021 Units of Gravity | Standard Deviation 0.755 |
| No ICU Acquired Weakness Group | End Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 60 Hz | 1.133 Units of Gravity | Standard Deviation 0.521 |
Primary
End Acceleration Measured in Tibialis Anterior
End acceleration is the twitch acceleration averaged over 5 twitches over the last second of stable twitches within the stimulation period. A reference range has not yet been established for this measurement.
Time frame: Day 1
Population: 1 subject data set on the No ICU Acquired Weakness Group, could not be analyzed due to excessive subject motion during the trial. One additional subject had no data due to a malfunction with the accelerometer firmware The device manufacturer was contacted and were able to update the device, but no data was recorded during that trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | End Acceleration Measured in Tibialis Anterior | Twitch acceleration at 40 Hz | 0.042 Units of Gravity | Standard Deviation 0.067 |
| ICU Acquired Weakness Group | End Acceleration Measured in Tibialis Anterior | Twitch acceleration at 60 Hz | 0.059 Units of Gravity | Standard Deviation 0.083 |
| ICU Acquired Weakness Group | End Acceleration Measured in Tibialis Anterior | Twitch acceleration at 20 Hz | 0.057 Units of Gravity | Standard Deviation 0.081 |
| No ICU Acquired Weakness Group | End Acceleration Measured in Tibialis Anterior | Twitch acceleration at 40 Hz | 0.767 Units of Gravity | Standard Deviation 0.517 |
| No ICU Acquired Weakness Group | End Acceleration Measured in Tibialis Anterior | Twitch acceleration at 20 Hz | 1.088 Units of Gravity | Standard Deviation 0.703 |
| No ICU Acquired Weakness Group | End Acceleration Measured in Tibialis Anterior | Twitch acceleration at 60 Hz | 0.640 Units of Gravity | Standard Deviation 0.565 |
Primary
Fatigue Ratio Measured in Extensor Carpi Radialis Longus
Fatigue ratio is the ending acceleration divided by peak acceleration during a given stimulation period. A reference range has not yet been established for this measurement. A higher ratio indicates less change from maximum. A lower score would indicate worse outcome.
Time frame: Day 1
Population: The team was unable to calculate change for 2 subjects in the ICU Acquired Weakness group. These had palpable contractions, but not large enough to displace the skin above the muscle. 1 subject's results were accidentally deleted and the device manufacturer deemed them unrecoverable. Another subject had no data due to software malfunction, the device manufacturer was able to update the device, but no data was recorded during that trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 40 Hz | 0.306 ratio | Standard Deviation 0.194 |
| ICU Acquired Weakness Group | Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 60 Hz | 0.639 ratio | Standard Deviation 0.136 |
| ICU Acquired Weakness Group | Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 20 Hz | 0.578 ratio | Standard Deviation 0.266 |
| No ICU Acquired Weakness Group | Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 20 Hz | 0.862 ratio | Standard Deviation 0.284 |
| No ICU Acquired Weakness Group | Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 40 Hz | 0.562 ratio | Standard Deviation 0.349 |
| No ICU Acquired Weakness Group | Fatigue Ratio Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 60 Hz | 0.707 ratio | Standard Deviation 0.223 |
Primary
Fatigue Ratio Measured in Tibialis Anterior
Fatigue ratio is the ending acceleration divided by peak acceleration during a given stimulation period. A reference range has not yet been established for this measurement.
Time frame: Day 1
Population: The team was unable to calculate change for 3 subjects in the ICU Acquired Weakness group. These had palpable contractions, but not large enough to displace the skin above the muscle. 1 subject's results were accidentally deleted and the device manufacturer deemed them unrecoverable. Another subject had no data due to software malfunction, the device manufacturer was able to update the device, but no data was recorded during that trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | Fatigue Ratio Measured in Tibialis Anterior | Twitch acceleration at 2 Hz | 0.610 ratio | Standard Deviation 0.364 |
| ICU Acquired Weakness Group | Fatigue Ratio Measured in Tibialis Anterior | Twitch acceleration at 4 Hz | 0.471 ratio | Standard Deviation 0.414 |
| ICU Acquired Weakness Group | Fatigue Ratio Measured in Tibialis Anterior | Twitch acceleration at 6 Hz | 0.437 ratio | Standard Deviation 0.414 |
| No ICU Acquired Weakness Group | Fatigue Ratio Measured in Tibialis Anterior | Twitch acceleration at 2 Hz | 0.899 ratio | Standard Deviation 0.351 |
| No ICU Acquired Weakness Group | Fatigue Ratio Measured in Tibialis Anterior | Twitch acceleration at 4 Hz | 0.572 ratio | Standard Deviation 0.247 |
| No ICU Acquired Weakness Group | Fatigue Ratio Measured in Tibialis Anterior | Twitch acceleration at 6 Hz | 0.549 ratio | Standard Deviation 0.265 |
Primary
Peak Acceleration Measured in Extensor Carpi Radialis Longus
The highest acceleration over a single muscle twitch will be used as the peak acceleration. Peak acceleration will be measured in acceleration in number of times gravity (g). Higher twitch acceleration is a better response.
Time frame: Day 1
Population: 2 subjects data sets in the No ICU Acquired Weakness Group, were lost due to device malfunction. One additional subject had no data due to a malfunction with the accelerometer firmware The device manufacturer was contacted and were able to update the device, but no data was recorded during that trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | Peak Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 60Hz | 0.373 units of Gravity | Standard Deviation 0.402 |
| ICU Acquired Weakness Group | Peak Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 20 Hz | 0.476 units of Gravity | Standard Deviation 0.467 |
| ICU Acquired Weakness Group | Peak Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 40 Hz | 0.541 units of Gravity | Standard Deviation 0.591 |
| No ICU Acquired Weakness Group | Peak Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 60Hz | 1.300 units of Gravity | Standard Deviation 0.662 |
| No ICU Acquired Weakness Group | Peak Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 20 Hz | 1.639 units of Gravity | Standard Deviation 0.772 |
| No ICU Acquired Weakness Group | Peak Acceleration Measured in Extensor Carpi Radialis Longus | Twitch acceleration at 40 Hz | 1.608 units of Gravity | Standard Deviation 0.803 |
Primary
Peak Acceleration Measured in Tibialis Anterior
The highest acceleration over a single muscle twitch will be used as the peak acceleration. Peak acceleration will be measured in acceleration in number of times gravity (g). Higher twitch acceleration is a better response.
Time frame: Day 1
Population: 1 subject data set in the No ICU Acquired Weakness Group, could not be analyzed due to excessive subject motion during the trial. One additional subject had no data due to a malfunction with the accelerometer firmware The device manufacturer was contacted and were able to update the device, but no data was recorded during that trial.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | Peak Acceleration Measured in Tibialis Anterior | Twitch acceleration at 40 Hz | 0.102 Units of Gravity | Standard Deviation 0.144 |
| ICU Acquired Weakness Group | Peak Acceleration Measured in Tibialis Anterior | Twitch acceleration at 20 Hz | 0.105 Units of Gravity | Standard Deviation 0.151 |
| ICU Acquired Weakness Group | Peak Acceleration Measured in Tibialis Anterior | Twitch acceleration at 60 Hz | 0.101 Units of Gravity | Standard Deviation 0.153 |
| No ICU Acquired Weakness Group | Peak Acceleration Measured in Tibialis Anterior | Twitch acceleration at 40 Hz | 1.029 Units of Gravity | Standard Deviation 0.585 |
| No ICU Acquired Weakness Group | Peak Acceleration Measured in Tibialis Anterior | Twitch acceleration at 60 Hz | 0.593 Units of Gravity | Standard Deviation 0.494 |
| No ICU Acquired Weakness Group | Peak Acceleration Measured in Tibialis Anterior | Twitch acceleration at 20 Hz | 1.115 Units of Gravity | Standard Deviation 0.677 |
Primary
Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus
The time, in seconds, until peak acceleration is reached will be assessed at 2, 4 and 6 Hz. There is not a reference range for the time to peak force and at this time it is unclear if a shorter or longer time to peak force indicates a more desirable state of health.
Time frame: Day 1 at 2 Hz, Day 1 at 4 Hz, Day 1 at 6 Hz
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 2 Hz | 64.7 Seconds | Standard Deviation 69.3 |
| ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 4 Hz | 9.8 Seconds | Standard Deviation 14.1 |
| ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 6 Hz | 1.5 Seconds | Standard Deviation 1.8 |
| No ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 2 Hz | 119.5 Seconds | Standard Deviation 55.1 |
| No ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 4 Hz | 64.6 Seconds | Standard Deviation 56.2 |
| No ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Extensor Carpi Radialis Longus | Day 1 at 6 Hz | 33.7 Seconds | Standard Deviation 53.2 |
Primary
Time to Peak Acceleration Measured in Tibialis Anterior
The time, in seconds, until peak acceleration is reached will be assessed. There is not a reference range for the time to peak force and at this time it is unclear if a shorter or longer time to peak force indicates a more desirable state of health.
Time frame: Day 1
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 at 2 Hz | 45.5 Seconds | Standard Deviation 68.6 |
| ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 at 4 Hz | 22.0 Seconds | Standard Deviation 47.9 |
| ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 at 6 Hz | 8.8 Seconds | Standard Deviation 19.6 |
| No ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 at 2 Hz | 100.1 Seconds | Standard Deviation 53 |
| No ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 at 4 Hz | 32.3 Seconds | Standard Deviation 43.3 |
| No ICU Acquired Weakness Group | Time to Peak Acceleration Measured in Tibialis Anterior | Day 1 at 6 Hz | 19.3 Seconds | Standard Deviation 27.1 |