The proposed study is a prospective, observational study assessing the recovery of muscle and physical function in patients surviving critical illness (n =150) at hospital discharge (baseline) and repeated serially. Patients will be enrolled after life-saving modalities have been weaned near hospital discharge. Patients will participate in testing at baseline, 3-, 6-, 12-, and 24-months after hospital discharge. In a subset of patients (n = 18), muscle biopsies will be performed at baseline and then repeated once at either 12- or 24-months after hospital discharge.
The overarching goal of the proposed study is to determine the trajectories of physical recovery and cellular markers involved with the underlying failure to recover muscle after critical illness, while exploring which characteristics are associated with sustained physical disability. This proposal will examine muscle pathophysiology carefully aligned with physical function outcomes in order to longitudinally assess the recovery, or failed recovery, of muscle function in participants after critical illness: Aim 1: Determine the long-term trajectory of muscle strength, physical function and ADL recovery in ICU survivors. Patients (n = 150) will participate in a battery of tests to determine muscle and physical function aligned with self-reported measures of ADLs and quality of life at hospital discharge, 3-, 6-, 12-, and 24-months post. Aim 2: Assess cellular changes in skeletal muscle in ICU survivors contributing to long-term physical dysfunction. In a subgroup of patients enrolled in Aim 1, muscle biopsies will be collected at baseline and long-term follow-up to determine oxidative stress, mitochondrial function, and cellular senescence.
Study Type
OBSERVATIONAL
Enrollment
150
University of Kentucky, Lexington, Kentucky 40536
Lexington, Kentucky, United States
Muscle Strength measured by Chair Rise Test
Performance on 5x sit to stand test will be the primary outcome measure representing lower extremity muscle strength ; measured as time in seconds to complete 5 repetitive sit-stands.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Functional Capacity
The 6-minute walk test (6MWT), which measures the distance a participant can walk in six minutes and serves as an indicator of cardiopulmonary function, will be used as a primary outcome.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Muscle morphology # 1
Myofiber size
Time frame: Percent change from baseline to 12 months
Muscle morphology #2
Myofiber type
Time frame: Percent change from baseline to 12 months
Lower-extremity Muscle Power
Muscular Power: Power will be assessed using a linear potentiometer (HUMAC-360, CSMi, Stoughton, MA) to record the velocity and peak-velocity of a functional movement using a Shuttle MiniPress (Shuttle Systems, Bellingham, WA) as hamstring/gluteal pressdown. Outcome measure is Watts.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Muscle Size and Quality measured by Ultrasound
Ultrasound imaging will be performed to acquire images of quadriceps and tibialis anterior to measure muscle cross-sectional area, muscle thickness and echo intensity of muscles.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Activities of Daily Living (ADL)
Katz ADL will be used to assess ADL. The range of scores are 0 - 6 with a higher score being an better outcome.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Health Reported Quality of Life
5 Dimension Euro-Quality of Life (EQ-5D) is a self-report instrument including 5 questions and a visual analog scale (0-100) used to measure subjective quality of life with a higher score being a better outcome.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Fatigue
The Functional Assessment of Chronic Illness Therapy (FACIT-fatigue instrument) will be used to measure subjective fatigue and quality of life. All items are summed to create a single score with a range from 0 to 52. Items are reverse scored when appropriate to provide a scale in which higher scores represent better functioning and a higher quality of life.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Physical Frailty
Physical frailty will be quantified using Fried Frailty Phenotype with five criteria (weight loss, weakness, exhaustion, gait speed, and physical activity) and the Clinical Frailty Scale. Scoring is 0-5 with: ≥3/5 criteria met indicates frailty; 1-2/5 indicates pre-or-intermediate frailty; 0/5 indicates non-frail.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Physical Activity
Patients will wear an Actigraph (Garmin, Vivofit 4) or an Oura ring to measure the number of steps per day. The outcome measure will be average number of steps per day over a seven day period.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Muscle strength of quadriceps
Strength of quadriceps muscle will be recorded using a hand-held dynamometry, Lafayette Manual Muscle Test System Model-01165 (Lafayette Company, Lafayette, IN). Outcome is measured in kilograms.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Grip Strength
Hand grip strength will be assessed with a handgrip dynamometry (HGD), Jamar Hydraulic dynamometer (Sammons Preston Rolyan, Bolingbrook, IL, USA). Outcome is measured in kilograms (kgs).
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Physical function
The Short Physical Performance Battery (SPPB) assesses balance, repeated sit-to-stand performance, and 4-meter gait speed. Each component is scored and converted to an ordinal scale, with the total score ranging from 0 to 12.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
Physical function
Timed-up and Go Test (TUG), which is a measure of mobility and fall risk requiring patients to stand from a chair and walk short-distance for time in seconds.
Time frame: Baseline and repeated 3-, 6-, 12-, and 24-months after baseline assessment.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.