Project 4B: Lower Extremity Strength Training in ICU Patients

Subjects will be treated five days per week, for 30 minutes each session. Muscle stimulation will be conducted for four seconds every 15 seconds, thus the subjects will undergo four stimulations per minute. Muscle stimulation will be adjusted until there is a visible or palpable bilateral quadriceps contraction.

Quadriceps strength will be measured on the initial day of study approximately every seven days thereafter and on the final day of study participation. For this measurement, patients will remain supine in their bed and the dominant leg will be placed on a frame that will hold the knee at a 60° angle. A cuff will be placed around the ankle and connected to an electronic dynamometer that will record the force generated during the stimulation. The muscle will be stimulated to contract with magnetic stimulators placed over the body of the quadriceps muscle and stimulated at 100% of power output.

This procedure will be done at the end of participation in the study.The biopsy will be performed with a sterile needle, which will be inserted through the skin. A skin incision (approximately 1/4" long) will be made in order to insert the needle. The biopsy procedure yields two small pieces of muscle tissue (200 mg total), each about half the size of the eraser on a pencil. After the biopsy is taken, the incision will be closed using a steri-strip bandage (no stitches are required), and a sterile dressing will be placed over the site to reduce the risk of bleeding.

Biopsy samples will be obtained under local anesthesia (up to 20 milliliters of 1% Lidocaine administered subcutaneously). Lidocaine, a drug to numb your pain will be injected into the skin and muscle tissue. The injection of the numbing medication will be slightly painful and is similar to receiving a shot into your arm for a vaccination. This medication numbs the skin and muscle so that you do not feel pain when the biopsy is obtained.

Prior to starting the muscle biopsy, you can receive a drug, Versed, to help you relax during the procedure. 1-2 milligrams of Versed will be administered intravenously (in the vein) through an existing peripheral or central intravenous catheter. This procedure drug is given as needed and can be repeated one time as needed.

Prior to starting the muscle biopsy, you can receive a drug, Fentanyl, to make you more comfortable during the procedure. 50-100 micrograms of Fentanyl will be administered intravenously (in the vein) through an existing peripheral or central intravenous catheter. This procedure drug is given as needed and can be repeated one time as needed.

Blood and urine samples will be obtained and examined for markers inflammation and muscle catabolism. Sampling will occur at time of entry into study, and then once every 2-4 days and on the final day of participation or the last day of study (day 28). Peripheral blood will be collected from an existing venous line, or by venipuncture, if required. Urine will be collected from an existing catheter or if the patient is able to void on their own then we will provide a specimen cup. There will be no more than 14 ml of blood drawn at any given time point and a collection of 15 ml of urine at each time point.

An investigator will perform range of motion on both legs, five days per week. The range of motion activity will include the investigator helping you bend and straighten each knee approximately 12 times. Rotation of the leg at the hip will also be performed by bending your knee and gently rotating your upper leg in a clockwise and counterclockwise motion. The range of motion will be performed on each leg and repeated five days per week.