Pedal Pump Clinical Trial on Edema V2

The Pedal Pump is a device which engages the feet of patients while they are in bed. The device is placed between the foot board and the patient's feet. It provides gentle, on-and-off pressure to the feet, which, in turn, mobilizes the whole body in a rhythmic, calming manner.

The proposed hypotheses of the Pedal Pump are primarily based on the health benefits provided by normal walking. They include, but are not limited to…

Physiological Benefits:

• Increase lymphatic flow within the body
• Increase blood flow back to the heart and into the tissues
• Increase intestinal peristalsis
• Increase kidney filtration
• Increase myofascial and musculoskeletal movement

Proposed Patient-Centered Benefits:

• Decrease lower extremity fluid volume
• Decrease lower back pain
• Decrease neck pain
• Increase return of bowel function after intra-abdominal surgery

For this second, feasibility study the Investigators will be investigating if the Pedal Pump is tolerated by hospitalized patients, and if so, does it decrease lower extremity edema.

Treatment:

• Patients will lay with the head of the bed elevated at a 45-60 degree angle (i.e., in Fowler's position)
• Patients will receive the Pedal Pump treatment applied to both feet for 10 minutes continuously, provided the treatment is tolerated by the patient.

Objective Measure: Assessor will record grade of Pre-Treatment Edema:

• Edema: Mild, ~2 mm depression that rebounds immediately.
• Edema: Moderate, ~4 mm depression that rebounds in 10 to 15 seconds.
• Edema: Deep, ~6 mm depression that may persist for a minute or longer.
• Edema: Very severe, ~8 mm depression lasting several min. with visible distortion.

Objective Measures: Assessments of the feet and legs will be taken pre-treatment (Minute 0) and post-treatment (Minute 10-15):

• Bilateral Mid-Thigh Circumferences (15 cm above superior patella), Mid-Calf Circumferences (largest circumference), Ankle Circumferences (superior to the malleoli)
• The Assessor will use a skin marker to mark the location where he or will measure, marking horizontal lines above and below the measuring tape over the ankle, calf, and mid-thigh. He or she will use the same location for pre-treatment and post-treatment measurements. The measuring tape will not have slack and will not be so tight to cause pitting edema.

Thresholds for clinically meaningful change:

• Circumference change ≥1 cm at any location

Treatment vs Sham:

• 20 patients (⅔) receiving the Treatment and 10 patients (⅓) receiving the Sham.
• Randomization will occur via 30 sealed envelopes shuffled and then distributed to the Operators.

Routine care:

• Patients will socialize, watch TV, read a book, use their phones or laptops, or otherwise spend their time how they prefer. However, unless there is an adverse outcome or the treatment needs to be aborted, they will keep their feet connected to the heel protector pillows which will be engaging the device during the entire 10 minutes.
• Patients will continue to receive diuretics and other treatment for lower extremity edema. Because the effects of medicines on lower extremity edema are usually seen in hours and not minutes. In other words, if a significant effect is shown within 10 minutes while the device is activated, then the effect would have been from the Pedal Pump's treatment in those 10 minutes.

Patient Data will be obtained from the patient directly and/or from Electronic Health Record after the consent form is signed. Data will include:

• Age
• Sex
• Active CHF
• Active chronic venous insufficiency
• Acute kidney disease
• Chronic kidney disease
• End Stage Renal Disease (ESRD)
• Active HTN
• MI history
• Stroke history
• Diabetes history
• Smoking 5+ years history

Data Storage and Analysis:

• The initial data will be written on paper by the patients and clinical assessors. Papers will be collected by the Hillcrest Pedal Pump Investigation team. The data collected (without patient identifiers) will be manually uploaded to HIPAA-compliant Google Sheets or Microsoft Excel. Papers will be stored in a fireproof filing box until scanned into PDF for storage in a HIPAA-compliant Google Drive Folder.
• Investigators will use a Double Data Entry protocol (two different people type the data, and a system checks for mismatches) to ensure data integrity.

Statistical methods:

• Continuous variables (circumferences) will be analyzed by a blinded statistician using a paired t-test (pre vs. post) and an independent t-test or repeated measures ANOVA to compare the Treatment group directly against the Sham control group.
• Investigators will analyze the Objective measures to establish standard deviation, p-values, and confidence intervals to define clinical significance.

Handling of missing data:

• If an assessor does not complete 30% or more of questions on the forms, the entry will be voided altogether.

Investigators will use an Intention-to-Treat Analysis (i.e., analyzing all subjects' data to discover how the device may be experienced in real life by different hospitalized subjects).

Device Description and Engineering Safety:

• Device mechanism: Applying a cephlad-directed load to the plantar surfaces of the feet without causing dorsiflexion.
• Mechanical specifications: A 3D printed platform and casing with a motor inside and on-off switch outside of the casing. See video below for visual details.
• Device Specifications: Power source is provided from a standard USA electrical outlet (120V). Power cord includes an AC / DC Adapter. Input: 100-240V. Output: 20-24V with 3-5 amp input into motor. Frequency/power: Device moves laterally with frequency of 1 cycle every 1.5 seconds and a max torque of 160 kg-cm.
• Contact materials: Patients' feet will be in socks of the patient's choice which will contact the plastic covers of the heel protector pillows. The heel protector pillows will contact the Pedal Pump platform.
• Safety: If a small internal piece of the device breaks, the patient will be protected by the device's platform and then additional protection from heel protector pillows.
• Emergency Stop: If the patient has a need for emergent cessation of treatment, the patient can at any time move his or her feet away from the device (i.e. there is not any restraint placed on the patient's feet). The Operator can also turn off the device at any moment.

Inclusion criteria

• Bilateral lower extremity edema of at least mild severity judged by the treating clinician to be due to CHF, chronic venous insufficiency, kidney disease, lymphedema, or other etiologies of fluid overload conditions.
• Medically stable
• Able to remain in Fowler position for 10 minutes
• Patients in the ER, observation, or admitted to the hospital for any period of time; outpatients (specifically CHF clinic patients)
• Patients must give informed consent to participate. The patient must be able to read the consent form (in English or Spanish) or give consent after the form is translated for the patient.

Exclusion criteria

• Lipedema (fat distribution) as the only cause for edema
• Pressure ulcers
• Active DVT (i.e. Patients who have signs of acute unilateral swelling must have a documented negative lower extremity venous duplex ultrasound within the current admission before they will be included in the trial.)
• Symptomatic peripheral vascular disease
• Wounds or infections in the feet, legs, buttocks, or back deemed unfit for treatment per the trained Operator.
• Leg or back surgery in previous 30 days
• Known pregnancy
• Severe osteoporosis/fracture risk