The Effects of INP on Peripheral Circulation in Dialysis Patients and Patients With PAD and Leg Ulcers

The Effects of Intermittent Negative Pressure on Peripheral Circulation in Dialysis Patients and Patients With Lower Limb Ischemia and Leg Ulcers

This experimental study will look at the effects of INP therapy for two patient groups: 1) patients with reduced peripheral circulation and chronic wounds in patients with renal disease (dialysis patients); 2) and peripheral arterial disease and leg ulcers. The project is designed as a non-randomized clinical trial with single-subject multiple baseline design. Also the intervention will be subjected on the same leg for each individual throughout the study period. The other leg will act as a control. A baseline measure with patient history collection will be performed before a four-week intervention period. These measures include: Segmental pulse-volume-recording, Segmental skin perfusion pressure with a laser Doppler sensor and a pressure cuff to evaluate reactive hyperemia (Sensilase, Väsamed) and a health survey (SF-12/EQ-5D-5L) or similar. After four weeks and eight weeks of intervention, the same tests will be repeated. A final follow-up test will be two weeks after cessation of the intermittent negative pressure intervention. The study will look at the effect of INP on renal failure patients who are given dialysis at a dialysis center located at Oslo University Hospital, Ullevål. Otivio AS has supplied the FlowOx devices and provided the necessary training to perform this project. Outcome variables assessed before, during and after the 10-week study period will be: wound healing, quality of life, skin perfusion pressure and segmental pulse-volume recording. The aim of this project is to prospectively examine and elucidate the effect of intermittent negative pressure therapy on clinically relevant measures related to the reduction of peripheral macro- and microcirculation in patients with renal failure undergoing dialysis treatment.

The hypothesis of the study is:

• Application of INP in patients with renal failure, by the use of the FlowOx™ device, will improve wound healing and peripheral circulation in the foot compared to before treatment (baseline) in patients undergoing dialysis treatment.
• Application of INP in patients with PAD, by the use of the FlowOx™ device, will improve macro- and microcirculation and wound healing in the foot compared to before treatment (baseline) in patients with chronic wounds.

Inclusion Criteria:

• Able and willing to provide informed consent
• Age: 18-96 years
• Affected foot/shoe size <46 (approximate foot length< 29,5 cm)
• Receiving hemodialysis ≥3 times per week for 1 hour per treatment OR
• Peripheral arterial disease and leg ulcer

Exclusion criteria:

• Incapable to consent voluntarily, i.e. patients who are not able to consent due to their mental status, or who are not willing or able to perform the negative pressure therapy in a sitting position
• Not adhering to the INP therapy program
• Patients with an expected life-span less than 3 months
• Patients in whom the remaining limb is non-functional, for example due to previous stroke
• Patients in which a deep venous thrombosis or pulmonary embolism is suspected
• Limbs with uncontrolled infection
• Previous lumbar sympathectomy
• Bilateral amputation of lower extremity