Effect of cathodal and anodal electrical stimulation on pressure ulcer healing

The purpose of this prospective, parallel-group, randomized, double-blind, controlled, clinical trial is to evaluate the activity of cytokines, growth factors and healing rates of pressure ulcers (PU) in people with central nervous system injures after 4 weeks of intervention involving standard wound care (SWC), SWC in conjunction with high voltage monophasic pulsed current (HVMPC) delivered by the cathode, and SWC combined with HVMPC delivered by the anode as the treatment electrodes. Demographic information on the patients will be compiled during standardized interviews and physical examinations, as well as from additional examinations of the patients and the documentation of their concomitant diseases. The patients’ physical and mental conditions, activity, mobility and incontinence will be assessed using the Norton scale (a score < 14 indicated a high risk of PU development). To assess the possibility of friction and shear and wound moisture, as well as sensory perception of the patients, their physical activity and mobility the Braden Scale will be applied (a score < 16 pointed to a high risk of PU development). Patients’ nutritional status will be identified by means of the Nutritional Risk Score (NRS-2002). Wound severity at enrolment will be assessed based on the National Pressure Ulcer Advisory Panel criteria: Category II ulcers = partial-thickness loss of the dermis presenting as a shallow open ulcer with a red pink wound bed, without slough; Category III ulcers = full-thickness tissue loss; subcutaneous fat may be visible but bone, tendon or muscle are not exposed; Category IV ulcers = full-thickness tissue loss with exposed tendon, muscle or bone. Slough or eschar may be present on some parts of the wound bed. Can include undermining and tunnelling. SWC programme administered to both electrical stimulation groups. All patients will be treated to prevent the development of new PUs. Pressure-redistribution surfaces, devices and pillows will be applied as needed. A nurse or physiotherapist will reposition the immobile patients every 2 hours at the least. Blood tests will be carried out to screen for nutritional status markers and metabolic disorders such as anaemia (iron deficiency anaemia or anaemia of chronic disease), thyroid dysfunction, impaired glycaemic control, dehydration, protein deficit, hypoalbuminemia. Wounds will be regularly assessed by the attending physician over the period of the study to select topical treatments appropriately addressing moisture control, bacterial burden, and debridement needs; microbiological culture and sensitivity tests will also be performed. A team formed of a physician, a nurse, a physical therapist and a dietician will make comprehensive, interdisciplinary assessments of the patients to develop SWC programmes meeting their specific demands, for instance consisting of nutritional intervention, optimization of the wound dressing protocol, and incontinence management. The clinician caregivers will be blinded to participant’s group. Patients in both electrical stimulation groups will receive similar standard topical care, selected to address their individual needs and to promote moist interactive healing. All immobilized patients will receive low-molecular-weight heparin (enoxaparin) as a standard therapy. Patients with elevated leukocyte levels will be treated with antibiotics selected following microbiological culture and sensitivity testing of the PU swab. Electrical stimulation with the cathode. In the cathode ES group, patients will be administered HVMPC in addition to SWC. The device for applying HVMPC will be the Intelect Advanced Combo (by Chattanooga, USA). The device generates a twin-peak monophasic pulse consisting of two 77- microsecond exponential pulses in rapid succession (the twin-peak pulse duration was 154 microseconds). Pulse frequency will be 100 pps. ES will not cause muscle contractions. Patients who retained the sensory function will only experience sensory effects. Amperage will be applied at a level of 0.36 A. If the sensory experience is too strong (patients with sensory function) the amperage will be reduced but not below 0.25 A. Accordingly, the electrodes will deliver an electrical charge of 250- 360 microcoulomb per second. This HVMPC protocol has been adopted following the positive results of earlier clinical trials on patients with PUs and venous leg ulcers.. Each patient will have his or her own set of electrodes made of conductive carbon rubber. The treatment electrode (of a size matching the wound surface area) will be placed on an aseptic gauze pad saturated with physiological saline overlaying the wound site. The dispersive electrode (bigger than the treatment electrode) closing the electrical circuit will be positioned at least 20 cm from the PU. Before and after each ES procedure, the electrodes will be sterilized in a disinfectant solution. Over the period of the intervention, the negative electrode (cathode) will be used to treat PUs. The authors of some other clinical studies on PUs have also used cathodal stimulations. In the experiment, five 50-minute sessions will be held per week (one a day), following the approach adopted by other authors. PUs will be thoroughly cleansed with a 0.9% sodium chloride solution and covered with the earlier described dressings immediately after the ES procedure. Electrical stimulation with the anode. Patients in the anodal ES group will receive HVMPC in the same way as patients in the cathodal ES group, but the treatment electrode will be the anode. The authors of other clinical studies on PUs used anodal stimulation. HVMPC with the cathode (in the cathode ES group) and with the anode (in the anode ES group) will be applied for a period of 4 weeks (total of 20 HVMPC sessions), during which wounds will be observed for healing progress.