The effectiveness of electrical stimulation and ultrasound in pressure ulcer treatment.

Aim of study: The research aimed to establish whether electrical stimulation (ES) with high voltage pulsed current (HVPC) and high frequency ultrasound (HFUS) can be effectively applied to promote the healing of stage II, III and IV pressure ulcers in geriatric patients , whether HVPC and HFUS help decrease wound surface area, and whether HVPC and HFUS have a significant effect on how fast wounds heal. The research involved a group of elderly patients (aged 60+) suffering from diseases typical of geriatric age. Their overall health state was, in most cases, poor, they were confined to bed and unable to change position on their own, and logical contact with them was very difficult or impossible. Intervention: Study enrollment. Patients with pressure ulcers screened for the study were residents of nursing and care centers in Silesia (Poland). The study eligibility of a patient was determined by their physician. The eligibility criteria were the following: older than 60 years of age, a stage II, III or IV pressure ulcer of at least 0.5 cm2 located on the trunk, buttock region, lower and upper extremities, persisting for a minimum of 1 month but not longer than 12 months. If a patient had two pressure ulcers, both were evaluated for healing progress. Patients with more than two pressure ulcers were not eligible to participate in the experiment. Other excluding criteria were neoplasm, lymphatic system diseases, central nervous system demyelinating diseases and cirrhosis of the liver. Patients with deep, tunneling, necrotic wounds likely to involve osteomyelitis and requiring surgical intervention were also excluded from the study. Allocation to groups / randomization. After the selected patients, or their legal guardians, gave consent to take part in the study, they were randomly divided between three groups: a high-voltage pulsed current group (HVPC group), high-frequency ultrasound group (HFUS group) and a control group (CG). The main investigator in charge of patients’ allocation to groups had 100 envelopes, each containing a piece of paper marked with A (HFUS group), B (HFUS group) or C (control group). The envelopes were opened one by one in the presence of a physiotherapist and the patient concerned was directed to the appropriate comparative group. The demographic information on the subjects was obtained from standardized interviews with the subjects, physical examinations, as well as from additional examinations of the patients and their history of concomitant diseases available in medical documentation. Wound severity at enrolment was assessed according to the National and European Pressure Ulcer Advisory Panel criteria: partial-thickness loss of the dermis – stage II ulcers; full-thickness tissue loss – stage III pressure ulcers; full-thickness tissue loss with exposed bone, tendon or muscle - Stage IV pressure ulcer. Treatment. All patients received treatment to prevent the development of additional pressure ulcers. Pressure-redistribution surfaces, devices and pillows were applied as needed. A physiotherapist or a nurse repositioned patients who could not move unaided at least every 2 hours. Those who could communicate logically and change position were asked to do so in order to relieve pressure affecting the ulcer area as often as they could. Wounds were assessed throughout the period of the experiment to select topical treatments appropriately addressing moisture control, bacterial burden and debridement needs. A comprehensive, interdisciplinary assessment was conducted to develop an standard wound care (SWC) program taking account of the specific requirements of each subject, which included nutritional intervention, optimization of the wound dressing protocol, and continence management. Patients in all groups received similar standard topical care, which was selected each time to address the needs of individual subjects and to promote moist interactive healing. Wounds were first cleansed with 0.9% sodium chloride, potassium permanganate or octenidine/phenoxyethanol, and then the ulcer base was covered with the dressing. Wound dressings included, regardless of the group, non-adherent gauze pads, dressings moistened with 0.9% sodium chloride, hydrogel, solcoseryl, and calendulae anthodia extractum. If wound debridement was needed or infection was suspected, fibrinolysin/deoxyribonuclease, colistinum and sulfathiazolum natricum (only in the control group) were additionally administered. All immobilized patients received low-molecular-weight heparin (enoxaparin) as a standard therapy. Patients with elevated leukocyte levels were treated with antibiotics selected following the microbiological culture and sensitivity testing of pressure ulcers. In all subjects that gave their consent to additional blood tests blood samples were collected at the beginning of the treatment period to determine: total protein, hemoglobin and hematocrit levels, and total lymphocyte count. HVPC - group Patients in group A additionally received electrical stimulation with HVPC. The device used for this purpose was the Intelect Advanced Combo (Chattanooga, USA). The voltage exceeded 50 V. Twin monophasic triangular pulses lasting 50 microseconds in total and having a frequency of 100 pps were applied. The amperage utilized during HVPC procedures evoked a tingling sensation in the patients, but no motor effects were induced. The electric charge equal to 2.5 - 7.5 micro-Coulombs per impulse (250-750 micro-Coulombs per second) was delivered to the treatment electrodes. Current characteristic were selected as per previously published protocols from clinical studies and in vivo studies performed on animals. The electrodes were made of conductive carbon rubber. Each patient had his/her own set of electrodes. The treatment electrode was placed on an aseptic gauze pad saturated with physiological saline overlying the wound site. The dispersive electrode (closing the electric circuit) was positioned at least 20 cm from the pressure ulcer (proximally or distally, depending on its location). After each procedure, the electrodes were sterilized in a disinfectant solution. Patients received five 50-minute procedures per week (one procedure per day). Treatment continued until healing or for a maximum of 6 weeks. The cathode was introduced as the active electrode at the beginning of the treatment period to stimulate granulation tissue growth and then was replaced by the anode. Before ES was applied, pressure ulcers were thoroughly cleansed with 0.9% sodium chloride solution. As soon as the procedure was complete, dressings mentioned were applied. HFUS - group The treatment B group was additionally administered HFUS. Its parameters were selected as per previously published protocols from clinical studies and in vivo studies performed on animals. The acoustic beam was generated by the Intelect Advanced apparatus (Chatanooga Group, USA). The procedures were performed on the periwound and wound areas covered with sterile ultrasound gel (Aquasonic, Parker, USA). The effective radiating area (ERA) of the transducer was equal to 4.0cm2. In the experiment, pulsed ultrasound of 1 MHz and a duty cycle of 20% (impulse time was equal to 2 ms and interval was equal to 8 ms) was used. The spatial average temporal peak (SATP) was equal to 0.5 W/cm2 and the spatial average temporal average (SATA) was equal to 0.1 W/cm2. The beam non-uniformity ratio was maximum 5:1. Sonotherapy was applied for 1 min per cm2 of ulcer area (1 min per US probe area) in the first week, for 2 min per cm2 in the second week, and for 3 min per 1 cm2 between the third week and the end of the experiment. Sessions were held once a day, 5 days a week, over a period of 6 weeks. Before and after each procedure the ultrasound transducer was sterilized in a disinfectant solution. Pressure ulcers were thoroughly cleansed with 0.9% sodium chloride solution in preparation of the procedure and then they were covered with the aforementioned dressings as soon as it was over.