TENS for Relief of Postoperative Pain in Orthopedic Patients

Transcutaneous Electrical Nerve Stimulation (TENS) Integrated Into Pants for Relief of Postoperative Pain in Orthopedic Patients

To ensure early mobilization, minimize suffering, and to prevent postoperative complications postoperative pain, should be reduced as soon and as effectively as possible. A non-pharmacological post-operative intervention in terms of the application of transcutaneous electrical nerve stimulation (TENS), could have the potential to accelerate early mobilization and reduce the use of opioids. The overall aim is to demonstrate that the addition of TENS to standard postoperative pain management of orthopedic patients can alleviate pain during mobilization and at rest

Annually, more than 200 million people undergo surgery worldwide and the number is increasing.To ensure early mobilization, minimize suffering, and to prevent postoperative complications and subsequent mortality, postoperative pain, should be reduced as soon and as effectively as possible. Acute complications include impaired mobility, respiratory difficulties, pneumonia, protracted healing processes, thromboembolic events like deep vein thrombosis or pulmonary embolism, and prolonged need for care . Acute postoperative pain also has several negative long-term effects gas, risk of residual pain, higher mortality risk and worsened patient outcome at 6 months especially in hip fractures of older individuals. A non-pharmacological post-operative intervention in terms of the application of transcutaneous electrical nerve stimulation (TENS), could have the potential to accelerate early mobilization and reduce the use of opioids .TENS is a non-invasive method that delivers electrical impulses through electrodes placed on the skin and has been shown to be an effective supplement that can decrease postoperative pain after thoracic and abdominal surgery . However, it is yet unclear whether TENS after orthopedic hip prosthesis surgery can reduce post-operative pain to improve early mobilization, decrease opioid consumption and shorten hospitalization time. The overall aim is to demonstrate that the addition of TENS to standard postoperative pain management of orthopedic patients can alleviate pain during mobilization and at rest. The primary aim of this feasibility study using a CE-marked TENS device with applied textile electrodes in a pair of pants is to reduce postoperative pain during mobilization following hip prosthesis surgery.

transcutaneous electrical nerve stimulation, Patient Global Impression of Change, numeric pain rating scale

This study will be a prospective, randomized, single-blinded, placebo-controlled repeated measures design.

Fifteen of the patients will be randomized to the intervention and 15 will receive placebo (non-active TENS treatment). The outcome assessor will be masked to the intervention.

The Chattanooga Physio TENS (DJO Global, Vista, CA) will be applied with mixed burst / TENS alternated, which is a 30-minutes programmed. The stimulation frequencies of this alternative vary every 3 seconds, producing a combined stimulation of 80 Hz and 2 Hz. The energy intensity level will firstly be adjusted for 80 Hz (TENS) until a tingling sensation is felt, and then the procedure will be repeat for 2 Hz to produce visible, but not painful, muscle twitches. The patient will use a pair of pants with integrated stimulation electrodes, to which the CE-marked TENS device (Chattanooga Physio, DJO Nordic, Malmö, Sweden) will be connected and used to provide pain relief, in addition to usual postoperative care. The TENS device will be connected to the textile electrodes of the pants, which are located just 5cm in front, respectively behind the hip incision dressing.

The control group will also receive the TENS-pants described above with integrated stimulation electrodes, connected to TENS treatment. However, the TENS treatment to the control group will be set so that no electricity will reach the patient. In all other regards, the control group will follow the same protocol as the intervention group.

A 11-point numeric pain rating scale (Minimum 0, Maximum 10, higher score means worse outcome, i.e more pain) assessment will be performed during inactivity

A 11-point numeric pain rating scale (Minimum 0, Maximum 10, higher score means worse outcome, i.e more pain) assessment will be performed during activity after the Standardized three-meter Walking test (WALK3m)

The patient's belief about the efficacy of treatment, which ranged from 1 (minimum, "no change") to 7 (maximum, "a great deal better") will be assessed by PGIC.

The Standardized three-meter Walking test (WALK3m). With a stopwatch, the patient will be instructed to walk a 3 meters distance beginning from a marked position, in comfortable steps, to a stop position, turn around and walk back to the marked position where he or she started. The timing will begin when the patient starts on the word go, and the timing will end when the patient stopped at the marked position where they started.

Extra analgesic consumption during the entire intervention will be documented. Under the intervention period, which is the first two times 30-minute TENS stimulation intervention, a 30-minute inactive interval, and there after another two times 30-minute stimulation intervention, all supplementary analgesics consumed will be documented to assess and evaluate the effect of the intervention.

A short follow-up will be performed before discharge 24 hours after the surgery. The patient in both active and placebo groups will be a asked the following questions: Was TENS therapy comfortable for you? Would you like to use TENS again if you would undergo another surgery in the future? Were the TENS trousers comfortable to wear for you? The NRS will also be used to measure patient's satisfaction of the TENS- treatment (from 0, no satisfaction, to 10, major satisfaction with the treatment)

Inclusion Criteria: Patients 18 years and above. Diagnosis of hip prosthesis surgery or hip fracture surgery. Must be cognitively adequate. Must be without terminal illness. Exclusion Criteria: Pregnancy Skin wounds Pacemaker Intracardiac defibrillator Ongoing thrombolysis or thromboprophylaxis treatment Class 3 and 4 heart disease Difficulties to understand the Swedish language Drug and narcotic abuses Postoperative delirium syndrome Epidural catheter.