Percutaneous electrical nerve stimulation as a non-pharmacological strategy in oxaliplatin-induced neuropathy: evidence from a randomized clinical trial

Percutaneous Ultrasound-Guided Neuromodulation Group: The following steps will be undertaken: 1. Ultrasound Localization of the Nerve: A linear probe will be positioned on the anterior aspect of the elbow in a transverse plane. In this view, the median nerve will be visualized between the heads of the pronator teres muscle, medial to the brachial artery (1 min). 2. Selection of the Approach Type: Depending on the anatomical disposition of the nerve, either a short-axis approach (introducing the needle in a plane parallel to the probe) or a long-axis approach (introducing the needle from the medial end of the probe) may be employed (1 min). 3. Assessment of Safety Measures: Localization of surrounding veins and arteries will be conducted using the Doppler function of the ultrasound machine, along with measurement of the distance from the skin to the target nerve to determine the appropriate needle size (5 min). 4. Pre-Intervention Measures: Hand washing, donning gloves and a probe cover, and skin antisepsis using a chlorhexidine-based antiseptic will be performed (5 min). 5. Ultrasound-Guided Intervention: The needle will be inserted and advanced toward the target tissue with real-time visualization using ultrasound. The needle should be positioned within the epineurium of the median nerve. Subsequently, a transcutaneous electrode will be placed on the ventral aspect of the forearm, and a monopolar electrode will be connected to the needle, aiming to reproduce a motor or sensory response over the nerve (1 min). 6. Peripheral Nerve Electrostimulation: A peripheral nerve stimulator (Endomed 484) will be utilized to apply a continuous biphasic rectangular current, adjusting the frequency to 1-2 Hz and the pulse width to 200-250 µs. The intensity will be gradually increased to a tolerable threshold for the patient (the patient will be asked after each increase in intensity until the maximum point prior to reproducing pain is found) and maintained for the 30-minute duration of stimulation. To ensure that the nerve is being correctly stimulated, involuntary contractions will be observed in the musculature that innervates and the patient will report a tingling sensation along the nerve territory. 7. Post-Intervention Measures: The needle will be withdrawn, followed by 30 seconds of compression with a sterile gauze (1 min). The treatment will be performed in a treatment room of the hospital and will be applied by a physiotherapist with expertise in ultrasound.