Video Aula Eletroanalgesia

Summary

This educational lecture explains how Transcutaneous Electrical Nerve Stimulation (TENS) can be used in physiotherapy to control pain. The instructor introduces the concept of pain as a complex sensory and emotional experience and describes how TENS delivers pulsed electrical currents through the skin to reduce pain perception. The lesson covers the main parameters of TENS devices, including frequency, pulse duration, and stimulation modes such as conventional, acupuncture-like, and burst TENS. It also explains the physiological mechanisms behind pain modulation, electrode placement options, and practical guidelines for safe and effective application. Emphasis is placed on proper patient evaluation, diagnosis, monitoring, and documenting treatment outcomes.

Takeaways

• 😀 Pain is a subjective sensory and emotional experience often associated with real or potential tissue damage, and is one of the most common complaints in physiotherapy.
• 😀 TENS (Transcutaneous Electrical Nerve Stimulation) is a non-invasive method that delivers electrical stimulation through the skin to reduce pain perception.
• 😀 TENS uses pulsed biphasic currents with symmetrical or asymmetrical pulses, typically between 50 and 300 microseconds, and frequencies from 1 to 200 Hz.
• 😀 TENS devices usually offer at least two output channels and allow modulation of parameters such as mode, frequency, pulse width, and intensity.
• 😀 Conventional TENS uses high-frequency, short-duration pulses to stimulate large myelinated A-beta fibers, activating the gate control mechanism to block pain signals quickly but for a short duration.
• 😀 Acupuncture-like TENS uses low-frequency, longer-duration pulses to stimulate small myelinated A-delta fibers, producing slower-onset but longer-lasting analgesia through mechanisms like enkephalins and descending inhibition.
• 😀 Burst TENS combines low-frequency bursts with intervals of rest, stimulating both A-beta and A-delta fibers to provide rapid and long-lasting pain relief.
• 😀 The choice of TENS parameters should be guided by the desired analgesic effect and duration, taking into account the patient’s reported pain intensity.
• 😀 Proper electrode placement is essential and can be over the painful area, the same dermatome, trigger points, peripheral nerves, or nerve roots, depending on patient comfort and response.
• 😀 Pain must be clinically assessed before TENS application, and treatment should focus on symptom management rather than addressing the underlying cause; monitoring and documenting patient response is critical.
• 😀 Simple tools such as visual analog scales and validated pain questionnaires can be used to measure pain before and after TENS treatment.
• 😀 Safety and adherence to contraindications are essential; the physiotherapist should remain with the patient during application to adjust parameters as needed.

Q & A

What is the main goal of this lesson?

The main goal of the lesson is to teach how to use electrotherapy for pain control, including understanding the parameters of the TENS current and being able to prescribe and apply it properly.

What does the acronym TENS stand for and what does it mean?

TENS stands for Transcutaneous Electrical Nerve Stimulation, which refers to electrical stimulation applied through the skin to prevent the sensation of pain.

What are the key characteristics of the current used in TENS?

The current used in TENS is a biphasic pulsed current, with pulse durations ranging from 50 to 300 microseconds and frequencies between 1 and 200 Hz.

What are the different types of TENS modulations mentioned in the lesson?

The lesson describes several TENS modulations, including conventional TENS, acupuncture TENS, and burst TENS.

What is the difference between conventional TENS and acupuncture TENS?

Conventional TENS uses high frequency and short pulse duration to stimulate large-diameter fibers (A-beta), providing quick but short-lasting pain relief. Acupuncture TENS uses low frequency and longer pulse duration to stimulate smaller fibers (A-delta), providing slower but longer-lasting relief.

How does TENS work to block pain?

TENS works by activating mechanoreceptors and blocking pain transmission at the presynaptic level, as well as activating endogenous pain control systems such as the descending pain pathway.

What is the mechanism of analgesia in burst TENS?

In burst TENS, pain relief is achieved by stimulating both A-beta and A-delta fibers, which activates the pain gate mechanism and enhances the body's natural pain control system, providing long-lasting relief.

Why is it important to diagnose pain before applying electrotherapy?

It is crucial to diagnose pain before applying electrotherapy because TENS is a symptomatic treatment, meaning it only addresses the pain and not its underlying cause. Proper diagnosis ensures effective treatment.

What should be done during the application of electrotherapy?

During electrotherapy application, the practitioner should stay close to the patient to adjust parameters, especially the intensity of the current, and monitor the patient's responses to ensure the desired result is achieved.

What are some methods to measure pain before and after treatment?

Pain can be measured using tools like the Visual Analog Scale (VAS) and pain questionnaires, which have been validated in Portuguese for use with patients.