What are the guidelines for using TENS (Transcutaneous Electrical Nerve Stimulation) for pain management?

Guidelines for Using TENS for Pain Management

TENS (Transcutaneous Electrical Nerve Stimulation) is strongly recommended against for pain management in osteoarthritis of the knee and/or hip due to lack of demonstrated benefit. 1

Effectiveness of TENS by Pain Condition

Osteoarthritis

• Knee and Hip OA: TENS is strongly recommended against by the American College of Rheumatology/Arthritis Foundation 1
  • Studies examining TENS for knee OA have been of low quality with small sample sizes and variable controls
  • Available evidence demonstrates a lack of benefit for knee OA

Low Back Pain

• Chronic Low Back Pain: Evidence is insufficient to support TENS use 1

  • One lower-quality trial found TENS superior to placebo
  • A larger, higher-quality trial found no differences between TENS and sham TENS
  • One higher-quality trial found TENS superior to superficial massage

• Subacute Low Back Pain: TENS appears moderately inferior to spinal manipulation 1

Cancer-Related Pain

• Cancer Survivors: Limited evidence for TENS in cancer-related pain 1
  • A Cochrane review of three RCTs found insufficient evidence to recommend TENS
  • Only one feasibility study suggested TENS may improve bone pain in cancer patients
  • Two studies found no significant differences between TENS and control groups

Chemotherapy-Induced Peripheral Neuropathy (CIPN)

• One phase II trial compared Scrambler therapy to TENS for CIPN 1
  • Scrambler therapy showed better outcomes (50% documented improvement) compared to TENS (16-28% improvement)
  • Patients were more likely to recommend Scrambler therapy than TENS

Stroke Rehabilitation

• TENS has been studied for improving mobility after stroke 1
  • Three RCTs provided evidence of potential benefit, particularly when combined with task-related activity
  • However, a meta-analysis found insufficient research to make conclusions about TENS effectiveness in improving gait

TENS Application Parameters

Technical Specifications

• TENS involves using a small, battery-operated device to provide continuous electrical impulses via surface electrodes 1
• The goal is to provide symptomatic relief by modifying pain perception
• Parameters typically include:
  • Frequency settings (commonly high frequency 35-110 Hz or low frequency 4 Hz)
  • Intensity levels (either "low" - strong but comfortable, or "high" - strong and uncomfortable but not painful) 2

Safety Considerations

• Adverse effects are generally minor 1:
  • Skin irritation (reported in approximately one-third of patients)
  • Rarely, severe dermatitis requiring discontinuation

Special Populations

Sickle Cell Disease

• TENS has been suggested in a case report for thoracotomy-associated pain in sickle cell disease patients 1
• However, this is based on limited evidence (single case report)

Clinical Decision Making

When to Consider TENS

Despite the general lack of strong evidence for TENS, it might be considered in specific scenarios:

1. When conventional pain management approaches have failed
2. As an adjunct to exercise for patients with chronic pain 3
3. When patients prefer non-pharmacological approaches
4. For short-term pain relief rather than long-term management

When to Avoid TENS

1. As primary therapy for osteoarthritis of knee or hip 1
2. As a standalone treatment without other pain management approaches
3. When expecting significant long-term benefits

Common Pitfalls in TENS Use

1. Overestimating effectiveness: The scientific evidence for clinical effectiveness of TENS is limited 4
2. Inadequate parameter selection: Studies have not established optimal stimulation parameters for pain relief 5
3. Lack of long-term assessment: Most studies evaluate short-term effects, leaving questions about long-term effectiveness unanswered 5
4. Relying on single-dose evaluations: These are unhelpful for making clinical decisions about long-term effectiveness 5
5. Expecting universal response: Alternating-frequency TENS does not result in large hypoalgesic effects 2

Alternative Non-Pharmacological Approaches

For conditions where TENS is not recommended, consider these evidence-based alternatives:

• For Osteoarthritis: Topical NSAIDs (strongly recommended for knee OA), topical capsaicin (conditionally recommended for knee OA) 1
• For Low Back Pain: Exercise, cognitive-behavioral therapy, progressive relaxation, interdisciplinary rehabilitation, and spinal manipulation 1
• For Cancer Pain: Acceptance-based interventions, relaxation, guided imagery, meditation or hypnosis 1

In summary, while TENS is widely used in clinical practice, current guidelines and evidence do not support its use for osteoarthritis of the knee and hip, and evidence is insufficient or conflicting for other pain conditions.