What is the step-by-step procedure for a trigger point injection?

Trigger Point Injection: Step-by-Step Procedure

Trigger point injections should be performed using a standardized technique with proper patient positioning, sterile preparation, and appropriate needle insertion to ensure maximum efficacy and safety while minimizing complications.

Patient Preparation and Equipment

Equipment Needed:

• 25-gauge, 1.5-inch needle (shorter needles for superficial muscles)
• 3 mL syringe
• Local anesthetic (0.25% lidocaine is commonly used)
• Antiseptic solution
• Sterile gloves
• Gauze
• Adhesive bandages
• Puncture-resistant sharps container

Patient Positioning:

• Position the patient to allow access to the affected muscle while keeping it in a relaxed state
• Ensure good lighting and a comfortable position for both patient and provider

Step-by-Step Procedure

1. Preliminary Steps

• Use appropriate hand hygiene methods before starting 1
• Screen patient for contraindications (bleeding disorders, anticoagulation therapy, local infection)
• Ensure adequate lighting of the treatment area 1

2. Trigger Point Identification

• Palpate for a hypersensitive bundle or nodule of muscle fiber with harder than normal consistency 2
• Confirm the trigger point by eliciting:
  • Local pain directly over the affected area
  • Referred pain pattern in a characteristic distribution
  • Local twitch response when properly stimulated 2

3. Site Selection and Preparation

• Select injection site free from veins, lesions, and scars 1
• Clean the site with antiseptic swab using circular motion from center outward 1
• Allow site to dry thoroughly before administering injection 1

4. Needle Insertion Technique

• Rest the treatment area on a firm, well-lit surface 1
• Stretch skin slightly to stabilize the area 1
• Hold needle with bevel up at a 90° angle to the skin surface 1
• Insert needle directly into the trigger point in a smooth but not jabbing movement 1
• Advance needle until the trigger point is engaged (patient may report a reproduction of their pain) 2

5. Injection Administration

• Consider aspiration to ensure needle is not in a blood vessel
• Inject solution slowly into the trigger point 1
• If using local anesthetic, inject approximately 0.1-0.3 mL per trigger point
• If performing dry needling, insert the needle and stimulate the trigger point without injecting solution

6. Post-Injection Technique

• Remove needle without pressing the area 1
• If blood or fluid is present, blot site lightly with gauze 1
• Discard used needle and syringe immediately in puncture-resistant container without recapping 1
• Apply gentle pressure to the injection site if needed

7. Documentation

• Document date and time of injection, location of trigger points treated, solution used, patient's response, and any complications 1

Post-Procedure Care Instructions

• The injection site may be sore for 24-48 hours
• Apply ice for 20 minutes several times during the first 24 hours to reduce soreness
• Perform gentle stretching exercises of the affected muscle groups
• Avoid strenuous activity of the injected muscle for 3-4 days
• Schedule follow-up as needed

Clinical Pearls and Pitfalls

Important Considerations:

• Ultrasound guidance may be beneficial, particularly in the cervicothoracic region to avoid pneumothorax or when treating obese patients 3
• Multiple trigger points may need to be treated in a single session
• No single pharmacologic agent has been proven superior to another in trigger point injections 4
• Dry needling has shown similar efficacy to injections with solutions in many studies 5

Potential Complications:

• Local pain or bruising at injection site
• Vasovagal syncope
• Pneumothorax (particularly with injections near the thoracic region)
• Infection (rare with proper technique)

Efficacy Considerations:

• Trigger point injections should be reserved for patients whose myofascial pain has been refractory to less invasive treatments 4
• Consider combining injections with other modalities such as physical therapy, massage, or stretching for optimal results
• Multiple treatment sessions may be necessary for chronic myofascial pain

By following this standardized approach to trigger point injections, clinicians can effectively treat myofascial pain while minimizing the risk of complications.