What equipment is needed for a trigger point injection to treat a back spasm in a patient?

Equipment for Trigger Point Injection for Back Spasm

For a trigger point injection to treat back spasm, you need: a 22-25 gauge needle (1.5-3.5 inches long depending on patient body habitus), a syringe (3-10 mL), local anesthetic (0.5% lidocaine or 0.25-0.5% bupivacaine), alcohol swabs, gloves, and marking pen—steroids are NOT recommended for trigger point injections. 1, 2

Essential Equipment List

Needles

• 22-25 gauge needle is the standard size for trigger point injections 1
• Length: 1.5 inches (38mm) for most patients, but up to 3.5 inches (90mm) may be needed for obese patients or deep muscle trigger points 1, 3
• A 28-gauge thin needle (60-90mm) can be used for more superficial trigger points or to minimize patient discomfort 3
• Avoid needles smaller than 25 gauge as they may be too flexible and difficult to control, though they cause less tissue trauma 1

Syringes and Injectate

• 3-10 mL syringe depending on the number of trigger points being treated 4
• 0.5% lidocaine is the recommended local anesthetic 1, 2, 5
• Alternative: 0.25-0.5% bupivacaine for longer duration of action 1, 6
• Do NOT use glucocorticosteroids in trigger point injections—guidelines specifically recommend against steroids for this indication 1, 2

Additional Supplies

• Alcohol swabs for skin preparation 6, 7
• Sterile gloves 6, 7
• Marking pen to identify trigger points before injection 3
• Gauze or cotton balls for post-injection pressure 4
• Adhesive bandage 4

Critical Safety Equipment (Must Be Immediately Available)

Resuscitative equipment must be immediately available before performing any trigger point injection, as local anesthetics can cause systemic toxicity even with small doses 6, 7:

• Oxygen supply and delivery system 6, 7
• Suction equipment 6
• Airway management equipment (bag-valve-mask, oral airways) 6, 7
• Emergency medications including benzodiazepines for seizures and vasopressors for cardiovascular collapse 6, 7
• Cardiac monitor and blood pressure monitoring capability 6, 7

Technique-Specific Considerations

Needle Selection Algorithm

• For superficial paraspinal trigger points: 22-25 gauge, 1.5 inch needle 1, 4
• For deep quadratus lumborum or multifidus trigger points: 22-25 gauge, 2.5-3.5 inch needle 1, 3
• For obese patients (BMI >30): Consider 3.5 inch needle to reach deep muscle layers 1, 3
• For patients with needle phobia or high pain sensitivity: Consider 25-28 gauge needle, though this may increase procedure time 1, 3

Medication Dosing

• Maximum safe dose of lidocaine without epinephrine: 4.5 mg/kg (approximately 300mg for a 70kg adult) 7
• Maximum safe dose of bupivacaine: 2.5 mg/kg (approximately 175mg for a 70kg adult) 6
• Typical volume per trigger point: 0.5-2 mL 1, 4, 5
• Limit to 6 total injection sites per session (up to 3 levels bilaterally) to avoid excessive medication exposure 2

Important Clinical Caveats

When NOT to Perform Trigger Point Injections

• Do not perform if patient has radiculopathy—epidural steroid injections are more appropriate for radicular symptoms 2, 8
• Avoid in patients with severe hepatic disease as they cannot metabolize amide local anesthetics normally and are at higher risk of toxicity 6, 7
• Use caution in patients with cardiovascular disease as they may be less able to compensate for AV conduction changes 6, 7
• Contraindicated in areas with active infection 6, 7

Common Pitfalls to Avoid

• Failing to aspirate before injection—always aspirate to ensure you are not in a blood vessel, as intravascular injection can cause immediate systemic toxicity 6, 7
• Using corticosteroids in trigger point injections—evidence shows no benefit over local anesthetic alone, and guidelines specifically recommend against this practice 1, 2
• Performing injections without resuscitative equipment immediately available—this is a critical safety violation 6, 7
• Injecting too rapidly—slow injection reduces pain and allows time to detect early signs of toxicity 6, 7
• Not eliciting a local twitch response—studies show that eliciting the local twitch response during needle insertion is essential for optimal therapeutic effect 5

Post-Injection Monitoring

• Monitor for 15-30 minutes after injection for signs of local anesthetic toxicity: restlessness, anxiety, tinnitus, dizziness, blurred vision, tremors, or drowsiness 6, 7
• Warn patients about post-injection soreness which occurs in 42-100% of patients and typically lasts 24-48 hours 5
• Advise patients to avoid strenuous activity for 24-48 hours after injection 4

Documentation Requirements

• Document quantifiable improvement (≥50% pain reduction for ≥2 months) if repeat injections are being considered 2, 8
• Do not repeat injections more frequently than every 2 months if therapeutic effect is achieved 2, 8
• Limit to 4 sets of injections total without documented clinical response 8