What are the indications, contraindications, and procedural steps for performing a stellate ganglion block?

Stellate Ganglion Block: Indications, Contraindications, and Procedural Steps

Primary Indications

Stellate ganglion block (SGB) is most strongly recommended for complex regional pain syndrome (CRPS) as part of multimodal treatment when there is consistent improvement and increasing duration of pain relief. 1

Pain-Related Indications

• CRPS (Complex Regional Pain Syndrome): Primary indication with strong consensus support from ASA and ASRA for use in multimodal treatment protocols 1
• Sympathetically mediated pain in the upper extremity, head, face, and neck regions 1, 2
• Vascular insufficiency in upper limbs to improve perfusion 3
• Herpes zoster affecting the upper extremity and upper thorax 2

Non-Pain Indications (Emerging Evidence)

• Refractory ventricular arrhythmias: Unilateral or bilateral SGB reduces arrhythmia burden and defibrillation events for 24-72 hours, providing a bridge to definitive therapies like catheter ablation, surgical sympathectomy, or heart transplantation 4
• Cardiovascular sympathetic stimulation: Grade B/C recommendation for obtunding stress response and improving perioperative hemodynamic stability 3
• Menopausal hot flashes: Grade B/C recommendation for symptom relief refractory to conventional management 3

Important Limitation

SGB should NOT be used for long-term treatment of non-CRPS neuropathic pain, as there is insufficient evidence supporting this indication 1

Contraindications and Special Precautions

Absolute Contraindications

• Active COVID-19 infection or suspected cases: SGB near the head and neck area poses aerosol generation risk and requires airborne precautions in addition to droplet precautions 1
• Patient refusal or inability to provide informed consent 2

Relative Contraindications and Cautions

• Anticoagulation: While ultrasound-guided SGB can be performed safely even on anticoagulation 4, careful risk-benefit assessment is required
• Respiratory compromise: Avoid in patients with significant respiratory dysfunction, as the procedure can affect respiratory function 1
• Contralateral recurrent laryngeal nerve palsy: Risk of bilateral vocal cord paralysis 5

Critical Safety Considerations

• Life-threatening complications occur in 1.7 per 1,000 blockades, primarily from inadvertent subarachnoid or intra-arterial injection 5
• Specific complications include: CNS complications/convulsions (most common), high subarachnoid block, high epidural blockade, pneumothorax, and allergic reactions 5

Procedural Steps and Technique

Pre-Procedure Requirements

Mandatory safety measures before performing SGB: 5

• Establish intravenous access (72% of practitioners)
• Have assistant present (73% of practitioners)
• Anticonvulsant drugs immediately available
• Resuscitation equipment and drugs for intubation at bedside
• ECG monitoring (28% use routinely, but strongly recommended)
• Oxygen and ventilating devices prepared

Patient Positioning

• Supine position with neck slightly extended 6
• Head rotated slightly to the side opposite the block 6

Imaging Guidance Approach

Ultrasound guidance is strongly recommended to reduce risk of local anesthetic systemic toxicity 1, 4

Alternative: Fluoroscopic Oblique Technique 6

1. Direct fluoroscopic beam anteroposteriorly until C5/6 disc is well visualized
2. Rotate beam obliquely ipsilateral to the side being blocked
3. Under real-time imaging, advance 25-gauge spinal needle in single pass to contact bone
4. Needle tip should rest at junction between uncinate process and vertebral body

Traditional Paratracheal Access 2

• Approach at C6 level (Chassaignac's tubercle)
• Palpate carotid artery and retract laterally
• Direct needle medially to contact transverse process

Injection Protocol

• Aspiration test mandatory before injection (100% of practitioners perform this) 5
• Test dose: Administer 0.5-2 mL local anesthetic first (53% of practitioners use test doses) 5
• Local anesthetic choice: 82% of departments prefer bupivacaine 5
• Calculate safe maximum dose of local anesthetic before procedure 1

Verification of Block Success

Assess for Horner's syndrome (miosis, ptosis, anhidrosis) on ipsilateral side, indicating successful sympathetic blockade 2

Common Pitfalls and How to Avoid Them

Critical Safety Issues

• Aspiration tests and test doses do NOT guarantee proper administration and do not prevent all complications 5
• Never perform without immediate resuscitation capability, as inadvertent intravascular or subarachnoid injection can cause rapid deterioration 5
• Reduce sedation doses if used pre-procedurally to avoid respiratory compromise 1

Technical Considerations

• Use ultrasound guidance whenever possible rather than landmark-based techniques to minimize complications 1, 4
• Avoid in COVID-19 patients unless absolutely necessary, and use full airborne precautions if performed 1
• Consider alternative opioid administration to stellate ganglion, which has shown similar therapeutic results with lower complication rates 5

Duration of Effect

• For ventricular arrhythmias, expect 24-72 hours of effect, which serves as a bridge to definitive therapy rather than long-term solution 4
• For CRPS, look for consistent improvement and increasing duration of pain relief with repeated blocks before continuing therapy 1