Can steroids be used in a Sphenopalatine Ganglion (SPG) block?

Steroids in Sphenopalatine Ganglion (SPG) Block

Steroids can be used in sphenopalatine ganglion blocks, particularly when administered as intratympanic injections for conditions like sudden sensorineural hearing loss, with dexamethasone (4-24 mg/mL) being the most commonly used steroid preparation.

Evidence for Steroid Use in SPG Blocks

The use of steroids in nerve blocks is supported by clinical practice guidelines, though specific evidence for SPG blocks is limited. The American Society of Anesthesiologists guidelines for chronic pain management indicate that:

• Steroids are commonly used as adjuncts in various nerve blocks 1
• For sympathetic nerve blocks (similar to SPG blocks), local anesthetics with or without steroids may be used as components of multimodal treatment 1

Steroid Formulations and Administration

When using steroids in SPG blocks, the following considerations apply:

Formulations:

• Dexamethasone is the most commonly used steroid for nerve blocks, with concentrations ranging from 4-24 mg/mL 2
• Methylprednisolone (30-62.5 mg/mL) is an alternative option with potentially superior outcomes in some applications 2, 1

Administration Technique:

• Typical volume: 0.4-0.8 mL of steroid solution
• Patient positioning: After injection, patients should remain with the treated side up for 15-30 minutes to maximize contact time 2
• Multiple injections may be required for optimal effect (typically 3-4 injections over 2 weeks) 2

Efficacy Considerations

The efficacy of steroid use in nerve blocks varies by indication:

• Higher concentrations of steroids appear to yield better outcomes (24 mg/mL dexamethasone shows superior results compared to 10 mg/mL) 2
• Methylprednisolone may show superior outcomes compared to dexamethasone in some applications (84% vs 64% improvement rates) 2

Safety Profile and Adverse Effects

Potential adverse effects of steroid use in SPG blocks include:

• Transient pain at injection site
• Brief vertigo
• Potential infection
• Vasovagal or syncopal episodes during injection 2

The advantage of local steroid administration is minimal systemic side effects, making it suitable for patients who cannot tolerate systemic steroids due to conditions like diabetes, hypertension, or glaucoma 1, 2.

Clinical Applications

SPG blocks with steroids may be considered for:

1. Refractory headache conditions, particularly cluster headaches 3
2. Various facial pain syndromes 3
3. As an adjunctive treatment for conditions where sympathetic blockade is beneficial 4

Important Caveats

• While steroids are commonly used in nerve blocks, the specific evidence for their use in SPG blocks is more limited than for other applications like intratympanic injections
• Consider patient-specific factors including comorbidities and contraindications to steroid use
• Monitor for potential adverse effects, particularly with repeated administrations

For optimal outcomes, consider referral to specialized pain centers for patients who do not respond to initial SPG block with steroids, as alternative techniques or combinations may be required 1.