Safety - Is Stellate Ganglion Block (SGB) Experimental and Is It High Risk?
The Stellate Ganglion Block (SGB) is increasingly discussed in the context of trauma-related disorders, PTSD, and severe autonomic dysregulation. As interest grows, so too do questions — particularly:
- Is SGB experimental?
- Does it pose significant risk?
- How does it compare to standard psychiatric treatments?
This article reviews the procedural history, safety data, regulatory context, and evidence base to clarify these concerns.
Is the Stellate Ganglion Block an Experimental Procedure?
The Stellate Ganglion Block (SGB) is not an experimental procedure. It is a long-established regional anaesthetic technique with an expanding evidence base in trauma-related disorders.
Off-label does not mean experimental. It means the indication is not yet formally listed on regulatory approval documentation.
When performed under appropriate clinical governance, with informed consent and careful patient selection, it represents a proportionate, mechanistically rational, and comparatively low-risk adjunctive intervention.
As with any evolving area of medicine, ongoing research is essential. But equating SGB with experimental or high-risk practice does not accurately reflect the procedural history, safety profile, or current evidence base.
Specifically: The SGB is a well-established regional anaesthetic procedure that has been used in medicine for over 70 years. It involves the injection of local anaesthetic around the stellate ganglion — part of the cervical sympathetic chain — to temporarily interrupt sympathetic outflow.
Established Medical Uses
SGB has long been used for
- Complex Regional Pain Syndrome (CRPS) and sympathetically mediated pain disorders
- Neuropathic pain
- Vascuylar insufficency
- Refractory angina
It is routinely performed by trained anaesthetists and pain specialists, typically under ultrasound or fluoroscopic guidance.
Is the SGB high risk?
When performed under modern ultrasound guidance by trained clinicians, SGB isgenerally considered low risk.
Common Transient Effects
- Temporary Horner’s syndrome (expected physiological sign)
- Hoarsness
- Local warmth
- Mild discomfort
The overall serious complication rate in modern image-guided practice is low.
Importantly,SGB
- Does not involve systemic daily medication exposure
- Does not cause metabolic syndrome or require ongoing dose escalation
- Has no addiction potential
- Does not cause tardive Dyskinesia
Risk Comparison in Psychiatry
In evaluating “significant risk,” context matters.
Common psychiatric interventions carry recognised risks - here is their breakdown:
- SSRI's : Suicidality (youth), serotonin syndrome
- Antipsychotics: Metabolic syndrome, movement disorders
- Benzodiazepines: Dependence, cognitive impairment
- Mood stabilisers: Organ toxicity
- Ketamine: Dissociation, hypertension
- ECT: Cognitive impairment, anaesthesia risks
- Deep Brain Stimulation : Intracranial surgery risks
The rationale: how can this be used in PTSD and anxiety?
The procedure is established.
The psychiatric indication is evolving.
Using an established medical procedure for a new indication is known as off-label practice, which is common and lawful in medicine when supported by:
- Plausible mechanism
- Peer-reviewed evidence
- Clinical judgment with a risk-benefit assessment
- Informed consent.
Examples of off-label psychiatric practices include:
- Propranolol for performance anxiety
- Clonidine/guanfacine for ADHD
- Ketamine for depression prior to TGA registration
- Antipsychotics for behavioural disturbances
- Beta blockers for trauma hyper-arousal.
PTSD and severe anxiety disorders are increasingly conceptualised as disorders of persistent sympathetic hyperactivation.
The stellate ganglion plays a central role in
- Sympathetic tone
- Fight-or-flight responses
Research suggests SGB may reduce:
- Hyperarousal
- startle response
- Irritability
- Physiological reactivity to trauma cues
Proposed mechanisms include modulation of norepinephrine signalling and functional changes in amygdala-related circuits.
While mechanistic models continue to evolve, the physiological rationale is coherent and grounded in autonomic neuroscience.
Regulatory perspective in Australia
In Australia:
- Off-label practice is permitted when clinically justified
- We look at
- evidence -informed rationale
- documented risk-benefit assessment
- informed consent
The SGB is an an adjunctive autonomic modulation intervention for carefully selected treatment-resistant patients with significant sympathetic hyper-arousal.
Used responsibly, with clinical governance, it sits within the broader spectrum of psychiatric and neurological care.
Key References
- Rae Olmsted KL et al. (2020). Effect of Stellate Ganglion Block Treatment on Posttraumatic Stress Disorder Symptoms: A Randomized Clinical Trial. JAMA Psychiatry.
- Hanling SR et al. (2016). Stellate Ganglion Block for Treatment of PTSD: A Randomized, Double-Blind, Controlled Trial. Regional Anesthesia & Pain Medicine.
- Mulvaney SW et al. (2014). The Use of Stellate Ganglion Block in the Treatment of PTSD. Military Medicine.
- Lipov EG et al. (2012). Successful Use of Stellate Ganglion Block in PTSD: Case Series. Pain Practice.
- Lynch JH et al. (1996 onward). Established safety literature on stellate ganglion block in pain medicine.
- Australian Medical Board. Good Medical Practice: A Code of Conduct for Doctors in Australia (Off-label prescribing guidance).
