JC: Intra-arrest Stellate Ganglion Block

Background

We’ve talked a lot about refractory shockable cardiac arrest at St Emlyns’s. In many ways it’s the frustration of seeing a patient who has a condition that we think we should be able to correct, and yet we cannot. Ordinarilly we derscribe refractory VF/VT as persisting VF/VT for more than three shocks. While traditional Advanced Cardiac Life Support (ACLS) is still our standard approach, emerging interventions like extracorporeal CPR (ECPR), double sequential external defibrillation (DSED), and vector change defibrillation offer potential benefits for select patients. But not all of these are accessible, nor are they widely recommended, nor are they in all the guidelines (yet).

I’ve heard a little about percutaneous stellate ganglion block (PSGB) for refractory VF/VT recently. I must admit that this sounded a bit odd as the link between a nerve block and achieving defibrillation, especailly at some distance from the heart itself is a bit of a leap. PSGB is a technique historically used for pain such as complex regional pain syndromes, or for vascular conditions such as peripheral vascular disease. Essentially the block aims to put local anaesthetic around the stellate ganglion anterior to the first rib. The stellate ganglion is formed at the point where the inferior cervical ganglion meets the first thoracic ganglion on the sympathetic trunk. A successful block will have the following effects.

Vasodilation
Increases blood flow to the arm and face
Reduced sweating in face and upper limb
Warmth and redness of the face or arm
Pain relief (for nerve-related pain like CRPS or post-herpetic neuralgia)
May cause Horner’s syndrome
Has been trialed in PTSD and long COVID

It also affects the sympathetic drive to the heart which is where its potential use in VF/VT has arisen. The STAR study was published in 2024 and was a multicentre trial of patients who had electrical storm (defined as multiple episodes of VF/VT and that suggested a 92% suppression rate of VA using PSGB in patients . That appears to have been done in cardiology patients in hospital though and was more of a preventive strategy in patients who had multiple VF/VT episodes. This of course is very different to the sort of patients we see in EM/PHEM practice. There is a big difference between preventing something vs. stopping it once it has happened.

The paper by Vlok et al. (2025) tackles this very question. Their scoping review summarises 32 cases where PSGB was attempted during cardiac arrest. To be honest the idea of performing a nerve block, into the neck, close to major vessels and during a cardiac arrest appears to be…….., well somewhat sporting, but if that’s where the research leads, St Emlyn follows. The abstract is below, but as always please read the full paper yourself and come to your pwn conclusions.

Background: Percutaneous stellate ganglion blockade (PSGB) is increasingly considered for the management of refractory ventricular arrhythmias (VA). The role of intra-arrest PSGB remains unknown, however it may represent a simple intervention for shockable cardiac arrest. The primary objective of this scoping review was to explore all published cases describing the use of PSGB in the treatment of shockable cardiac arrest.

Methods: A scoping review of all cases of PSGB performed intra-arrest was performed across multiple databases. Studies were included if they described the use of intra-arrest PSGB in humans. Studies were qualitatively assessed to describe data regarding the technique, training of the proceduralist, patient demographics, context of the arrest, clinical outcomes, and complications. This study was reported according to the PRISMA-ScR checklist.

Results: A total of 13 studies with 32 individual cases of PSGB being used intra-arrest were identified. Of these, 23 cases reported whether the patients achieved return of spontaneous circulation (ROSC), and 19 (82.6%) were confirmed to successfully achieve ROSC post-PSGB. Numerous aetiologies of cardiac arrest were reported, including acute myocardial infarction (AMI) (31.3%), cardiomyopathy (12.5%), and toxicology (3%). Of the 32 cases, 23 (71.9%) were performed by landmark technique, and lignocaine represented the most common local anaesthetic of choice and was confirmed to have been used as a sole agent in 8 of 19 cases (42.1%) that reported their formulation. No definitive procedure-related complications were described in this cohort. One ongoing trial was identified, aiming to assess PSGB in the prehospital setting.

Conclusions: PSGB has been described in as a rescue strategy for refractory cardiac arrest in 32 individual reported cases from a variety of underlying aetiologies. The included studies are susceptible to publication bias. Currently, no randomised data exists, however the LIVE study is eager

What kind of study is this?

This is a scoping review, not a systematic review or a meta-analysis. The authors sought to map the breadth of existing literature, with no predefined outcome measures or statistical synthesis. This is appropriate for a topic that is still emerging and where the data are sparse and heterogeneous.

Following PRISMA-ScR guidance, the authors searched across multiple major databases, including MEDLINE, Embase, and CENTRAL, as well as grey literature. The review included published and unpublished case reports, case series, and observational studies involving humans undergoing intra-arrest PSGB. Animal studies and blocks performed outside of cardiac arrest were excluded.

Scoping reviews aim to identify trends, gaps, and feasibility questions in the literature. That makes this review an important first step, but not one designed to prove efficacy or safety.

Tell me about the patients

Across the 13 included studies, 32 individual cases were identified. The patient population was heterogenous, with a slight male predominance (65% of the 23 patients whose sex was reported). Ages ranged widely, with one case involving a 17-year-old and others involving older adults with underlying cardiac pathology.

Most cases were conducted in hospital settings, typically emergency departments or intensive care units. There were no documented prehospital applications, though one ongoing trial (the LIVE study) aims to change that. Most PSGBs were unilateral; only one was bilateral.

Importantly, the arrest aetiologies were varied. Around a third of cases (31.3%) were related to acute myocardial infarction (AMI), while others were linked to cardiomyopathy, arrhythmogenic conditions like Wolff-Parkinson-White syndrome, toxicological overdoses (e.g., lacosamide), and structural heart disease. This breadth of pathology hints at the generalisability of the intervention—but also makes standardisation tricky.

There is a useful video on this website that shows how to do a stellate block under USS guidance, just in case you want to know a little more about the practicalities.

https://www.youtube.com/watch?v=B6ROeVFUJSY

What were the measured outcomes in this study?

The authors focused on a narrative synthesis rather than quantitative outcomes. Still, they extracted key clinical endpoints from the cases:

Return of spontaneous circulation (ROSC)
Survival to hospital admission
Survival to hospital discharge
Complications attributable to the block
Technical details (e.g., local anaesthetic used, landmark vs ultrasound technique, proceduralist specialty)

The critical limitation is that ROSC was only reported in 23 of the 32 cases. Moreover, survival to discharge was inconsistently documented, and neurological outcomes, arguably the most important metric, were scarcely mentioned.

What are the main results?

Here’s the data in a nutshell:

ROSC was achieved in 19 out of 23 cases (82.6%) where it was reported.
Twelve patients survived to hospital discharge, representing 63.2% of the 19 with known ROSC outcomes.
Lignocaine was the most commonly used local anaesthetic, used as the sole agent in 42.1% of the cases when recorded.
Most blocks were performed using the landmark technique (72%), though 21.9% used ultrasound guidance.
No procedure-related haematomas or major complications were confirmed. Two possible adverse events were reported: a seizure (possibly related to lignocaine toxicity or inadvertent vascular injection), and a stroke (likely cardioembolic, not directly due to the block).
In four cases, PSGB was performed without interrupting CPR.

Of course lots of additional interventions were done, including DSED, ECPR, REBOA, and various anti-arrhythmics. This makes attributing benefit to PSGB alone quite difficult.

Tell me about the methods and reliability of the results

This is a pretty good scoping review.The authors followed a protocol, applied clear inclusion criteria, and openly acknowledged limitations. They also highlight the need for randomised trials, of which the LIVE study ClinicalTrials.gov ID: NCT04168970 is a promising example. The LIVE study is a prehospital study looking at PSGB in out of hospital cardiac arrest.

But let’s talk about the elephant in the resus bay: publication bias. Case reports and series disproportionately highlight successes. It’s highly plausible that unsuccessful or complicated PSGB attempts went unreported, inflating the apparent success rate.

Moreover, ROSC after PSGB does not mean success (really). Many of these patients had already received multiple shocks, full ACLS, and adjuncts like ECPR. It’s possible that ROSC simply occurred coincidentally after PSGB, especially in lengthy resuscitations where the next shock was due anyway. This is always an issue in reviews of observational trials.

There’s also a pragmatic question: can the block be performed without disrupting als? In four cases that did happen, which suggests that it can. Most blocks were done using landmark technique. I love a landmark technique for many procedures, but that’s because I am old school and it’s not the comfort zone of most younger colleagues, especially when you consider the anatomy of the neck to be full of ‘interesting’ structures.

No major haemorrhages or airway complications were reported, even in patients who received thrombolysis or were on ECMO. However, a misplaced needle could do harm, especially in anticoagulated patients.

Should we change practice based on this study?

Not yet. This review is hypothesis-generating, not practice-changing.

We’re still in early days. The data here are promising enough to justify further investigation, but not implementation as standard care. It’s plausible that PSGB could become a useful tool in refractory VF, perhaps as a bridge when ECPR is unavailable or as an adjunct in high-resource centres. But we need more clarity on:

When to perform the block (e.g., after how many shocks?)
How to perform it safely (landmark vs ultrasound)
What formulation to use (2% lignocaine or longer acting agents?)
Who should/can perform it?
Whether it improves meaningful outcomes like neurologically intact survival

Until the LIVE study or other trials provide high-level evidence, PSGB should be considered experimental. For now, we’d caution against deploying it in everyday practice outside of research settings or highly select situations, such as prolonged refractory VF with no other options available and a trained doctor ready to go.

Summary

This is an interesting review, from a group who are clearly very excited about this potential therapy, but it’s not ready for widespread clinical practice. However, this paper probably does tell us that intra-arrest PSGB is technically feasible, low-cost, and might be safe, and in 82.6% of reported cases, it was temporally associated with ROSC. However, correlation is not causation, and there is almost certainly a lot of publication bias here. The data is messy, inconsistent, and confounded by co-interventions.

References

Vlok R et al. “Intra-arrest percutaneous stellate ganglion block: a scoping review.” J Emerg Crit Care Med. 2025;9:13.
LIVE study. https://www.centerwatch.com/clinical-trials/listings/NCT04168970/percutaneous-left-stellate-ganglion-block-in-out-of-hospital-cardiac-arrest-due-to-refractory-ventricular-arrhythmias-live-study
STAR study. https://academic.oup.com/eurheartj/article/45/10/823/7592053?login=true
Baldi E, Dusi V, Rordorf R, Currao A, Compagnoni S, Sanzo A, Gentile FR, Frea S, Gravinese C, Angelini F, Cauti FM, Iannopollo G, De Sensi F, Gandolfi E, Frigerio L, Crea P, Zagari D, Casula M, Binaghi G, Sangiorgi G, Barone L, Persampieri S, Dell’Era G, Patti G, Colombo C, Mugnai G, Tavella D, Notaristefano F, Barengo A, Falcetti R, Girardengo G, D’Angelo G, Tanese N, Sgromo V, De Ferrari GM, Savastano S; all the STAR study group. Efficacy of early use of percutaneous stellate ganglion block for electrical storms. Eur Heart J Acute Cardiovasc Care. 2024 Dec 3;13(11):757-765. doi: 10.1093/ehjacc/zuae109. PMID: 39317656.