Sympathetic nerve blocks for persistent pain in adults with inoperable abdominopelvic cancer.

BACKGROUND: Persistent visceral pain is an unpleasant sensation coming from one or more organs within the body. Visceral pain is a common symptom in those with advanced cancer. Interventional procedures, such as neurolytic sympathetic nerve blocks, have been suggested as additional treatments that may play a part in optimising pain management for individuals with this condition. OBJECTIVES: To evaluate the benefits and harms of neurolytic sympathetic nerve blocks for persistent visceral pain in adults with inoperable abdominopelvic cancer compared to standard care or placebo and comparing single blocks to combination blocks. SEARCH METHODS: We searched the following databases without language restrictions on 19 October 2022 and ran a top-up search on 31 October 2023: CENTRAL; MEDLINE via Ovid; Embase via Ovid; LILACS. We searched trial registers without language restrictions on 2 November 2022: ClinicalTrials.gov; WHO International Clinical Trials Registry Platform (ICTRP). We searched grey literature, checked reference lists of reviews and retrieved articles for additional studies, and performed citation searches on key articles. We also contacted experts in the field for unpublished and ongoing trials. Our trial protocol was preregistered in the Cochrane Database of Systematic Reviews on 21 October 2022. SELECTION CRITERIA: We searched for randomised controlled trials (RCTs) comparing any sympathetic nerve block targeting sites commonly used to treat abdominal pelvic pain from inoperable malignancies in adults to standard care or placebo. DATA COLLECTION AND ANALYSIS: We independently selected trials based on predefined inclusion criteria, resolving any differences via adjudication with a third review author. We used a random-effects model as some heterogeneity was expected between the studies due to differences in the interventions being assessed and malignancy types included in the study population. We chose three primary outcomes and four secondary outcomes of interest. We sought consumer input to refine our review outcomes and assessed extracted data using Cochrane's risk of bias 2 tool (RoB 2). We assessed the certainty of evidence using the GRADE system. MAIN RESULTS: We included 17 studies with 1025 participants in this review. Fifteen studies with a total of 951 participants contributed to the quantitative analysis. Single block versus standard care Primary outcomes No included studies reported our primary outcome, 'Proportion of participants reporting no worse than mild pain after treatment at 14 days'. The evidence is very uncertain about the effect of sympathetic nerve blocks on reducing pain to no worse than mild pain at 14 days when compared to standard care due to insufficient data (very low-certainty evidence). Sympathetic nerve blocks may provide small to 'little to no' improvement in quality of life (QOL) scores at 14 days after treatment when compared to standard care, but the evidence is very uncertain (standardised mean difference (SMD) -0.73, 95% confidence interval (CI) -1.70 to 0.25; I² = 87%; 4 studies, 150 participants; very low-certainty evidence). The evidence is very uncertain about the risk of serious adverse events as defined in our review as only one study contributed data to this outcome. Sympathetic nerve blocks may have an 'increased risk' to 'no additional risk' of harm compared with standard care (very low-certainty evidence). Secondary outcomes Sympathetic nerve blocks showed a small to 'little to no' effect on participant-reported pain scores at 14 days using a 0 to 10 visual analogue scale (VAS) for pain compared with standard care, but the evidence is very uncertain (mean difference (MD) -0.44, 95% CI -0.98 to 0.11; I² = 56%; 5 studies, 214 participants; very low-certainty evidence). There may be a 'moderate to large' to 'little to no' reduction in daily consumption of opioids postprocedure at 14 days with sympathetic nerve blocks compared with standard care, but the evidence is very uncertain (change in daily consumption of opioids at 14 days as oral milligrams morphine equivalent (MME): MD -41.63 mg, 95% CI -78.54 mg to -4.72 mg; I² = 90%; 4 studies, 130 participants; very low-certainty evidence). The evidence is very uncertain about the effect of sympathetic nerve blocks on participant satisfaction with procedure at 0 to 7 days and time to need for retreatment or treatment effect failure (or both) due to insufficient data. Combination block versus single block Primary outcomes There is no evidence about the effect of combination sympathetic nerve blocks compared with single sympathetic nerve blocks on the proportion of participants reporting no worse than mild pain after treatment at 14 days because no studies reported this outcome. There may be a small to 'little to no' effect on QOL score at 14 days after treatment, but the evidence is very uncertain (very low-certainty evidence). The evidence is very uncertain about the risk of serious adverse events with combination sympathetic nerve blocks compared with single sympathetic nerve blocks due to limited reporting in the included studies (very low-certainty evidence). Secondary outcomes The evidence is very uncertain about the effect of combination sympathetic nerve blocks compared with single sympathetic nerve blocks on participant-reported pain score and change in daily consumption of opioids postprocedure, at 14 days. There may be a small to 'little to no' effect, but the evidence is very uncertain (very low-certainty evidence). There is no evidence about the effect on participant satisfaction with procedure at 0 to 7 days and time to need for retreatment or treatment effect failure (or both) due to these outcomes not being measured by the studies. Risk of bias The risk of bias was predominately high for most outcomes in most studies due to significant concerns regarding adequate blinding. Very few studies were deemed as low risk across all domains for any outcome. AUTHORS' CONCLUSIONS: There is limited evidence to support or refute the use of sympathetic nerve blocks for persistent abdominopelvic pain due to inoperable malignancy. We are very uncertain about the effect of combination sympathetic nerve blocks compared with single sympathetic nerve blocks. The certainty of the evidence is very low and these findings should be interpreted with caution.

Effect duration of lumbar sympathetic ganglion neurolysis in patients with complex regional pain syndrome: a prospective observational study.

Lumbar sympathetic ganglion neurolysis (LSGN) has been used for long-term pain relief in patients with complex regional pain syndrome (CRPS). However, the actual effect duration of LSGN has not been accurately measured. This prospective observational study measured the effect duration of LSGN in CRPS patients and investigated the relationship between temperature change and pain relief. After performing LSGN, the skin temperatures of both the maximum pain site and the plantar area in the affected and unaffected limbs were measured by infrared thermography, and pain intensity was assessed before and at 2 weeks, 1 month, and 3 months. The median time to return to baseline temperature was calculated using survival analysis. The skin temperature increased significantly at all-time points relative to baseline in both regions (maximum pain site: 1.4 °C ± 1.0 °C, plantar region: 1.28 °C ± 0.8 °C, all P < 0.001). The median time to return to baseline temperature was 12 weeks (95% confidence interval [CI] 7.7-16.3) at the maximum pain site and 12 weeks (95% CI 9.4-14.6) at the plantar area. Pain intensity decreased significantly relative to baseline, at all-time points after LSGN. In conclusion, the median duration of the LSGN is estimated to be 12 weeks.

Stellate Ganglion Block Therapy for Complex Regional Pain Syndrome: A Systematic Review and Meta-Analysis.

BACKGROUND: Sympathetic ganglion block (SGB) technique is becoming increasingly prevalent in the treatment of complex regional pain syndromes (CRPS). Given the varied reported effectiveness of these techniques and the heterogeneity of treatment regimens, there is an urgent need for consistent and high-quality evidence on the efficacy and safety of such procedures. OBJECTIVES: This study aimed to compare the efficacy of SGB therapy for CRPS-related pain. STUDY DESIGN: A meta-analysis of randomized controlled trials (RCTs). METHODS: PubMed, EMBASE, Web of Science, CINAHL, US National Institutes of Health Clinical Trials Registry, Google Scholar, and Cochrane Library Databases were systematically searched between January 1967 and April 2023. A meta-analysis of the included RCTs on SGB was conducted to evaluate the effectiveness and risk of bias (ROBs) of SGB. RESULTS: After screening 8523 records, 12 RCTs were included in this meta-analysis. Compared with controls, the visual analog pain score decreased by a weighted mean difference (WMD) of -6.24 mm (95% CI, -11.45, -1.03; P = 0.019) in the random-effects model, and the numerical scale score was reduced by a WMD of -1.17 mm (95% CI, -2.42, 0.08; P = 0.067) in the fixed-effects model, indicating a pain relief. The methodological quality of the included RCTs was high, with an average PEDro score of 7.0 (range: 5-9). LIMITATIONS: The number of included trials was limited. CONCLUSIONS: SGB therapy can reduce pain intensity in patients with CRPS with few adverse events. However, owing to the relatively high heterogeneity of the included RCTs, a larger sample of high-quality RCTs is needed to further confirm this conclusion.

Differential posttraumatic stress disorder symptom cluster response to stellate ganglion block: secondary analysis of a randomized controlled trial.

Empirically supported treatments for posttraumatic stress disorder (PTSD) exist, but research suggests these therapies are less effective, acceptable, and feasible to deliver to active duty service members (SMs) compared to civilians. Stellate ganglion block (SGB) procedure, in which a local anesthetic is injected around the cervical sympathetic chain or stellate ganglion to temporarily inhibit sympathetic nervous activity, is gaining popularity as an alternative PTSD treatment in military settings. However, it is unknown whether certain PTSD symptoms are more responsive to SGB than others. The current study involved a secondary analysis of data collected from a previous randomized controlled trial of SGB compared to sham (normal saline) injection (N = 113 SMs). PTSD symptoms were assessed via clinical interview and self-report at baseline and 8 weeks post-SGB or sham. Logistic regression analyses showed that the marked alterations in arousal and reactivity PTSD symptom cluster demonstrated the greatest symptom severity reductions after SGB, relative to sham. The reexperiencing cluster also showed pronounced response to SGB in clinician-rated but not self-reported outcomes. Post-hoc item-level analyses suggested that arousal and reactivity cluster findings were driven by reductions in hypervigilance, concentration difficulties, and sleep disturbance, whereas clinician-rated reexperiencing cluster findings were driven by reductions in physiological reactions to trauma cues, emotional reactions to trauma cues, and intrusions. Our findings align with a burgeoning literature positioning SGB as a potential novel or adjunctive PTSD treatment. Results could guide future hypothesis-driven research on mediators of therapeutic change during SGB for PTSD symptoms in SMs.

Efficacy of ganglion impar block combined with pudendal nerve pulsed radiofrequency for pudendal neuralgia management-a randomized clinical trial.

BACKGROUND: Pudendal neuralgia is a chronic and debilitating condition. Its prevalence ranges from 5 to 26%. Currently, therapeutic approaches to treat pudendal neuralgia include patient education, medication management, psychological and physical therapy, and procedural interventions, such as nerve block, trigger point injections, and surgery. Drug therapy has a limited effect on pain relief. A pudendal nerve block may cause a significant decrease in pain scores for a short time; however, its efficacy significantly decreases over time. In contrast, pudendal nerve pulsed radiofrequency can provide pain relief for 3 months, and ganglion impar block has been widely used for treating chronic perineal pain and chronic coccygodynia. This study aimed to determine the efficacy and safety of monotherapy (pudendal nerve pulsed radiofrequency) and combination therapy (pudendal nerve pulsed radiofrequency plus ganglion impar block) in patients with pudendal neuralgia. METHODS: This randomized, controlled clinical trial will include 84 patients with pudendal neuralgia who failed to respond to drug or physical therapy. Patients will be randomly assigned into one of the two groups: mono or combined treatment groups. The primary outcome will be a change in pain intensity measured using the visual analog scale. The secondary outcomes will include a Self-Rating Anxiety Scale score, Self-Rating Depression Scale score, the use of oral analgesics, the Medical Outcomes Study Health Survey Short Form-36 Item score, and the occurrence of adverse effects. The study results will be analyzed using intention-to-treat and per-protocol analyses. Primary and secondary outcomes will be evaluated between the mono and combined treatment groups. Subgroup analyses will be conducted based on the initial ailment, age, and baseline pain intensity. The safety of the treatment will be assessed by monitoring adverse events, which will be compared between the two groups. DISCUSSION: This study protocol describes a randomized, controlled clinical trial to determine the efficacy and safety of mono and combination therapies in patients with pudendal neuralgia. The study results will provide valuable information on the potential benefits of this combination therapy and contribute to the development of more effective and safer treatments for patients with pudendal neuralgia. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2200061800).

Efficacy of ultrasound-guided stellate ganglion block in relieving acute postoperative pain: a systematic review and meta-analysis.

OBJECTIVE: The efficacy of ultrasound-guided stellate ganglion block (SGB) in alleviating postoperative pain remains unclear. This meta-analysis was performed to determine the efficacy of ultrasound-guided SGB in relieving acute postoperative pain in patients undergoing surgery with general anesthesia. METHODS: This systematic review and meta-analysis focused on randomized controlled trials comparing SGB with control or placebo. The primary outcome was the pain score at 24 hours after surgery. A random-effects model was used to calculate the mean difference (MD) or risk ratio with a confidence interval (CI) of 95%. RESULTS: Eight studies involving 470 patients were included in the meta-analysis. The results revealed that ultrasound-guided SGB was significantly associated with a lower pain score at 24 hours after surgery (MD = -0.74; 95% CI = -1.39, -0.08; I2 = 86%; low evidence) and at 8 hours after surgery (MD = -0.65; 95% CI = -1.03, -0.28; I2 = 29%; moderate evidence). CONCLUSION: Ultrasound-guided SGB is effective in alleviating acute postoperative pain. However, considering the limited number of trials performed to date, more large-scale and high-quality randomized controlled trials are required to confirm these findings.

Clinical effect of perioperative stellate ganglion block on mechanical ventilation and respiratory function of elderly patients with septic shock.

BACKGROUND: Here we investigated the effect of a stellate ganglion block on the perioperative mechanical ventilation and postoperative recovery of respiratory function of elderly patients with infectious shock. METHODS: Thirty-six elderly patients with septic shock who underwent emergency general anesthesia at our hospital were randomly divided into treatment (T) and control (C) groups (n = 18 each). Group T received a preoperative stellate ganglion block, whereas group C received normal saline. Procalcitonin and C-reactive protein levels were compared preoperatively and at 1 and 7 days postoperative. Mean arterial pressure, oxygen saturation, and mean pulmonary artery pressure were measured preoperative and postoperative as well as at 1 and 7 days later. A blood gas analysis was performed preoperatively, at the end of the operation, during extubation, and at 1 and 7 days postoperative. Intubation under general anesthesia, the completion of anesthesia, and spontaneous respiratory recovery involve pulmonary dynamic compliance, plateau pressure, and mechanical ventilation. RESULTS: General condition did not differ significantly between groups (P > .05). However, mean arterial pressure at the end of surgery and at 1 and 7 days postoperative were significantly higher in group T versus C (P < .05). Furthermore, mean oxygen saturation at the end of surgery and at 1 and 7 days postoperative was significantly lower in group T versus C (P < .05), while procalcitonin and C-reactive protein levels were significantly lower at 1 and 7 days postoperative. Group T had significantly better arterial partial pressure of carbon dioxide, partial pressure of oxygen, and partial pressure of oxygen/fraction of inspired oxygen than group C at the end of surgery, during extubation, and at 1 and 7 days postoperative (P < .05). CONCLUSION: Group T exhibited superior inflammatory responses and respiratory function. Stellate ganglion block in elderly patients with septic shock reduces inflammation, improves mechanical ventilation perioperatively, and promotes postoperative recovery and respiratory function.

Retrospective Evaluation of the Effect of Lumbar Sympathetic Blockade on Pain Scores, Fontaine Classification, and Collateral Perfusion Status in Patients with Lower Extremity Peripheral Arterial Disease.

Background and Objectives: The aim of this retrospective study was to evaluate the effect of lumbar sympathetic block (LSB) on pain scores, Fontaine Classification, and collateral perfusion status in patients with lower extremity peripheral artery disease (PAD), in whom revascularization is impossible. Material and Methods: Medical records of 21 patients with PAD who underwent LSB with a combination of local anesthetics, steroids, and patient follow-up forms containing six-month follow-ups between January 2020 and March 2021 were retrospectively reviewed. Numeric Rating Scale (NRS), Pain Detect Questionnaire (PDQ) scores, Fontaine Classification Stages, and collateral perfusion status (collateral diameter and/or development of neovascularization) evaluated by arterial color Doppler Ultrasound (US) from the medical records and follow-up forms of the patients were reviewed. Results: NRS and PDQ scores were significantly lower, and regression of the Fontaine Classification Stages was significantly better after the procedure at the first, third, and sixth month than at the baseline values (p < 0.001). Only four patients (19%) had collaterals before the procedure. An increase in the collateral diameter after LSB was noted in three out of four patients. Before the procedure, 17 patients had no prominent collateral. However, in thirteen of these patients, after LSB, neovascularization was detected during the six-month follow-up period (three patients in the first month, seven patients in the third month, and thirteen patients in the sixth month). The number of patients evolving neovascularization after LSB was found to be statistically significant at the third and sixth months compared to the initial examination (p < 0.001). Conclusions: LSB with the use of local anesthetic and steroids in patients with lower extremity PAD not only led to lower NRS and PDQ scores, but also resulted in regressed Fontaine Classification Stages and better collateral perfusion status.

Cease the storm - Successful stellate ganglion block in terminating refractory electrical storm.

An electrical storm also known as a ventricular tachycardia storm (VT storm) tends to recur and form a vicious cycle, eventually leading to a refractory electrical storm, refractory to electrical and pharmacological cardioversion. The treatment of refractory VT storm is challenging. Here we discuss the case of a middle-aged gentleman who presented to our emergency department 6 months apart with a refractory VT storm. When all the anti-arrhythmic agents and multiple cardioversion attempts failed in terminating the storm, we attempted ultrasound-guided stellate ganglion block. On both occasions, it successfully terminated the storm. Hence emergency physicians need to be aware of the right technique and timing of stellate ganglion block and ultrasound-guided needle tracking, as it can be a final rescue technique in treating refractory electrical storm in the emergency department.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias.

BACKGROUND: Ventricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry. OBJECTIVES: This study examined the efficacy of SGB for treatment/temporization of refractory VT/VF. METHODS: The authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB. RESULTS: In total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001). CONCLUSIONS: In the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients.

BACKGROUND: Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects. OBJECTIVES: The authors sought to describe the safety and efficacy of PICB in patients with refractory ES. METHODS: We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes. RESULTS: A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed. CONCLUSIONS: In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

Stellate ganglion block for treating post-COVID-19 parosmia.

BACKGROUND: Post-COVID parosmia may be due to dysautonomia and sympathetic hyperresponsiveness, which can be attenuated by stellate ganglion block (SGB). This study evaluates SGB as a treatment for post-COVID olfactory dysfunction (OD). METHODS: Retrospective case series with prospective data of patients with post-COVID OD undergoing unilateral (UL) or bilateral (BL) SGB. Patients completed Brief Smell Identification Tests (BSIT) (12 points maximum) and post-procedure surveys including parosmia severity scores on a scale of 1 (absent) to 10 (severe). Scores were compared from before treatment (pre-SGB) to after first (SGB1) or second (SGB2) treatments in overall, UL, and BL cohorts. RESULTS: Forty-seven patients with post-COVID OD underwent SGB, including 23 UL and 24 BL. Twenty patients completed pre- and post-SGB BSITs (eight UL and 12 BL). Twenty-eight patients completed postprocedure surveys (11 UL and 17 BL). There were no differences in BSIT scores from pre-SGB to post-SGB1 or post-SGB2 for the overall (p = 0.098), UL (p = 0.168), or BL (p = 0.230) cohorts. Parosmia severity for the overall cohort improved from pre-SGB (8.82 ± 1.28) to post-SGB1 (6.79 ± 2.38) and post-SGB2 (5.41 ± 2.35), with significant differences from pre-SGB to post-SGB1 (p < 0.001) and pre-SGB to post-SGB2 (p < 0.001), but not post-SGB1 to post-SGB2 (p = 0.130). Number of parosmia triggers decreased for overall (p = 0.002), UL (p = 0.030) and BL (p = 0.024) cohorts. Quality of life (QOL) improved for all cohorts regarding food enjoyment, meal preparation, and socialization (p < 0.05). CONCLUSION: SGB may improve subjective parosmia and QOL for patients with post-COVID OD, however it may not affect odor identification. Further placebo-controlled studies are warranted.

Stellate ganglion block for the management of electrical storm: An observational study.

INTRODUCTION: Electrical storm is a life-threatening emergency with a high mortality rate. When acute conventional treatment is ineffective, stellate ganglion block can help control arrhythmia by providing a visceral cervicothoracic sympathetic block. The objective of this study is to assess the effectiveness and safety of stellate ganglion block in the management of refractory arrhythmic storm. METHOD: Follow-up of a cohort of patients with refractory electrical storm that met the criteria for performing stellate ganglion block. The block was ultrasound-guided at C6 using local anaesthetic and a steroid - left unilateral first, bilateral if no response, followed by fluoroscopy-guided radiofrequency ablation at C7 if there was a favourable response but subsequent relapse. RESULTS: Seven patients were included. The in-hospital mortality rate was 14.29%. Four patients received unilateral and 3 bilateral stellate ganglion block. Six were ablated and 1 received an implantable cardioverter-defibrillator. Electrical storm was controlled temporarily beyond the effect of the local anaesthetic in all patients. Three patients underwent radiofrequency ablation and 2 underwent surgical thoracic sympathectomy. The only side effect was Horner's syndrome, which was observed in all cases after administering a stellate ganglion block with local anaesthetic. Two patients died after discharge and 4 are alive at the time of writing, 3 of them have not been re-admitted for ventricular events for more than 2 years. CONCLUSION: Ultrasound-guided stellate ganglion block is an effective and safe complement to standard cardiological treatment of refractory electrical storm.