Ultrasound-Guided Suprazygomatic Sphenopalatine Ganglion Block for Postdural Puncture Headache Resistant to Epidural Blood Patch: A Case Report.

Even though epidural blood patch (EBP) is thought to be the definitive treatment for severe cases of postdural puncture headache (PDPH), it may be accompanied by complications like adhesion arachnoiditis, and cauda equina syndrome, especially if the injection is repeated. The sphenopalatine ganglion (SPG) block is a new minimally invasive technique for the treatment of PDPH, with variable results according to the clinical situation and deployed approach. We describe a case of PDPH resistant to EBP in which we successfully managed symptoms using ultrasound-guided suprazygomatic SPG block to deliver local anesthetic directly into pterygopalatine fossa, thus avoiding a second EBP.

[Sphenopalatine ganglion block : a promising approach for headache and supratentorial intracranial surgery ?] / Le bloc du ganglion sphénopalatin : un traitement prometteur pour les céphalées et la chirurgie intracrânienne supratentorielle ?

We aimed to determine whether sphenopalatine ganglion block (SPGB) had a place as a treatment for headache, as well as its place as an anterior component of scalp block for supratentorial intracranial surgery. Using the keywords «sphenopalatine ganglion¼, «sphenopalatine ganglion block¼, «pain¼, «surgery¼ and «craniotomy¼ in PubMed and Google Scholar, we identified 14 relevant articles. The methods used to perform the block and the treatment of control groups differed between studies. The main outcomes studied were reduction in pain scores and hemodynamic variations during supratentorial intracranial surgery. All articles concluded that SPGB was equal or superior compared with other procedures. Although there are still several points to be studied, considering the ease of application, the low number of complications and the results of the studies, the use of SPGB for the headache treatment and in neurosurgery as an anterior component of scalp block seems appropriate.

Cette revue de la littérature narrative vise à déterminer la place du bloc du ganglion sphénopalatin (BGSP) comme traitement des céphalées ainsi que sa place comme composante antérieure du bloc de scalp pour la chirurgie intracrânienne supratentorielle. Avec les mots-clés «ganglion sphénopalatin¼, «bloc du ganglion sphénopalatin¼, «douleur¼, «chirurgie¼ et «crâniotomie dans PubMed et Google Scholar, nous avons identifié 14 articles pertinents. Les méthodes de réalisation du bloc ainsi que les traitements des groupes témoins différaient selon les études. Les résultats principaux étudiés étaient la réduction des scores de douleur ainsi que les variations hémodynamiques au cours de la chirurgie intracrânienne supratentorielle. Tous les articles ont conclu à la non-infériorité ou la supériorité du BGSP en comparaison à d'autres procédures. Bien que plusieurs points restent à étudier, compte tenu de la facilité d'application, du peu de complications et des résultats, l'utilisation du BGSP pour le traitement des céphalées et en neurochirurgie comme composante antérieure du bloc de scalp semble appropriée.

Intranasal sphenopalatine ganglion block by lignocaine spray for postdural puncture headache following spinal anesthesia: a randomized clinical trial.

INTRODUCTION: In a randomized clinical study, we investigated the effectiveness of nasal lignocaine spray and swabs in treating postdural puncture headache (PDPH) after spinal anesthesia. MATERIAL AND METHODS: Group S patients received two puffs of lignocaine 10% spray in both nostrils followed by cotton soaked in normal saline, and group B patients received two puffs of saline spray in both nostrils followed by a cotton swab soaked in lignocaine 2%. Patients were assessed before the procedure and 30 minutes, 60 minutes, 2 h, 24 h, 48 h, and 72 h after the procedure for pain relief with the help of a visual analogue scale (VAS). Hemodynamic parameters and adverse effects were also recorded. Normally distributed continuous variables were expressed as mean (95% confidence interval) whereas non-normally distributed variables were expressed as median (IQR). Repeated measures analysis of variance was used to compare the VAS score at different time points between test and control groups. The difference in means between the two groups was compared using the independent sample t -test. The paired t-test was used to compare the changes in clinical and laboratory variables. RESULTS: At each time point, the mean VAS score for pain was substantially different between the two groups. Moreover, until the second hour, the VAS score was significantly lower in group S than in group B. No significant intervention-related adverse effect was observed in either group. CONCLUSIONS: Without any noticeable side effects, lignocaine 10% spray is more successful in treating PDPH after spinal anesthesia, particularly in the first two hours.

Trans-nasal sphenopalatine ganglion block for post-dural puncture headache management: a meta-analysis of randomized trials

Abstract Objective: To evaluate the efficacy and safety of trans-nasal Sphenopalatine Ganglion (SPG) block over other treatments for Post-Dural Puncture Headache (PDPH) management. Methods: A systematic literature search was conducted on databases for Randomized Controlled Trials (RCTs) comparing trans-nasal SPG blockade for the management of PDPH over other treatment modalities. All outcomes were pooled using the Mantel-Haenszel method and random effect model. Analyses of all outcomes were performed as a subgroup based on the type of control interventions (conservative, intranasal lignocaine puffs, sham, and Greater Occipital Nerve [GON] block). The quality of evidence was assessed using the GRADE approach. Results: After screening 1748 relevant articles, 9 RCTs comparing SPG block with other interventions (6 conservative treatments, 1 sham, 1 GON and 1 intranasal lidocaine puff) were included in this meta-analysis. SPG block demonstrated superiority over conservative treatment in pain reduction at 30 min, 1 h, 2 h, 4 h after interventions and treatment failures with "very low" to "moderate" quality of evidence. The SPG block failed to demonstrate superiority over conservative treatment in pain reduction beyond 6 h, need for rescue treatment, and adverse events. SPG block demonstrated superiority over intranasal lignocaine puff in pain reduction at 30 min, 1 h, 6 h, and 24 h after interventions. SPG block did not show superiority or equivalence in all efficacy and safety outcomes as compared to sham and GON block. Conclusion: Very Low to moderate quality evidence suggests the superiority of SPG block over conservative treatment and lignocaine puff for short-term pain relief from PDPH. PROSPERO Registration: CRD42021291707.

Trans-nasal sphenopalatine ganglion block for post-dural puncture headache management: a meta-analysis of randomized trials.

OBJECTIVE: To evaluate the efficacy and safety of trans-nasal Sphenopalatine Ganglion (SPG) block over other treatments for Post-Dural Puncture Headache (PDPH) management. METHODS: A systematic literature search was conducted on databases for Randomized Controlled Trials (RCTs) comparing trans-nasal SPG blockade for the management of PDPH over other treatment modalities. All outcomes were pooled using the Mantel-Haenszel method and random effect model. Analyses of all outcomes were performed as a subgroup based on the type of control interventions (conservative, intranasal lignocaine puffs, sham, and Greater Occipital Nerve [GON] block). The quality of evidence was assessed using the GRADE approach. RESULTS: After screening 1748 relevant articles, 9 RCTs comparing SPG block with other interventions (6 conservative treatments, 1 sham, 1 GON and 1 intranasal lidocaine puff) were included in this meta-analysis. SPG block demonstrated superiority over conservative treatment in pain reduction at 30 min, 1 h, 2 h, 4 h after interventions and treatment failures with "very low" to "moderate" quality of evidence. The SPG block failed to demonstrate superiority over conservative treatment in pain reduction beyond 6 h, need for rescue treatment, and adverse events. SPG block demonstrated superiority over intranasal lignocaine puff in pain reduction at 30 min, 1 h, 6 h, and 24 h after interventions. SPG block did not show superiority or equivalence in all efficacy and safety outcomes as compared to sham and GON block. CONCLUSION: Very Low to moderate quality evidence suggests the superiority of SPG block over conservative treatment and lignocaine puff for short-term pain relief from PDPH. PROSPERO REGISTRATION: CRD42021291707.

Sphenopalatine ganglion block - a new treatment for burning mouth syndrome?: a case report

Abstract Burning mouth syndrome is a poorly understood entity for which current treatment modalities fail to provide effective relieve. Branches of the maxillary and mandibular nerves are responsible for the innervation of the affected area. These are also the nerves involved in trigeminal neuralgia, an entity where sphenopalatine block has proved to be effective. We present a case of a patient with burning mouth syndrome in whom a bilateral sphenopalatine ganglion block was successfully performed for pain treatment. It is an easy and safe technique that can be a valuable treatment option for these patients, although more studies are needed.

Early versus late sphenopalatine ganglion block with ropivacaine in postdural puncture headache: an observational study

Abstract Background Postdural puncture headache (PDPH) is a common complication of neuraxial techniques which delays patients' discharge. Sphenopalatine ganglion block (SPGB) is a safe bedside technique with comparable efficacy to Epidural Blood Patch, the gold-standard treatment. There is no evidence on the ideal timing for SPGB performance. We aimed to evaluate the difference between early versus late SPGB concerning efficacy, symptom recurrence and hospital length of stay. Methods We present an observational study with 41 patients diagnosed with PDPH who were submitted to SPGB with ropivacaine 0,75%. The study sample (n = 41) was divided in two groups: an early (less than 24 hours after diagnosis) and a late (more than 24 hours after diagnosis) SPGB group. Pain was evaluated 15 minutes after the block and follow up occurred daily until patients were discharged. Patients' demographic characteristics, neuraxial technique, timing of SPGB, qualitative pain relief and post-SPGB length of stay were registered and analyzed with SPSS statistics (v26) software. Results Early SPGB resulted in a significant reduction in length of stay (p = 0,009) and symptom recurrence (p = 0,036), showing equally effective pain relief, compared to late SPGB. Conclusions SPGB was equally effective in both groups. Data showed that early SPGB reduces length of hospital stay and symptom recurrence, which potentially allows early resumption of daily activities and a reduction in total health costs.

Effect of neuropathic pain on sphenopalatine ganglion block responses in persistent idiopathic facial pain.

OBJECTIVES: Management of persistent idiopathic facial pain (PIFP) can be challenging. Sphenopalatine ganglion (SPG) has been the target for the interventional treatment of many facial pain syndromes. However, possible factors that may affect SPG block success are unknown. It was aimed to investigate the effect of neuropathic pain on SPG block outcomes in PIFP, which includes a heterogeneous patient group. METHODS: All of the patients underwent fluoroscopy-guided SPG block with an injection of 40 mg of 2% lidocaine and 8 mg of dexamethasone. The patients were assigned to 2 groups according to existence of neuropathic pain determined with the DN4 questionnaire score: 19 patients with neuropathic pain (Group 1) and 15 patients without neuropathic pain (Group 2). Preprocedural and postprocedural Visual Analog Scale (VAS) scores were compared between the 2 groups. RESULTS: The mean age of the patients was 47.65 ± 6.50 years. The average pain duration was 52.95 ± 34.81 weeks. A significantly greater decrease was detected in the VAS scores at 1 week (p = 0.036) and 1 month (p < 0.001) in Group 1 when compared to Group 2. Moreover, the proportion of patients with >50% improvement in the VAS scores at 1 week (p = 0.012) and 1 month (P = 0.017) was significantly lower in Group 1 than in Group 2. DISCUSSION: SPG block appears as a safe, effective, and rapid method to treat PIFP, especially in cases with neuropathic pain. Neuropathic pain may be a predictor for pain relief in interventional procedures targeting SPG in the treatment of PIFP.

Sphenopalatine ganglion block ... a new treatment for burning mouth syndrome?: a case report.

Burning mouth syndrome is a poorly understood entity for which current treatment modalities fail to provide effective relieve. Branches of the maxillary and mandibular nerves are responsible for the innervation of the affected area. These are also the nerves involved in trigeminal neuralgia, an entity where sphenopalatine block has proved to be effective. We present a case of a patient with burning mouth syndrome in whom a bilateral sphenopalatine ganglion block was successfully performed for pain treatment. It is an easy and safe technique that can be a valuable treatment option for these patients, although more studies are needed.

Early versus late sphenopalatine ganglion block with ropivacaine in postdural puncture headache: an observational study.

BACKGROUND: Postdural puncture headache (PDPH) is a common complication of neuraxial techniques which delays patients.ÇÖ discharge. Sphenopalatine ganglion block (SPGB) is a safe bedside technique with comparable efficacy to Epidural Blood Patch, the gold-standard treatment. There is no evidence on the ideal timing for SPGB performance. We aimed to evaluate the difference between early versus late SPGB concerning efficacy, symptom recurrence and hospital length of stay. METHODS: We present an observational study with 41 patients diagnosed with PDPH who were submitted to SPGB with ropivacaine 0,75%. The study sample (n=41) was divided in two groups: an early (less than 24hours after diagnosis) and a late (more than 24hours after diagnosis) SPGB group. Pain was evaluated 15minutes after the block and follow up occurred daily until patients were discharged. PATIENTS: ÇÖ demographic characteristics, neuraxial technique, timing of SPGB, qualitative pain relief and post-SPGB length of stay were registered and analyzed with SPSS statistics (v26) software. RESULTS: Early SPGB resulted in a significant reduction in length of stay (p=0,009) and symptom recurrence (p=0,036), showing equally effective pain relief, compared to late SPGB. CONCLUSIONS: SPGB was equally effective in both groups. Data showed that early SPGB reduces length of hospital stay and symptom recurrence, which potentially allows early resumption of daily activities and a reduction in total health costs.

[Chronic headaches due to idiopathic cerebrospinal fluid hypotension treated with sphenopalatine ganglion block]. / Céphalées chroniques sur hypotension de liquide céphalorachidien idiopathique traitées par bloc sphénopalatin.

Sphenopalatine ganglion block (SPGB) is a well-known technique of anesthesia used for the treatment of many types of facial pain syndromes. Its utility in the treatment of headaches due to cerebrospinal fluid hypotension, caused by dural breach or not, seems established but the lack of strong studies proving its efficacy or its superiority compared to epidural blood patch doesn't allow it, for now, to be a part of the official treatment algorithm. We report the case of a patient presenting idiopathic cerebrospinal hypotension (Schaltenbrand syndrome) treated effectively with a sphenopalatine ganglion block using the intranasal approach.

Le bloc du ganglion sphénopalatin (BGSP) est une technique d'anesthésie connue de longue date et utilisée comme proposition de traitement dans de nombreux types de syndromes d'algie de la face. Son utilité dans le traitement des céphalées sur hypotension de liquide céphalorachidien, causées ou non par une brèche durale, semble établie. Cependant, l'absence d'études solides démontrant son efficacité ou sa supériorité par rapport au «blood patch¼ épidural ne permet pas, à l'heure actuelle, de lui donner une place précise dans l'algorithme de prise en charge. Nous rapportons le cas d'un patient présentant un syndrome d'hypotension intracrânienne idiopathique ou spontanée (syndrome de Schaltenbrand) ayant bénéficié d'un traitement efficace par bloc du ganglion sphénopalatin par voie intra-nasale.

Transnasal Sphenopalatine Ganglion Block for Management of Postdural Puncture Headache in Non-Obstetric Patients.

BACKGROUND: This study investigated the efficacy and safety of transnasal sphenopalatine ganglion block (SPGB) for treatment of postural puncture headache (PDPH) in non-obstetric patients. METHODS: This retrospective study was conducted at the Ankara Research and Educational Hospital, in Turkey, and included 26 non-obstetric patients (age, ≥18 years) who were diagnosed with PDPH and unresponsive to conservative therapy or unable to continue it because of side effects. Transnasal SPGB was performed in each nostril. Pain severity was assessed with the Visual Analogue Scale (VAS) at 15 min, 30 min, 24 h, and 48 h after the procedure, while patients were seated. The patients were monitored for 48 h for adverse effects (AEs). Patient treatment satisfaction was assessed at 48 h after the procedure by using the Patient Global Impression of Change (PGIC) scale. RESULTS: Headache at 15 min post-procedure was relieved rapidly. At 24 h post-procedure, nearly half of patients (42.3%) had no pain, and all patients (100%) had a VAS score of <3. Nasal discomfort, throat numbness, and nausea were AEs reported after SPGB; however, these AEs were completely relieved at 24 h after the procedure. According to the PGIC scale scores at 48 h post-procedure, 73.1% of patients evaluated themselves as "much improved" and 26.9% evaluated themselves as "very much improved". CONCLUSION: When PDPH does not respond to conservative treatment, it may be treated effectively with transnasal SPGB, which is a noninvasive, safe, well-tolerated, and straightforward method with a low complication rate.

Sphenopalatine Ganglion Nerve Block for the Treatment of Migraine Headaches in the Pediatric Population.

BACKGROUND: Persistent headaches and migraines are common in pediatrics with various treatment options. The sphenopalatine ganglion (SPG) has been identified as communicating with the parasympathetic autonomic nervous system and pain receptors. In adults, SPG block is an established treatment but there is no published literature in pediatrics. OBJECTIVES: The purpose of this study is to analyze the SPG block in pediatrics. STUDY DESIGN: Retrospective, single-center study. SETTING: This study was conducted at Phoenix Children's Hospital in Phoenix, Arizona. METHODS: A comprehensive review of patient charts from 2015-2018 of all pediatric SPG blockades performed by interventional radiology were included in the analysis. Utilizing fluoroscopic guidance, a SphenoCath was inserted into each nostril and after confirming position, and 4% lidocaine injected. Pre- and postprocedural pain was assessed using the Visual Analog Scale (VAS). Immediate and acute complications were documented. RESULTS: A total of 489 SPG blocks were performed in patients between ages 6 and 26 years who were diagnosed with migraine or status migrainosus. One hundred percent technical success was achieved with mean reduction of pain scores of 2.4, which was statistically significant (P < 0.0001). There were no immediate or acute complications. LIMITATIONS: Results of this study were based on retrospective study. The use of VAS may be subjective, and the need of a prospective study may be necessary. CONCLUSIONS: With 100% technical success, statistically significant pain reduction, and no complications, we support SPG block in the pediatric population as a simple, efficacious, and safe treatment option for refractory headaches. It is routinely performed in less than 10 minutes and commonly negates the need for inpatient headache pain management. Given its minimal invasivity, we support the use of SPG blockade as a therapeutic treatment in refractory pediatric migraines as it reduces the need for intravenous medications, prolonged pain control, or hospital admission.

Interventional Procedures in Episodic Migraine.

PURPOSE OF REVIEW: Migraine is a common disorder which in many cases can be adequately treated with medications. However, there are some patients who may either not respond to medications or have contraindications to their use. In this review, we will evaluate the available literature on the interventional procedures available to treat patients with episodic migraine. We will review the technical details of performing the procedures, the potential mechanisms of action, and available data on their effectiveness. RECENT FINDINGS: Recent studies conducted on the subject of interventional procedures including peripheral nerve blocks and onabotulinumtoxinA indicate that some patients with episodic migraine may find benefit from such procedures. In patients with episodic migraine whom traditional treatments have not been effective or are contraindicated, interventional procedures may offer an opportunity to provide additional treatment options.

Acute effect of sphenopalatine ganglion block with lidocaine in a patient with SUNCT.

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing/short-lasting unilateral neuralgiform headache with cranial autonomic features (SUNCT/SUNA) is a rare severe headache. At the time of an attack, it can hinder a patient from eating and requires acute intervention. The sphenopalatine ganglion is an extracranial parasympathetic ganglion with both sensory and autonomic fibers. Sphenopalatine ganglion block has long been used in the treatment of headache, particularly when conventional methods have failed. Here, we present a patient who was resistant to intravenous lidocaine, but responded rapidly to sphenopalatine ganglion block during an acute episode of SUNCT/SUNA.

[Self-applied sphenopalatine ganglion block for postdural puncture headache: four case reports]. / Bloqueio do gânglio esfenopalatino autoaplicado para cefaleia pós­punção dural: relato de quatro casos.

BACKGROUND AND OBJECTIVES: The Sphenopalatine Ganglion Block (SGB) is an effective, low-risk treatment option for Postdural Puncture Headache (PDPH) refractory to conservative management. CASE REPORT: This report presents four complex cases of patients with headache related to low cerebrospinal fluid pressure. Three of them were successfully treated with the application of local anesthetic topical drops through the nasal cavity. CONCLUSION: The novel approach described in this report has minimal risks of discomfort or injury to the nasal mucosa. It is quick to apply and can be administered by the patient himself.

Self-applied sphenopalatine ganglion block for postdural puncture headache: four case reports / Bloqueio do gânglio esfenopalatino autoaplicado para cefaleia pós-punção dural: relato de quatro casos

Abstract Background and objectives The Sphenopalatine Ganglion Block (SGB) is an effective, low-risk treatment option for Postdural Puncture Headache (PDPH) refractory to conservative management. Case report This report presents four complex cases of patients with headache related to low cerebrospinal fluid pressure. Three of them were successfully treated with the application of local anesthetic topical drops through the nasal cavity. Conclusion The novel approach described in this report has minimal risks of discomfort or injury to the nasal mucosa. It is quick to apply and can be administered by the patient himself.

Resumo Justificativa e objetivos: O Bloqueio do Gânglio Esfenopalatino (BGEP) é opção de tratamento efetivo associado a baixo risco para Cefaleia Pós-Punção Dural (CPPD) refratária às medidas conservadoras. Relato de caso: Este relato apresenta quatro pacientes com alta complexidade que apresentaram cefaleia relacionada à baixa pressão do líquido cefaloraquidiano. Três pacientes foram tratados com sucesso pela instilação de gotas de anestésico local tópico na cavidade nasal. Conclusões: A nova abordagem descrita neste relato apresenta riscos mínimos de desconforto ou lesão à mucosa nasal. A aplicação é rápida e pode ser administrada pelo próprio paciente.

Lidocaine Versus Bupivacaine in the Treatment of Headache with Intranasal Sphenopalatine Nerve Block.

BACKGROUND: Intranasal sphenopalatine ganglion (SPG) block has been shown to be an effective treatment for headaches. Multiple therapeutic agents have been studied, although the wide availability and low cost of lidocaine and bupivacaine have made them attractive treatment options. To the authors knowledge, no study has yet demonstrated superiority of one anesthetic over the other. OBJECTIVE: To determine the efficacy of lidocaine versus bupivacaine when performing intranasal sphenopalatine ganglion (SPG) block for the treatment of headaches. STUDY DESIGN: Retrospective cohort study. SETTING: A single tertiary care academic institutionMETHODS: This retrospective study identified patients who underwent SPG block at a single institution from January 1, 2014 to December 20, 2017. Patients were included if they were treated with either lidocaine or bupivacaine and had both pre- and post-procedure pain scores recorded on a 0-10 scale. Patients were excluded if they were less than 18 years of age. RESULTS: 386 total procedures were performed. 303 (78.5%) were lidocaine delivered via the SphenoCath device, and 83 (21.5%) were bupivacaine delivered via the Tx360 device. 90.2% of treatments (n = 348) decreased the patient's pain level. Of the treatments performed with lidocaine, 89.1% (n = 270) resulted in improvement of the patient's pain level with a mean decrease in pain level of 3.1 (SD ± 2.3). Of the treatments performed with bupivacaine, 94.0% (n = 78) resulted in improvement of the patient's pain level, with a mean decrease in pain level of 3.0 (SD ± 1.9). No statistically significant difference was found between the 2 anesthetics. LIMITATIONS: The retrospective study design may introduce selection bias. Both lidocaine and bupivacaine were administered by different devices (Sphenocath and Tx360 respectively) which may account for differences in initial treatment success. There were differences in the size of the two groups, which may also introduce error. CONCLUSIONS: This study demonstrates similar efficacy of SPG block performed with lidocaine or bupivacaine. While no difference was found, the particular advantages and disadvantages of the intranasal delivery device may influence physician choice. KEY WORDS: Sphenopalatine ganglion nerve block, lidocaine, bupivacaine, sphenocath, Tx360, pain intervetnio, headache, miimally invasive therapy.

Sphenopalatine ganglion block for the treatment of postdural puncture headache: a randomised, blinded, clinical trial.

BACKGROUND: Current treatment of postdural puncture headache includes epidural blood patch (EBP), which is invasive and may result in rare but severe complications. Sphenopalatine ganglion block is suggested as a simple, minimally invasive treatment for postdural puncture headache. We aimed to investigate the analgesic effect of a transnasal sphenopalatine ganglion block with local anaesthetic vs saline. METHODS: We conducted a blinded, randomised clinical trial including adults fulfilling the criteria for EBP. Participants received a sphenopalatine ganglion block bilaterally with 1 ml of either local anaesthetic (lidocaine 4% and ropivacaine 0.5%) or placebo (saline). Primary outcome was pain in upright position 30 min post-block, measured on a 0-100 mm VAS. RESULTS: We randomised 40 patients with an upright median pain intensity of 74 and 84 mm in the local anaesthetic and placebo groups at baseline, respectively. At 30 min after sphenopalatine ganglion block, the median pain intensity in upright position was 26 mm in the local anaesthetic group vs 37 mm in the placebo group (estimated median difference: 5 mm; 95% confidence interval: -14 to 21; P=0.53). In the local anaesthetic group, 50% required an EBP compared with 45% in the placebo group (P=0.76). CONCLUSIONS: Administration of a sphenopalatine ganglion block with local anaesthetic had no statistically significant effect on pain intensity after 30 min compared with placebo. However, pain was reduced and EBP was avoided in half the patients of both groups, which suggests a major effect not necessarily attributable to local anaesthetics. CLINICAL TRIAL REGISTRATION: NCT03652714.