Early stellate ganglion block for improvement of postoperative cerebral blood flow velocity after aneurysmal subarachnoid hemorrhage: results of a pilot randomized controlled trial.

OBJECTIVE: Stellate ganglion block (SGB) is a commonly used sympathetic nerve block technique that may have benefits for patients with aneurysmal subarachnoid hemorrhage (aSAH) in the early stage. Cerebral vasospasm (CVS), one of the most common complications of aSAH, is accompanied by an abnormal increase in cerebral blood flow velocity (CBFV) and neurological dysfunction. In this pilot study the authors sought to determine the feasibility of early SGB for CVS in aSAH patients by observing the incidence of symptomatic CVS. METHODS: Prior to receiving surgical treatment, patients with aSAH were randomly assigned to the SGB group or the non-SGB group. The primary outcome was the incidence of symptomatic CVS within 14 ± 2 days after the onset of aSAH. As a higher CBFV is often associated with CVS and a poor prognosis, the mean CBFV of the middle cerebral artery was observed immediately after surgery and on postoperative days 1, 2, 3, 5, and 7. Other secondary outcomes included transcranial Doppler (TCD)/CTA-type CVS, delayed cerebral ischemia during hospitalization, new cerebral infarction within 3 months, adverse events (AEs), and clinical prognosis. RESULTS: Symptomatic CVS occurred in 40% of patients in the non-SGB group and in 20% in the SGB group (RR 0.50, 95% CI 0.22-1.16). Continuous TCD sonography revealed that the postoperative mean CBFV was lower in the SGB group than in the non-SGB group (F = 3.608, p = 0.02). In addition, the percentages of patients with CVS evaluated by TCD (TCD-CVS) and total new infarctions within 3 months were also significantly lower than those in patients with CVS (TCD-CVS 36.7% vs 70%, RR 0.52, 95% CI 0.31-0.89, and total new infarctions 26.7% vs 53.3%, RR 0.50, 95% CI 0.25-0.99). In terms of AEs and mortality, there were no significant differences between the two groups. CONCLUSIONS: This pilot study demonstrated for the first time, to the authors' knowledge, that early SGB is feasible and has the potential to reduce the risk of CVS and improve the prognosis of aSAH. This method may be a new treatment for patients with aSAH that may have more advantages than traditional therapeutic drugs and is worth further study. Clinical trial registration no.: NCT04691271 (ClinicalTrials.gov).

Utility of Cervical Sympathetic Block in Treating Post-Traumatic Stress Disorder in Multiple Cohorts: A Retrospective Analysis.

BACKGROUND: Post-traumatic stress disorder (PTSD) is a prevalent and debilitating condition in the United States. Success rates for evidence-based therapies are inconsistent, and many suffer in silence due to the stigmata associated with seeking traditional mental health care. This has led clinicians to explore new therapeutic options, with cervical sympathetic blockade (CSB), performed at the stellate and/or superior cervical ganglion levels, recently emerging as a promising treatment option. Rapid therapeutic onset, improved compliance, and high clinical efficacy rates have made this an attractive approach for both providers and patients. However, to date, CSB as a treatment of PTSD has primarily been used in male patients with military-related trauma. OBJECTIVE: To evaluate the efficacy of CSB as a treatment option for PTSD in both genders and multiple etiologies of psychological trauma. STUDY DESIGN: Retrospective cohort study. SETTING: An established anesthesia pain clinic in Chicago, IL, USA. METHODS: Following retroactive IRB approval, 484 consecutive cases of patients diagnosed with PTSD and treated with CSB, performed by a single provider (December 2016 - February 2020) were analyzed. The primary outcome measurement was the PTSD Checklist Score version DSM IV (PCL-4). Patient demographic and clinical information collected included age, gender, type of trauma leading to PTSD, history of suicidal attempts, and psychiatric medication use. RESULTS: After exclusion of cases due to missing data points, 327 patients were included in the final statistical analysis, having completed both PCL-4 pre and post CSB, between 7- and 30-days post-intervention. The patient population included military men (n = 97), civilian men (n = 85), military women (n = 13) and civilian women (n = 132). We identified 21 types of self-reported trauma leading to PTSD. Average decrease in PCL score for men and women was 28.59 and 29.2, respectively. Statistical analysis of the male population with a military background showed a significantly greater change in corresponding PCL scores than civilians (PCL-M change = -31.83 vs PCL-C change = -24.89). Likewise, women who had a military background had a significantly greater reduction in PCL score than civilians (39.15 vs 28.23). Statistically significant improvements in PTSD symptoms were noted independent of the causative trauma type, gender, age greater than 20, previous suicide attempts, or use of prescription medications for PTSD. Among the 21 types of reported trauma, 19 types reached statistical significance. LIMITATIONS: Limitations include the limited scope of observation giving exclusive focus on pre- and post-PCL data, the limited duration of observation, the self-reported nature of the patient-provided data, and the provision of treatment by a single physician. CONCLUSION: CSB seems to be an effective treatment for PTSD symptoms irrespective of gender, trauma type, PTSD-related drug use, suicide attempt, or age.

Peripheral Nerve Blocks and Potentially Attributable Adverse Events in Older People with Hip Fracture: A Retrospective Population-based Cohort Study.

BACKGROUND: Peripheral nerve blocks are being used with increasing frequency for management of hip fracture-related pain. Despite converging evidence that nerve blocks may be beneficial, safety data are lacking. This study hypothesized that peripheral nerve block receipt would not be associated with adverse events potentially attributable to nerve blocks, as well as overall patient safety incidents while in hospital. METHODS: This was a preregistered, retrospective population-based cohort study using linked administrative data. This study identified all hip fracture admissions in people 50 yr of age or older and identified all nerve blocks (although we were unable to ascertain the specific anatomic location or type of block), potentially attributable adverse events (composite of seizures, fall-related injuries, cardiac arrest, nerve injury), and any patient safety events using validated codes. The study also estimated the unadjusted and adjusted association of nerve blocks with adverse events; adjusted absolute risk differences were also calculated. RESULTS: In total, 91,563 hip fracture patients from 2009 to 2017 were identified; 15,631 (17.1%) received a nerve block, and 5,321 (5.8%; 95% CI, 5.7 to 6.0%) patients experienced a potentially nerve block-attributable adverse event: 866 (5.5%) in patients with a block and 4,455 (5.9%) without a block. Before and after adjustment, nerve blocks were not associated with potentially attributable adverse events (adjusted odds ratio, 1.05; 95% CI, 0.97 to 1.15; and adjusted risk difference, 0.3%, 95% CI, -0.1 to 0.8). CONCLUSIONS: The data suggest that nerve blocks in hip fracture patients are not associated with higher rates of potentially nerve block-attributable adverse events, although these findings may be influenced by limitations in routinely collected administrative data.

Effects of Local Anesthetic Volume (Standard Versus Low) on Incidence of Hemidiaphragmatic Paralysis and Analgesic Quality for Ultrasound-Guided Superior Trunk Block After Arthroscopic Shoulder Surgery.

BACKGROUND: Relative to interscalene block, superior trunk block (STB) provides comparable analgesia and a reduced risk of hemidiaphragmatic paralysis. However, the incidence of hemidiaphragmatic paralysis remains high when a standard volume (15 mL) of local anesthetic is used. This study aimed to evaluate the effects of local anesthetic volume of STB on the incidence of phrenic nerve palsy, as well as its analgesic efficacy following arthroscopic shoulder surgery. METHODS: Patients scheduled for elective arthroscopic shoulder surgery were randomized to receive ultrasound-guided STB using either 5- or 15-mL 0.5% ropivacaine before general anesthesia. The primary outcome was the incidence of hemidiaphragmatic paralysis at 30 minutes after block. The secondary outcomes were pulmonary function, grade of sensory and motor blockade, pain score, opioid consumption, adverse effects, and satisfaction. RESULTS: Relative to standard-volume STB, low-volume STB was associated with a lower incidence of hemidiaphragmatic paralysis after block (14.3 [4.8%-30.3%] vs 65.7 [46.8%-80.9%]; difference 51.4% [95% confidence intervals {CIs}, 29.0%-67.1%]; P < .0001) and at the postanesthesia care unit (9.4% vs 50.0%; difference 40.6 [95% CI, 18.9%-57.7%]; P = .0004). Pulmonary function was also better preserved in the low-volume group than in the standard-volume group. The extent of the sensory and motor blocks was significantly different between the groups. Pain-related outcomes, satisfaction, and any adverse events were not significantly different between the groups. CONCLUSIONS: Low-volume STB provided a lower incidence of hemidiaphragmatic paralysis with no significant difference in analgesic efficacy relative to standard-volume STB for arthroscopic shoulder surgery.

Beware the Wandering Needle: Inadvertent Intramedullary Injection During an Attempted Cervical Medial Branch Block.

A 27-year-old man developed sudden neck pain, severe quadriparesis, and right shoulder allodynia during an outpatient cervical medial branch block procedure. Cervical spine imaging revealed evidence of an interlaminar needle trajectory with abnormal signal in the right hemicord at the level of C4, consistent with intramedullary injection and contusion. Following a 48-hour stay in the intensive care unit, during which hemodynamic vasopressor support was administered to optimize spinal cord perfusion, the patient exhibited almost complete neurologic recovery with resolution of the neuropathic pain. He was eventually discharged home and underwent outpatient physical therapy for a mild residual right hemiparesis.

Ultrasound versus thoracoscopic-guided paravertebral block during thoracotomy.

BACKGROUND: Paravertebral block can be performed with the aid of surgical landmarks, ultrasound, or a thoracoscope. This study was designed to compare ultrasound-guided paravertebral block with the thoracoscopic technique. METHODS: This prospective randomized comparative study included 40 adults scheduled for elective thoracic surgery. Study participants were randomized to an ultrasound group or a thoracoscope group. A catheter for paravertebral block was inserted prior to thoracotomy with real-time ultrasound visualization in the ultrasound group, and under thoracoscopic guidance in the thoracoscope group. Total analgesic consumption, visual analogue pain score, technical difficulties, and complications were compared between the 2 groups. RESULTS: Total analgesic consumption in the first 24 hours was less in the ultrasound group than in the thoracoscope group (rescue intravenous fentanyl 121.25 ± 64.01 µg in the ultrasound group vs. 178.75 ± 91.36 µg in the thoracoscope group; p = 0.027). Total paravertebral bupivacaine consumption was 376.00 ± 33.779 mg in the ultrasound group and 471.50 ± 64.341 mg in the thoracoscope group (p < 0.001). Technical difficulties and complications in terms of time consumed during the maneuver, more than one needle pass, and pleural puncture were significantly lower in the ultrasound group than in the thoracoscope group. CONCLUSION: Ultrasound-guided paravertebral catheter insertion is more effective, technically easier, and safer than the thoracoscope-assisted technique.

A retrospective case series of patients who have undergone coeliac plexus blocks for the purpose of alleviating pain due to intra-abdominal malignancy.

BACKGROUND: Coeliac plexus block (CPB) is an interventional pain management option for patients with pancreatic or other upper abdominal malignancy. AIMS: To assess the safety, utilization, and outcomes of CPBs in the local context. METHODS AND RESULTS: We conducted a retrospective case series of all patients with cancer who underwent CPB at 4 Sydney teaching hospitals from March 2010 to February 2016. We recorded baseline demographic data, details of the injectate, procedural approach and survival, as well as pain scores and analgesic use at 4 time points of interest. Thirty-nine procedures were performed during the study period. Twenty-four were performed endoscopically, 14 were performed via a bilateral percutaneous posterior approach by Pain Specialists or Radiologists and 1 was performed intraoperatively by a Surgeon. Patients had experienced pain for a mean of 17 weeks prior to CPB. Prior to CPB, the mean pain score was 8.8 out of 10. The mean pain score was reduced at 48 hours, 2 weeks, and 4 weeks following CPB (P < .01). The mean oral morphine equivalent daily dose prior to CPB was 362 mg which was reduced at 48 hours and 2 weeks but increased at the 4 weeks following CPB. One patient developed a bacteremia but otherwise no complications were observed. CONCLUSION: CPB is performed by a number of approaches and is well tolerated. The approach selected appears to depend on patient anatomy, preference, and availability of local expertise. Local clinicians could consider CPB earlier in the management of malignant epigastric pain.

Retrospective evaluation of pain in patients with coccydynia who underwent impar ganglion block.

BACKGROUND: We aimed to evaluate pain scores one year after impar ganglion block in patients with coccydynia who did not benefit from conservative treatment. METHODS: The medical records of 29 patients with coccydynia were reviewed. Patients who were referred to the algology clinic and underwent impar ganglion blocks were retrospectively evaluated. Demographic data, time to the onset of pain, causes of pain, X-ray findings, administered invasive procedures, and visual analog scale (pain) scores were recorded. RESULTS: A total of 29 patients were included in the study, 10 males (34%) and 19 females (66%). The average age and body mass index were 53.45 ± 9.6 and 29.55 ± 4.21 respectively. In 21 patients, the onset of pain was associated with trauma. Nineteen patients (65.5%) had anterior coccygeal angulation. The average visual analog scale score before undergoing an impar ganglion block was 7.4 ± 1. After the procedure, the scores at < 3 months, 3-6 months and 6 months-1 year follow-up intervals were significantly lower (p < 0.05). Furthermore, visual analog scale scores at the 3-6 months and 6 months-1 year periods were significantly lower in patients who received diagnostic blocks plus pulse radiofrequency thermocoagulation than in patients who underwent a diagnostic block only. CONCLUSIONS: The impar ganglion block provides effective analgesia without complications in patients with coccydynia. Pulse radiofrequency thermocoagulation combined with a diagnostic block prolongs the analgesic effect of the procedure.

Daring discourse: are we ready to recommend neuraxial anesthesia and peripheral nerve blocks during the COVID-19 pandemic? A pro-con.

The recent joint statement from the American Society of Regional Anesthesia and Pain Medicine (ASRA) and the European Society of Regional Anesthesia and Pain Therapy (ESRA) recommends neuraxial and peripheral nerve blocks for patients with coronavirus disease 2019 (COVID-2019) illness. The benefits of regional anesthetic and analgesic techniques on patient outcomes and healthcare systems are evident. Regional techniques are now additionally promoted as a mechanism to reduce aerosolizing procedures. However, caring for patients with COVID-19 illness requires rapid redefinition of risks and benefits-both for patients and practitioners. These should be fully considered within the context of available evidence and expert opinion. In this Daring Discourse, we present two opposing perspectives on adopting the ASRA/ESRA recommendation. Areas of controversy in the literature and opportunities for research to address knowledge gaps are highlighted. We hope this will stimulate dialogue and research into the optimal techniques to improve patient outcomes and ensure practitioner safety during the pandemic.

Efficacy and safety of periprostatic nerve block combined with perineal subcutaneous anaesthesia and intrarectal lidocaine gel in transrectal ultrasound guided transperineal prostate biopsy: A Prospective Randomised Controlled Trial.

BACKGROUND: To determine the efficacy and safety of a periprostatic nerve block combined with perineum subcutaneous anaesthesia and intrarectal lidocaine gel for transrectal ultrasound-guided transperineal prostate biopsy (TPBx) through a prospective randomised controlled trial. METHODS: In total, 216 patients from May 2018 to November 2018 were randomly assigned to the experimental group and the control group at a ratio of 1:1. The experimental group received a periprostatic nerve block combined with subcutaneous perineal anaesthesia and intrarectal lidocaine gel. The control group received total intravenous anaesthesia. A visual analogue scale (VAS) score (0-10) was used to evaluate pain at different stages. The operative time, duration of hospitalisation, intraoperative vital signs, perioperative complications and clinicopathological features were recorded. RESULTS: The overall detection rate of prostate cancer was 40.74%, and the median Gleason score was 8 for all patients diagnosed with prostate cancer. No significant differences in terms of detection rates, Gleason scores and ISUP/WHO Grade Groups were found between the two groups (P > 0.05). The experimental group had no pain or just met the criteria for mild pain during the biopsy, which was significantly alleviated after the biopsy, and had a shorter operation time compared with that of the control group (P < 0.05). Compared with the control group, the experimental group had more stable haemodynamics and respiratory status and fewer surgical complications (P < 0.05). CONCLUSIONS: In multiple aspects, a periprostatic nerve block combined with subcutaneous perineal anaesthesia and intrarectal lidocaine gel is a safer and more efficient approach to local anaesthesia for TPBx that can almost replace total intravenous anaesthesia and is worthwhile applying in the clinical setting.

Tonic-clonic seizure during the ultrasound-guided stellate ganglion block because of an injection into an unrecognized variant vertebral artery: A case report.

RATIONALE: Recent years have witnessed a marked improvement in the safety and accuracy of nerve blocks with the help of ultrasound and other visualization technologies. This study reports a challenging case of a severe complication during the ultrasound-guided stellate ganglion block. PATIENT CONCERNS: A 28-year-old male patient with refractory migraine complained episodic pulsatile pain with photophobia, haphalgesia of the scalp for 3 years. INTERVENTIONS: Ultrasound-guided stellate ganglion block with 4 ml of 1% lidocaine was administrated. OUTCOMES: A sudden loss of consciousness and tonic-clonic seizure was occurred after negative aspiration and test dose. Further sonographic examination revealed a variation in the left vertebral artery, which remained unrecognized during the needle insertion because of its sliding ability under the differential pressure applied by the probe. LESSONS: Inadvertent intra-arterial injection of a local anesthetic agent could be minimized under the ultrasound guidance with various protective strategies, including the determination of any prior variation, optimizing the block route, maintaining a constant probe pressure, and using saline for the test dosage. This case resulted in the implementation of new protocols of the ultrasound-guided stellate ganglion block in our department.

Stellate ganglion block and cardiac sympathetic denervation in patients with inappropriate sinus tachycardia.

BACKGROUND: Inappropriate sinus tachycardia (IST) remains a clinical challenge because patients often are highly symptomatic and not responsive to medical therapy. OBJECTIVE: To study the safety and efficacy of stellate ganglion (SG) block and cardiac sympathetic denervation (CSD) in patients with IST. METHODS: Twelve consecutive patients who had drug-refractory IST (10 women) were studied. According to a prospectively initiated protocol, five patients underwent an electrophysiologic study before and after SG block (electrophysiology study group). The subsequent seven patients had ambulatory Holter monitoring before and after SG block (ambulatory group). All patients underwent SG block on the right side first, and then on the left side. Selected patients who had heart rate reduction ≥15 beats per minute (bpm) were recommended to consider CSD. RESULTS: The mean (SD) baseline heart rate (HR) was 106 (21) bpm. The HR significantly decreased to 93 (20) bpm (P = .02) at 10 minutes after right SG block and remained significantly slower at 97(19) bpm at 60 minutes. Left SG block reduced HR from 99 (21) to 87(16) bpm (P = .02) at 60 minutes. SG block had no significant effect on blood pressure or HR response to isoproterenol or exercise (all P > .05). Five patients underwent right (n = 4) or bilateral (n = 1) CSD. The clinical outcomes were heterogeneous: one patient had complete and two had partial symptomatic relief, and two did not have improvement. CONCLUSION: SG blockade modestly reduces resting HR but has no significant effect on HR during exercise. Permanent CSD may have a modest role in alleviating symptoms in selected patients with IST.

Peripheral nerve blocks are not associated with increased risk of perioperative peripheral nerve injury in a Veterans Affairs inpatient surgical population.

BACKGROUND AND OBJECTIVES: Perioperative peripheral nerve injury (PNI) is a known complication in patients undergoing surgery with or without regional anesthesia. The incidence of new PNI in a Veterans Affairs (VA) inpatient surgical population has not been previously described; therefore, the incidence, risk factors, and clinical course of new PNI in this cohort are unknown. We hypothesized that peripheral nerve blocks do not increase PNI incidence. METHODS: We conducted a 5-year review of a Perioperative Surgical Home database including all consecutive surgical inpatients. The primary outcome was new PNI between groups that did or did not have peripheral nerve blockade. Potential confounders were first examined individually using logistic regression, and then included simultaneously together within a mixed-effects logistic regression model. Electronic records of patients with new PNI were reviewed for up to a year postoperatively. RESULTS: The incidence of new PNI was 1.2% (114/9558 cases); 30 of 3380 patients with nerve block experienced new PNI (0.9%) compared with 84 of 6178 non-block patients (1.4%; p=0.053). General anesthesia alone, younger age, and American Society of Anesthesiologists physical status <3 were associated with higher incidence of new PNI. Patients who received transversus abdominis plane blocks had increased odds for PNI (OR, 3.20, 95% CI 1.34 to 7.63), but these cases correlated with minimally invasive general and urologic surgery. One hundred PNI cases had 1-year follow-up: 82% resolved by 3 months and only one patient did not recover in a year. CONCLUSIONS: The incidence of new perioperative PNI for VA surgical inpatients is 1.2% and the use of peripheral nerve blocks is not an independent risk factor.

Impact of Neck Position on the Probability of Common Carotid Artery Puncture During Ultrasound-Guided Stellate Ganglion Block.

BACKGROUND: The carotid artery must be avoided during stellate ganglion block. However, information on optimal neck position during the ultrasound-guided approach is limited. OBJECTIVE: To investigate the relation between the target area of the procedure and the carotid artery in different neck positions. DESIGN: Observational study. SETTING: Tertiary university. PARTICIPANTS: A total of 30 sides of the neck from 18 healthy participants were included. METHODS: An ultrasound transducer was placed at the level of the anterior tubercle of C6 with a short-axis view for measuring the distance from the tip of the C6 anterior tubercle to the margin of the carotid artery. The participants were first examined through ultrasonography in 3 different rotational neck positions (neutral, semicontralateral rotation, and full-contralateral rotation), in the supine position. After changing to the lateral decubitus position, the measurement was performed again in the same 3 neck positions. MAIN OUTCOME MEASURES: The C6 anterior tubercle to carotid distance was measured with ultrasound. RESULTS: The C6 anterior tubercle to carotid distance was the longest with full-contralateral neck rotation (P < .05). The distance was longer in the semicontralateral neck rotation compared with the neutral neck position (P < .05). Supine or decubitus positions did not affect the distance. CONCLUSIONS: We suggest that the full-contralateral neck rotation posture in either the supine or decubitus position is most beneficial for avoiding damage to the carotid artery during the ultrasound-guided stellate ganglion block. LEVEL OF EVIDENCE: Not applicable.

Feasibility of subcutaneous implantable cardioverter-defibrillator implantation with opioid sparing truncal plane blocks and deep sedation.

INTRODUCTION: The subcutaneous implantable cardioverter-defibrillator (S-ICD) is most commonly implanted under general anesthesia (GA), due to the intraoperative discomfort associated with tunneling and dissection. Postoperative pain can be substantial and is often managed with opioids. There is a growing interest in transitioning away from the routine use of GA during S-ICD implantation, while also controlling perioperative discomfort without the use of narcotics. As such, we assessed the feasibility of a multimodal analgesia regimen that included regional anesthesia techniques in patients undergoing S-ICD implantation. METHODS AND RESULTS: Twenty patients received truncal plane block (TBL) immediately before S-ICD implantation. The first 10 patients were implanted under general anesthesia (GA + TBL), and the next 10 patients were implanted under deep sedation (DS + TBL). Additionally, the DS + TBL patients were also prescribed a structured regimen of nonopioid analgesics in the perioperative period. Opioid consumption was calculated as milligram morphine equivalents (MME). In-hospital opioid consumption was significantly lower in the patients implanted with DS + TBL (MME = 0) as compared with patients receiving GA + TBL (MME = 60; P = 0.004). CONCLUSIONS: Subcutaneous ICD implantation with anesthesia-delivered DS and a multimodal anesthetic regimen that includes TBL is feasible and associated with significantly less perioperative opioid consumption.

The effect of stellate ganglion block on the function of arteriovenous fistulas for hemodialysis: A randomized trial.

BACKGROUND AND PURPOSE: The best access for hemodialysis is an autologous arteriovenous fistula (AVF). The most helpful way for vasodilation in the upper limb is stellate ganglion block. We aim to evaluate the effect of stellate ganglion block on outcome of vascular access for dialysis. MATERIALS AND METHODS: Some 105 hemodialysis patients were randomly allocated to three groups: In group 1, stellate ganglion block was performed before fistula surgery. Group 2 had stellate ganglion block after surgery and group 3 was control group without any block. Primary outcome for all groups was functional dialysis, which is defined as successful hemodialysis for 1 month. RESULTS: The three groups were similar in age, gender, and underlying diseases. Stellate ganglion block before operation had a meaningful increase in successful hemodialysis rate, when compared with the other groups (p = 0.02). CONCLUSION: Stellate ganglion block before arteriovenous fistula surgery in the upper limbs improves hemodialysis success rate.

Extrapyramidal signs occurring after sympathetic block for complex regional pain syndrome responding to diphenhydramine: Two case reports.

RATIONALE: To present an unusual extrapyramidal motor response occurring after a sympathetic block in CRPS and its successful treatment with diphenhydramine. PATIENT CONCERNS: Severe pain related to Complex Regional Pain Syndrome type 1 interfering with activities of daily living. DIAGNOSES: Complex Regional Pain Syndrome type 1. INTERVENTIONS: We report a video case reports of two patients with a diagnosis of CRPS type-I. Both patients exhibited similar presentation of unusual extrapyramidal motor response of the affected limb following lumbar sympathetic block. Both patients were treated with intravenous diphenhydramine to abort the extrapyramidal motor response. OUTCOMES: Both patients similarly responded to treatment with intravenous diphenhydramine with abrupt resolution of the motor response. LESSONS: Sympathetic blockade may interfere with the adaptive autonomic reflex circuits of the motor balance homeostasis in patients with complex regional pain syndrome. Disinhibition of extrapyramidal system may lead to immediate expression of extrapyramidal signs following the sympathetic block. Diphenhydramine, with its anti-histaminic and anticholinergic properties, may be effective in aborting such extrapyramidal signs, and should be considered as a treatment option in similar cases.

Risks and Benefits of Ultrasound, Nerve Stimulation, and Their Combination for Guiding Peripheral Nerve Blocks: A Retrospective Registry Analysis.

BACKGROUND: Ultrasound, nerve stimulation, and their combination are all considered acceptable ways to guide peripheral nerve blocks. Which approach is most effective and associated with the fewest complications is unknown. We therefore used a large registry to analyze whether there are differences in vascular punctures, multiple skin punctures, and unintended paresthesia. METHODS: Twenty-six thousand seven hundred and thirty-three cases were extracted from the 25-center German Network for Regional Anesthesia registry between 2007 and 2016 and grouped into ultrasound-guided puncture (n = 10,380), ultrasound combined with nerve stimulation (n=8173), and nerve stimulation alone (n = 8180). The primary outcomes of vascular puncture, multiple skin punctures, and unintended paresthesia during insertion were compared with conditional logistic regression after 1:1:1 propensity score matching. Results are presented as odds ratios and 95% CIs. RESULTS: Propensity matching successfully paired 2508 patients with ultrasound alone (24% of 10,380 patients), 2508 patients with a combination of ultrasound/nerve stimulation (31% of 8173 patients), and 2508 patients with nerve stimulation alone (31% of 8180 patients). After matching, no variable was imbalanced (standardized differences <0.1). Compared with ultrasound guidance alone, the odds of multiple skin punctures (2.2 [1.7-2.8]; P < .001) and vascular puncture (2.7 [1.6-4.5]; P < .001) were higher with nerve stimulation alone, and the odds for unintended paresthesia were lower with nerve stimulation alone (0.3 [0.1-0.7]; P = .03). The combined use of ultrasound/nerve stimulation showed higher odds of multiple skin punctures (1.5 [1.2-1.9]; P = .001) and lower odds of unintended paresthesia (0.4 [0.2-0.8]; P = .007) compared with ultrasound alone. Comparing the combined use of ultrasound/nerve stimulation with ultrasound alone, the odds for vascular puncture (1.3 [0.7-2.2]; P = .4) did not differ significantly. Systemic toxicity of local anesthetics was not observed in any patient with ultrasound guidance alone, in 1 patient with the combined use of ultrasound and nerve stimulation, and in 1 patient with nerve stimulation alone. CONCLUSIONS: Use of ultrasound alone reduced the odds of vascular and multiple skin punctures. However, the sole use of ultrasound increases the odds of paresthesia.