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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., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 International Anesthesia Research Society.)

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., (Copyright © 2021, the American Society of Anesthesiologists. All Rights Reserved.)

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.

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.

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.

Background: Fluoroscopy (FL)-guided lumbar sympathetic ganglion block (LSGB) is widely performed to diagnose and manage various diseases associated with sympathetically maintained pain. Recently, numerous ultrasound (US)-assisted procedures in pain medicine have been attempted, showing an advantage of low radiation exposure. This randomized, prospective trial compared the procedural outcomes and complications between FL-guided and US-assisted LSGBs., Methods: Fifty LSGBs were randomly divided into 2 groups: FL-guided (FL group) or US-assisted (US group) LSGB group. Both groups received FL-guided or US-assisted LSGB with 10 mL of 0.25% levobupivacaine. The primary end point was the total procedure time. Secondary outcomes were success rate, imaging time, onset time (based on temperature rise), dosage of radiation exposure, other procedure-related outcomes, and complications., Results: Total procedure time and success rate were not statistically different between the 2 groups, whereas imaging time of the US group was longer than that of the FL group (P = .012). The onset time was faster in the US group (P = .019), and bone touching during the procedure was less frequent in the US group (P = .001). Moreover, radiation exposure was significantly lower in the US group than in the FL group (P < .001). No serious complications were reported in all patients., Conclusions: US-assisted LSGB appears to be a feasible method with the added benefit of lower radiation exposure. In our study, we did not find an advantage of US-assisted LSGB over FL-guided LSGB in terms of performance time.

Intractable hiccups, although rare, may result in severe morbidity, including sleep deprivation, poor food intake, respiratory muscle fatigue, aspiration pneumonia, and death. Despite these potentially fatal complications, the etiology of intractable hiccups and definitive treatment are unknown. This study aimed to evaluate the effectiveness of continuous cervical epidural block in the treatment of intractable hiccups.Records from 28 patients with a history of unsuccessful medical and invasive treatments for hiccups were evaluated. Continuous cervical epidural block was performed with a midline approach at the C7-T1 or T1-T2 intervertebral space with the patient in the prone position. The epidural catheter was advanced through the needle in a cephalad direction to the C3-C5 level. Catheter placement was confirmed using contrast radiography. A 6-mL bolus of 0.25% ropivacaine was injected, and a continuous infusion of 4 mL/h of ropivacaine was administered through the epidural catheter using an infuser containing 0.75% ropivacaine (45 mL ropivacaine and 230 mL normal saline). When the hiccups stopped and did not recur for 48 hours, the catheter was removed.Cumulative complete remission rates were 60.71% after the first cervical epidural block, 92.86% after the second, and 100% after the third. One patient complained of dizziness that subsided. No other adverse effects were reported.Continuous C3-C5 level cervical epidural block has a successful remission rate. We suggest that continuous cervical epidural block is an effective treatment for intractable hiccups.

Purpose: The purpose of this study was to investigate the latency and amplitude of trigeminal somatosensory evoked potentials to clarify how nerve function on the contralateral side is affected after cervical sympathetic block (CSB)., Methods: Subjects comprised 16 volunteers. For CSB, the tip of a needle was contacted with the transverse process of the sixth cervical vertebra on the right side, and lidocaine was injected. Trigeminal somatosensory evoked potentials were recorded bilaterally from C5/C6 scalp positions. Pupil diameters were also measured. Electrical stimulations were applied to the left-side lower lip, and trigeminal somatosensory evoked potentials waveforms derived from both sides of the scalp were recorded. Then, electrical stimulations were applied to the right-side of the lower lip, and recording was again performed. Recordings were performed at 5, 15, and 30 minutes after CSB., Results: On the CSB side, pupil diameter decreased at 5 and 15 minutes after CSB. Trigeminal somatosensory evoked potentials at contralateral stimulation showed a prolongation of the latency in both P20 and N25 components on bilateral recording sites 5 and 15 minutes after CSB. Trigeminal somatosensory evoked potentials' amplitude at contralateral stimulation was smaller than at ipsilateral stimulation 5 minutes after CSB., Conclusions: Cervical sympathetic block prolongs the latency and reduces the amplitude of trigeminal somatosensory evoked potentials on the contralateral side.

Background: Ropivacaine is a long-acting local anesthetic used for continuous peripheral nerve catheter infusions. Catheters may remain in situ for prolonged time periods. In the present study, patients were enrolled to receive continuous peripheral nerve catheters with measurement of free serum ropivacaine concentrations., Methods: Peripheral nerve catheters were placed for postoperative pain management in trauma patients and infused with ropivacaine 0.2% or bolused with 0.5%. Blood samples were obtained from each subject on days 0 (preinfusion), 3, 5, 7, 10, and every third day until catheter removal. Serum free ropivacaine concentrations were measured via high-performance liquid chromatography and were compared using the Wilcoxon signed rank test., Results: One hundred thirty-three blood samples were analyzed in 35 patients; all serum free ropivacaine concentrations after infusion initiation (99 samples from 35 subjects) were below 0.34 mg/L (previously determined toxic threshold). The highest concentration achieved in a blood sample was 0.19 mg/L; all other values were <0.09 mg/L. The total amount of drug received during the study ranged from 1146 to 22,320 mg (median of 3722 mg). Catheters remained in situ for a median of 7 days (range: 3-23). From day 0 to 3 (preinfusion), 77% of the study participants had an increase in the serum free-fraction ropivacaine concentrations. The median concentration on day 3 was 0.025 mg/L (95% upper confidence limit for mean: 0.05, range: <0.01-0.19); P < 0.001 compared with preinfusion levels). From day 3 to 5, 68% of the participants had a decrease in the serum free ropivacaine concentrations (median level 0.016 mg/L [95% upper confidence limit for mean: 0.021] P = 0.007 for day 5 compared with day 3)., Conclusions: In this study, free serum ropivacaine concentrations remained well below toxic values despite large amounts of drug administration in combat-wounded patients. The administration of continuous ropivacaine infusions over prolonged time periods, coupled with multiple drug boluses, did not produce toxic or near-toxic serum concentrations.

Background: Intravascular and intramuscular injection of local anesthetics during lumbar sympathetic ganglion block (LSGB) can cause false positive or negative results in a diagnostic block, and complications. In the present study, we prospectively evaluated the incidence and possible factors causing intravascular and IM injection during LSGB., Methods: We evaluated 216 LSGBs in 83 patients. All LSGBs were performed by 1 of the authors using a 3-needle technique. After final needle position was confirmed by biplanar fluoroscopy, an aspiration test was conducted, and 1 mL of contrast was injected sequentially. Incidences of psoas muscle injection, blood flashback, and the presence of intravascular contrast spread on static and real-time fluoroscopy were assessed., Results: The incidence of psoas muscle injection of contrast was 21.3% (46/216), and it was associated with the level of injection (L2) significantly (chi(2) = 14.773, P = 0.001). The incidence of intravascular injection of contrast was 12.5% (27/216). Among 27 cases of documented intravascular injections, 5.1% (11/216) of patients showed contrast spread at the area where the sympathetic ganglion was presumed to be and to the vessels simultaneously, and 7.4% (16/216) of patients showed only intravascular injection of contrast. The sensitivity of the aspiration test and static radiography were 40.7% and 70.4%, respectively., Conclusions: LSGB at the L2 level showed the lowest incidence of psoas muscle injection of contrast in comparison with LSGB at L3 and L4. The aspiration test and static radiography frequently missed the intravascular injection of contrast during LSGBs.

Purpose of Review: Thoracic epidural anesthesia (TEA) is most frequently used after major surgery. However, despite ongoing research, the influence of TEA on the intestinal perioperative pathophysiology is not fully understood., Recent Findings: According to recent results, the splanchnic sympathetic activity is reduced during TEA both in animal models and in clinical TEA. The splanchnic sympathetic activity during high TEA is still unknown. Intestinal perfusion effects of TEA are still unclear as the technique and extent of TEA, hemodynamic alteration and size of measurement result in--seemingly--conflicting reports. Postoperative ileus after laparotomy is ameliorated by TEA. Recent findings suggest beneficial effects also after major laparoscopic procedures. Finally, the impact of TEA on the intestinal pathophysiology in critical illness is an area of growing clinical and scientific interest, although this knowledge is just at its beginning., Summary: Further research concerning the use of TEA in major laparoscopic procedures and its potential to improve or endanger anastomotic healing is warranted. The experimental studies of TEA in critical illness should be expanded.

Ultrasound has become a widely used tool within the practice of regional anesthesia, offering real-time visualization of the nerves, needle, and local anesthetic during performance of a block. A successful ultrasound-guided axillary block was performed on a healthy adult male undergoing wrist surgery. Postoperative review of the ultrasound video recording of the block suggested that an intraneural injection had occurred during the procedure. The patient had an effective block and suffered no adverse neurological effects. Recording and reviewing ultrasound images of a regional block can be important for documentation and educational purposes.

Background: The increasing popularity of continuous peripheral nerve blocks (CPNBs) warrants further study of their adverse effects and complications., Methods: Anterior sciatic, femoral, and interscalene brachial plexus CPNBs were performed preoperatively using standardized catheter techniques in orthopedic patients prior to general or spinal anesthesia. Complications and adverse effects related to CPNBs were prospectively evaluated., Results: We analyzed 1398 CPNBs in 849 consecutive patients (mean age 65 +/- 13 yr) between 2002 and 2004. Two-hundred-twenty-one patients received interscalene, 628 patients femoral, and 549 sciatic CPNBs, respectively. In all the latter patients, we performed both femoral and sciatic CPNBs. Overall, there were 9 cases of local inflammation at the insertion site (0.6%), and 3 local infections (pustule) (0.2%, all femoral CPNBs). In one patient undergoing a femoral technique, a retroperitoneal hematoma led to compression injury of the femoral nerve. Complete denervation of the quadriceps femoris muscle was confirmed by electroneuromyography. No other major neurological complications were noted. There was one case of methemoglobinemia associated with an interscalene CPNB. Vascular puncture occurred in approximately 6% of patients undergoing femoral and sciatic CPNBs. Catheter rupture was noted in one patient., Conclusions: Our results add to the evidence that major complications from CPNBs are rare. However, minor adverse effects associated with CPNBs may be more common.

Background and Purpose: The purpose of the present study was to evaluate the feasibility and safety of a locoregional cervical sympathetic block to improve cerebral perfusion in patients suffering from cerebral vasospasm after aneurysmal subarachnoid hemorrhage., Methods: Nine consecutive patients with symptoms of delayed ischemic deficits, induced by angiographically confirmed cerebral vasospasm, were treated with the injection of locoregional anesthesia to block the ascending cervical sympathetic chain at the level of the superior cervical ganglion. Neurological status was recorded before and after the procedure, and cerebral angiography was performed before and after the procedure., Results: No complications occurred in this short series. The procedure appeared to be simple and safe. Horner's signs appeared within 12+/-0.1 minutes and lasted for an average of 6.3+/-4 hours. In all patients, improved cerebral perfusion was detected at the confirmatory angiography but without change in vessel caliber. One patient died of the complications of the initial hemorrhage, and 2 died of the consequences of the severe vasospasm despite maximal medical treatment. In all the other cases, the neurological status promptly returned to normal within 48 hours after the locoregional treatment., Conclusions: Patients with mild to moderate symptoms seem to benefit greatly from transient ipsilateral cervical sympathetic block. This simple technique may be helpful when used as an adjunct to the standard therapy to improve cerebral perfusion.

Endoscopic ultrasound (EUS) was developed in the 1970s specifically for the purpose of improved imaging of the pancreas. The close proximity of the pancreas to the gastric and duodenal lumen allows EUS to obtain high-resolution images, unobstructed by overlying bowel gas. EUS has fewer complications than endoscopic retrograde cholangiopancreatography (ERCP) and can detect features of chronic pancreatitis (CP) in the pancreatic parenchyma and duct that are not visible to any other imaging modality. Because of this high sensitivity, questions have arisen whether EUS is oversensitive, especially to ''early" CP. Without a definitive gold standard against which to measure EUS (or ERCP and function testing), it is currently not possible to know the true accuracy of these modalities for early CP. There is now an extensive body of literature suggesting that these early changes detected by EUS correlate with histologic changes of CP, and may predict response to pancreatic therapy. EUS is uniquely suited to performing endoscopic cyst drainage for pancreatic pseudocysts and for controlling the pain of CP by EUS-directed celiac plexus block. For endoscopic cystenterostomy, EUS allows the endoscopist to localize the cyst, determine if the cyst is drainable, and guide a needle and stent into the cyst in a single step. Several major questions remain. Can EUS features of CP guide other forms of therapy for CP such as enzyme replacement, sphincter of Oddi therapy, and stent therapy? Can the detection of early CP by EUS, and subsequent therapy, delay or prevent the onset of more severe CP? Can EUS detect early forms for dysplasia and malignancy in patients who are at high risk for pancreatic carcinoma? Do changes of "early" CP detected by EUS progress to more classic changes (calicification) over time?

Neurolytic celiac plexus block (CPB) under radiological guidance is often performed to manage pain associated with pancreatic cancer. Serious complications related to the block are rare. Computed Tomography (CT)-guided neurolytic CPB is advocated to improve the efficacy of the block and to reduce the incidence of associated complications. We describe a case of superior mesenteric vein thrombosis associated with neurolytic CPB performed under CT guidance.

Unlabelled: Epidural blockade leads to a sympathetic block in affected segments and an increase of sympathetic out-flow from various unblocked segments. A limited upper thoracic epidural block (LUTEB) is used during coronary artery surgery affecting the cardiac sympathetic fibers cephalad to the fifth thoracic segment. This block does not extend to the sympathetic fibers innervating the gastrointestinal organs. A LUTEB may lead to an increase of sympathetic activity in the unaffected splanchnic sympathetic segments and the decrease in splanchnic blood flow may contribute to gastrointestinal ischemia after cardiac surgery. We tested the hypothesis that a LUTEB decreases splanchnic perfusion in anesthetized dogs. Thirteen dogs were chronically instrumented with aortic and left atrial catheters, which were used for pressure measurement, as well as injection and withdrawal of reference samples. Thoracic epidural catheters were placed under general anesthesia the day before the experiment. Splanchnic blood flow was determined by using colored microspheres. Induction of a LUTEB did not change general hemodynamics in awake dogs. Propofol anesthesia induced an increase in heart rate that was abolished after LUTEB. LUTEB also decreased mean arterial pressure during propofol anesthesia. We conclude that thoracic epidural anesthesia had no effect on splanchnic blood flow. In propofol anesthetized animals, liver blood flow was increased compared with awake animals; however, it did not change after induction of LUTEB., Implications: A sympathetic block in certain segments leads to increased sympathetic output in unblocked segments. For an upper thoracic epidural block, this might lead to impaired splanchnic perfusion. In awake and propofol-anesthetized, chronically instrumented dogs, however, a limited upper thoracic epidural blockade had no compromising effect on gastrointestinal perfusion.

To assess the efficacy of 4% topical lidocaine in spheno-palatine blocks, a randomized controlled trial was carried out on patients with chronic muscle pain syndromes. Sixty-one patients (42 with fibromyalgia (FM) and 19 with myofascial pain syndrome (MPS)) completed the trial. Outcome measures included pain intensity, a daily pain diary, headache frequency, sensitivity to pressure using a dolorimeter, anxiety, depression, and sleep quality. Patients were randomized to receive either 4% lidocaine or sterile water (placebo) 6 times over a 3-week period. Both subjects and investigators were blind to treatment allocation. The results showed that 4% lidocaine had no superiority over placebo in any of the outcome measures. Twenty-one subjects (35%) showed a decrease in pain which was greater than 30% of their baseline value. Of these 21 subjects, 10 received lidocaine and 11 received placebo. These data suggest that, in this population, 4% lidocaine is no better than placebo in the treatment of chronic muscle pain.

Over a 3-year period, neurolytic abdominal visceral sympathectomy was performed bilaterally with 15 ml of alcohol solution (14 ml of alcohol and 1 ml of contrast material) through each needle under CT guidance to relieve upper abdominal or back pain in 27 cancer patients. Using the CT monitor, our intention was to achieve splanchnic nerve neurolysis rather than celiac plexus neurolysis. After determining the trajectory for needle placement on the CT image at the L1 level, the needles were inserted bilaterally with a simple guide apparatus. The needle tips were successfully positioned in the retrocrural space in 48 (83%) of 54 insertions. Pain was substantially relieved in 20 of 21 patients receiving bilateral splanchnic nerve neurolysis. Tissue pressure was significantly higher after alcohol injection when the needle tips were located in the retrocrural space than when they were placed in the anterocrural space. CT images after alcohol injection revealed antero- and posterocrural spread in 11 of 21 patients who received bilateral splanchnic nerve neurolysis. It was speculated that the alcohol spread through the aortic hiatus or gaps of the diaphragmatic crura. No neurologic complications were encountered. It is concluded that CT guided alcohol splanchnic nerve neurolysis is an effective treatment for upper abdominal cancer pain, and that 15 ml of alcohol solution through each needle is enough for splanchnic nerve neurolysis.

Neurolytic celiac plexus block (NCPB) is an effective method for relief of the pain of pancreatic cancer, but many physicians are reluctant to use the technique because of the perception that the incidence of complications is high. We analyzed the incidence of complications and the quality of pain relief obtained during the use of NCPB in 136 patients with pancreatic cancer. Eighty-five percent of the patients had good pain relief that, in 75% of cases, lasted through the patients' remaining life. No permanent neurologic complications resulted, although two patients had a pneumothorax. Radiographically guided needle placement did not affect quality of pain relief or the incidence of complications. This neurolytic pain block is effective, has a low incidence of neurologic complications, and deserves more widespread use in patients with pancreatic cancer.

A distinct clinical syndrome of severe buttock pain radiating down the posterior surface of the ipsilateral leg and subsequent inability to ambulate has recently been recognized. The syndrome may develop in the parturient following a paracervical block. This study analyzes 4 cases from the authors' institution and reviews 2 cases from the literature. Onset of the syndrome ranges from 12 hours to 10 days but progressive improvement and complete recovery are the rule. The cause is believed to be secondary to direct trauma or hematoma formation in the area of the sacral plexus. Pelvic induration or a mass in the sacroiliac area may be noted bur abscess formation is not associated. Prevention is difficult but early recognition will facilitate treatment, which is mostly symptomatic.