Development of a Mobile Ultrasound‐Guided Peripheral Nerve Block and Catheter Service

Ultrasound guidance is associated with improved efficiency and success of peripheral nerve blockade and a decreased incidence of vascular puncture, making these interventions safer. Patients with peripheral nerve blocks report decreased pain and increased satisfaction scores. We present the development of a mobile ultrasound‐guided block service that allows for the safe and efficient placement of nerve blocks and perineural catheters at the nontraditional location of the patient's bedside and in the emergency department.     

Ultrasound‐Guided Proximal Suprascapular Nerve Block With Radiofrequency Lesioning for Patients With Malignancy‐Associated Recalcitrant Shoulder Pain

The classic suprascapular nerve block has limitations, such as postural requirements and lack of direct nerve visualization. This series investigated the analgesic effect of ultrasound‐guided supraclavicular suprascapular nerve blocks in patients with malignancy‐associated shoulder pain. Ablative radiofrequency lesioning of the suprascapular nerve in 6 patients provided substantial pain relief. The mean distance from the suprascapular nerve to the brachial plexus was 8.05 mm, and the mean angle of needle entry was 20.6°. This approach appears to be effective in relieving malignancy‐associated shoulder pain and is tolerated by patients unable to sit or lie prone.     

Nerve guidance with versus without prepuncture ultrasound visualization for psoas compartment block and perineural catheter insertion: A randomized, prospective, blinded study

Lumbar plexus block may offer significant advantages in terms of postoperative analgesia, patient satisfaction, surgical outcome and patient rehabilitation. Ultrasound guidance has been used to describe psoas compartment block-related anatomy and to estimate transverse process depth before needle insertion and prediction of actual needle-to plexus intercept depth. The aim of this prospective randomized blinded study is to compare the Nerve-Stimulation Guidance with versus without the Pre-puncture Ultrasound Visualization in terms of onset time of the lumbar plexus sensory and motor block in patients undergoing total hip replacement.46 patients undergoing total hip replacement were randomly allocated to receive posterior lumbar plexus block (LPB) using nerve stimulation guidance with (group US, n = 23) or without pre-puncture ultrasound imaging (group NS, n = 23).Onset time of sensory and motor blocks was recorded every 5 min for the first 30 min starting from the injection of the local anesthetic injection. Readiness for surgery was defined as complete numbness to pinprick test in the region supplied by the lumbar plexus and Bromage’s score = 3.Need for additional local anesthetic boluses or general anesthesia, intraoperative opioid consumption and first postoperative 24 h local anesthetic and rescue Analgesics consumption were also recorded.The time required for the execution of the block was 3 (2–15) min in Group US and 5 (2–20) min in Group NS (p = 0.06). The mean time to readiness for surgery was 12 ± 5 in Group US and 19 ± 6 min in Group NS (p = 0.04) . 3 Patients in Group US (13%) and 4 patients in Group NS (17%) (p = 0.73) required general anesthesia due to failed block. Intraoperative opioid consumption was similar in the two groups. There were no differences in complications, postoperative local anesthetic and rescue analgesics consumption and pain scores.Nerve-Stimulation technique combined with Pre-puncture Ultrasound Visualization for continuous lumbar plexus blocks is comparable to Nerve-Stimulation technique in terms of percentage of block success, intraoperative opioid consumption and postoperative pain relief. Pre-puncture Ultrasound Visualization may reduce the time required for readiness to surgery.     

Combined Sciatic and Lumbar Plexus Nerve Blocks for the Analgesic Management of Hip Arthroscopy Procedures: A Retrospective Review

Hip arthroscopy is a minimally invasive alternative to open hip surgery. Despite its minimally invasive nature, there can still be significant reported pain following these procedures. The impact of combined sciatic and lumbar plexus nerve blocks on postoperative pain scores and opioid consumption in patients undergoing hip arthroscopy was investigated. A retrospective analysis of 176 patients revealed that compared with patients with no preoperative peripheral nerve block, significant reductions in pain scores to 24 hours were reported and decreased opioid consumption during the post anesthesia care unit (PACU) stay was recorded; no significant differences in opioid consumption out to 24 hours were discovered. A subgroup analysis comparing two approaches to the sciatic nerve block in patients receiving the additional lumbar plexus nerve block failed to reveal a significant difference for this patient population. We conclude that peripheral nerve blockade can be a useful analgesic modality for patients undergoing hip arthroscopy.     

Ultrasound and pain in children: A review

Ultrasound guidance has been demonstrated to improve block characteristics in children including shorter block performance time, higher success rates, shorter onset time, longer block duration, less volume of local anesthetic agents and visibility of neuraxial structures.Clinical studies in children suggest that ultrasound guidance has some advantages over more traditional nerve stimulation-based techniques for regional block. However, the advantage of ultrasound guidance on safety over traditional has not been adequately demonstrated in children except ilio-inguinal blocks.There are only a limited number of randomized control trails in children comparing ultrasound guided peripheral nerve block with other techniques. Available evidence in children demonstrates that ultrasound guided peripheral nerve blocks improve the quality, onset, duration and success rate of nerve blocks and help to lower the local anesthetic volume needed to perform blocks.     

Safety and Efficacy of the Infraclavicular Nerve Block Performed at Low Current

Abstract:   It has recently been suggested that peripheral nerve or plexus blocks performed with the use of a nerve stimulator at low currents (<0.5 mA) may result in neurologic damage. We studied the infraclavicular nerve block, performed with the use of a nerve stimulator and an insulated needle, in a prospective evaluation of efficacy and safety. During a one-year period, 248 patients undergoing infraclavicular nerve block were evaluated for block success rate and incidence of neurologic complication. All blocks were performed with the use of a nerve stimulator and an insulated needle at ≤0.3 mA. Success rate was 94%, which increased to 96% with surgical infiltration of local anesthetic. There were no intraoperative or immediate postoperative complications noted. After one week, only one patient had a neurologic complaint, and this was surgically related, referable to surgery performed on the radial nerve. We conclude that infraclavicular nerve blocks performed at low currents (≤0.3 mA) are safe and effective.     

Sonographically guided infraclavicular brachial plexus block in adults: a retrospective analysis of 1146 cases.

OBJECTIVE: The aim of this study was to analyze our experience in 1146 cases of sonographically guided infraclavicular brachial plexus block (ICBPB) performed over 32 months. METHODS: Anesthetic records of 1146 cases of sonographically guided ICBPB performed by our staff were studied retrospectively with the use of a database created by an automated anesthesia record-keeping system. The rates of successful blocks, failed blocks necessitating conversion to general anesthesia or requiring supplementation with local anesthetics, those requiring larger-than-usual doses of sedation, and complications were determined. Analysis included an attempt to determine the possible causes of inadequate blocks and complications. RESULTS: In 1138 patients (99.3%), the block was successful. Six patients had incomplete blocks requiring general anesthesia, and another 2 patients needed local anesthetic supplementation by the surgeons. Ninety-seven percent of the blocks were performed by residents directly supervised by an attending anesthesiologist who held the ultrasound probe. The mean age+/-SD of the patients was 39+/-15 years; the mean duration of surgery was 165+/-114 minutes; and the male-female ratio was 4:1. More than 50% of patients were obese. There were no reported cases of nerve injury, pneumothorax, or local anesthetic toxicity. Arterial punctures occurred in 8 (0.7%) patients, but all were inconsequential. CONCLUSIONS: The data from this retrospective study suggest that sonographic guidance provides a high success rate (99.3%) and improved safety for ICBPB. The increased operator team experience virtually eliminates failure and complications.     

Occipital Neuromodulation: Ultrasound Guidance for Peripheral Nerve Stimulator Implantation

We report a case of chronic left‐sided occipital neuralgia in a 21‐year old female patient. The patient in question suffered from chronic greater occipital neuralgia for a duration of many years, which had been refractory to other conservative medical management strategies. Blockade of the greater occipital nerve with local anesthetic was consistently useful in attenuating the patient's pain, though the effects were always short lived. Consequently, a successful trial of greater occipital nerve stimulation was undertaken. Compared with spinal cord stimulation, peripheral nerve stimulation devices are often more difficult to precisely place given limited ability to visualize soft tissues with traditional fluoroscopic guidance. Additionally, there are anatomic subtleties relevant to the greater occipital nerve that potentially complicate stimulator lead placement, both from the standpoint of optimal neuromodulation efficacy and maximum safety. Ultrasound technology is a maturing imaging modality that allows soft tissue visualization and is consequently useful in addressing each of these aforementioned concerns. The specific use of high‐frequency ultrasound guidance for this procedure simplified the initial device placement and allowed proper visualization of soft tissue structures, which facilitates precise device deployment. Additionally, the ability to identify relevant vascular structures may further increase the safety of stimulator lead placement. The potential advantages of ultrasound‐augmented procedural techniques, specifically as they pertain to occipital stimulator lead placement, are discussed with particular emphasis on potentially decreasing intraoperative and postoperative complications while optimizing stimulation efficacy.     

Ultrasound‐Guided Transversus Abdominis Plane Catheter for Chronic Abdominal Pain

Abstract Background and Objectives: Neural blockade of the thoracolumbar nerves supplying the anterior abdominal wall through transversus abdominis plane (TAP) has been investigated for different applications mainly for the acute pain management following abdominal surgical procedures. The role of this block for chronic pain syndromes is still to be discovered, and its value in chronic abdominal pain needs to be studied. We are presenting new application of the TAP technique for management of chronic abdominal pain syndrome using the continuous infusion. Case report: We present a case of an 18‐year‐old girl who underwent an uneventful laparoscopic cholecystectomy. Postoperatively, patient complained of chronic pain at the site of the surgery. All diagnostic and imaging studies were negative for a surgical or a medical cause. Multiple interventions including epidural blocks, transcutaneous electrical neural stimulation, and celiac plexus blocks had failed to relieve the pain. After discussion with the patient about the diagnostic nature of the procedure and the likelihood of recurrence of pain, TAP block was performed on the right side with significant improvement of pain for about 24 hours. The degree of pain relief experienced by the patient was very dramatic, which encouraged us to proceed with an indwelling TAP catheter to allow for continuous infusion of a local anesthetic. The patient was sent home with the continuous infusion through a TAP catheter for 2 weeks. From the day of catheter insertion and up to 9 months of follow‐up, patient had marked improvement of her pain level as well as her functional status and ability to perform her daily activities, after which our acute pain team stopped following the patient. Conclusion: A successful TAP block confirmed the peripheral (somatic) source of the abdominal pain and provided temporary analgesia after which an indwelling catheter was inserted, which provided prolonged pain relief.     

Clinical Utility of Low‐Volume Ultrasound‐Guided Interscalene Blockade

Objective. The purpose of this series is to describe cases in which ultrasound guidance was used to allow patients to receive the benefits of regional anesthesia while safely circumventing traditional contraindications to interscalene blockade (ISB). Methods. Targeted low‐volume ISB was performed in 3 patients in whom this procedure would typically be contraindicated because of phrenic nerve blockade or risk of local anesthetic toxicity. A patient with severe respiratory dysfunction, a patient undergoing bilateral shoulder surgery, and a patient requiring awake fiberoptic intubation underwent low‐volume ultrasound‐guided ISB. The ultrasound technique involved the use a low local anesthetic volume, anatomic identification of the brachial plexus trunk, needle placement opposite the phrenic nerve position, and control over local anesthetic spread. Results. In both patients in whom diaphragmatic paralysis was a concern, postoperative respiratory parameters indicated successful regional analgesia without evidence of phrenic nerve blockade. In the patient requiring an additional regional anesthetic procedure, ISB was performed with a local anesthetic volume low enough to avoid exceeding toxic safety thresholds. Conclusions. Although further studies are warranted, we report on 3 cases in which ultrasound guidance was used to allow patients to receive the benefits of regional anesthesia while safely avoiding standard contraindications to ISB. Ultrasound technology may allow providers to perform low‐volume brachial plexus blockade while avoiding issues related to phrenic nerve blockade and systemic local anesthetic toxicity.     

Preliminary Study of Ergonomic Behavior During Simulated Ultrasound‐Guided Regional Anesthesia Using a Head‐Mounted Display

A head‐mounted display provides continuous real‐time imaging within the practitioner's visual field. We evaluated the feasibility of using head‐mounted display technology to improve ergonomics in ultrasound‐guided regional anesthesia in a simulated environment. Two anesthesiologists performed an equal number of ultrasound‐guided popliteal‐sciatic nerve blocks using the head‐mounted display on a porcine hindquarter, and an independent observer assessed each practitioner's ergonomics (eg, head turning, arching, eye movements, and needle manipulation) and the overall block quality based on the injectate spread around the target nerve for each procedure. Both practitioners performed their procedures without directly viewing the ultrasound monitor, and neither practitioner showed poor ergonomic behavior. Head‐mounted display technology may offer potential advantages during ultrasound‐guided regional anesthesia.     

外周神经刺激器定位腰丛-坐骨神经阻滞在血管外科下肢手术中的应用

目的观察外周神经刺激器定位下的腰丛-坐骨神经阻滞应用于血管外科患者下肢手术的效果。方法20例血管外科拟行单侧下肢手术的患者,施行单侧腰丛-坐骨神经阻滞。腰丛阻滞为腰肌间隙入路,坐骨神经阻滞为臀区入路。采用神经刺激器定位技术,刺激器电流频率1 Hz,起始强度1 mA,麻醉总量为1%利多卡因30 mL、0.5%罗哌卡因30 mL。结果20例患者均阻滞完善,麻醉效果满意,术中生命体征平稳,血流动力学稳定。结论神经刺激器定位技术下腰丛-坐骨神经阻滞定位准确,客观指征明显,效果可靠,对患者各系统干扰小,对有严重合并症患者更为适用。     

Ultrasound‐guided dorsal penile nerve block performed in a case of zipper entrapment injury

Injury to the penis resulting from zipper entrapment is a painful condition that presents a unique anesthetic challenge to the emergency physician and may even require procedural sedation for removal. In this case report, we describe successful removal of zipper entrapment from the penis of a 34‐year‐old patient after the application of an ultrasound‐guided dorsal penile nerve block. We discuss the anatomy, sonographic features, and steps required for the nerve block procedure. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45 :589–591, 2017     

Ultrasound‐Guided Paravertebral Neurolytic Block: A Report of Two Cases

Paravertebral block is commonly used in the treatment for acute and chronic pain. The duration of paravertebral block could theoretically be prolonged with neurolytic agents. We report two cases of ultrasound‐guided neurolytic paravertebral blocks in patients suffering from intense cancer‐related thoracic pain. Ultrasound was used to identify the space and plane of injection at the mid‐thoracic level. Absolute alcohol was used to block the nerves at different segments. The two patients had great pain relief. Neurolytic paravertebral block can be a useful technique in patients with intractable cancer pain. Because of the risk of complication, it is recommended that this technique should be limited to relief of intractable pain in cancer patients with a poor prognosis.     

Case Study of Phrenic Nerve Paralysis: “I Can't Breathe!”

BackgroundThe anatomic course of the phrenic nerve runs in the fascia covering the anterior scalene muscle. Interscalene blocks are commonly performed by an anesthesiologist for shoulder surgery, such as a rotator cuff repair, total shoulder replacement, humeral fracture, or other arm surgery. Phrenic nerve palsy or paralysis is a known complication from interscalene block and is covered in multiple case reports and series in both Anesthesia and Neurosurgical literature, but only one case report in the Emergency Medicine literature.Case ReportThis case involves a 57-year-old man who had an uncomplicated arthroscopic rotator cuff repair with placement of interscalene block under care of anesthesia. He was discharged with a pain pump in place and then subsequently presented to the Emergency Department (ED) later that same day for evaluation of dyspnea. Using point-of-care ultrasound, his right diaphragm did not appear to be moving. Chest x-ray study revealed an elevated right hemidiaphragm. He was diagnosed with iatrogenic right phrenic nerve paralysis from interscalene block.Why Should an Emergency Physician Be Aware of This?Emergent diagnosis of phrenic nerve paralysis in the ED is complicated by a distressed patient and need for quick intervention. Most formal tests for this diagnosis are not immediately available to emergency physicians. Ultrasound is a rapid and reproducible, noninvasive resource with high sensitivity and specificity, making it an ideal imaging modality for the emergent evaluation of possible phrenic nerve palsy or paralysis.     

Ultrasound in interventional pain management

Ultrasound (US) is an increasingly used imaging technique in interventional pain management. It allows the identification of soft tissues, vessels and nerves, without exposing patients and personnel to radiation. Imaging can be performed continuously and the fluid injected is visualized in a real time fashion. Possible applications are nerve blocks of the cervical and lumbar zygapophysial joints, stellate ganglion block, intercostal nerve blocks, blocks of painful stump neuromas, caudal epidural injections and injections of trigger/tender points. Due to direct nerve visualization, US has a potential application for destructive procedures, such as cryoanalgesia, radiofrequency lesions or chemical neurolysis. Limitations are the poor resolution of narrow-gauge needles, the lost of resolution with increasing working depth and possible interference of echoes from overlying structures with the image of the target area. US opens new perspectives in interventional pain management. However, there is a need for clinical trials investigating efficacy and safety of US-guided pain procedures. Until these studies are made, US can not replace fluoroscopy or computed tomography in routine clinical practice and remainS domain of well-trained and experienced physicians. The limited evidence supporting the clinical utility of nerve blocks remains a problem, irrespective of the imaging technique employed.     

Ultrasound and chronic pain

Ultrasound (US) is an increasingly used imaging technique in interventional pain management. It allows the identification of soft tissues, vessels and nerves, without exposing patients and personnel to radiation. Imaging can be performed continuously and the fluid injected is visualized in a real time fashion. Possible applications are nerve blocks of the cervical and lumbar zygapophysial joints, stellate ganglion block, intercostal and paravertebral nerve blocks, inguinal nerve blocks, occipital nerve blocks, blocks of painful stump neuromas, caudal epidural injections and injections of trigger/tender points. Due to direct nerve visualization, US has a potential application for destructive procedures, such as cryoanalgesia, radiofrequency lesions or chemical neurolysis. Limitations are the poor resolution of narrow-gauge needles, the loss of resolution with increasing working depth and possible interference of echoes from overlying structures with the image of the target area. US opens new perspectives in interventional pain management. However, there is a need for more clinical trials investigating efficacy and safety of US-guided pain procedures. Until these studies are completed, US can not replace fluoroscopy or computed tomography in most interventional pain procedures and remains the domain of well-trained and experienced physicians. The limited evidence supporting the clinical utility of nerve blocks remains a problem, irrespective of the imaging technique employed.     

Ultrasound and chronic pain: Innovative approaches

Ultrasound (US) is an increasingly used imaging technique in interventional pain management. It allows the identification of soft tissues, vessels and nerves, without exposing patients and personnel to radiation. Imaging can be performed continuously and the fluid injected is visualized in a real time fashion. Possible applications are nerve blocks of the cervical and lumbar zygapophysial joints, stellate ganglion block, intercostal and paravertebral nerve blocks, inguinal nerve blocks, occipital nerve blocks, blocks of painful stump neuromas, caudal epidural injections and injections of trigger/tender points. Due to direct nerve visualization, US has a potential application for destructive procedures, such as cryoanalgesia, radiofrequency lesions or chemical neurolysis. Limitations are the poor resolution of narrow-gauge needles, the loss of resolution with increasing working depth and possible interference of echoes from overlying structures with the image of the target area. US opens new perspectives in interventional pain management. However, there is a need for more clinical trials investigating efficacy and safety of US-guided pain procedures. Until these studies are completed, US cannot replace fluoroscopy or computed tomography in most interventional pain procedures and remains the domain of well-trained and experienced physicians. The limited evidence supporting the clinical utility of nerve blocks remains a problem, irrespective of the imaging technique employed.     

超声引导锁骨上臂丛神经阻滞临床效果观察

摘 要　目的：观察超声实时引导锁骨上臂丛神经阻滞应用于上肢手术病人的临床效果。方法：120例行上肢手术的病人，ASAⅠ～Ⅲ级，均行锁骨上臂丛神经阻滞，随机分为三组，每组40例：神经刺激器组（N组）和超声引导A组（UA组）的局麻药为0.5%罗哌卡因20ml，超声引导B组（UB组）的局麻药为0.375%罗哌卡因20ml。观察桡神经、正中神经、尺神经、肌皮神经、前臂内侧皮神经感觉阻滞效果和肩关节、肘关节和腕关节运动阻滞程度，评定手术全程的麻醉效果，记录并发症。结果：与N组比较， UA组和UB组感觉阻滞效果较完善(P<0.01)。与N组和UA组比较，UB组腕关节、肘关节和肩关节运动阻滞程度较轻(P<0.05)。UA组和UB的麻醉效果较N组好(P<0.01)。三组均未记录到相关并发症发生。结论：超声引导技术改善了锁骨上臂丛神经阻滞的效果，能降低局麻药浓度或用量并保证镇痛效果完善，临床应用价值较高。     

Image Guidance Technologies for Interventional Pain Procedures: Ultrasound,Fluoroscopy, and CT

Chronic pain is a common medical condition. Patients who suffer uncontrolled chronic pain may require interventions including spinal injections and various nerve blocks. Interventional procedures have evolved and improved over time since epidural injection was first introduced for low back pain and sciatica in 1901. One of the major contributors in the improvement of these interventions is the advancement of imaging guidance technologies. The utilization of image guidance has dramatically improved the accuracy and safety of these interventions. The first image guidance technology adopted by pain specialists was fluoroscopy. This was followed by CT and ultrasound. Fluoroscopy can be used to visualize bony structures of the spine. It is still the most commonly used guidance technology in spinal injections. In the recent years, ultrasound guidance has been increasingly adopted by interventionists to perform various injections. Because its ability to visualize soft tissue, vessels, and nerves, this guidance technology appears to be a better option than fluoroscopy for interventions including SGB and celiac plexus blocks, when visualization of the vessels may prevent intravascular injection. The current evidence indicates the efficacies of these interventions are similar between ultrasound guidance and fluoroscopy guidance for SGB and celiac plexus blocks. For facet injections and interlaminar epidural steroid injections, it is important to visualize bony structures in order to perform these procedures accurately and safely. It is worth noting that facet joint injections can be done under ultrasound guidance with equivalent efficacy to fluoroscopic guidance. However, obese patients may present challenge for ultrasound guidance due to its poor visualization of deep anatomical structures. Regarding transforaminal epidural steroid injections, there are limited evidence to support that ultrasound guidance technology has equivalent efficacy and less complications comparing to fluoroscopy. However, further studies are required to prove the efficacy of ultrasound-guided transforaminal epidural injections. SI joint is unique due to its multiplanar orientation, irregular joint gap, partial ankylosis, and thick dorsal and interosseous ligament. Therefore, it can be difficult to access the joint space with fluoroscopic guidance and ultrasound guidance. CT scan, with its cross-sectional images, can identify posterior joint gap, is most likely the best guidance technology for this intervention. Intercostal nerves lie in the subcostal grove close to the plural space. Significant risk of pneumothorax is associated with intercostal blocks. Ultrasound can provide visualization of ribs and pleura. Therefore, it may improve the accuracy of the injection and reduce the risk of pneumothorax. At present time, most pain specialists are familiar with fluoroscopic guidance techniques, and fluoroscopic machines are readily available in the pain clinics. In the contrast, CT guidance can only be performed in specially equipped facilities. Ultrasound machine is generally portable and inexpensive in comparison to CT scanner and fluoroscopic machine. As pain specialists continue to improve their patient care, ultrasound and CT guidance will undoubtedly be incorporated more into the pain management practice. This review is based on a paucity of clinical evidence to compare these guidance technologies; clearly, more clinical studies is needed to further elucidate the pro and cons of each guidance method for various pain management interventions.