Ultrasound-guided rhomboid intercostal block (RIB) for acute scapula fracture in the emergency department.

INTRODUCTION: Proper pain in acute scapular fractures can be challenging to achieve due to their anatomy and location. While the current mainstay of treatment relies on opioids, the Rhomboid Intercostal Block (RIB) has been utilized for anesthesia to effectively treat pain for scapular fractures. However, it has not yet been utilized in the emergency department (ED). CASE REPORT: In this case report, we present the first documented use of RIB to treat pain safely and effectively in a 69-year-old male with a scapula fracture following a ground-level fall in the ED. The RIB was performed under ultrasound guidance, providing precise localization and administration of the nerve block. CONCLUSION: The RIB demonstrated successful pain management in the ED. Although hopeful, further research is needed to understand limitations, potential side effects, length of pain control, and overall clinical outcomes of the RIB in the ED.

Ultrasound guided costoclavicular block in pediatric population: A prospective observational study.

BACKGROUND: The costoclavicular space serves as an alternative approach to the infraclavicular brachial plexus block, and numerous studies in adults have demonstrated promising outcomes for distal upper limb surgery. Blocking the brachial plexus at this level is potentially advantageous because the cords are relatively superficial, located in close proximity to each other and easily identified using ultrasound. AIMS: This study aimed to assess the success rate and feasibility of costoclavicular block in children undergoing unilateral below elbow upper limb surgery. METHODS: Thirty children aged 2-12 years scheduled for unilateral below elbow surgery under general anesthesia were included. Costoclavicular block was performed under ultrasound and nerve stimulator guidance with 0.5% ropivacaine, 0.5 mL/kg. Success was evaluated based on the absence of significant hemodynamic response to skin incision made 20 min after the block. The sono-anatomy of costoclavicular space, ease of needling, complications, and the post-operative pain scores were assessed. RESULTS: The mean age and weight of the children were 6.5 ± 3.8 years and 19.7 ± 9.1 kg, respectively. The success rate of costoclavicular block in our cohort is 100%. Sonographic visualization was graded as excellent (Likert Scale 2) in 90% of cases. The plexus was located at a depth of 1.4 ± 0.3 cm from the skin, the lateral extent of cords from the artery was 0.8 ± 0.4 cm and they were observed inferior and lateral to the artery. The mean needling time was 3.6 ± 1.1 min. None of the children experienced complications such as vascular or pleural puncture, hematoma, Horner's syndrome or diaphragmatic palsy. Postoperative pain scores were low, and no rescue analgesia was required. CONCLUSIONS: In conclusion, the costoclavicular block exhibited a notably high success rate in pediatric population. This study substantiates that the three cords of the brachial plexus are consistently visible and superficial during ultrasound examination using this approach, confirming their separation from vascular structures and the reliable achievement of blockade without observed complications.

Investigation of Appropriate Scaling of Networks and Images for Convolutional Neural Network-Based Nerve Detection in Ultrasound-Guided Nerve Blocks.

Ultrasound imaging is an essential tool in anesthesiology, particularly for ultrasound-guided peripheral nerve blocks (US-PNBs). However, challenges such as speckle noise, acoustic shadows, and variability in nerve appearance complicate the accurate localization of nerve tissues. To address this issue, this study introduces a deep convolutional neural network (DCNN), specifically Scaled-YOLOv4, and investigates an appropriate network model and input image scaling for nerve detection on ultrasound images. Utilizing two datasets, a public dataset and an original dataset, we evaluated the effects of model scale and input image size on detection performance. Our findings reveal that smaller input images and larger model scales significantly improve detection accuracy. The optimal configuration of model size and input image size not only achieved high detection accuracy but also demonstrated real-time processing capabilities.

Novel use of ultrasound-guided transgluteal sciatic nerve block to treat severe herpes zoster pain along the S1 dermatome.

Patients presenting with herpes zoster (HZ) to emergency departments (EDs) across the United States represent a significant number of visits and have pain that is difficult to manage, sometimes even requiring opioid medications for adequate analgesia. Ultrasound-guided nerve blocks (UGNBs) are becoming more integrated into the ED physician's tool box for a multimodal approach to analgesia in various indications. Here we describe a novel use of the transgluteal sciatic UGNB for treatment of HZ pain along the S1 dermatome. A 48-year-old woman presented to the ED with right-sided leg pain associated with a HZ rash. After initially failing non-opioid pain management, the ED physician performed a transgluteal sciatic UGNB for our patient, leading to successful complete resolution of her pain, with no adverse effects reported. Our case highlights the potential role of using the transgluteal sciatic UGNB for analgesia related to HZ-related pain, as well as its potential opioid-sparing benefits. Although UGNBs require a baseline understanding of ultrasound technique for procedural guidance, this skillset has recently been incorporated as core competency within emergency medicine training in the United States. UGNBs should therefore be considered in the multimodal analgesic armamentarium for the ED treatment of HZ pain.

Clavipectoral plane block performed in the emergency department for analgesia after clavicular fractures.

Clavicle fractures are common injuries in the Emergency Department (ED). Adequate pain control with oral or intravenous medications is the central aspect of treatment. The ultrasound-guided clavipectoral plane block (CPB), previously described in anesthesia literature, offers complete analgesia of the clavicle with a low adverse effect profile. In this case series, we describe the first reported utilization of the CPB for analgesia for acute clavicular fractures in the ED. We performed the CPB for distal and midshaft clavicular fractures on patients who suffered from a variety of traumatic accidents including bicycle accidents, motorcycle accidents, and motor vehicle accidents. All patients experienced significant reductions in their reported pain without any reported complications. Given the need to provide patients with appropriate pain control in the ED, the CPB offers an effective, simple method for providing analgesia without known significant risks, including without the risks associated with high-dose systemic analgesia.

Efficacy and safety of remimazolam for procedural sedation during ultrasound-guided transversus abdominis plane block and rectus sheath block in patients undergoing abdominal tumor surgery: a single-center randomized controlled trial.

BACKGROUND: To explore the efficacy and safety of remimazolam for procedural sedation during ultrasound-guided nerve block administration in patients undergoing abdominal tumor surgery, in order to improve and optimize remimazolam use in procedural sedation and clinical anesthesia. METHODS: The enrolled patients were randomly divided into three groups: 50 patients in the remimazolam group (R group), 50 patients in the dexmedetomidine group (D group), and 50 patients in the midazolam group (M group). Before administering an ultrasound-guided nerve block, all patients received sufentanil AND remimazolam or midazolam or dexmedetomidine. Remimazolam 5 mg was administered intravenously in group R, dexmedetomidine 0.6 µg/kg was administered intravenously in group D, and midazolam 0.025 mg/kg was administered intravenously in group M. Sedation was evaluated by the Modified Observer's Assessment of Alertness and Sedation scale.When the Modified Observer's Alertness/Sedation (MOAA/S) score was ≤ 2, block operation was started. If the target sedation level was not reached, rescue sedatives of remimazolam 2.5 mg may be intravenously given in group R, dexmedetomidine 0.4 µg/kg be intravenously given in group D, 0.01 mg/kg midazolam may be intravenously given in Group M. Hemodynamic indicators (systolic and diastolic blood pressure, heart rate), pulse oxygen saturation, depth of anesthesia (Narcotrend), MOAA/S,and the incidences of hypoxemia, injection pain, bradycardia and requirement for rescue sedatives were monitored and recorded. RESULTS: Compared with the control groups (midazolam and dexmedetomidine groups), the Narcotrend index and MOAA/S decreased more in the remimazolam group (P < 0.01). Compared with the control groups, the incidence of hypoxemia and injection pain was slightly higher in the remimazolam group, but the difference was not statistically significant (P > 0.05). Compared with the dexmedetomidine group, the incidence of bradycardia was significantly lower in the remimazolam group. CONCLUSION: Remimazolam can be used safely for procedural sedation during ultrasound-guided nerve block administration in patients undergoing abdominal tumor surgery. The sedation effect is better than that with either midazolam or dexmedetomidine, and sedation can be achieved quickly without obvious hemodynamic fluctuations. Remimazolam is associated with better heart rate stability, and slightly higher incidences of hypoxemia and injection pain than are midazolam and dexmedetomidine (no statistically significant difference). The higher incidence of hypoxemia with remimazolam may be related to enhanced sufentanil opioid analgesia, and the mechanism of injection pain with remimazolam must be studied further and clarified. TRIAL REGISTRATION: This study was approved by the Ethics Committee of Anhui Provincial Cancer Hospital (Ethical Review 2021, No. 23) and registered at https://www.chictr.org.cn  (ChiCTR2000035388). The pre-registration time of this experiment is 09/08/2020, due to ethical committee of the hospital met irregularly,the ethical approval time is 21/06/2021. The recruitment of patients began after the ethical approval (21/06/2021) and registration update (06/07/2021).The study protocol followed the CONSORT guidelines. The study protocol was performed in the relevant guidelines.

Ultrasound-Guided Serratus Anterior Plane Block (SAPB) Improves Pain Control in Patients With Rib Fractures.

OBJECTIVES: The serratus anterior plane block (SAPB) is an ultrasound-guided compartment block; limited data suggest that it can decrease pain in patients with rib fractures or chest wall pain. We sought to determine the effect of SAPB on pain and incentive spirometry (IS) maximal vital capacity in adult patients with rib fractures. METHODS: We enrolled a prospective sample of adult patients with at least two unilateral rib fractures who were being admitted for pain control. SAPB was performed by trained emergency physicians. Patients reported pain on an 11-point Numeric Rating Scale at rest and during IS, before, 15, and 60 minutes after SAPB. RESULTS: Mean pain scores decreased by 1.8 (SD 2.17, 95% confidence interval [CI]: 0.79-2.81) at 15 minutes and 2.5 (SD 2.69, 95% CI: 1.24-3.76) at 60 minutes. Compared to pre-block pain scores during IS, mean pain scores decreased by 1.95 (SD 1.99, 95% CI: 1.02-2.88) at 15 minutes and 2.4 (SD 2.42, 95% CI: 1.27-3.53) at 60 minutes. Mean maximum vital capacity increased by 232 mL (SD 406, 95% CI: 36-427) at 60 minutes. Zero SAPB-attributable complications were identified in the 24 hours post-enrollment. CONCLUSIONS: In patients with multiple rib fractures, SAPB reduced pain scores at rest and during IS, and increased maximal vital capacity. The SABP may be a safe and effective modality for pain control in trauma patients with multiple rib fractures.

Usefulness of ultrasonography guided femoral and lateral femoral cutaneous nerve blocks in providing analgesia before giving spinal anaesthesia in patients undergoing surgery for intertrochanteric fracture of femur: A randomized clinical trial.

Background and Aims: It is challenging to give the patient position for subarachnoid block (SAB) as intertrochanteric (IT) fracture of the femur produces intolerable pain. In this study, we have analyzed the usefulness of combined ultrasonography (USG)-guided femoral nerve block (FNB) and lateral femoral cutaneous nerve block (LFCNB) to reduce the fracture pain before performing SAB. Material and Methods: A prospective, randomized, comparative study was conducted on 60 American society of anesthesiologists (ASA) grade I and II patients (18-80 years) scheduled for elective IT fracture surgery. Group A (n = 30) patients received USG-guided FNB and LFCNB using 0.75% ropivacaine before SAB. Group B patients (n = 30) received SAB only. All the patients received SAB (3 mL of 0.5% bupivacaine) by an anesthesiologist blinded to the patient groups. The patients were observed for quality of patient positioning for SAB, perioperative visual analog scale (VAS) scores, time to administration of SAB, and duration of analgesia and motor blockade. Statistical analysis was done by Student's t-test and Chi-square test. Results: Baseline VAS score (T1) was similar in both the groups. Mean T2 (VAS score just before SAB) in group-A (3.2 ± 0.98) was lower compared to group-B (8.23 ± 0.7) with P < 0.0001. The quality of patient positioning in group-A was good to optimal but in group-B, it was satisfactory to not satisfactory. Group-A had longer mean duration of analgesia 804 ± 114.28 minutes with P value < 0.0001 than group-B in which it was 200 ± 28.77 min. Backache was significant in group-B with P value of 0.038 compared to group-A. Conclusion: USG-guided FNB and LFCNB can be used as an effective supplementation to SAB in patients undergoing surgery for IT fracture of the femur as it reduces fracture site pain, provides good patient positioning during SAB, and prolongs postoperative analgesia.

Use of Continuous Electrical Impedance Measurement for Accurate Nerve Block in Rabbits.

OBJECTIVE: To perform an effective and safe nerve block, the needle must be placed near the target nerve while avoiding nerve damage. Our objective was to conduct an animal study to determine whether changes in electrical impedance (EI) could be used to guide the needle and achieve a safe and accurate nerve block. METHODS: We measured the EI of rabbit tissues during ultrasound-guided sciatic nerve block using a bipolar needle via the in-plane needle approach. The EI values and needle track on the ultrasound monitor were video-recorded. When there was a change in the EI, the needle advancement was stopped, and a stained anesthetic was injected. Subsequently, the animals were euthanized, and the anesthetic-stained tissue was examined via dissection, while the other tissue was preserved at -80°C for microscopic analysis. RESULTS: The EI remained stable as the needle advanced through the muscle (extraneural); however, it markedly decreased when the needle tip contacted the nerve or slightly punctured the epineurium (paraneural). The mean extra- and paraneural EIs were 4.92 ± 1.31 kΩ (range, 2.39-9.67 kΩ) and 2.86 ± 0.96 kΩ (range, 1.66-5.13 kΩ), respectively. Examination of the dissections and cryostat sections showed anesthetic delivery around the nerve. CONCLUSIONS: EI values differed between extra- and paraneural sites, and monitoring these values allowed prediction of the needle tip location with respect to the target nerve. Real-time EI measurement could improve the nerve block.

Role of ultrasound-guided perineural injection of the posterior antebrachial cutaneous nerve for diagnosis and potential treatment of chronic lateral elbow pain.

OBJECTIVE: To examine diagnostic and therapeutic utility of novel ultrasound-guided perineural injection of posterior antebrachial cutaneous nerve in chronic lateral elbow pain. MATERIALS AND METHODS: We performed a retrospective analysis of ultrasound-guided perineural injection of the posterior antebrachial cutaneous nerve with local anesthetic with or without corticosteroid in patients with chronic lateral elbow pain. Data variables collected included patient demographics, illness course, diagnostic ultrasound findings, immediate pre- and post-injection pain using numeric rating pain scale between 0 and 10, injection complications, and post-injection outcomes. RESULTS: Fifteen patients (9 females and 6 males) with average age 46.9 (range 16-69 years) underwent 20 perineural injections between 2009 and 2019. Patients had on average 84% reduction in pain immediately after the injection (median pre- and post-procedure numeric rating pain scale of 6 and 0, respectively, p < 0.001). Patients had pain relief for an average of 15 h (range 2-48 h) when only local anesthetic was injected, compared with average pain relief of 26.5 days (range 2 h-43 days) when local anesthetic was combined with corticosteroid, p = 0.01. CONCLUSION: Novel ultrasound-guided perineural anesthetic injections around the posterior antebrachial cutaneous nerve can be performed safely and have diagnostic and potentially therapeutic utility in select patients with chronic refractory lateral elbow pain.

Novel Use of 3-Point Genicular Nerve Block for Acute Knee Pain in the Emergency Department.

BACKGROUND: Ultrasound-guided genicular nerve blocks (GNBs) in the emergency department (ED) have easily identifiable anatomic targets and offer an opportunity to provide safe, effective, motor-sparing analgesia for acute knee pain. Case Report A 68-year-old woman presented with acute, 8/10 right knee pain due to an isolated right lateral tibial plateau fracture. After informed consent and with the ultrasound in the sagittal plane, the superior lateral (SLGN), superior medial (SMGN), and inferior medial (IMGN) genicular nerves were identified at the junction of their respective femoral or tibial epicondyle and femoral or tibial epiphysis. The skin was anesthetized and an echogenic needle was inserted under ultrasound guidance to inject 1.0 mL of 0.5% bupivacaine around the right SLGN, SMGN, and IMGN. Approximately 30 minutes after the GNBs, the patient reported 0/10 pain at rest and 1/10 pain with movement. She did not require opioids during her ED visit or upon discharge. Why Should an Emergency Physician Be Aware of This? GNBs show promise as a useful tool to provide acute and medium-term motor-sparing analgesia in a patient with acute knee pain. GNBs have easy-to-recognize anatomic targets on ultrasound and may be a suitable adjunct or alternative to a multimodal pain regimen in the emergency department.

Review of Ilioinguinal Nerve Blocks for Ilioinguinal Neuralgia Post Hernia Surgery.

PURPOSE OF REVIEW: The purpose of this review is to evaluate the current evidence on ultrasound-guided ilioinguinal nerve blocks for ilioinguinal neuralgia post hernia surgery. METHODS: A literature search was performed to find all relevant case reports, case series, prospective or retrospective cohort studies, and randomized controlled trials (RCTs) where ultrasound-guided or landmark-based ilioinguinal nerve blocks were used for ilioinguinal neuralgia post-inguinal hernia surgery. RECENT FINDINGS: A total of six studies were identified with suitable data for inclusion. Three studies were retrospective, two studies were prospective, and one study was a randomized controlled trial. A total of 133 subjects were enrolled across these studies. Approximately 55-70% had a beneficial analgesic response to treatment. No major complications were reported in these studies. Ultrasound- and landmark-based ilioinguinal nerve blocks are safe and effective for pain relief post inguinal hernia surgery. Although there were two studies that did not show a statically significant difference in both techniques, the ultrasound-guided injection has the advantage of direct visualization of pathology, more accurate needle placement, and decreased risks of intravascular injections.

An Innovative Pain Control Method Using Peripheral Nerve Block and Patient-Controlled Analgesia With Ketorolac After Bone Surgery in the Ankle Area: A Prospective Study.

Although postoperative pain is inevitable after bone surgery, there is no general consensus regarding its ideal management. We hypothesized that the combination of ultrasound-guided peripheral nerve block (PNB) and patient-controlled analgesia (PCA) with ketorolac would be useful for pain control and reducing opioid usage. This prospective study aimed to evaluate the effectiveness of this method. This study included 95 patients aged >18 years who underwent bone surgery in the ankle area from June to December 2018. All operations were performed under anesthetic PNB, and additional PNB was given for pain control ∼11 hours after preoperative PNB. An additional PCA with ketorolac, started before rebound pain was experienced, was used for pain control in group A (49 patients) but not group B (46 patients). We used intramuscular injection with pethidine or ketorolac as rescue analgesics if pain persisted. A visual analogue scale (VAS) for pain was used to quantify pain at 6, 12, 18, 24, 36, 48, and 72 hours postoperatively. Patient satisfaction was assessed, along with side effects in both groups. VAS pain scores differed significantly between the groups at 24 hours after the operation (p = .013). All patients in group A were satisfied with the pain control method; however, 5 patients in group B were dissatisfied (p = .001), 3 owing to severe postoperative pain and 2 owing to postoperative nausea and vomiting. An average of 0.75 and 11.40 mg pethidine per patient was used in groups A and B, respectively, for 3 days. We concluded that the combined use of ultrasound-guided PNB and PCA with ketorolac can be an effective postoperative method of pain control that can reduce opioid usage.

Incidence of sub-perineural injection using a targeted intracluster supraclavicular ultrasound-guided approach in cadavers.

BACKGROUND: Multi-injection targeted intracluster injection ultrasound-guided supraclavicular brachial plexus block has been advocated to provide a faster onset of anaesthesia compared with a double injection technique. By placing the needle within clusters of hypoechoic structures, corresponding to neural tissue, this technique may increase needle trauma and the incidence of nerve injury. This study assessed the rate of sub-perineural needle placement with a single intracluster brachial plexus injection in the supraclavicular fossa of human cadavers. METHODS: A single ultrasound-guided intracluster brachial plexus injection was performed bilaterally at the supraclavicular fossa on 21 lightly embalmed clinical grade cadavers. Using an in-plane technique, an echogenic needle was positioned to target the middle or lower trunk 'cluster', where 0.2 ml black India ink was injected. An effort was taken to avoid the hypoechoic structures with the needle tip. Tissue samples were assessed histologically by two experienced reviewers. RESULTS: All 42 injections were sonographically assessed to be within the 'main cluster'. Ink was extra-epineural in 13/41 (32%), sub-epineural but outside perineurium in 18/41 (44%), and sub-perineural in 10/41 sections (24%; 95% confidence interval, 13-41%). The histology from one injection was uninterpretable. Of the 10 sub-perineural deposits, the ink was intrafascicular in nine sections. CONCLUSIONS: We observed a high rate of sub-perineural injection with a single intracluster injection. Thus the targeted intracluster injection supraclavicular block cannot be recommended until further evidence is available regarding the safety of this technique.

Ultrasound-guided peripheral forearm nerve block for digit fractures in a pediatric emergency department.

Although ultrasound-guided peripheral nerve block (UGPNB) has recently been introduced into pediatric emergency departments (EDs), knowledge of its use is still limited among pediatric emergency physicians. Ultrasound-guided ulnar nerve block (UGUNB) is a form of peripheral nerve block available for controlling the pain caused by phalangeal injuries, but studies of its use in pediatric patients are still scarce. The aim of this case series was to describe the experience of UGUNB use for pediatric phalangeal fractures in a pediatric ED setting. In all the patients with phalangeal fractures, the ulnar nerve was successfully visualized using a hockey-stick type transducer. Approximately 0.1-0.2 mg/kg of 1% lidocaine was used as the nerve block. The procedure was effective for pain control, and fracture reduction was successfully performed without the need for rescue analgesia. This case series demonstrated that UGUNB has the potential to be a useful alternative to conventional pain management in pediatric fifth digit injuries.

Management of an Acute Exacerbation of Chronic Neuropathic Pain in the Emergency Department: A Case to Support Ultrasound-Guided Forearm Nerve Blocks.

BACKGROUND: Acute on chronic neuropathic pain is often refractory to analgesics and can be challenging to treat in the emergency department (ED). In addition, systemic medications such as opiates and nonsteroidal inflammatory drugs have risks, including hypotension and kidney injury, respectively. Difficulties in managing pain in patients with neuropathy can lead to prolonged ED stays, undesired admissions, and subsequent increased health care costs. CASE REPORT: We describe the case of a 51-year-old woman who presented to the ED on two separate occasions for left forearm pain secondary to chronic ulnar neuropathy. During her first ED visit, the patient received multiple rounds of intravenous opiates and required hospital admission, which was complicated by opiate-induced hypotension. During her second visit, she underwent an ultrasound-guided ulnar nerve block performed by the emergency physician; her pain resolved and she was discharged home. WHY SHOULD EMERGENCY PHYSICIANS BE AWARE OF THIS?: Ultrasound-guided nerve blocks are an effective, safe, and relatively inexpensive alternative to opioids. Our case demonstrates that emergency providers may be able to perform ultrasound-guided regional anesthesia to treat an acute exacerbation of chronic neuropathic pain.

Comparison of lidocaine and lidocaine-epinephrine for the paravertebral brachial plexus block in dogs.

OBJECTIVE: To compare the motor and sensory block efficacy and duration of a modified paravertebral brachial plexus block (PBPB) after administration of lidocaine alone (LI) or combined with epinephrine (LE). STUDY DESIGN: Prospective, randomized, blinded, crossover study. ANIMALS: A total of eight healthy female Beagle dogs. METHODS: Under general anesthesia, modified PBPB was performed on the left thoracic limb using neurostimulation and/or ultrasound guidance to administer lidocaine (2 mg kg-1; 0.2 mL kg-1) either alone (treatment LI, n = 10) or with epinephrine (1:100,000; treatment LE, n = 9). Sensory block was evaluated through reaction to a painful mechanical stimulus applied at five sites on the limb. Motor block effect was evaluated according to visual gait assessments and thoracic limb vertical force measurements under dynamic and static conditions. Data were analyzed using repeated-measures generalized estimating equations. All statistical tests were performed two-sided at the α = 0.05 significance threshold. RESULTS: The duration of sensory block did not differ significantly between treatments. Visible gait impairment was more persistent in LE than in LI (118 ± 63 minutes for LI and 163 ± 23 minutes for LE; mean ± standard deviation) (p = 0.027). At nadir value, dynamic peak vertical force was lower in LE than in LI (p = 0.007). For both dynamic and static evaluations, the nadir and the return to baseline force were delayed in LE (return to normal at 180-200 minutes) when compared with LI (130-140 minutes) (p < 0.005). CONCLUSIONS AND CLINICAL RELEVANCE: The addition of epinephrine to lidocaine prolonged the duration and increased the intensity of the regional block, as verified by visual gait assessment and kinetic analysis. No significant difference was noted between treatments regarding sensory blockade. Kinetic analysis could be useful to evaluate regional anesthetic effect in dogs.

Feasibility of the head-mounted display for ultrasound-guided nerve blocks: a pilot simulator study.

The head-mounted display (HMD) has the potential to improve the quality of ultrasound-guided procedures. The aim of this non-clinical crossover designed study is to evaluate the feasibility of the HMD for ultrasound-guided nerve block. Eight experienced anesthesiologists performed ultrasound-guided peripheral nerve blocks on a training simulator with a standard approach and with an upside-down approach. Each approach was performed with a control conventional method and with an HMD. The ultrasound image and operating field were recorded by video camera. The procedure time and fractional percentage of time with the needle visible on the ultrasound image were determined. The needle insertion times were 10.4 ± 7.2 s with the control method and 6.8 ± 5.3 s with the HMD method for the standard approach (p = 0.03), and 18.1 ± 10.1 with the control method and 11.8 ± 9.5 s with the HMD method for the upside-down approach (p = 0.002). The fractional percentages of time with the needle visible on the ultrasound image were 34.1 ± 20.9 with the control method and 56.5 ± 13.6% with the HMD method for the standard approach (p < 0.001), and 20.1 ± 13.4 with the control method and 38.2 ± 21.2% with the HMD method for the upside-down approach (p = 0.001). In conclusion, this pilot study using a simulation model indicated that the use of an HMD shortened the procedure time and improved the needle visibility on ultrasound.

Ultrasound-guided ilioinguinal/iliohypogastric block did not reduce emergence delirium after ambulatory pediatric inguinal hernia repair: a prospective randomized double-blind study.

PURPOSE: Emergence delirium (ED) is a common postoperative complication of ambulatory pediatric surgery done under general anesthesia with sevoflurane. However, perioperative analgesic techniques have been shown to reduce sevoflurane-induced ED. The primary objective of this investigation was to examine whether an ultrasound-guided ilioinguinal/iliohypogastric (II/IH) nerve block for ambulatory pediatric inguinal hernia repair could reduce the incidence of sevoflurane-induced ED. METHODS: The subjects of this prospective randomized double-blind study were 40 boys ranging in age from 1 to 6 years, who were scheduled to undergo ambulatory inguinal hernia repair. The patients were randomized to either receive or not to receive an ultrasound-guided II/IH nerve block (Group B and Group NB, respectively). General anesthesia was maintained with sevoflurane and nitrous oxide. The primary outcome assessed was ED, evaluated using the Pediatric Anesthesia Emergence Delirium (PAED) scale 30 min after emergence from general anesthesia. The secondary outcomes assessed were postoperative pain, evaluated using the Behavioral Observational Pain Scale (BOPS), and the amount of intra-operative sevoflurane given. RESULTS: The median PAED scale scores did not differ between Groups B and NB at 30 min (P = 0.41). BOPS scores also did not differ significantly between the groups, but the mean amount of intraoperative sevoflurane given was significantly lower in Group B than in Group NB (P < 0.01). CONCLUSIONS: Ultrasound-guided II/IH nerve block for ambulatory pediatric inguinal hernia repair did not reduce ED, but it did decrease the amount of intra-operative sevoflurane needed. CLINICAL TRIAL REGISTRATION: UMIN000008586.