The PReliMinAry (Pain Relief in Major Amputation) Survey.

OBJECTIVES: Major Lower Limb Amputation (MLLA) is associated with significant peri- and post-operative pain and has been identified as a research priority by patient and healthcare groups. The PReliMinAry survey was designed to evaluate existing MLLA analgesia strategies; identifying areas of equipoise and informing future research. METHODS: A targeted multi-national, multi-disciplinary survey was conducted via SurveyMonkey® (October 5, 2020-November 3, 2020) and advertised via social media and society email lists. The 10-questions explored 'pain-team' services, pre-operative neuroleptic medication, pre-incision peripheral nerve blocks and catheters, surgically placed nerve catheters, post-operative adjunctive regimens, future research engagement and equipoise. RESULTS: Seventy-six responses were received from 60 hospitals worldwide. Twelve hospitals(20%) had a dedicated MLLA pain team, 7(12%) had none. Most pain teams (n = 52; 87%) assessed pain with a 0-10 numerical rating scale. Over half of respondents "never" preloaded patients with oral neuroleptic agents(n= 42/76; 55%). Forty-seven hospitals(78%) utilized patient controlled opioid analgesia. Most hospitals are able to provide pre-incision loco-regional peripheral nerve blocks, nerve catheters and surgical nerve catheters (95%, 77%, and 90% respectively), but use was variable. Ultrasound(US) guided peripheral nerve catheters were "infrequently" or "never" used in 57% of hospitals, whilst 23% "infrequently" or "never" utilize surgically placed nerve catheters. CONCLUSIONS: The survey revealed a preference towards 'single-shot' nerve blocks and surgical catheters. A difference between the use of US guided nerve catheters and those surgically placed likely reflects the difference of literature evaluating these techniques. Most respondents felt there was equipoise surrounding future trials evaluating nerve blocks/catheters, but less so for surgical catheters.

Ultrasound-directed reduction of distal radius fractures in adults: a systematic review.

OBJECTIVE: To conduct a systematic review of the clinical literature to determine whether ultrasound can be used to improve the reduction of distal radius fractures in adults in the ED. METHODOLOGY: A study protocol was registered on PROSPERO. EMBASE, PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov of the US National Library of Medicine were searched for studies evaluating ultrasound-assisted distal radial fracture reductions in comparison with standard care. The primary outcome of interest was manipulation success rates, defined as the proportion of fracture manipulations resulting in acceptable anatomical alignment, with secondary outcome being subsequent surgical intervention rates in ultrasound and standard care group of patients. RESULTS: 248 were screened at title and abstract, and 10 studies were included for a narrative synthesis. The quality of this evidence is limited but suggests ultrasound is accurate in determining distal radius fracture reduction and may improve the quality of reduction compared with standard care. However, there is insufficient evidence to determine whether this affects the rate of subsequent surgical intervention or functional outcome. CONCLUSION: There is a lack of evidence that using ultrasound in the closed reduction of distal radius fractures benefits patients. Properly conducted randomised controlled trials with patient-orientated outcomes are crucial to investigate this technology.

Regional Variation in Usage of Ultrasound-Guided Femoral Access in the Vascular Quality Initiative.

BACKGROUND: Access site complications are among the most common complications following peripheral vascular interventions. Previous studies have demonstrated a reduced rate of complications with ultrasound-guided vascular access (UGVA). The objective of this study is to evaluate the regional use of UGVA within the Vascular Quality Initiative (VQI). METHODS: The VQI peripheral intervention module between 2010 and 2018 was evaluated. Regional ID was used to compare distribution of ultrasound usage. Regions were grouped into terciles based on the rate of ultrasound use. Patients were categorized based on type of access. Primary outcome was use of ultrasound across regions. Secondary outcomes were access site complications. RESULTS: Over 43,000 cases across the 18 VQI regions were evaluated. The average rate of ultrasound usage was 71% across the regions with a wide variation (range 38-97%). There is a significant difference in utilization among the top third (87%), middle third (79%), and bottom third (58%) (P < 0.001). Average sheath size was similar across all 3 groups. A higher use of ultrasound-guided access was associated with significantly fewer access site complications (top third 1.96% vs. bottom third 3.04%, P < 0.001), the most significant of which was a decreased rate of access site hematoma (top third 1.37% vs. bottom third 2.35%, P < 0.001). CONCLUSIONS: This is the first study to evaluate ultrasound-guided access across VQI regions. Our results demonstrate that despite strong evidence supporting the utilization of UGVA, there remains a wide variation in ultrasound usage across VQI regions. This is also the first study to show that the prevalence of ultrasound use in peripheral vascular interventions (PVI) is inversely related to access site complications. Given all of the data supporting the usage of UGVA across numerous specialties, our findings encourage the consideration of an ultrasound-first approach for vascular access in PVI and the implementation of targeted strategies and evidence-based guidelines to enhance UGVA utilization in PVI.

Recent Advances in Vascular Imaging.

Recent advances in vascular imaging have enabled us to uncover the underlying mechanisms of vascular diseases both ex vivo and in vivo. In the past decade, efforts have been made to establish various methodologies for evaluation of atherosclerotic plaque progression and vascular inflammatory changes in addition to biomarkers and clinical manifestations. Several recent publications in Arteriosclerosis, Thrombosis, and Vascular Biology highlighted the essential roles of in vivo and ex vivo vascular imaging, including magnetic resonance image, computed tomography, positron emission tomography/scintigraphy, ultrasonography, intravascular ultrasound, and most recently, optical coherence tomography, all of which can be used in bench and clinical studies at relative ease. With new methods proposed in several landmark studies, these clinically available imaging modalities will be used in the near future. Moreover, future development of intravascular imaging modalities, such as optical coherence tomography-intravascular ultrasound, optical coherence tomography-near-infrared autofluorescence, polarized-sensitive optical coherence tomography, and micro-optical coherence tomography, are anticipated for better management of patients with cardiovascular disease. In this review article, we will overview recent advances in vascular imaging and ongoing works for future developments.

Ultrasound-guided peripheral vascular catheterization in pediatric patients: a narrative review.

Peripheral vascular catheterization (PVC) in pediatric patients is technically challenging. Ultrasound guidance has gained the most interest in perioperative and intensive care fields because it visualizes the exact location of small target vessels and is less invasive than other techniques. There have been a growing number of studies related to ultrasound guidance for PVC with or without difficult access in pediatric patients, and most findings have demonstrated its superiority to other techniques. There are various ultrasound guidance approaches, and a comprehensive understanding of the basics, operator experience, and selection of appropriate techniques is required for the successful utilization of this technique. This narrative review summarizes the literature regarding ultrasound-guided PVC principles, approaches, and pitfalls to improve its clinical performance in pediatric settings.

Ultrasonographic measurement of the optic nerve sheath in the differential diagnosis and follow-up of migraine with and without aura: A pilot study.

OBJECTIVE: Headache continues to be a common cause of emergency admissions. At first glance, primary headaches may not be distinguished from secondary headaches. This study aimed to evaluate the use of ultrasonic measurement of optic nerve sheath diameter (ONSD) in the clinical diagnosis of migraine patients during attack and during periods without attacks. PATIENTS AND METHODS: This prospective study was conducted at the emergency department and neurology outpatient clinic of a tertiary hospital between October 2019 and January 2020. Patients diagnosed with episodic migraine and between ages 18-60 were included in the study. Migraine diagnosis and classification were based on criteria from the 2018 International Classification of Headache Disorders. ONSD measurement was performed with ultrasonography. ONSD measurements of the same migraine patients during attack and attack-free periods were compared with measurements of healthy volunteers. RESULTS: A total of 82 participants consisting of 42 migraine patients and 40 control subjects were evaluated. In the control group, mean ONSD of the right eye was 4.88 ±â€¯0.31 mm and mean ONSD of the left eye was 4.86 ±â€¯0.31 mm. Mean ONSD measurement of the left eye was 4.80 ±â€¯0.36 mm and mean ONSD of the right eye was 4.82 ±â€¯0.37 during the attack period of the migraine patients. There was no significant difference between the migraine patients and the control group according to right and left eye ONSD measurements (attack-free period: p = 0.200, p = 0.448; attack period: p = 0.338, p = 0.660, respectively). There was no significant difference between ONSD measurements during the attack period and attack-free period in migraine patients (right eye p = 0.32; left eye p = 0.532). CONCLUSION: The results of our study indicate that ONSD measurements may provide clinical insight into differential diagnosis preceding neuroimaging in migraine patients. On the other hand, since our study is the first on this topic, it should be noted that further studies are needed to come to a conclusion.

Efficacy of ultrasound-guided technique for radial artery catheterization in pediatric populations: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: The use of an ultrasound-guided technique for radial arterial catheterization has not been well established in pediatric patients. We conducted a systematic review and meta-analysis to evaluate the efficacy of the ultrasound-guided technique for radial artery catheterization in pediatric populations. METHOD: A systematic review of PubMed, Medline, Embase, and the Cochrane library was performed from their date of inception to December 2019. In this meta-analysis, we conducted online searches using the search terms "ultrasonography," "ultrasonics," "ultrasound-guided," "ultrasound," "radial artery," "radial arterial," "catheter," "cannula," and "catheterization." The rate of the first-attempt and total success, mean attempts to success, mean time to success, and incidence of complications (hematomas) were extracted. Data analysis was performed with RevMan 5.3.5. RESULTS: From 7 relevant studies, 558 radial artery catheterizations were enrolled, including 274 ultrasound-guided and 284 palpation catheterizations. The ultrasound-guided technique could significantly improve the rate of first-attempt and total success (RR 1.78, 95% CI 1.46 to 2.18, P < 0.00001; RR 1.33; 95% CI 1.20 to 1.48; P < 0.00001). However, there was significant heterogeneity for the total success rate among the included studies (I2 = 67%). The ultrasound-guided radial artery catheterization was also associated with less mean attempts and mean time to success (WMD - 1.13, 95% CI - 1.58 to - 0.69; WMD - 72.97 s, 95% CI - 134.41 to - 11.52) and lower incidence of the hematomas (RR 0.17, 95% CI 0.07 to 0.41). CONCLUSIONS: The use of the ultrasound-guided technique could improve the success rate of radial arterial catheterization and reduce the incidence of hematomas in pediatric patients. However, the results should be interpreted cautiously due to the heterogeneity among the studies.

Current Image-Guided Interventions in Pediatric Surgery.

Traditionally, surgical technique has not included imaging modalities. Image guidance had largely been left to radiology specialties. However, in recent years, tremendous advances in imaging have taken place with improvements in image quality, portability, and accessibility. With these advances, surgeons have begun to realize the benefits of fusing image guidance with traditional surgical approaches. Subsequently, many novel surgical approaches utilizing image guidance have been developed that allow for precise, safe, and minimally invasive management of conditions that previously required open surgical intervention.

Long-term ultrasound follow-up of intrathyroidal ectopic thymus in children.

OBJECTIVE: To present the sonographic follow-up of intrathyroidal ectopic thymus (IET) in children and adolescent patients. PATIENTS: Out of the 507 children referred to FNAB between 2006 and 2018, 30 (5.9%) pediatric patients (10 females), mean age 5.7 years (1.2-13.8, median 4.9 years) were diagnosed with IET. METHODS: A retrospective analysis of medical files of patients diagnosed with IET between 2006 and 2018. Assessed data included ultrasound characterisation, elastographic strain ratio (SR) results and hormonal evaluation. RESULTS: Analysis of thyroid US scans revealed that the mean age at the first thyroid ultrasound was 5.7 (1.2-13.8, median 4.9) years, and at the last US 10.7 (3.7-18, median 10.5) years. The mean time of the IET observation was 59.6 (2-148, median 53.5) months. On US, IET was hypoechoic with multiple linear and punctate echoes, hypovascular, fusiform on longitudinal plane and round or polygonal on an axial plane, more common in the right thyroid lobe (66.7%) and located in the posterior part of the lobes (54.5%), bilateral in two patients and multifocal in one patient. SR of IET was similar to the surrounding normal thyroid tissue. Complete regression of IET was observed in 12/30 patients after a mean time of 81.7 months (median 76.5), at the mean age of 13.7 (9.2-18, median 13.9) years. FNAB was performed in 10/30 and a hemithyroidectomy in 1/30 IET patients. In the FNAB (+) group, patients were younger (5.08 vs 6.08 years) and lesions were larger (0.12 ml vs 0.05 ml) than in the FNAB (-) group. All patients with IET were euthyroid with negative TPOAb and TgAb levels. CONCLUSION: The reproducibility of unique ultrasound features of IETs allows for safe long-term follow-up of these benign lesions in the majority of pediatric patients: not only monitoring the regression of IET but also screening towards the rare occurrence of a tumor arising from the IET.

Trends and Outcomes of Intravascular Imaging-guided Percutaneous Coronary Intervention in the United States.

INTRODUCTION: Intravascular imaging-guided percutaneous coronary intervention (PCI) has shown to improve outcomes in randomized controlled trials. However, there are little real-world data about intravascular imaging utilization during PCI and its outcomes in the United States. METHODS: We conducted an observational analysis on the use of intravascular imaging (Intravascular Ultrasound or Optical Coherence Tomography)-guided PCI in 2,425,036 patients undergoing PCI between January 2010 and December 2014 from the Nationwide Inpatient Sample database. Utilizing propensity score matching, 83,988 matched pairs were identified. The primary outcome was in-hospital mortality. The secondary outcomes included cardiogenic shock and acute kidney injury. RESULTS: Among the 2,425,036 patients, 161,808 (6.7%) underwent imaging-guided PCI. Use of imaging-guidance increased from 6% in 2010 to 6.6% in 2014 (Ptrend < 0.001). The in-hospital mortality was significantly different between imaging-guided PCI and angiography-guided PCI [1.0% vs. 1.5%; adjusted OR: 0.67; 95% confidence interval (CI): 0.54-0.83, P < 0.001]. The rates of cardiogenic shock (2.5% vs. 3.1%; adjusted OR: 0.78; 95% CI: 0.66-0.93; P = 0.005) were significantly lower in imaging-guided PCI group and acute kidney injury rates (7.0% vs. 7.1%; adjusted OR: 0.99; 95% CI: 0.89-1.12; P = 0.919) were not significantly different. CONCLUSIONS: Imaging-guided PCI is associated with lower in-hospital mortality. Yet, a small proportion of patients undergoing PCI have imaging-guidance.

Ultrasound-guided bilateral quadratus lumborum block vs. intrathecal morphine for postoperative analgesia after cesarean section: a randomized controlled trial.

BACKGROUND: Adequate pain control after cesarean section (CS) is crucial for mothers caring for newborns, and early ambulation to avoid thromboembolism and chronic abdominal and pelvic pain. This randomized controlled trial compared the efficacy of quadratus lumborum block (QLB) and intrathecal morphine (ITM) for analgesia after CS. METHODS: Ninety women at ≥ 37 weeks pregnancy scheduled for elective CS were enrolled. All patients received spinal anesthesia and post-operative QLB. They were randomly allocated to Control (anesthesia: 0.1 ml saline, QLB: 24 ml saline), ITM (anesthesia: 0.1 mg morphine, QLB: 24 ml saline), or QLB groups (anesthesia: 0.1 ml saline, QLB: 24 ml 0.375% ropivacaine). Integrated analgesia score (IAS) and numerical rating scale (NRS) scores at rest and during movement, morphine requirements in the first 48 h, time to first morphine dose, and morphine-related side effects were recorded. RESULTS: IASs and NRS scores at rest and during movement were significantly lower in QLB and ITM group than in Control group. Moreover, IASs and NRS scores at rest and during movement were lower in QLB group than in ITM group. Time to first morphine dose was significantly longer in QLB group than in ITM and Control group. Furthermore, morphine requirements in the first 48 h were significantly lower in QLB group than ITM and Control group. Incidence of morphine-related side effects was significantly higher in ITM group than in QLB and Control group. CONCLUSIONS: QLB and ITM are effective analgesic regimens after CS. However, QLB provides better long-lasting analgesia and reduced total postoperative morphine consumption.

Intravascular ultrasound, optical coherence tomography, and fractional flow reserve use in acute myocardial infarction.

BACKGROUND: There are limited data on the use of intravascular ultrasound (IVUS), optical coherence tomography (OCT), and fractional flow reserve (FFR) during acute myocardial infarction (AMI). OBJECTIVES: To assess the temporal trends of IVUS, OCT, and FFR use in AMI. METHODS: A retrospective cohort study from the National Inpatient Sample (2004-2014) was designed to include AMI admissions that received coronary angiography. Administrative codes were used to identify percutaneous coronary intervention (PCI), IVUS, OCT, and FFR. Outcomes included temporal trends, inhospital mortality and resource utilization stratified by IVUS, OCT, or FFR use. RESULTS: In 4,419,973 AMI admissions, IVUS, OCT, and FFR were used in 2.6%, 0.1%, and 0.6%, respectively. There was a 22-fold, 118-fold, and 33-fold adjusted increase in IVUS, OCT, and FFR use, respectively, in 2014 compared to the first year of use. Non-ST-elevation AMI presentation, male sex, private insurance coverage, admission to a large urban hospital, and absence of cardiac arrest and cardiogenic shock were associated with higher IVUS, OCT, or FFR use. PCI was performed in 83.2% of the IVUS, OCT, or FFR cohort compared to 64.2% of the control group (p < .001). The cohort with IVUS/OCT/FFR use had lower inhospital mortality (adjusted odds ratio 0.53 [95% confidence interval 0.50-0.56]), more frequent discharges to home (83.7% vs. 76.8%), shorter hospital stays (4.3 ± 4.4 vs. 5.0 ± 5.5 days) and higher hospitalization costs ($90,683 ± 74,093 vs. $74,671 ± 75,841). CONCLUSIONS: In AMI, the use of IVUS, OCT, and FFR has increased during 2004-2014. Significant patient and hospital-level disparities exist in the use of these technologies.

Point of care ultrasound for the clinical anesthesiologist.

Diagnostic ultrasonography was first utilized in the 1940s. The past 70+ years have seen an explosion in both ultrasound technology and availability of ultrasound technology to more and more clinicians. As ultrasound technology and availability have grown, the utility of ultrasound technology in the clinical setting as only been limited by clinicians' imagination. Due to its lack of radiation, non-invasive nature, and gentle learning curve, medical ultrasonography is now a tremendously useful Point of Care technology in the clinical arena. What follows is a discussion of Point of Care Ultrasound (PoCUS) and how it can be incorporated in the daily practice of any regional anesthesiology. While most regional anesthesiologists usually focus on the interventional aspects of ultrasonography (i.e. nerve blocks), our discussion will center on the diagnostic value of ultrasonography-especially concerning assessment of cardiac physiology and pathophysiology, gastric anatomy, airway anatomy, and intracranial pathophysiology. After reading and reviewing this chapter, the learner will have the knowledge to start training themselves in a variety of PoCUS exams that will allow rapid diagnosis of normal and abnormal patient conditions. Once an accurate diagnosis is established, the anesthesiologist and his/her team can then confidently optimize an anesthetic pain, prevent harm, and/or treat a patient condition. In this day and age, the ability to rapidly establish an accurate diagnosis cannot be overstated-especially in a critical situation. It is the authors' sincerest hope that the following discussion will help regional anesthesiologist to become even better and well-rounded clinical leaders.

Recent technological advancements in regional anesthesia.

Just two decades ago, regional anesthesia was performed blindly with dubious outcomes and little support from surgeons and patients. Technological advances in regional anesthesia have revolutionized techniques and largely improved outcomes. Ultrasound (US) technology continues to advance and has become more affordable. Improvements have come in the form of picture quality, resolution, portability, and smaller equipment. The US technology can identify otherwise unrecognized pathology and can help to optimize patient flow by allowing for more accurate triage and effective treatments and providing timelier interventions. In recent years, several different strategies to help improve and ease US-guided needle identification and placement have been developed, including magnetically guided needle US technology. Three-dimensional (3D) and four-dimensional (4D) US use is another potential way to help improve first-pass success and limit patient harm for regional anesthetics. The advent of echogenic needles and the resulting improvement in needle visualization under US has had a positive impact on physician comfort in performing regional anesthesia and on visualization time of the needle during US-guided procedures. To reduce variability and to reduce the anesthesiologist's workload, the use of robots in regional anesthesia has been assessed in recent years. Peripheral nerve stimulation (PNS) has also demonstrated efficacy in acute and chronic pain settings. Additional research and randomized controlled trials are necessary to evaluate novel technologies.

Point-of-Care Ultrasound for Obstructive Sleep Apnea Screening: Are We There Yet? A Systematic Review and Meta-analysis.

BACKGROUND: Perioperative diagnosis of obstructive sleep apnea (OSA) has important resource implications as screening questionnaires are overly sensitive, and sleep studies are expensive and time-consuming. Ultrasound (US) is a portable, noninvasive tool potentially useful for airway evaluation and OSA screening in the perioperative period. The objective of this systematic review was to evaluate the correlation of surface US with OSA diagnosis and to determine whether a point-of-care ultrasound (PoCUS) for OSA screening may help with improved screening in perioperative period. METHODS: A search of all electronic databases including Medline, Embase, and Cochrane Database of Systematic Reviews was conducted from database inception to September 2017. Inclusion criteria were observational cohort studies and randomized controlled trials of known or suspected OSA patients undergoing surface US assessment. Article screening, data extraction, and summarization were conducted by 2 independent reviewers with ability to resolve conflict with supervising authors. Diagnostic properties and association between US parameters (index test) and OSA diagnosis using sleep study (reference standard) were evaluated. The US parameters were divided into airway and nonairway parameters. A random-effects meta-analysis was planned, wherever applicable. RESULTS: Of the initial 3865 screened articles, 21 studies (7 airway and 14 nonairway) evaluating 3339 patients were included. Majority of studies were conducted in the general population (49%), respirology (23%), and sleep clinics (12%). No study evaluated the use of US for OSA in perioperative setting. Majority of included studies had low risk of bias for reference standard and flow and timing. Airway US parameters having moderate-good correlation with moderate-severe OSA were distance between lingual arteries (DLAs > 30 mm; sensitivity, 0.67; specificity, 0.59; 1 study/66 patients); mean resting tongue thickness (>60 mm; sensitivity, 0.85; specificity, 0.59; 1 study/66 patients); tongue base thickness during Muller maneuver (MM; sensitivity, 0.59; specificity, 0.78; 1 study/66 patients); and a combination of neck circumference and retropalatal (RP) diameter shortening during MM (sensitivity, 1.0; specificity, 0.65; 1 study/104 patients). Nonairway US parameters having a low-moderate correlation with moderate-severe OSA were carotid intimal thickness (pooled correlation coefficient, 0.444; 95% confidence interval [CI], 0.320-0.553; P value = .000, 8 studies/727 patients) and plaque presence (sensitivity, 0.24-0.75; specificity, 0.13-1.0; 4 studies/1183 patients). CONCLUSIONS: We found that a number of airway and nonairway parameters were identified with moderate to good correlation with OSA diagnosis in the general population. In future studies, it remains to be seen whether PoCUS screening for a combination of these parameters can address the pitfalls of OSA screening questionnaires.

Emerging techniques in atherosclerosis imaging.

Atherosclerosis is a chronic immunomodulated disease that affects multiple vascular beds and results in a significant worldwide disease burden. Conventional imaging modalities focus on the morphological features of atherosclerotic disease such as the degree of stenosis caused by a lesion. Modern CT, MR and positron emission tomography scanners have seen significant improvements in the rapidity of image acquisition and spatial resolution. This has increased the scope for the clinical application of these modalities. Multimodality imaging can improve cardiovascular risk prediction by informing on the constituency and metabolic processes within the vessel wall. Specific disease processes can be targeted using novel biological tracers and "smart" contrast agents. These approaches have the potential to inform clinicians of the metabolic state of atherosclerotic plaque. This review will provide an overview of current imaging techniques for the imaging of atherosclerosis and how various modalities can provide information that enhances the depiction of basic morphology.

Novel nerve imaging and regional anesthesia, bio-impedance and the future.

Ultrasound technology has transformed the practice of regional anaesthesia. Anaesthesiologists routinely use real-time images to guide needle and local anaesthetic placement adjacent to nerves. It is widely accepted that the era of ultrasonography has improved peripheral nerve block success rates and lessened the dose of local anaesthetic required to achieve success. Contemporary reports of harm in relation to nerve injury or local anaesthetic systemic toxicity are reassuring. The safety and efficacy of regional anaesthesia have thus been enhanced. Ultrasound guidance is, however, not a panacea. Ultrasound guidance requires the development of complex psychomotor skills. Harm may still occur where the needle or local anaesthetic is misplaced, resulting in nerve injury, vascular injury or local anaesthetic systemic toxicity. Advances in both imaging and needle technology may further enhance the safety and efficacy of ultrasound-guided regional anaesthesia. This review will focus on peer review literature to characterise the clinical challenges and explore the potential solutions.