Ultrasound-Guided Peripheral Nerve Blocks for Shoulder Dislocation in the Emergency Department: A Systemic Review.

BACKGROUND: Shoulder dislocations are among the most common orthopedic emergencies encountered in the emergency department (ED). Ultrasound-guided peripheral nerve blocks (USG-PNBs) are increasingly being used for acute pain management in the ED, but clinical evidence supporting their utility for shoulder dislocation is limited and often conflicting. OBJECTIVE: The aim of this review was to summarize and evaluate the utility of USG-PNB for analgesia during closed reduction of dislocated shoulders in the ED. METHODS: Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic literature search of the PubMed, Scopus, and Cochrane databases was performed from database inception to September 2022. We included clinical studies examining USG-PNB for pain management of dislocated shoulders in the ED. Information collected from eligible studies included patient demographic characteristics, USG-PNB approach, alternate analgesia techniques, anesthetic regimens, clinical outcomes, and adverse events. RESULTS: Five studies met inclusion criteria, all of which were randomized controlled trials comparing USG-PNB with procedural sedation and analgesia. Pooled patient satisfaction scores were similar for both analgesia methods (3.5 ± 0.6 vs. 3.9 ± 0.6 out of 5; p = 0.76). Patients managed with procedural sedation and analgesia achieved higher rates of overall shoulder reduction (100% vs. 67%; p < 0.001) and successful reduction on the first attempt (86% vs. 48%; p < 0.001). The USG-PNB groups in all but one study had shorter lengths of ED stay. Overall, USG-PNB was associated with a lower risk of adverse events and complications (3.9% vs. 24.9%; p < 0.001), especially adverse respiratory events (0% vs. 14.7%; p < 0.001). CONCLUSIONS: USG-PNBs performed by adequately trained emergency physicians should be considered a safe and effective alternative for analgesia during closed reduction of dislocated shoulders in the ED, particularly in patients with cardiorespiratory comorbidities.

The effect of display size on ultrasound interpretation.

OBJECTIVES: Ultrasound (US) is an essential component of emergency department patient care. US machines have become smaller and more affordable. Handheld ultrasound (HUS) machines are even more portable and easy to use at the patient's bedside. However, miniaturization may come with consequences. The ability to accurately interpret ultrasound on a smaller screen is unknown. This pilot study aims to assess how screen size affects the ability of emergency medicine clinicians to accurately interpret US videos. METHODS: This pilot study enrolled a prospective convenience sample of emergency medicine physicians. Participants completed a survey and were randomized to interpret US videos starting with either a phone-sized screen or a laptop-sized screen, switching to the other device at the halfway point. 50 unique US videos depicting right upper quadrant (RUQ) views of the Focused Assessment with Sonography in Trauma (FAST) examination were chosen for inclusion in the study. There were 25 US videos per device. All of the images were previously obtained on a cart-based machine (Mindray M9) and preselected by the study authors. Participants answered "Yes" or "No" in response to whether they identified free fluid. The time that each participant took to interpret each video was also recorded. Following the assessment, participants completed a post-interpretation survey. The goal of the pilot was to determine the accuracy of image interpretation on a small screen as compared to a laptop-sized screen. Statistical analyses were performed using MATLAB (The MathWorks, Inc., Natick, MA). Nonparametric statistical tests were utilized to compare subgroups, with a Wilcoxon signed rank test used for paired data and a Wilcoxon rank sum test for unpaired data. RESULTS: 52 emergency medicine physicians were enrolled in the study. The median accuracy of US interpretation for phone versus laptop image screen was 88.0% and 87.6% (p = 0.67). The mean time to interpret with phone versus laptop screen was 293 and 290 s (p = 0.66). CONCLUSIONS: The study found no statistically significant difference in the accuracy of US interpretation nor time spent interpreting when the pre-selected RUQ videos generated on a cart-based ultrasound machine were reviewed on a phone-sized versus a laptop-sized screen. This pilot study suggests that the accuracy of US interpretation may not be dependent upon the size of the screen utilized.

Cross-specialty Collaboration and Education for Neurosurgical Trainees: Teaching Arterial Line Placement Under Ultrasound Guidance.

Introduction Interprofessional collaboration (IPC) increases patient safety. IPC is learned through task-based exercises, such as ultrasound (U/S)-guided arterial lines. We set out to teach U/S-guided arterial lines as a framework to improve IPC between emergency medicine and neurosurgery residents. The objectives of the study were to provide a U/S session to teach the proper arterial line placement technique, to assess post-workshop arterial line placement competency and attitude toward U/S for procedural guidance, and to improve interdepartmental relationships through IPC. Methods The course was completed in 2018 and consisted of pre-workshop assignments, the workshop, a competency assessment, and a post-workshop survey for neurosurgical residents. After a didactic and hands-on training session, trainees completed a simulated U/S-guided arterial line placement. Trainees then completed a post-workshop assessment. Results There were a total of 21 participants out of 24 total residents, an 87.5% participation rate. Prior to the workshop, on a 5-point Likert scale, where 1 is not at all likely and 5 is very likely, the residents reported they would use U/S 1.7/5, with 57% of respondents answering 1 out of 5. After the workshop, on the same Likert scale, the residents reported using U/S first 3.6/5 (P < 0.05) with 52% of the respondents answering 4 out of 5. After the course, the belief that the landmark technique is non-inferior decreased to 28.6% of respondents. Conclusions The overall goal of this workshop was to improve patient care through continuing education. Using IPC as the framework, the workshop significantly increased the reported likelihood of using U/S for arterial line placement.

Unorthodox Use of Point-of-care Ultrasound to Evaluate Seizures.

It can be difficult to distinguish between syncope and seizure. Some stigmata of seizure include post-ictal period, tongue-biting or incontinence. A less common finding after a seizure is a posterior shoulder dislocation. Posterior shoulder dislocation is commonly missed and may be the only finding after a seizure, thus aiding in diagnosis. In this case report, we discuss the incidence of posterior shoulder dislocations and their utility in differentiating syncope from seizure, as well as the ability to diagnose and evaluate for proper reduction of posterior shoulder dislocations using ultrasound.

Ultrasonography in Undergraduate Medical Education: A Systematic Review.

OBJECTIVES: The purpose of this study was to conduct a systematic review of the evidence of educational outcomes associated with teaching ultrasonography (US) to medical students. METHODS: A review of databases through 2016 was conducted for research studies that reported data on teaching US to medical students. Each title and abstract were reviewed by teams of 2 independent abstractors to determine whether the article would be ordered for full-text review and subsequently by 2 independent authors for inclusion. Data were abstracted with a form developed a priori by the authors. RESULTS: Ninety-five relevant unique articles were included (of 6936 identified in the databases). Survey data showed that students enjoyed the US courses and desired more US training. Of the studies that assessed US-related knowledge and skill, most of the results were either positive (16 of 25 for knowledge and 24 of 58 for skill) or lacked a control (8 of 25 for knowledge and 27 of 58 for skill). The limited evidence (14 of 95 studies) of the effect of US training on non-US knowledge and skill (eg, anatomy knowledge or physical examination skill) was mixed. CONCLUSIONS: There is ample evidence that students can learn US knowledge and skills and that they enjoy and want US training in medical school. The evidence for the effect of US on external outcomes is limited, and there is insufficient evidence to recommend it for this purpose at this time.

A Three-dimensional Printed Low-cost Anterior Shoulder Dislocation Model for Ultrasound-guided Injection Training.

Anterior shoulder dislocations are the most common, large joint dislocations that present to the emergency department (ED). Numerous studies support the use of intraarticular local anesthetic injections for the safe, effective, and time-saving reduction of these dislocations. Simulation training is an alternative and effective method for training compared to bedside learning. There are no commercially available ultrasound-compatible shoulder dislocation models. We utilized a three-dimensional (3D) printer to print a model that allows the visualization of the ultrasound anatomy (sonoanatomy) of an anterior shoulder dislocation. We utilized an open-source file of a shoulder, available from embodi3D® (Bellevue, WA, US). After approximating the relative orientation of the humerus to the glenoid fossa in an anterior dislocation, the humerus and scapula model was printed with an Ultimaker-2 Extended+ 3D® (Ultimaker, Cambridge, MA, US) printer using polylactic acid filaments. A 3D model of the external shoulder anatomy of a live human model was then created using Structure Sensor®(Occipital, San Francisco, CA, US), a 3D scanner. We aligned the printed dislocation model of the humerus and scapula within the resultant external shoulder mold. A pourable ballistics gel solution was used to create the final shoulder phantom. The use of simulation in medicine is widespread and growing, given the restrictions on work hours and a renewed focus on patient safety. The adage of "see one, do one, teach one" is being replaced by deliberate practice. Simulation allows such training to occur in a safe teaching environment. The ballistic gel and polylactic acid structure effectively reproduced the sonoanatomy of an anterior shoulder dislocation. The 3D printed model was effective for practicing an in-plane ultrasound-guided intraarticular joint injection. 3D printing is effective in producing a low-cost, ultrasound-capable model simulating an anterior shoulder dislocation. Future research will determine whether provider confidence and the use of intraarticular anesthesia for the management of shoulder dislocations will improve after utilizing this model.

Ultrasound measurement of inferior vena cava collapse predicts propofol-induced hypotension.

STUDY OBJECTIVES: Hypotension is a common side effect of propofol, but there are no reliable methods to determine which patients are at risk for significant propofol-induced hypotension (PIH). Ultrasound has been used to estimate volume status by visualization of inferior vena cava (IVC) collapse. This study explores whether IVC assessment by ultrasound can assist in predicting which patients may experience significant hypotension. METHODS: This was a prospective observational study conducted in the operating suite of an urban community hospital. A convenience sample of consenting adults planned to receive propofol for induction of anesthesia during scheduled surgical procedures were enrolled. Bedside ultrasound was used to measure maximum (IVCmax) and minimum (IVCmin) IVC diameters. IVC-CI was calculated as [(IVCmax-IVCmin)/IVCmax × 100%]. The primary outcome was significant hypotension defined as systolic blood pressure (BP) below 90mmHg and/or administration of a vasopressor to increase BP during surgery. RESULTS: The study sample comprised 40 patients who met inclusion criteria. Mean age was 55years, (95%CI, 49-60) with 53% female. 55% of patients had significant hypotension after propofol administration. 76% of patients with IVC-CI≥50% had significant hypotension compared to 39% with IVC-CI<50%, P=.02. IVC-CI≥50% had a specificity of 77.27% (95%CI, 64.29%-90.26%) and sensitivity of 66.67% (95%CI, 52.06%-81.28%) in predicting PIH. The odds ratio for PIH in patients with IVC-CI≥50% was 6.9 (95%CI, 1.7-27.5). CONCLUSION: Patients with IVC-CI≥50% were more likely to develop significant hypotension from propofol. IVC ultrasound may be a useful tool to predict which patients are at increased risk for PIH.

Risk factors associated with difficult venous access in adult ED patients.

OBJECTIVE: The objective was to determine risk factors associated with difficult venous access (DVA) in the emergency department (ED). METHODS: This was a prospective, observational study conducted in the ED of an urban tertiary care hospital. Adult patients undergoing intravenous (IV) placement were consecutively enrolled during periods of block enrollment. The primary outcome was DVA, defined as 3 or more IV attempts or use of a method of rescue vascular access to establish IV access. Univariate and multivariate analyses for factors predicting DVA were performed using logistic regression. RESULTS: A total of 743 patients were enrolled, of which 88 (11.8%) met the criteria for DVA. In the adjusted analysis, only 3 medical conditions were significantly associated with DVA: diabetes (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.1-2.8), sickle cell disease (OR 3.8, 95% CI 1.5-9.5), and history of IV drug abuse (OR 2.5, 95% CI 1.1-5.7). Notably, age, body mass index, and dialysis were not. Of patients who reported a history of requiring multiple IV attempts in the past for IV access, 14% met criteria for DVA on this visit (OR 7.7 95% CI 3-18). Of the patients who reported a history of IV insertion into the external jugular, ultrasound-guided IV placement, or a central venous catheter for IV access, 26% had DVA on this visit (OR 16.7, 95% CI 6.8-41). CONCLUSIONS: Nearly 1 of every 9 to 10 adults in an urban ED had DVA. Diabetes, IV drug abuse, and sickle cell disease were found to be significantly associated with DVA.

Resuscitation of the pregnant patient: What is the effect of patient positioning on inferior vena cava diameter?

STUDY OBJECTIVE: Patients in the third trimester of pregnancy presenting to the emergency department (ED) with hypotension are routinely placed in the left lateral tilt (LLT) position to relieve inferior vena cava (IVC) compression from the gravid uterus thereby increasing venous return. However, the relationship between patient position and proximal intrahepatic IVC filling has never assessed directly. This study set out to determine the effect of LLT position on intrahepatic IVC diameter in third trimester patients under real-time visualization with ultrasound. METHODS: This prospective observational study on the labor and delivery floor of a large urban academic teaching hospital enrolled patients between 30 and 42 weeks estimated gestational age from August 2011 to March 2012. Patients were placed in three different positions: supine, LLT, and right lateral tilt (RLT). After the patient was in each position for at least 3 min, IVC ultrasound using the intercostal window was performed by one of three study sonologists. Maternal and fetal hemodynamics were also monitored and recorded in each position. RESULTS: A total of 26 patients were enrolled with one excluded from data analysis due to inability to obtain IVC measurements. The median IVC maximum diameter was 1.26 cm (95% confidence interval [CI] 1.13-1.55) in LLT compared to 1.13 cm (95% CI 0.89-1.41) in supine, p=0.01. When comparing each individual patient's LLT to supine measurement, LLT lead to an increase in maximum IVC diameter in 76% (19/25) of patients with the average LLT measurement 29% (95% confidence interval 10-48%) larger. Six patients had the largest maximum IVC measurement in the supine position. No patients experienced any hemodynamic instability or distress during the study. CONCLUSION: IVC ultrasound is feasible in late pregnancy and demonstrates an increase in diameter with LLT positioning. However, a quarter of patients had a decrease in IVC diameter with tilting and, instead, had the largest IVC diameter in the supine position suggesting that uterine compression of the IVC may not occur universally. IVC assessment at the bedside may be a useful adjunct in determining optimal positioning for resuscitation of third trimester patients.

Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters.

STUDY OBJECTIVES: Obtaining intravenous (IV) access in the emergency department (ED) can be especially challenging, and physicians often resort to placement of central venous catheters (CVCs). Use of ultrasound-guided peripheral IV catheters (USGPIVs) can prevent many "unnecessary" CVCs, but the true impact of USGPIVs has never been quantified. This study set out to determine the reduction in CVCs by USGPIV placement. METHODS: This was a prospective, observational study conducted in 2 urban EDs. Patients who were to undergo placement of a CVC due to inability to establish IV access by other methods were enrolled. Ultrasound-trained physicians then attempted USGPIV placement. Patients were followed up for up to 7 days to assess for CVC placement and related complications. RESULTS: One hundred patients were enrolled and underwent USGPIV placement. Ultrasound-guided peripheral IV catheters were initially successfully placed in all patients but failed in 12 patients (12.0%; 95 confidence interval [CI], 7.0%-19.8%) before ED disposition, resulting in 4 central lines, 7 repeated USGPIVs, and 1 patient requiring no further intervention. Through the inpatient follow-up period, another 11 patients underwent CVC placement, resulting in a total of 15 CVCs (15.0%; 95 CI, 9.3%-23.3%) placed. Of the 15 patients who did receive a CVC, 1 patient developed a catheter-related infection, resulting in a 6.7% (95 CI, 1.2%-29.8%) complication rate. CONCLUSION: Ultrasound prevented the need for CVC placement in 85% of patients with difficult IV access. This suggests that USGPIVs have the potential to reduce morbidity in this patient population.

The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity.

INTRODUCTION: Ultrasound-guided peripheral intravenous catheters (USGPIVs) have been observed to have poor durability. The current study sets out to determine whether vessel characteristics (depth, diameter, and location) predict USGPIV longevity. METHODS: A secondary analysis was performed on a prospectively gathered database of patients who underwent USGPIV placement in an urban, tertiary care emergency department. All patients in the database had a 20-gauge, 48-mm-long catheter placed under ultrasound guidance. The time and reason for USGPIV removal were extracted by retrospective chart review. A Kaplan-Meier survival analysis was performed. RESULTS: After 48 hours from USGPIV placement, 32% (48/151) had failed prematurely, 24% (36/151) had been removed for routine reasons, and 44% (67/151) remained in working condition yielding a survival probability of 0.63 (95% confidence interval [CI], 0.53-0.70). Survival probability was perfect (1.00) when placed in shallow vessels (<0.4 cm), moderate (0.62; 95% CI, 0.51-0.71) for intermediate vessels (0.40-1.19 cm), and poor (0.29; 95% CI, 0.11-0.51) for deep vessels (≥1.2 cm); P < .0001. Intravenous survival probability was higher when placed in the antecubital fossa or forearm locations (0.83; 95% CI, 0.69-0.91) and lower in the brachial region (0.50; 95% CI, 0.38-0.61); P = .0002. The impact of vessel depth and location was significant after 3 hours and 18 hours, respectively. Vessel diameter did not affect USGPIV longevity. CONCLUSION: Cannulation of deep and proximal vessels is associated with poor USGPIV survival. Careful selection of target vessels may help improve success of USGPIV placement and durability.