Just the facts: brachial plexus blocks for upper extremity injuries in the emergency department.

Ultrasound-guided nerve blocks (UGNBs) are becoming a more common method for pain control in the emergency department. Specifically, brachial plexus blocks have shown promise for acute upper extremity injuries as well as an alternative to procedural sedation for glenohumeral reductions. Unfortunately, there is minimal discussion in the EM literature regarding phrenic nerve paralysis (a well-known complication from brachial plexus blocks). The anatomy of the brachial plexus, its relationship to the phrenic nerve, and why ultrasound-guided brachial plexus blocks can cause phrenic nerve paralysis and resultant respiratory impairment will be discussed. The focus on patient safety is paramount, and those with preexisting respiratory conditions, extremes of age or weight, spinal deformities, previous neck injuries, and anatomical variations are at greater risk. We put forth different block strategies for risk mitigation, including patient selection, volume and type of anesthetic, block location, postprocedural monitoring, and specific discharge instructions. Understanding the benefits and risks of UGNBs is critical for emergency physicians to provide effective pain control while ensuring optimal patient safety.

Does needle positioning with magnetic field induction improve central venous catheterization performance by novice learners?

OBJECTIVE: The novel ultrasound magnetic needle navigation technique can visualize the entire needle and identify its projected trajectory. We hypothesized that this technique increases the first-attempt success rate of central venous puncture by novice learners compared with the conventional needle navigation technique. METHODS: This prospective, randomized, controlled trial with a crossover design included 50 participants with limited prior experience in US-guided procedures. Participants were randomly assigned to novel or conventional technique groups and asked to perform central venous cannulation in a phantom task trainer. After the first successful attempt, participants were allocated to the other technique group. RESULTS: Although participants in the novel technique group had a higher first-attempt success rate than did those in the conventional technique group, this difference was not statistically significant (p = 0.17). The total number of attempts also did not significantly differ (p = 0.16). The conventional technique group had more needle redirections (p = 0.01) and a longer time to successful cannulation (p = 0.01). The number of adverse effects (p = 0.32) did not differ between groups. Participant confidence levels were higher in the novel technique group (p < 0.001). CONCLUSIONS: Magnetic needle navigation can reduce the number of needle redirections, shorten the time to successful cannulation, and increase confidence levels by novice learners for successful US-guided central venous access.

Evaluation of Soft-Tissue Hematomas With Real-Time, Contrast-Enhanced Ultrasound: A Pilot Study With Preliminary Findings.

ABSTRACT: In this study, we investigated the feasibility of using contrast-enhanced ultrasound (CEUS) to detect active hemorrhage in patients presenting with soft-tissue hematomas. Adult patients with clinically suspected, actively bleeding hematomas were prospectively enrolled. Contrast-enhanced ultrasound was used to assess for contrast extravasation. Ultrasound results were compared with those of multidetector computed tomographic (MDCT) imaging, operative findings, and clinical course. Sixteen patients (9 women, 7 men; mean age, 69 [SD, 13] years) were enrolled. Thirteen patients underwent MDCT imaging during their initial visit, and for 11, CEUS and computed tomography (CT) findings were concordant. The remaining patients had a negative CEUS study that was consistent with their clinical course. In 8 patients, CT imaging showed active extravasation (6 arterial, 1 indeterminate, 1 slow venous). Contrast-enhanced ultrasound and CT findings were concordant for all cases of arterial bleeding. For 1 patient, CEUS provided superior diagnostic information by identifying a pseudoaneurysm. The 2 discrepant patient cases had a ≥3-hour delay between CT and CEUS, and in 1 patient, CEUS was limited by body habitus. The second patient had no active bleeding identified in the operating room. Compared with CT, CEUS had a sensitivity and specificity of 75% and 100%, respectively, and positive and negative predictive values were 100% and 71%, respectively. Diagnostic accuracy was 85% in this limited study. Contrast-enhanced ultrasound is a promising alternative to MDCT in select patients and may sometimes provide superior clinical information. Limiting factors are large hematoma size, unfavorable anatomic location, and body habitus.

Precise Limb Tourniquet Arterial Occlusion Pressure Determination using Real-Time Ultrasonography and a Capacitive-Based Force Sensor.

BACKGROUND: Hemorrhage control prior to shock onset is increasingly recognized as a time-critical intervention. Although tourniquets (TQs) have been demonstrated to save lives, less is known about the physiologic parameters underlying successful TQ application beyond palpation of distal pulses. The current study directly visualized distal arterial occlusion via ultrasonography and measured associated pressure and contact force. METHODS: Fifteen tactical officers participated as live models for the study. Arterial occlusion was performed using a standard adult blood pressure (BP) cuff and a Combat Application Tourniquet Generation 7 (CAT7) TQ, applied sequentially to the left mid-bicep. Arterial flow cessation was determined by radial artery palpation and brachial artery pulsed wave doppler ultrasound (US) evaluation. Steady state maximal generated force was measured using a thin-film force sensor. RESULTS: The mean (95% CI) systolic blood pressure (SBP) required to occlude palpable distal pulse was 112.9mmHg (109-117); contact force was 23.8N [Newton] (22.0-25.6). Arterial flow was visible via US in 100% of subjects despite lack of palpable pulse. The mean (95% CI) SBP and contact force to eliminate US flow were 132mmHg (127-137) and 27.7N (25.1-30.3). The mean (95% CI) number of windlass turns to eliminate a palpable pulse was 1.3 (1.0-1.6) while 1.6 (1.2-1.9) turns were required to eliminate US flow. CONCLUSIONS: Loss of distal radial pulse does not indicate lack of arterial flow distal to upper extremity TQ. On average, an additional one-quarter windlass turn was required to eliminate distal flow. Blood pressure and force measurements derived in this study may provide data to guide future TQ designs and inexpensive, physiologically accurate TQ training models.

Real-time Ultrasound-Guided Manual Testicular Detorsion: A Case Report.

INTRODUCTION: Acute testicular torsion is a surgical emergency due to acute testicular ischemia. Manual testicular detorsion is a testis-saving, bedside therapeutic when performed correctly and in a timely fashion. This procedure is most commonly performed blindly with pain relief as the endpoint for detorsion. However, up to one-third of patients continued to show signs of residual torsion in the operating room even using pain relief as the stopping point for the procedure. CASE REPORT: We present a case demonstrating the utility of color Doppler ultrasound to confirm complete manual detorsion in a 14-year-old male with acute testicular torsion. The patient underwent 360-degree detorsion and had relief of pain; however, color Doppler demonstrated incomplete return of flow to the testis. After an additional 180-degree turn was made, color Doppler demonstrated complete return of normal vascular flow to the torsed testis. CONCLUSION: When it comes to testicular viability, timely restoration of blood flow to the testicle is of utmost importance. Manual detorsion is a non-invasive intervention that can be quickly and effectively performed at the bedside. Moreover, using color Doppler ultrasound guidance can ensure that physicians detorse in the proper direction and to completion, by providing instant visualization of restorative flow and ensuring reperfusion of the testis while awaiting definitive surgical management.

Ultrasound-Guided Great Saphenous Vein Access: Revisiting an Old Friend in a New Location.

BACKGROUND: Early recognition of difficult intravenous (i.v.) access and use of ultrasound-guided techniques prior to multiple attempts are important steps in improving patient care in the emergency department (ED). Success rates for ultrasound-guided peripheral i.v. (PIV) cannulation are affected by depth, size of target vessel, and predictability of anatomy. The great saphenous vein (GSV) in the medial distal thigh may provide an alternative site for ultrasound-guided cannulation in cases of difficult peripheral venous access. OBJECTIVES: Our objective was to determine the feasibility of ultrasound-guided GSV PIV placement as an alternative site for patients with difficult i.v. access. METHODS: Participants were prospectively enrolled from a convenience sample of patients presenting to the ED in June and July 2019. Inclusion criteria were age 18 years and older, and a history of difficult i.v. access or two unsuccessful nursing staff attempts. Ultrasound-guided access was conducted with an in-plane or out-of-plane approach on the basis of proceduralist preference. RESULTS: Twenty patients were enrolled; 1 patient withdrew consent prior to cannulation. GSV cannulation was successful in 14 (73.7%) of the 19 patients. Phlebotomy, blood transfusion, i.v. medications including norepinephrine, and i.v. computed tomography contrast medium were successfully performed via GSV access. No reported infection, thrombosis, or extravasation was identified throughout the cannulation dwell time, hospitalization, or for 72 h after discharge. CONCLUSION: Ultrasound-guided GSV PIV placement is a feasible alternative in situations of difficult i.v. access. No unforeseen complication or safety issue was identified. Blood products, medications, and contrast medium were successfully administered safely.

"Swirling right ventricular" sign as a marker of right ventricular dysfunction in two patients with submassive pulmonary embolism.

Assessing the right ventricular function in patients with submassive pulmonary embolism (PE) is pivotal when determining the appropriate treatment pathway. We describe two cases of submassive PE requiring systemic thrombolysis, in which intravenous saline contrast demonstrated a noticeable lack of forward flow in the right ventricle. This technique potentially may indicate impending right ventricular functional collapse and the need for more aggressive intervention.

Increased body mass index is associated with decreased imaging quality of point-of-care abdominal aortic ultrasonography.

BACKGROUND: Given that abdominal aorta is a retroperitoneal structure, increased body mass index (BMI) may have an adverse effect upon the quality of aortic ultrasonographic imaging. PURPOSE: To assess the hypothesis that increased BMI is associated with worsening point-of-care abdominal aortic ultrasonographic image quality. METHODS: This is a retrospective single-center study of point-of-care abdominal aortic ultrasound examinations performed in an academic emergency department (ED) with fellowship-trained emergency ultrasonography faculty performing quality assurance review. RESULTS: Mean ± SD BMI was 27.4 ± 6.2, among the 221 included records. The overall quality rating decreased as BMI increased (correlation coefficient - 0.24; P < .001) and this persisted after adjustment for age and sex (P < .001). Although BMI was higher on average in the records that were of insufficient quality for clinical decisions when compared with those of sufficient quality (mean BMI 28.7 vs 27.0), this did not reach statistical significance in a univariable setting (P = .11) or after adjusting for age and sex (P = .14). CONCLUSION: This study data shows a decrease in point-of-care abdominal aorta ultrasound imaging quality as BMI increases, though this difference did not result in a statistically significant impairment in achieving the minimum quality for clinical decisions. This finding may help ameliorate some clinician concerns about ultrasonography for patients with high BMI.

Ruptured Ectopic Pregnancy with an Intrauterine Device: Case Report and Sonographic Considerations.

INTRODUCTION: Ectopic pregnancy carries a high morbidity and mortality; patients are at risk for rupture and life-threatening hemorrhage. CASE REPORT: We present a rare case of ruptured abdominal ectopic pregnancy in a patient with a well-positioned intrauterine device (IUD) and discuss the diagnostic utility that transabdominal point-of-care ultrasound (POCUS) can have when performed at the bedside. CONCLUSION: While pregnancy with an IUD in place is rare, when it is encountered the emergency provider should maintain a high degree of suspicion for extrauterine pregnancy and perform prompt evaluation for hemorrhagic shock using diagnostic POCUS.

Increased body mass index does not impact the imaging quality of focused assessment with sonography in trauma.

BACKGROUND: Many clinicians believe that a patient's body mass index (BMI) affects the likelihood of obtaining high quality ultrasound images. OBJECTIVES: To assess the hypothesis that increased BMI is associated with worsening focused assessment with sonography in trauma (FAST) image quality. METHODS: We conducted a retrospective single-center study of FAST examinations performed in a large academic emergency department (ED) with fellowship-trained emergency ultrasonography faculty performing quality assurance review. RESULTS: Mean (SD) BMI was 28.0 (6.6) among the 302 included studies. The overall quality rating tended to decrease as BMI increased but did not achieve statistical significance in a univariable setting (P = .06) or after adjustment for age and sex (P = .06). Operators perception of image adequacy was largely unaffected by BMI, with the exception of the pericardial view. CONCLUSION: This study did not identify a statistically significant difference in FAST quality with increased BMI. This result may help assuage clinician concerns about ultrasonography for patients in the ED.

The Efficacy of Novel Commercial Tourniquet Designs for Extremity Hemorrhage Control: Implications for Spontaneous Responder Every Day Carry.

INTRODUCTION: Tourniquets (TQs) save lives. Although military-approved TQs appear more effective than improvised TQs in controlling exsanguinating extremity hemorrhage, their bulk may preclude every day carry (EDC) by civilian lay-providers, limiting availability during emergencies. STUDY OBJECTIVE: The purpose of the current study was to compare the efficacy of three novel commercial TQ designs to a military-approved TQ. METHODS: Nine Emergency Medicine residents evaluated four different TQ designs: Gen 7 Combat Application Tourniquet (CAT7; control), Stretch Wrap and Tuck Tourniquet (SWAT-T), Gen 2 Rapid Application Tourniquet System (RATS), and Tourni-Key (TK). Popliteal artery flow cessation was determined using a ZONARE ZS3 ultrasound. Steady state maximal generated force was measured for 30 seconds with a thin-film force sensor. RESULTS: Success rates for distal arterial flow cessation were 89% CAT7; 67% SWAT-T; 89% RATS; and 78% TK (H 0.89; P = .83). Mean (SD) application times were 10.4 (SD = 1.7) seconds CAT7; 23.1 (SD = 9.0) seconds SWAT-T; 11.1 (SD = 3.8) seconds RATS; and 20.0 (SD = 7.1) seconds TK (F 9.71; P <.001). Steady state maximal forces were 29.9 (SD = 1.2) N CAT7; 23.4 (SD = 0.8) N SWAT-T; 33.0 (SD = 1.3) N RATS; and 41.9 (SD = 1.3) N TK. CONCLUSION: All novel TQ systems were non-inferior to the military-approved CAT7. Mean application times were less than 30 seconds for all four designs. The size of these novel TQs may make them more conducive to lay-provider EDC, thereby increasing community resiliency and improving the response to high-threat events.

Effect of two tourniquet techniques on peripheral intravenous cannulation success: A randomized controlled trial.

OBJECTIVES: Peripheral intravenous (IV) cannulation is the most common procedure performed in the emergency department (ED). Elastic tourniquets (ETs) and blood pressure cuffs (BPCs) are frequently used for venodilation. Although BPCs lead to increased venodilation and decreased compressibility, it is unclear whether this translates into a meaningful patient-centered outcome. This study aimed to determine whether one method is superior for success on the first attempt. METHODS: This was a prospective, single-blinded, randomized controlled trial in the ED of a tertiary care center. A convenience sample of adult patients was randomly assigned to an ET or BPC with a cover concealing the type of tourniquet. The primary outcome was success rate on the first attempt. Secondary outcomes were number of attempts, number of providers, and rate of rescue techniques. RESULTS: Of the 121 patients enrolled, 119 qualified for analysis. In the ET group, 42 of 59 patients (71%) had successful IV cannulation on first attempt compared with 43 of 60 (72%) in the BPC group (P = .95). The number of attempts (P = .87), number of nurses (P = .67), and use of rescue techniques (P = .32) did not differ significantly. A history of difficult IV access and site other than the antecubital vein were associated with decreased success. CONCLUSIONS: ETs and BPCs performed similarly in providing venodilation for successful peripheral IV cannulation. History of difficult IV access and IV site are important factors in determining the likelihood of success.

Effect of Intranasal Vasoconstrictors on Blood Pressure: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: Treatment for epistaxis includes application of intranasal vasoconstrictors. These medications have a precaution against use in patients with hypertension. Given that many patients who present with epistaxis are hypertensive, these warnings are commonly overridden by clinical necessity. OBJECTIVE: Our aim was to determine the effects of intranasal vasoconstrictors on blood pressure. METHODS: We conducted a single-center, randomized, double-blind, placebo-controlled trial from November 2014 through July 2016. Adult patients being discharged from the emergency department (ED) at Mayo Clinic (Rochester, Minnesota) were recruited. Patients were ineligible if they had a contraindication to study medications, had a history of hypertension, were currently taking antihypertensive or antidysrhythmic medications, or had nasal abnormalities, such as epistaxis. Subjects were randomized to one of four study arms (phenylephrine 0.25%; oxymetazoline 0.05%; lidocaine 1% with epinephrine 1:100,000; or bacteriostatic 0.9% sodium chloride [saline]). Blood pressure and heart rate were measured every 5 min for 30 min. RESULTS: Sixty-eight patients were enrolled in the study; of these, 63 patients completed the study (oxymetazoline, n = 15; phenylephrine, n = 20; lidocaine with epinephrine, n = 11; saline, n = 17). We did not observe any significant differences in mean arterial pressure over time between phenylephrine and saline, oxymetazoline and saline, or lidocaine with epinephrine and saline. The mean greatest increases from baseline in mean arterial pressure, systolic and diastolic blood pressure, and heart rate for each treatment group were also not significantly different from the saline group. CONCLUSIONS: Intranasal vasoconstrictors did not significantly increase blood pressure in patients without a history of hypertension. Our findings reinforce the practice of administering these medications to patients who present to the ED with epistaxis, regardless of high blood pressure.

Emergency and critical care applications for contrast-enhanced ultrasound.

INTRODUCTION: Contrast-enhanced ultrasound (CEUS) using intravascular microbubbles has potential to revolutionize point-of-care ultrasonography by expanding the use of ultrasonography into clinical scenarios previously reserved for computed tomography (CT), magnetic resonance imaging, or angiography. METHODS: We performed a literature search and report clinical experience to provide an introduction to CEUS and describe its current applications for point-of-care indications. RESULTS: The uses of CEUS include several applications highly relevant for emergency medicine, such as solid-organ injuries, actively bleeding hematomas, or abdominal aortic aneurysms. Compared with CT as the preeminent advanced imaging modality in the emergency department, CEUS is low cost, radiation sparing, repeatable, and readily available. It does not require sedation, preprocedural laboratory assessment, or transportation to the radiology suite. CONCLUSIONS: CEUS is a promising imaging technique for point-of-care applications in pediatric and adult patients and can be applied for patients with allergy to CT contrast medium or with impaired renal function. More high-quality CEUS research focusing on accuracy, patient safety, health care costs, and throughput times is needed to validate its use in emergency and critical care settings.

Point-of-Care Ultrasound Diagnosis of Traumatic Abdominal Wall Hernia.

Traumatic abdominal wall hernias due to blunt abdominal trauma in pediatric patients can pose a diagnostic challenge because of spontaneous hernia reduction. Ultrasonography may be superior to computed tomography for this indication in some cases because of the ability to dynamically and repeatedly assess the area of injury. Herniation can be induced or exaggerated via Valsalva maneuvers, which can facilitate its detection during dynamic assessment. We present the case of a 3-year-old boy who sustained blunt abdominal trauma, with a resultant abdominal wall hernia that was diagnosed using point-of-care ultrasound imaging. This hernia was not visualized with computed tomography, and point-of-care ultrasonography expedited admission for operative repair.

Diagnosis of an actively bleeding rectus sheath hematoma by Contrast- Enhanced ultrasound.

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Identification of Peroneal Tenosynovitis by Point-of-Care Ultrasonography.

BACKGROUND: Ankle pain is a frequent chief complaint, and although peroneal tendon disorders are relatively uncommon, if treated inappropriately they may cause persistent pain and dysfunction. Peroneal tendon disorders, including the tendon sheath inflammatory condition tenosynovitis, are a major cause of chronic lateral ankle pain. Although magnetic resonance imaging has emerged as the modality of choice to assess the majority of these injuries, dynamic ultrasonography detects tendon pathology such as tenosynovitis. CASE REPORT: A 69-year-old woman presented to the Emergency Department (ED) after several months of atraumatic, progressive right foot and ankle pain. On physical examination, she had swelling and point tenderness posterior and inferior to the lateral malleolus, which was exacerbated by eversion. Plain radiography of the foot and ankle showed only soft tissue swelling. Bedside ultrasonography performed by the emergency physician quickly identified findings consistent with peroneal tenosynovitis without tears. Management with a walking boot and nonsteroidal antiinflammatory drugs was initiated prior to discharge. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In this case of peroneal tenosynovitis, point-of-care ultrasonography was used to promptly and accurately identify hyperemia, synovial thickening, and a marked effusion within the right peroneal tendon sheath. Nonoperative treatment of tenosynovitis was initiated in the ED while findings were subsequently confirmed with magnetic resonance imaging. Emergency physicians should be aware of the utility of identifying tenosynovitis by point-of-care ultrasonography, which can expedite nonoperative management and prevent long-term complications.