Critical Ultrasound Journal最新文献

Objectives: To show that medical students can evaluate the internal jugular vein (IJV) and its anatomical variations after rapid and focused training. We also aimed to evaluate the success rate of IJV puncture in simulation following traditional techniques (TTs) and monitored via ultrasound (US).

Materials and methods: Six medical students without experience with US were given 4 h of theoretical-practical training in US, and then evaluated the IJV and common carotid artery (CCA) of 105 patients. They also simulated a puncture of the IJV at a demarcated point, where a TT was theoretically performed.

Results: Adequate images were obtained from 95% of the patients; the IJV, on the right side, was more commonly found in the anterolateral position in relation to the CCA (38%). On the left side, the most commonly position observed was the anterior (36%). The caliber of the IJV relative to the CCA greatly varied. The success rate in the IJV puncture simulation, observed with US, by the TTs was 55%.

Conclusion: The training of medical students to recognize large neck vessels is a simple, quick, and feasible task and that can be integrated into the undergraduate medical curriculum.

Background: Focused cardiac ultrasound (FOCUS) is a core competency for pediatric emergency medicine (PEM) fellows. The objectives of this study were (1) to evaluate test characteristics of PEM-fellow-performed FOCUS for pericardial effusion and diminished cardiac function and (2) to assess image interpretation independent of image acquisition.

Methods: PEM fellows performed and interpreted FOCUS on patients who also received cardiology service echocardiograms, the reference standard. Subsequently, eight different PEM fellows remotely interpreted a subset of the PEM-acquired and cardiology-acquired echocardiograms.

Results: Eight PEM fellows performed 54 FOCUS exams, of which two had pericardial effusion and four had diminished function. PEM fellow FOCUS had a sensitivity of 50.0% (95% CI 9.19-90.8) and specificity of 100.0% (95% CI 91.1-100.0) for detecting diminished function, and sensitivity of 50.0% (95% CI 2.67-97.33) and specificity of 98.1% (95% CI 88.42-99.9) for detecting pericardial effusions. When PEM fellows remotely interpreted 15 echocardiograms, the sensitivity was 81.3% (95% CI 70.7-88.8) and specificity 75% (95% CI 67.0-81.0) for detecting diminished function, and sensitivity of 76.3% (95% CI 65.0-85.0) and specificity 94.4% (95% CI 89.0-97.0) for detecting pericardial effusion. There were no differences in sensitivity and specificity of PEM fellows' interpretation of FOCUS studies compared to their interpretation of cardiology echocardiograms. Interrater reliability for interpretation of remote images (kappa) was 0.66 (95% CI 0.59-0.73) for effusion and 0.31 (95% CI 0.24-0.38) for function among the fellows.

Conclusion: Novice PEM fellow sonologists (a physician who performs and interprets ultrasound) in the majority of instances were able to acquire and remotely interpret FOCUS images with limited training. However, they made real-time interpretation errors and likely need further training to incorporate real-time image acquisition and interpretation into their practice.

Background: Fluid responsiveness is an important topic for clinicians. Aggressive hydration has been shown to lead to worse outcomes. The aim of this study was to investigate the sensitivity and specificity of mitral valve (MV) velocity time integral (VTI) as a non-invasive marker of volume responsiveness.

Methods: This was a prospective observational study conducted in a tertiary emergency department. End-stage renal disease patients presenting to the emergency department requiring emergent hemodialysis were enrolled. A focused echocardiogram was done on enrolled patients. Two sets of measurements were obtained before and after hemodialysis. During each scanning session, the left ventricular outflow tract and the mitral valve VTI were obtained before and after a passive leg raise maneuver.

Results: 54 patients were enrolled, of which, 30 (55%) were male. The mean age was 47.4 years. The mean volume of fluid removed was 3.89 ± 0.91 L. All patients had a diagnosis of hypertension, 22 (41%) patients were diabetic, 14 (26%) patients had coronary artery disease, and 19 (35%) patients had congestive heart failure. The mean change in LVOT VTI was 1.83% (95% CI 0.12-3.55) in the pre-dialysis group and 15.05% (95% CI 12.76-17.34) in the post-hemodialysis cohort. The mean change in MV VTI was 3.74% (95% CI 2.84-4.65) in the pre-dialysis cohort and 12.95% (95% CI 11.50-14.39) in the post-dialysis cohort. For patients who had < 4 L removed, the mean delta LVOT VTI post-hemodialysis was 12.64% (95% CI 9.79-15.49) and the mean delta MV VTI was 10.48% (95% CI 8.28-12.69). For patients who had > 4 L removed, the mean delta LVOT VTI was 16.84% (95% CI 13.47-20.22) and the mean MV VTI was 14.77% (95% CI 13.03-16.51). Mitral valve VTI with PLR was found to have a sensitivity of 89.18% and a specificity of 94.11% in detecting volume responsiveness.

Conclusion: Mitral valve velocity time integral in conjunction with passive leg raise seem to correlate with volume responsiveness in hemodialysis patients.

Background: Right iliac fossa abdominal pain is a common reason for emergency ward admissions, its etiology is difficult to diagnose. It can be facilitated by an imaging examination, such as a Computerized Tomography scan which exposes the patient to ionizing radiation and implies delays. A bedside ultrasound performed by emergency physicians could avoid these issues. The aim of our study was to assess the performance of ultrasound carried out at the patient's bedside by an emergency physician compared with a clinical-laboratory examination for the diagnosis of a surgical pathology in right iliac fossa pain.

Methods: This is a single-center prospective cohort study conducted in an Emergency Department receiving 19,000 patients per year. All patients presenting pain in the right iliac fossa were included by four (out of ten) emergency physicians certified in an ultrasound examination. A full grid pattern scan ultrasound of the abdominal cavity with analysis of the right iliac fossa was performed. The primary outcome was to compare the diagnosis performance of bedside ultrasound and clinical-laboratory examination to detect a surgical pathology. Two emergency physicians who did not participate in the study made the final diagnosis (i.e., surgical or non-surgical pathology) by reviewing the entire medical chart of each patient.

Results: From January 2011 to July 2013, 158 patients with a median age of 17 [13-32] years were analyzed. The diagnosed cases were: appendicitis (53), non-specific abdominal pain (48), lymphadenitis (22), ileitis (11), complicated ovarian cysts (7), neoplasias (5), inflammatory or infectious colitis (5), inguinal herniations (3), bowel obstructions (2), and salpingitis (2). The accuracy of ultrasound diagnoses was 0.89 (95% CI 0.84-0.94) versus 0.70 (95% CI 0.57-0.82) for diagnoses based on clinical-laboratory examination only (p < 0.001).

Conclusion: Bedsides, ultrasound allows an accurate diagnosis of a surgical pathology in 89% of cases, which is more efficient than the clinical-laboratory examination.

Hypertensive emergency is a life-threatening state. End-organ damage affecting the heart accounts for up to 52% of hypertensive emergencies commonly encountered in the emergency department. Recent evidence indicates that strain echocardiography with computerized speckle-tracking is more sensitive at identifying hypertension induced changes in the left ventricle (LV) mechanical function than traditional 2-D echocardiography. We present a case demonstrating the use of emergency physician performed point-of-care strain echocardiography to identify and quantify LV mechanical dysfunction during a hypertensive crisis and to monitor improvement over 6 h.

Systolic anterior motion (SAM) after mitral valve repair (MVR) can adversely affect hemodynamics due to exacerbation of left ventricular outflow tract obstruction and mitral regurgitation. Intraoperative transient SAM after MVR can usually be managed with hemodynamic maneuvers under continuous monitoring by transesophageal echocardiography (TEE). However, during postoperative intensive care management, transient SAM is seldom diagnosed and the start of treatment may be delayed. We present a case of transient SAM after MVR with abrupt deterioration due to junctional rhythm in the intensive care unit (ICU). TEE revealed that conversion from normal sinus rhythm into junctional rhythm induced the exacerbation of SAM. TEE was useful for identifying the etiology of unstable hemodynamics after cardiac surgery in the ICU, similar to its use in the operating room.

Background: An accurate physical examination is essential in the care of critically ill and injured patients. However, to diagnose or exclude a pneumothorax, chest auscultation is unreliable compared to lung ultrasonography. In the dynamic prehospital environment, it is desirable to have the best possible ultrasound transducer readily available. The objective is to assess the difference between a linear-array, curved-array, and phased-array ultrasound transducer in the assessment for pneumothorax and to determine which is best.

Methods: In this double-blinded, cross-sectional, observational study, 15 observers, experienced in lung ultrasonography, each assessed 66 blinded ultrasound video clips of either normal ventilation or pneumothorax that were recorded with three types of ultrasound transducers. The clips were recorded in 11 adult patients that underwent thoracoscopic lung surgery immediately before and after the surgeon opened the thorax. The diagnostic accuracy of the three transducers, elapsed time until a diagnosis was made, and the perceived image quality was recorded.

Results: In total, 15 observers assessed 990 ultrasound video clips. The overall sensitivity and specificity were 98.2% and 97.2%, relatively. No significant difference was found in the diagnostic performance between transducers. A diagnosis was made slightly faster in the linear-array transducer clips, compared to the phased-array transducer (p = .031). For the linear-, curved-, and phased-array transducer, the image quality was rated at a median (interquartile range [IQR]) of 4 (IQR 3-4), 3 (IQR 2-4), and 2 (IQR 1-2), relatively. Between the transducers, the difference in image quality was significant (p < .0001).

Conclusions: There was no difference in diagnostic performance of the three transducers. Based on image quality, the linear-array transducer might be preferred for (prehospital) lung ultrasonography for the diagnosis of pneumothorax.

Background: Traditional landmark thoracostomy technique has a known complication rate up to 30%. The goal of this study is to determine whether novice providers could more accurately identify the appropriate intercostal site for thoracostomy by ultrasound guidance.

Methods: 33 emergency medicine residents and medical students volunteered to participate in this study during routine thoracostomy tube education. A healthy volunteer was used as the standardized patient for this study. An experienced physician sonographer used ultrasound to locate a site at mid-axillary line between ribs 4 and 5 and marked the site with invisible ink that can only be revealed with a commercially available UV LED light. Participants were asked to identify the thoracostomy site by placing an opaque marker where they would make their incision. The distance from the correct insertion site was measured in rib spaces. The participants were then given a brief hands-on training session using ultrasound to identify the diaphragm and count rib spaces. The participants were then asked to use ultrasound to identify the proper thoracostomy site and mark it with an opaque marker. The distance from the proper insertion site was measured and recorded in rib spaces.

Results: The participants correctly identified the pre-determined intercostal space using palpation 48% (16/33) of the time, versus the ultrasound group who identified the proper intercostal space 91% (30/33) of the time. On average, the traditional technique was placed 0.88 rib spaces away (95 CI 0.43-1.03), while the ultrasound-guided technique was placed 0.09 rib spaces away (95 CI 0.0-0.19) [P = 0.003].

Conclusions: The ability to accurately locate the correct intercostal space for thoracostomy incision was improved under ultrasound guidance. Further studies are warranted to determine if this ultrasound-guided technique will decrease complications with chest tube insertion and improve patient outcomes.

Background: Point-of-care ultrasound (PoCUS) is spreading throughout Emergency Medicine, Critical Care and Pre-hospital Care. However, there is an underlying inherited conflict with the established specialties performing comprehensive examinations. It has been stated that PoCUS is disruptive innovation. If this is true the definition might open up for a new perspective on differentiating comprehensive ultrasound from PoCUS. PoCUS in the light of disruptive innovation is a different perspective on ultrasound that has not before been academically scrutinized.

Methods: In this paper we investigate if PoCUS is in fact disruptive innovation. This is done by comparative analysis with the point of departure in disruptive innovation theory known from the business world.

Results: We find that a disruptive innovation process is happening. This new knowledge allows us to put forward advice for the stakeholders in the field of ultrasound. It also allows us to challenge the conventional pyramid of expertise used to describe different types of ultrasound. The perspective of this paper is mutual understanding of similarities and differences between conventional and point-of-care ultrasound. Only with this understanding the stakeholders can collaborate and use the full spectrum of ultrasound for the benefit of the patient.