Critical Ultrasound Journal最新文献

Background: Transesophageal echocardiography (TEE) offers several advantages over transthoracic echocardiography (TTE). Despite these advantages, use of TEE by emergency physicians (EPs) remains rare, as no focused TEE protocol for emergency department (ED) use has been defined nor have methods of training been described.

Objective: This study aims to develop a focused TEE examination tailored for the ED and to evaluate TEE skill acquisition and retention by TEE-naïve EPs following a focused 4-h curriculum.

Methods: Academic EPs were invited to participate in a 4-h didactic and simulation-based workshop. The seminar emphasized TEE principles and views obtained from four vantage points. Following the training, participants engaged in an assessment of their abilities to carry out a focused TEE on a high-fidelity simulator. A 6-week follow-up session assessed skill retention.

Results: Fourteen EPs participated in this study. Immediately following the seminar, 14 (100 %; k = 1.0) and 10 (71.4 %, k = 0.65) successfully obtained an acceptable mid-esophageal four-chamber and mid-esophageal long-axis view. Eleven (78.6 %, k = 1.0) participants were able to successfully obtain an acceptable transgastric short-axis view, and 11 (78.6 %, k = 1.0) EPs successfully obtained a bicaval view. Twelve participants engaged in a 6-week retention assessment, which revealed acceptable images and inter-rater agreement as follows: mid-esophageal four-chamber, 12 (100 %; k = 0.92); mid-esophageal long axis, 12 (100 %, k = 0.67); transgastric short-axis, 11 (91.7 %, k = 1.0); and bicaval view, 11 (91.7 %, k = 1.0).

Conclusion: This study has illustrated that EPs can successfully perform this focused TEE protocol after a 4-h workshop with retention of these skills at 6 weeks.

Background: It is important to detect splenomegaly as it can have important diagnostic implications. Previous studies, however, have shown that the traditional physical examination is limited in its ability to rule in or rule out splenomegaly.

Objective: To determine if performing point-of-care ultrasonography (POCUS) in addition to the traditional physical examination improves the sensitivity and specificity for diagnosing splenomegaly.

Methods: This was a prospective trial of diagnostic accuracy. Physical and sonographic examinations for splenomegaly were performed by students, residents and attending physicians enrolled in an ultrasound training course. Participants received less than 1 h training for ultrasound diagnosis of splenomegaly. The findings were compared to radiographic interpretation of gold standard studies.

Setting/patients: Hospitalized adult patients at an academic medical center without severe abdominal pain or recent surgery who had abdominal CT, MRI or ultrasound performed within previous 48 h.

Results: Thirty-nine subjects were enrolled. Five patients had splenomegaly (12.5 %). The physical examination for splenomegaly had a sensitivity of 40 % (95 % CI 12-77 %) and specificity of 88 % (95 % CI 74-95 %) while physical examination plus POCUS had a sensitivity of 100 % (95 % CI 57-100 %) and specificity of 74 % (95 % CI 57-85 %). Physical examination alone for splenomegaly had an LR+ of 3.4 (95 % CI 0.83-14) and LR- of 0.68 (95 % CI 0.33-1.41); for physical exam plus POCUS the LR+ was 3.8 (2.16-6.62) and LR- was 0.

Conclusions: Point-of-care ultrasonography significantly improves examiners' sensitivity in diagnosing splenomegaly.

Background: Access to ultrasound has increased significantly in resource-limited settings, including the developing world; however, there remains a lack of sonography education and ultrasound-trained physician support in developing countries. To further investigate this potential knowledge gap, our primary objective was to assess perceived barriers to ultrasound use in resource-limited settings by surveying care providers who practice in low- and middle-income settings.

Methods: A 25-question online survey was made available to health care providers who work with an ultrasound machine in low- and middle-income countries (LMICs), including doctors, nurses, technicians, and clinical officers. This was a convenience sample obtained from list-serves of ultrasound and radiologic societies. The survey was analyzed, and descriptive results were obtained.

Results: One hundred and thirty-eight respondents representing 44 LMICs including countries from the continents of Africa, South America, and Asia completed the survey, with a response rate of 9.6 %. Ninety-one percent of the respondents were doctors, and 9 % were nurses or other providers. Applications for ultrasound were diverse, including obstetrics (75 %), DVT evaluation (51 %), abscess evaluation (54 %), cardiac evaluation (64 %), inferior vena cava (IVC) assessment (49 %), Focused Assessment Sonography for Trauma (FAST) exam (64 %), biliary tree assessment (54 %), and other applications. The respondents identified the following barriers to use of ultrasound: lack of training (60 %), lack of equipment (45 %), ultrasound machine malfunction (37 %), and lack of ultrasound maintenance capability (47 %). Seventy-four percent of the respondents wished to have further training in ultrasound, and 82 % were open to receiving distance learning or telesonography training. Subjects used communication tools including Skype, Dropbox, emailed photos, and picture archiving and communication system (PACS) as ways to communicate and receive feedback on ultrasound images.

Conclusions: Health care providers in the developing world identify lack of training as a primary barrier to regular use of ultrasound in their practice. While equipment requirements including maintenance and cost of machines are also important factors, future research is warranted on best practices for training methods, including telesonography and distance learning to enhance ultrasound use in low-resource settings.

Interest in ultrasound education in medical schools has increased dramatically in recent years as reflected in a marked increase in publications on the topic and growing attendance at international meetings on ultrasound education. In 2006, the University of South Carolina School of Medicine introduced an integrated ultrasound curriculum (iUSC) across all years of medical school. That curriculum has evolved significantly over the 9 years. A review of the curriculum is presented, including curricular content, methods of delivery of the content, student assessment, and program assessment. Lessons learned in implementing and expanding an integrated ultrasound curriculum are also presented as are thoughts on future directions of undergraduate ultrasound education. Ultrasound has proven to be a valuable active learning tool that can serve as a platform for integrating the medical student curriculum across many disciplines and clinical settings. It is also well-suited for a competency-based model of medical education. Students learn ultrasound well and have embraced it as an important component of their education and future practice of medicine. An international consensus conference on ultrasound education is recommended to help define the essential elements of ultrasound education globally to ensure ultrasound is taught and ultimately practiced to its full potential. Ultrasound has the potential to fundamentally change how we teach and practice medicine to the benefit of learners and patients across the globe.

Background: Pneumoperitoneum is a rare cause of abdominal pain characterized by a high mortality. Ultrasonography (US) can detect free intraperitoneal air; however, its accuracy remains unclear. The aims of this pilot study were to define the diagnostic performance and the reliability of abdominal US for the diagnosis of pneumoperitoneum.

Methods: This was a prospective observational study. Four senior and two junior physicians were shown, in an unpaired randomized order, abdominal US videos from 11 patients with and 11 patients without pneumoperitoneum. Abdominal US videos were obtained from consecutive patients presenting to ED complaining abdominal pain with the diagnosis of pneumoperitoneum established by CT. Abdominal US was performed according to a standardized protocol that included the following scans: epigastrium, right and left hypochondrium, umbilical area and right hypochondrium with the patient lying on the left flank. We evaluated accuracy, intra- and inter-observer agreement of abdominal US when reviewed by senior physicians. Furthermore, we compared the accuracy of a "2 scan-fast exam" (epigastrium and right hypochondrium) vs the full US examination and the accuracy of physicians expert in US vs nonexpert ones. Finally, accuracy of US was compared with abdominal radiography in patients with available images.

Results: Considering senior revision, accuracy of abdominal US was 88.6 % (95 % CI 79.4-92.4 %) with a sensitivity of 95.5 % (95 % CI 86.3-99.2 %) and a specificity of 81.8 % (95 % CI 72.6-85.5 %). Inter- and intra-observer agreement (k) were 0.64 and 0.95, respectively. Accuracy of a "2 scan-fast exam" (87.5 %, 95 % CI 77.9-92.4 %) was similar to global exam. Sensitivity of abdominal radiography (72.2 %, 95 % CI 54.8-85.7 %) was lower than that of abdominal US, while specificity (92.5 %, 95 % CI 79.5-98.3 %) was higher. Accuracy (68.2 %, 95 % CI 51.4-80.9 %) of junior reviewers evaluating US was lower than senior reviewers.

Conclusions: Senior physicians can recognize US signs of pneumoperitoneum with a good accuracy and reliability; sensitivity of US could be superior to abdominal radiography and a 2 fast-scan exam seems as accurate as full abdominal examination. US could be a useful bedside screening test for pneumoperitoneum. Trial registry ClinicalTrials.gov; No.: NCT02004925; URL: http://www.clinicaltrials.gov.

Background: The evaluation of fluid responsiveness in patients with hemodynamic instability remains to be challenging. This investigation aimed to determine whether respiratory variation in carotid Doppler peak velocity (ΔCDPV) predicts fluid responsiveness in patients with septic shock and lung protective mechanical ventilation with a tidal volume of 6 ml/kg.

Methods: We performed a prospective cohort study at an intensive care unit, studying the effect of 59 fluid challenges on 19 mechanically ventilated patients with septic shock. Pre-fluid challenge ΔCDPV and other static or dynamic measurements were obtained. Fluid challenge responders were defined as patients whose stroke volume index increased more than 15 % on transpulmonary thermodilution. The area under the receiver operating characteristic curve (AUROC) was compared for each predictive parameter.

Results: Fluid responsiveness rate was 51 %. The ΔCDPV had an AUROC of 0.88 (95 % confidence interval (CI) 0.77-0.95); followed by stroke volume variation (0.72, 95 % CI 0.63-0.88), passive leg raising (0.69, 95 % CI 0.56-0.80), and pulse pressure variation (0.63, 95 % CI 0.49-0.75). The ΔCDPV was a statistically significant superior predictor when compared with the other parameters. Sensitivity, specificity, and positive and negative predictive values were also the highest for ΔCDPV, with an optimal cutoff at 14 %. There was good correlation between ΔCDPV and SVI increment after the fluid challenge (r = 0.84; p < 0.001).

Conclusions: ΔCDPV can be more accurate than other methods for assessing fluid responsiveness in patients with septic shock receiving lung protective mechanical ventilation. ΔCDPV also has a high correlation with SVI increase after fluid challenge.

Background: Unrecognized esophageal intubations are associated with significant patient morbidity and mortality. No single confirmatory device has been shown to be 100 % accurate at ruling out esophageal intubations in the emergency department. Recent studies have demonstrated that point-of-care ultrasound (POCUS) may be a useful adjunct for confirming endotracheal tube placement; however, the amount of practice required to become proficient at this technique is unclear. The purpose of this study is to determine the amount of practice required by emergency physicians to become proficient at interpreting ultrasound video clips of esophageal and endotracheal intubations.

Methods: Emergency physicians and emergency medicine residents completed a baseline interpretation test followed by a 10 min online tutorial. They then interpreted POCUS clips of esophageal and endotracheal intubations in a randomly selected order. If an incorrect response was provided, the participant completed another practice session with feedback. This process continued until they correctly interpreted ten consecutive ultrasound clips. Descriptive statistics were used to summarize the data.

Results: Of the 87 eligible physicians, 66 (75.9 %) completed the study. The mean score on the baseline test was 42.9 % (SD 32.7 %). After the tutorial, 90.9 % (60/66) of the participants achieved proficiency after one practice attempt and 100 % achieved proficiency after two practice attempts. Six intubation ultrasound clips were misinterpreted, for a total error rate of 0.9 % (6/684). Overall, the participants had a sensitivity of 98.3 % (95 % CI 96.3-99.4 %) and specificity of 100 % (95 % CI 98.9-100 %) for detecting correct tube location. Scans were interpreted within an average of 4 s (SD 2.9 s) of the intubation.

Conclusions: After a brief online tutorial and only two practice attempts, emergency physicians were able to quickly and accurately interpret ultrasound intubation clips of esophageal and endotracheal intubations.

Respiratory failure requiring mechanical ventilation has been reported in patients with bilateral diaphragmatic paralysis due to CIDP. We report a case of CIDP that progressed to respiratory failure with normal chest radiography despite unilateral diaphragmatic paralysis. This manifestation would have been missed if ultrasound was not employed.

Splenic artery aneurysm is a rare but a potentially fatal condition. It is usually asymptomatic until it ruptures. Here, we present a case of ruptured splenic artery aneurysm in a 59-year-old gentleman presenting with epigastric pain and hypovolemic shock. The diagnosis was made by emergency ultrasound and CT scan, and he was managed by laparotomy and excision of the splenic artery aneurysm. Priorities in patient management lie in rapid resuscitation, diagnostic imaging, surgical consultation, and subsequent laparotomy. Pitfalls should be borne in mind to differentiate splenic artery aneurysm from abdominal aortic aneurysm when using the emergency ultrasound.

Three Doppler-derived techniques have been proposed to assess renal perfusion at bedside: Doppler-based renal resistive index (RI) which has been extensively but imperfectly studied in assessing renal allograft status and changes in renal perfusion in critically ill patients and for predicting the reversibility of an acute kidney injury (AKI), semi-quantitative evaluation of renal perfusion using colour-Doppler which may be easier to perform and may give similar information than RI and contrast-enhanced sonography that may allow more precise renal and cortical perfusion assessment. These promising tools have several obvious advantages including their feasibility, non-invasiveness, repeatability and potential interest in assessing renal function or perfusion. However, several limits need to be taken into account with these techniques, and promising results remain associated with large areas of uncertainty. This editorial will describe more carefully advantages and limits of these techniques and will discuss their potential interest in assessing renal perfusion.