Ultrasonographic applications after mass casualty incident caused by Wenchuan earthquake. ACTA ACUST UNITED AC. 2010;68:1417-1420. [PMID: 20234325 DOI: 10.1097/ta.0b013e3181c9b301]

Accuracy of Focused Assessment with Sonography for Trauma (FAST) in Disaster Settings: A Meta-Analysis and Systematic Review

Focused assessment with sonography for trauma (FAST) has been incorporated into the initial evaluation of trauma for decades. It is an important screening tool in the detection of intra-abdominal fluid. The objective of this study was to perform a systematic review of the use and accuracy of FAST as an imaging tool for blunt abdominal trauma in disaster/mass casualty settings. A systematic review of literature was conducted using key words and search terms. Two independent reviewers screened abstracts to determine inclusion using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS). For studies passing QUADAS, a meta-analysis was performed calculating sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). FAST results were compared with the gold standard, which was a combination of CT scan results, operative findings, and medical records of the clinical course. Initial database screening resulted in 133 articles, of which 21 were selected for QUADAS evaluation. Five studies passed QUADAS and were selected in the final meta-analysis, with a total of 4263 patients. The sensitivity of FAST was 92.1% (87.8–95.6), specificity 98.7% (96.0–99.9), PPV 90.7% (70.0–98.0), and NPV 98.8% (98.1–99.5) for the detection of intra-abdominal injury. In our meta-analysis, FAST was both sensitive and specific in the evaluation of trauma in the disaster setting.

Point-of-care ultrasonography for diagnosing thoracoabdominal injuries in patients with blunt trauma

BACKGROUND

Point-of-care sonography (POCS) has emerged as the screening modality of choice for suspected body trauma in many emergency departments worldwide. Its best known application is FAST (focused abdominal sonography for trauma). The technology is almost ubiquitously available, can be performed during resuscitation, and does not expose patients or staff to radiation. While many authors have stressed the high specificity of POCS, its sensitivity varied markedly across studies. This review aimed to compile the current best evidence about the diagnostic accuracy of POCS imaging protocols in the setting of blunt thoracoabdominal trauma.

OBJECTIVES

To determine the diagnostic accuracy of POCS for detecting and excluding free fluid, organ injuries, vascular lesions, and other injuries (e.g. pneumothorax) compared to a diagnostic reference standard (i.e. computed tomography (CT), magnetic resonance imaging (MRI), thoracoscopy or thoracotomy, laparoscopy or laparotomy, autopsy, or any combination of these) in patients with blunt trauma.

SEARCH METHODS

We searched Ovid MEDLINE (1946 to July 2017) and Ovid Embase (1974 to July 2017), as well as PubMed (1947 to July 2017), employing a prospectively defined literature and data retrieval strategy. We also screened the Cochrane Library, Google Scholar, and BIOSIS for potentially relevant citations, and scanned the reference lists of full-text papers for articles missed by the electronic search. We performed a top-up search on 6 December 2018, and identified eight new studies which may be incorporated into the first update of this review.

SELECTION CRITERIA

We assessed studies for eligibility using predefined inclusion and exclusion criteria. We included either prospective or retrospective diagnostic cohort studies that enrolled patients of any age and gender who sustained any type of blunt injury in a civilian scenario. Eligible studies had to provide sufficient information to construct a 2 x 2 table of diagnostic accuracy to allow for calculating sensitivity, specificity, and other indices of diagnostic test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts, and full texts of reports using a prespecified data extraction form. Methodological quality of individual studies was rated by the QUADAS-2 instrument (the revised and updated version of the original Quality Assessment of Diagnostic Accuracy Studies list of items). We calculated sensitivity and specificity with 95% confidence intervals (CI), tabulated the pairs of sensitivity and specificity with CI, and depicted these estimates by coupled forest plots using Review Manager 5 (RevMan 5). For pooling summary estimates of sensitivity and specificity, and investigating heterogeneity across studies, we fitted a bivariate model using Stata 14.0.

MAIN RESULTS

We included 34 studies with 8635 participants in this review. Summary estimates of sensitivity and specificity were 0.74 (95% CI 0.65 to 0.81) and 0.96 (95% CI 0.94 to 0.98). Pooled positive and negative likelihood ratios were estimated at 18.5 (95% CI 10.8 to 40.5) and 0.27 (95% CI 0.19 to 0.37), respectively. There was substantial heterogeneity across studies, and the reported accuracy of POCS strongly depended on the population and affected body area. In children, pooled sensitivity of POCS was 0.63 (95% CI 0.46 to 0.77), as compared to 0.78 (95% CI 0.69 to 0.84) in an adult or mixed population. Associated specificity in children was 0.91 (95% CI 0.81 to 0.96) and in an adult or mixed population 0.97 (95% CI 0.96 to 0.99). For abdominal trauma, POCS had a sensitivity of 0.68 (95% CI 0.59 to 0.75) and a specificity of 0.95 (95% CI 0.92 to 0.97). For chest injuries, sensitivity and specificity were calculated at 0.96 (95% CI 0.88 to 0.99) and 0.99 (95% CI 0.97 to 1.00). If we consider the results of all 34 included studies in a virtual population of 1000 patients, based on the observed median prevalence (pretest probability) of thoracoabdominal trauma of 28%, POCS would miss 73 patients with injuries and falsely suggest the presence of injuries in another 29 patients. Furthermore, in a virtual population of 1000 children, based on the observed median prevalence (pretest probability) of thoracoabdominal trauma of 31%, POCS would miss 118 children with injuries and falsely suggest the presence of injuries in another 62 children.

AUTHORS' CONCLUSIONS

In patients with suspected blunt thoracoabdominal trauma, positive POCS findings are helpful for guiding treatment decisions. However, with regard to abdominal trauma, a negative POCS exam does not rule out injuries and must be verified by a reference test such as CT. This is of particular importance in paediatric trauma, where the sensitivity of POCS is poor. Based on a small number of studies in a mixed population, POCS may have a higher sensitivity in chest injuries. This warrants larger, confirmatory trials to affirm the accuracy of POCS for diagnosing thoracic trauma.

ABCDE of prehospital ultrasonography: a narrative review

Prehospital point-of-care ultrasound used by nonradiologists in emergency medicine is gaining ground. It is feasible on-scene and during aeromedical transport and allows health-care professionals to detect or rule out potential harmful conditions. Consequently, it impacts decision-making in prioritizing care, selecting the best treatment, and the most suitable transport mode and destination. This increasing relevance of prehospital ultrasonography is due to advancements in ultrasound devices and related technology, and to a growing number of applications. This narrative review aims to present an overview of prehospital ultrasonography literature. The focus is on civilian emergency (trauma and non-trauma) setting. Current and potential future applications are discussed, structured according to the airway, breathing, circulation, disability, and environment/exposure (ABCDE) approach. Aside from diagnostic implementation and specific protocols, procedural guidance, therapeutic ultrasound, and challenges are reviewed.

Ultrasound diagnosis of fractures in mass casualty incidents

The role of point-of-care ultrasound in mass casualty incidents (MCIs) is still evolving. Occasionally, hospitals can be destroyed by disasters resulting in large number of trauma patients. CAVEAT and FASTER ultrasound protocols, which are used in MCIs, included extremity ultrasound examination as part of them. The literature supports the use of ultrasound in diagnosing extremity fractures both in hospitals and MCIs. The most recent systematic review which was reported by Douma-den Hamer et al in 2016 showed that the pooled ultrasound sensitivity and specificity for detecting distal forearm fractures was 97% and 95% respectively. Nevertheless, majority of these studies were in children and they had very high heterogeneity. The portability, safety, repeatability, and cost-effectiveness of ultrasound are great advantages when treating multiply injured patients in MCIs. Its potential in managing fractures in MCIs needs to be further defined. The operator should master the technique, understand its limitations, and most importantly correlate the sonographic findings with the clinical ones to be useful. This editorial critically reviews the literature on this topic, describes its principles and techniques, and includes the author’s personal learned lessons so that trauma surgeons will be encouraged to use ultrasound to diagnose fractures in their own clinical practice.

Disaster response team FAST skills training with a portable ultrasound simulator compared to traditional training: pilot study

Introduction

Pre-hospital focused assessment with sonography in trauma (FAST) has been effectively used to improve patient care in multiple mass casualty events throughout the world. Although requisite FAST knowledge may now be learned remotely by disaster response team members, traditional live instructor and model hands-on FAST skills training remains logistically challenging. The objective of this pilot study was to compare the effectiveness of a novel portable ultrasound (US) simulator with traditional FAST skills training for a deployed mixed provider disaster response team.

Methods

We randomized participants into one of three training groups stratified by provider role: Group A. Traditional Skills Training, Group B. US Simulator Skills Training, and Group C. Traditional Skills Training Plus US Simulator Skills Training. After skills training, we measured participants’ FAST image acquisition and interpretation skills using a standardized direct observation tool (SDOT) with healthy models and review of FAST patient images. Pre- and post-course US and FAST knowledge were also assessed using a previously validated multiple-choice evaluation. We used the ANOVA procedure to determine the statistical significance of differences between the means of each group’s skills scores. Paired sample t-tests were used to determine the statistical significance of pre- and post-course mean knowledge scores within groups.

Results

We enrolled 36 participants, 12 randomized to each training group. Randomization resulted in similar distribution of participants between training groups with respect to provider role, age, sex, and prior US training. For the FAST SDOT image acquisition and interpretation mean skills scores, there was no statistically significant difference between training groups. For US and FAST mean knowledge scores, there was a statistically significant improvement between pre- and post-course scores within each group, but again there was not a statistically significant difference between training groups.

Conclusion

This pilot study of a deployed mixed-provider disaster response team suggests that a novel portable US simulator may provide equivalent skills training in comparison to traditional live instructor and model training. Further studies with a larger sample size and other measures of short- and long-term clinical performance are warranted.

Wilderness medicine

BACKGROUND

Human activity in wilderness areas has increased globally in recent decades, leading to increased risk of injury and illness. Wilderness medicine has developed in response to both need and interest.

METHODS

The field of wilderness medicine encompasses many areas of interest. Some focus on special circumstances (such as avalanches) while others have a broader scope (such as trauma care). Several core areas of key interest within wilderness medicine are discussed in this study.

RESULTS

Wilderness medicine is characterized by remote and improvised care of patients with routine or exotic illnesses or trauma, limited resources and manpower, and delayed evacuation to definitive care. Wilderness medicine is developing rapidly and draws from the breadth of medical and surgical subspecialties as well as the technical fields of mountaineering, climbing, and diving. Research, epidemiology, and evidence-based guidelines are evolving. A hallmark of this field is injury prevention and risk mitigation. The range of topics encompasses high-altitude cerebral edema, decompression sickness, snake envenomation, lightning injury, extremity trauma, and gastroenteritis. Several professional societies, academic fellowships, and training organizations offer education and resources for laypeople and health care professionals.

CONCLUSIONS

THE FUTURE OF WILDERNESS MEDICINE IS UNFOLDING ON MULTIPLE FRONTS: education, research, training, technology, communications, and environment. Although wilderness medicine research is technically difficult to perform, it is essential to deepening our understanding of the contribution of specific techniques in achieving improvements in clinical outcomes.

Disaster triage after the Haitian earthquake

In the aftermath of the devastating Haitian earthquake, we became the primary relief service for a large group of severely injured earthquake victims. Finding ourselves virtually isolated with extremely limited facilities and a group of critically injured patients whose needs vastly outstripped the available resources we employed a disaster triage system to organize their clinical care. This report describes the specific injury profile of this group of patients, their clinical course, and the management philosophy that we employed. It provides useful lessons for similar situations in the future.

Point-of-care ultrasound in critically ill patients: Where do we stand?

Experience over the last 25 years has shown that point-of-care ultrasound is a very useful tool when used by nonradiologists. Its value will be optimized by understanding its limitations and by adopting a focused binary decision making approach to answer specific questions without going into detailed radiological studies. Point-of-care ultrasound became an extension of the clinical examination. There are extensive efforts trying to design low-cost portable ultrasound systems by changing the transducer design, the transmission and reception circuitry needs, or the beam forming algorithms which may lead to horizontal expansion of the use of reliable non expensive portable ultrasound machines. The successful story of using ultrasound by nonradiologists, the advanced technology, and the refinement of the educational methods will encourage future clinicians to use ultrasound in their domains.

Prospective application of clinician-performed lung ultrasonography during the 2009 H1N1 influenza A pandemic: distinguishing viral from bacterial pneumonia

Background

Emergency department visits quadrupled with the initial onset and surge during the 2009 H1N1 influenza pandemic in New York City from April to June 2009. This time period was unique in that >90% of the circulating virus was surveyed to be the novel 2009 H1N1 influenza A according to the New York City Department of Health. We describe our experience using lung ultrasound in a case series of patients with respiratory symptoms requiring chest X-ray during the initial onset and surge of the 2009 H1N1 influenza pandemic.

Methods

We describe a case series of patients from a prospective observational cohort study of lung ultrasound, enrolling patients requiring chest X-ray for suspected pneumonia that coincided with the onset and surge of the 2009 H1N1 influenza pandemic.

Results

Twenty pandemic 2009 H1N1 influenza patients requiring chest X-ray were enrolled during this time period. Median age was 6.7 years. Lung ultrasound via modified Bedside Lung Ultrasound in Emergency protocol assisted in the identification of viral pneumonia (n = 15; 75%), viral pneumonia with superimposed bacterial pneumonia (n = 7; 35%), isolated bacterial pneumonia only (n = 1; 5%), and no findings of viral or bacterial pneumonia (n = 4; 20%) in this cohort of patients. Based on 54 observations, interobserver agreement for distinguishing viral from bacterial pneumonia using lung ultrasound was ĸ = 0.82 (0.63 to 0.99).

Conclusions

Lung ultrasound may be used to distinguish viral from bacterial pneumonia. Lung ultrasound may be useful during epidemics or pandemics of acute respiratory illnesses for rapid point-of-care triage and management of patients.

Emergency medical rescue efforts after a major earthquake: lessons from the 2008 Wenchuan earthquake

Major earthquakes often result in incalculable environmental damage, loss of life, and threats to health. Tremendous progress has been made in response to many medical challenges resulting from earthquakes. However, emergency medical rescue is complicated, and great emphasis should be placed on its organisation to achieve the best results. The 2008 Wenchuan earthquake was one of the most devastating disasters in the past 10 years and caused more than 370,000 casualties. The lessons learnt from the medical disaster relief effort and the subsequent knowledge gained about the regulation and capabilities of medical and military back-up teams should be widely disseminated. In this Review we summarise and analyse the emergency medical rescue efforts after the Wenchuan earthquake. Establishment of a national disaster medical response system, an active and effective commanding system, successful coordination between rescue forces and government agencies, effective treatment, a moderate, timely and correct public health response, and long-term psychological support are all crucial to reduce mortality and morbidity and promote overall effectiveness of rescue efforts after a major earthquake.

Review article: Use of ultrasound in the developing world

As portability and durability improve, bedside, clinician-performed ultrasound is seeing increasing use in rural, underdeveloped parts of the world. Physicians, nurses and medical officers have demonstrated the ability to perform and interpret a large variety of ultrasound exams, and a growing body of literature supports the use of point-of-care ultrasound in developing nations. We review, by region, the existing literature in support of ultrasound use in the developing world and training guidelines currently in use, and highlight indications for emergency ultrasound in the developing world. We suggest future directions for bedside ultrasound use and research to improve diagnostic capacity and patient care in the most remote areas of the globe.

The future of pediatric US

Despite advances in other modalities, US remains an essential technology in pediatric imaging. Improvements in technology provide increasingly detailed anatomical images, and new techniques show promise in providing novel anatomical as well as physiological and structural information. Other specialties are recognizing the value of US to their patients and are increasingly performing their own examinations. Economic and social factors are also influencing the development and use of US. This review will evaluate many of these issues and demonstrate that the future of pediatric US is bright and that pediatric radiologists can and should continue to be leaders in its use and development.