Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinicians in detecting hemoperitoneum

Emergency Ultrasound Predicting the Need for Therapeutic Laparotomy among Blunt Abdominal Trauma Patients in a Sub-Saharan African Hospital

Background. The trauma burden globally accounts for high levels of mortality and morbidity. Blunt abdominal trauma (BAT) contributes significantly to this burden. Patient's evaluation for BAT remains a diagnostic challenge for emergency physicians. SSORTT gives a score that can predict the need for laparotomy. The objective of this study was to assess the accuracy of SSORTT score in predicting the need for a therapeutic laparotomy after BAT. Method. A prospective observational study. Eligible patients were evaluated for shock and the presence of haemoperitoneum using a portable ultrasound machine. Further evaluation of patients following the standard of care (SOC) protocol was done. The accuracy of SSORTT score in predicting therapeutic laparotomy was compared to SOC. Results. In total, 195 patients were evaluated; M : F ratio was 6 : 1. The commonest injuries were to the head 80 (42%) and the abdomen 54 (28%). A SSORTT score of >2 appropriately identified patients that needed a therapeutic laparotomy (with sensitivity 90%, specificity 90%, PPV 53%, and NPV 98%). The overall mortality rate was 17%. Conclusion. Patients with a SSORTT score of 2 and above had a high likelihood of requiring a therapeutic laparotomy. SSORTT scoring should be adopted for routine practice in low technology settings.

Isolated abdominal trauma: diagnosis and clinical management considerations

PURPOSE OF REVIEW

The scope of the present study is to review the topics of initial assessment, diagnosis and clinical management of an isolated abdominal trauma.

RECENT FINDINGS

Progress in the management of trauma patients increasing survival includes a multidisciplinary approach involving multiple specialties at presentation. If immediate surgical intervention is needed, 'damage control' is the best option; if not, it has been proven that conservative management is superior to operative, in terms of survival for the majority of intraabdominal injury. 'Open abdomen' should be performed in major abdominal traumas when indicated. Early enteral feeding is beneficial, even in the presence of 'open abdomen'.

SUMMARY

Abdominal trauma is a complex injury; the multidisciplinary approach has made nonoperative management feasible and effective. When surgical intervention is needed, it should be performed in an orderly fashion, within the context of the overall management.

Implementation of a successful incentive-based ultrasound credentialing program for emergency physicians

Introducion:

With the rapid expansion of emergency ultrasound, resident education in ultrasound has become more clearly developed and broadly integrated. However, there still exists a lack of guidance in the training of physicians already in practice to become competent in this valuable skill. We sought to employ a step-wise, goal-directed, incentive-based credentialing program to educate emergency physicians in the use of emergency ultrasound. Successful completion of this program was the primary outcome.

Methods:

The goal was for the physicians to gain competency in 8 basic ultrasound examinations types: aorta, focused assessment with sonography in trauma, cardiac, renal, biliary, transabdominal pelvic, transvaginal pelvic, and deep venous thrombosis. We separated the 2.5 year training program into 4 distinct blocks, with each block focusing on 2 of the ultrasound examination types. Each block consisted of didactic and hands-on sessions with the goal of the physician completing 25 technically-adequate studies of each examination type. There was a financial incentive associated with completion of these requirements.

Results:

A total of 31 physicians participated in the training program. Only one physician, who retired prior to the end of the 2.5 year period, did not successfully complete the program. All have applied for and received hospital privileging in emergency ultrasound and incorporated it into their daily practice.

Conclusion:

We found that a step-wise, incentive-based ultrasound training program with a combination of didactics and ample hands-on teaching was successful in the training of physicians already in practice.

Thorax, trachea, and lung ultrasonography in emergency and critical care medicine: assessment of an objective structured training concept

Background and Study objective. Focused lung ultrasound (LUS) examinations are important tools in critical care medicine. There is evidence that LUS can be used for the detection of acute thoracic lesions. However, no validated training method is available. The goal of this study was to develop and assess an objective structured clinical examination (OSCE) curriculum for focused thorax, trachea, and lung ultrasound in emergency and critical care medicine (THOLUUSE). Methods. 39 trainees underwent a one-day training course in a prospective educational study, including lectures in sonoanatomy and -pathology of the thorax, case presentations, and hands-on training. Trainees' pre- and posttest performances were assessed by multiple choice questionnaires, visual perception tests by interpretation video clips, practical performance of LUS, and identification of specific ultrasound findings. Results. Trainees postcourse scores of correct MCQ answers increased from 56 ± 4% to 82 ± 2% (mean± SD; P < 0.001); visual perception skills increased from 54 ± 5% to 78 ± 3% (P < 0.001); practical ultrasound skills improved, and correct LUS was performed in 94%. Subgroup analysis revealed that learning success was independent from the trainees' previous ultrasound experience. Conclusions. THOLUUSE significantly improves theoretical and practical skills for the diagnosis of acute thoracic lesions. We propose to implement THOLUUSE in emergency medicine training.

Emergency focussed assessment with sonography in trauma (FAST) and haemodynamic stability

Background

Focussed assessment with sonography in trauma (FAST) has assumed a key role in the rapid non-invasive assessment of thoracoabdominal trauma and assists in decreasing disposition time. This study evaluates FAST's efficacy with respect to haemodynamic stability in a South African emergency department (ED).

Methods

Data were collected prospectively by four emergency medicine doctors trained in emergency ultrasonography. FAST scans were performed by one ED doctor and timings, scan result and disposition were recorded. Patient haemodynamic stability was assessed by the emergency doctor performing the scan; subjectively at the time of scanning and objectively using calculation of the shock index. All scan results were subsequently verified by a second ED doctor in a blinded fashion and by CT scanning or operative intervention when clinically indicated.

Results

166 FAST scans were conducted of which 36 (21.7%) were positive. Mean age was 30.6 years (SD 12.8). 74.1% of patients sustained blunt traumatic injury. Doctors’ subjective haemodynamic stability assessments had higher specificity, sensitivity and predictive values than shock index alone. Haemodynamic instability and a positive FAST result were significantly related (p=0.004). Sensitivities and specificities of FAST scans for blunt and penetrating trauma were 93.1% and 100%, and 90.0% and 100%, respectively. Corresponding values for pneumothoraces were 84.6% and 100%.

Discussion

This study showed a valuable role for FAST in all traumas, particularly in haemodynamic compromise. As an addition to the physician's repertoire of bedside assessment tools, it improves diagnostic capabilities in comparison with simple haemodynamic assessments alone.

Avaliação epidemiológica das vítimas de trauma abdominal submetidas ao tratamento cirúrgico

OBJETIVO: avaliar o perfil epidemiológico e o desfecho das vítimas de trauma abdominal submetidas à laparotomia em hospital de urgência. MÉTODOS: estudo observacional, descritivo, longitudinal, com abordagem prospectiva, mediante entrevista de 100 pacientes com trauma abdominal submetidos ao tratamento cirúrgico e à avaliação dos seus prontuários. Período da coleta dos dados: setembro a novembro de 2011. RESULTADOS: Os pacientes mais acometidos pelo trauma abdominal foram do sexo masculino, de cor parda, na faixa etária de 25-49 anos, com baixa escolaridade, solteiros, católicos, com rendimento de um a dois salários mínimos. Houve uma predominância do trauma no ambiente urbano, no período noturno e no final de semana. O motivo mais frequente do trauma foi a tentativa de homicídio, associado ao uso de álcool e drogas ilícitas e o mecanismo a arma branca. A dor mostrou-se o sinal de alerta mais presente. A região mais afetada foi abdome superior e o fígado o órgão mais acometido. O tempo de internação hospitalar durou em torno de quatro a dez dias. A maioria teve alta sem sequela. Ocorreram dois óbitos. CONCLUSÃO: Foi marcante a associação do trauma abdominal com homens sob efeito de álcool e/ou drogas ilícitas, refletindo o contexto da violência interpessoal na sociedade atual. A despeito da magnitude do trauma, o desfecho foi satisfatório, apesar da ocorrência de óbitos, o que denota a importância dos hospitais de urgência de manter no seu corpo clínico uma equipe cirúrgica treinada.

False-negative FAST examination: associations with injury characteristics and patient outcomes

STUDY OBJECTIVE

Focused assessment with sonography in trauma (FAST) is widely used for evaluating patients with blunt abdominal trauma; however, it sometimes produces false-negative results. Presenting characteristics in the emergency department may help identify patients at risk for false-negative FAST result or help the physician predict injuries in patients with a negative FAST result who are unstable or deteriorate during observation. Alternatively, false-negative FAST may have no clinical significance. The objectives of this study are to estimate associations between false-negative FAST results and patient characteristics, specific abdominal organ injuries, and patient outcomes.

METHODS

This was a retrospective cohort study including consecutive patients who presented to an urban Level I trauma center between July 2005 and December 2008 with blunt abdominal trauma, a documented FAST, and pathologic free fluid as determined by computed tomography, diagnostic peritoneal lavage, laparotomy, or autopsy. Physicians blinded to the study purpose used standardized abstraction methods to confirm FAST results and the presence of pathologic free fluid. Multivariable modeling was used to assess associations between potential predictors of a false-negative FAST result and false-negative FAST result and adverse outcomes.

RESULTS

During the study period, 332 patients met inclusion criteria. Median age was 32 years (interquartile range 23 to 45 years), 67% were male patients, the median Injury Severity Score was 27 (interquartile range 17 to 41), and 162 (49%) had a false-negative FAST result. Head injury was positively associated with false-negative FAST result (odds ratio [OR] 4.9; 95% confidence interval [CI] 1.5 to 15.7), whereas severe abdominal injury was negatively associated (OR 0.3; 95% CI 0.1 to 0.5). Injuries to the spleen (OR 0.4; 95% CI 0.24 to 0.66), liver (OR 0.36; 95% CI 0.21 to 0.61), and abdominal vasculature (OR 0.17; 95% CI 0.07 to 0.38) were also negatively associated with false-negative FAST result. False-negative FAST result was not associated with mortality (OR 0.89; 95% CI 0.42 to 1.9), prolonged ICU length of stay (relative risk 0.88; 95% CI 0.69 to 1.12), or total hospital length of stay (relative risk 0.92; 95% CI 0.76 to 1.12). However, patients with false-negative FAST results were substantially less likely to require therapeutic laparotomy (OR 0.31; 95% CI 0.19 to 0.52).

CONCLUSION

Patients with severe head injuries and minor abdominal injuries were more likely to have a false-negative than true-positive FAST result. On the other hand, patients with spleen, liver, or abdominal vascular injuries are less likely to have false-negative FAST examination results. Adverse outcomes were not associated with false-negative FAST examination results, and in fact patients with false-negative FAST result were less likely to have a therapeutic laparotomy. Further studies are needed to assess the strength of these findings.

Does this adult patient have a blunt intra-abdominal injury?

CONTEXT

Blunt abdominal trauma often presents a substantial diagnostic challenge. Well-informed clinical examination can identify patients who require further diagnostic evaluation for intra-abdominal injuries after blunt abdominal trauma.

OBJECTIVE

To systematically assess the precision and accuracy of symptoms, signs, laboratory tests, and bedside imaging studies to identify intra-abdominal injuries in patients with blunt abdominal trauma.

DATA SOURCES

We conducted a structured search of MEDLINE (1950-January 2012) and EMBASE (1980-January 2012) to identify English-language studies examining the identification of intra-abdominal injuries. A separate, structured search was conducted for studies evaluating bedside ultrasonography.

STUDY SELECTION

We included studies of diagnostic accuracy for intra-abdominal injury that compared at least 1 finding with a reference standard of abdominal computed tomography, diagnostic peritoneal lavage, laparotomy, autopsy, and/or clinical course for intra-abdominal injury. Twelve studies on clinical findings and 22 studies on bedside ultrasonography met inclusion criteria for data extraction.

DATA EXTRACTION

Critical appraisal and data extraction were independently performed by 2 authors.

DATA SYNTHESIS

The prevalence of intra-abdominal injury in adult emergency department patients with blunt abdominal trauma among all evidence level 1 and 2 studies was 13% (95% CI, 10%-17%), with 4.7% (95% CI, 2.5%-8.6%) requiring therapeutic surgery or angiographic embolization of injuries. The presence of a seat belt sign (likelihood ratio [LR] range, 5.6-9.9), rebound tenderness (LR, 6.5; 95% CI, 1.8-24), hypotension (LR, 5.2; 95% CI, 3.5-7.5), abdominal distention (LR, 3.8; 95% CI, 1.9-7.6), or guarding (LR, 3.7; 95% CI, 2.3-5.9) suggest an intra-abdominal injury. The absence of abdominal tenderness to palpation does not rule out an intra-abdominal injury (summary LR, 0.61; 95% CI, 0.46-0.80). The presence of intraperitoneal fluid or organ injury on bedside ultrasound assessment is more accurate than any history and physical examination findings (adjusted summary LR, 30; 95% CI, 20-46); conversely, a normal ultrasound result decreases the chance of injury detection (adjusted summary LR, 0.26; 95% CI, 0.19-0.34). Test results increasing the likelihood of intra-abdominal injury include a base deficit less than -6 mEq/L (LR, 18; 95% CI, 11-30), elevated liver transaminases (LR range, 2.5-5.2), hematuria (LR range, 3.7-4.1), anemia (LR range, 2.2-3.3), and abnormal chest radiograph (LR range, 2.5-3.8). Symptoms and signs may be most useful in combination, particularly in identification of patients who do not need further diagnostic workup.

CONCLUSIONS

Bedside ultrasonography has the highest accuracy of all individual findings, but a normal result does not rule out an intra-abdominal injury. Combinations of clinical findings may be most useful to determine which patients do not require further evaluation, but the ideal combination of variables for identifying patients without intra-abdominal injury requires further study.

User's perceptions of remote trauma telesonography

We established a pilot tele-ultrasound system between a rural referring hospital and a tertiary care trauma centre to facilitate telementoring during acute trauma resuscitations. Over a 12-month period, 23 tele-ultrasound examinations were completed. The clinical protocol examined both the Focused Assessment with Sonography for Trauma (FAST) and the Extended FAST (EFAST) for pneumothoraxes. Twenty of the examinations were conducted during acute trauma resuscitations and three during live patient simulations. FAST examinations were completed in all 23 cases and EFAST examinations in 17 cases. There were 18 clinical users, of whom 14 completed a survey (76% response rate). Overall, 93% of respondents were either satisfied or very satisfied with the telemedicine interaction and agreed or strongly agreed that the technology could potentially benefit injured patients in the far north of Canada. In addition, 93% of the respondents felt that the project had improved collegiality between the two institutions involved. The majority of respondents (71%) agreed or strongly agreed that the project had improved their ultrasound skills. We believe that as further experience is obtained, tele-ultrasound will prove to be an important aid to the care of remotely injured and ill patients.

An overview of emergency ultrasound in the United States

BACKGROUND

As emergency ultrasound use explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field.

METHODS

Approaches to education, scanning, documentation, and organization are also described.

RESULTS

Machines have reduced in price and once purchased further material costs are low. Staffing costs in terms of training, etc have yet to be assessed, but indications from elsewhere are that these are low. Length of stay in the emergency department dramatically decreases, thus increasing patient satisfaction while maintaining an even higher standard of care.

CONCLUSION

Emergency screening ultrasound is now a nationally accepted tool for the rapid assessment of the emergency patient.

The technical errors of physicians learning to perform focused assessment with sonography in trauma

OBJECTIVES

The objective was to assess the incidence of various technical errors committed by emergency physicians (EPs) learning to perform focused assessment with sonography in trauma (FAST).

METHODS

This was a retrospective review of the first 75 consecutive FAST exams for each EP from April 2000 to June 2005. Exams were assessed for noninterpretable views, misinterpretation of images, poor gain, suboptimal depth, an incomplete exam, or backward image orientation.

RESULTS

A total of 2,223 FAST exams done by 85 EPs were reviewed. Multiple noninterpretable views or misinterpreted images occurred in 24% of exams for those performing their first 10 exams, 3.6% for those performing their 41st to 50th exams, and 0% for those performing their 71st to 75th exams (Cochran-Armitage trend test = 10.5, p < 0.0001). A single noninterpretable view, poor gain, suboptimal depth, incomplete exam, or backward image orientation occurred in 48% of exams for those performing their first 10 exams, 17% for those performing their 41st to 50th exams, and 5% for those performing their 71st to 75th exams (Cochran-Armitage trend test = 11.6, p < 0.0001).

CONCLUSIONS

The incidence of specific technical errors of EPs learning to perform FAST at our institution improved with hands-on experience. Interpretive skills improved more rapidly than image acquisition skills.

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.

Comparison of a multimedia simulator to a human model for teaching FAST exam image interpretation and image acquisition

OBJECTIVES

This study compared the effectiveness of a multimedia ultrasound (US) simulator to normal human models during the practical portion of a course designed to teach the skills of both image acquisition and image interpretation for the Focused Assessment with Sonography for Trauma (FAST) exam.

METHODS

This was a prospective, blinded, controlled education study using medical students as an US-naïve population. After a standardized didactic lecture on the FAST exam, trainees were separated into two groups to practice image acquisition on either a multimedia simulator or a normal human model. Four outcome measures were then assessed: image interpretation of prerecorded FAST exams, adequacy of image acquisition on a standardized normal patient, perceived confidence of image adequacy, and time to image acquisition.

RESULTS

Ninety-two students were enrolled and separated into two groups, a multimedia simulator group (n = 44), and a human model group (n = 48). Bonferroni adjustment factor determined the level of significance to be p = 0.0125. There was no difference between those trained on the multimedia simulator and those trained on a human model in image interpretation (median 80 of 100 points, interquartile range [IQR] 71-87, vs. median 78, IQR 62-86; p = 0.16), image acquisition (median 18 of 24 points, IQR 12-18 points, vs. median 16, IQR 14-20; p = 0.95), trainee's confidence in obtaining images on a 1-10 visual analog scale (median 5, IQR 4.1-6.5, vs. median 5, IQR 3.7-6.0; p = 0.36), or time to acquire images (median 3.8 minutes, IQR 2.7-5.4 minutes, vs. median = 4.5 minutes, IQR = 3.4-5.9 minutes; p = 0.044).

CONCLUSIONS

There was no difference in teaching the skills of image acquisition and interpretation to novice FAST examiners using the multimedia simulator or normal human models. These data suggest that practical image acquisition skills learned during simulated training can be directly applied to human models.

How long does it take to perform emergency ultrasound for the primary indications?

Purpose

Although emergency ultrasound (EU) is gaining popularity, EU is performed in a minority of emergency departments (EDs). The perception may exist that EU is too time-consuming. This study sought to determine the duration of EUs performed for the primary indications by staff emergency physicians (EPs).

Methods

A prospective, time–motion study was conducted on a convenience sample of EUs at the Sudbury Regional Hospital ED from June to August 2006. All EPs had Canadian EU certification. A research assistant timed EUs. Primary EU indications in Canada are: cardiac arrest evaluation, rule-out pericardial effusion, rule-out intraperitoneal free fluid in trauma, rule-out abdominal aortic aneurysm, and rule-in intrauterine pregnancy. Descriptive statistics are reported.

Results

Eleven EPs performed 66 EUs for the primary indications on 51 patients. The mean EU duration was 137.8 s (range 11–465; CI 123.0–162.6). There was no difference in the duration of EUs performed by the two most experienced EPs (n = 37; duration = 129.4; CI = 96.4–162.4) compared to the other EPs (n = 29; duration = 148.4; CI = 110.6–186.2). Although subgroups were small, positive (n = 8; duration = 199.4; CI = 97.4–301.4), negative (n = 49; duration = 123.3; CI = 97.9–148.7), and indeterminate (n = 9; duration = 161.6; CI = 91.5–231.7) EUs did not differ in duration. There is some suggestion of differences in duration between types of EU, although again the subgroups were small: cardiac (n = 21; duration = 90.3; CI = 62.6–118.0), abdominal (n = 22; duration = 157.1; CI = 111.9–202.3), aneurysm (n = 15; duration = 170.1; CI = 117.5–222.7), transabdominal pelvic (n = 5; duration = 89.8; CI = 40.3–139.1), transvaginal (n = 3; duration = 246.0; CI = 30.6–461.4).

Conclusion

When performed by staff EPs with EU certification, mean EU duration for the primary indications was brief regardless of EP’s experience, EU type, or results.

Learning curve of emergency physicians using emergency bedside sonography for symptomatic first-trimester pregnancy

OBJECTIVE

The purpose of this study was to prospectively assess the learning curve of emergency physician training in emergency bedside sonography (EBS) for first-trimester pregnancy complications.

METHODS

This was a prospective study at an urban academic emergency department from August 1999 through July 2006. Patients with first-trimester vaginal bleeding or pain underwent EBS followed by pelvic sonography (PS) by the Department of Radiology. Results of EBS were compared with those of PS using a predesigned standardized data sheet.

RESULTS

A total of 670 patients underwent EBS for first-trimester pregnancy complications by 1 of 25 physicians who would go on to perform at least 25 examinations. The sensitivity and specificity of EBS for an intrauterine pregnancy increased from 80% (95% confidence interval [CI], 71%-87%) and 86% (95% CI, 76%-93%), respectively, for a physician's first 10 examinations to 100% (95% CI, 73%-100%) and 100% (95% CI, 63%-100%) for those performed after 40 examinations. Likewise, the sensitivity and specificity for an adnexal mass or ectopic pregnancy changed from 43% (95% CI, 28%-64%) and 94% (95% CI, 89%-97%) to 75% (95% CI, 22%-99%) and 89% (95% CI, 65%-98%), whereas the sensitivity and specificity for a molar pregnancy changed from 71% (95% CI, 30%-95%) and 98% (95% CI, 94%-99%) to 100% (95% CI, 20%-100%) and 100% (95% CI, 81%-100%). Although detection of an intrauterine or a molar pregnancy improved with training, even with experience including 40 examinations, the sensitivity of EBS for an adnexal mass or ectopic pregnancy was less than 90%.

CONCLUSIONS

There is an appreciable learning curve among physicians learning to perform EBS for first-trimester pregnancy complications that persists past 40 examinations.

Accuracy of clinician-performed point-of-care ultrasound for the diagnosis of fractures in children and young adults

INTRODUCTION

Injury is a major cause of death and disability in children and young adults worldwide. X-rays are routinely performed to evaluate injuries with suspected fractures. However, the World Health Organisation estimates that up to 75% of the world population has no access to any diagnostic imaging services. Use of clinician-performed point-of-care ultrasound to diagnose fractures is not only feasible in traditional healthcare settings, but also in underserved or remote settings. Our objective was to determine the accuracy of clinician-performed point-of-care ultrasound for the diagnosis of fractures in children and young adults presenting to an acute care setting.

METHODS

We conducted a prospective cohort study of patients aged <25 years that presented to emergency departments with injuries requiring X-rays or CT for suspected fracture. Paediatric emergency physicians with a 1h training session diagnosed fractures by point-of-care ultrasound. X-rays or CT were used as the reference standard to determine test performance characteristics.

RESULTS

Point-of-care ultrasound was performed on 212 children and young adults with 348 suspected fractures. Forty-two percent of all bones imaged were non-long bones. The prevalence rate of fracture was 24%. Overall: sensitivity-73% (95% CI: 62-82%), specificity-92% (95% CI: 88-95%); long bones: sensitivity-73% (58-84%), specificity-92% (86-95%); non-long bones: sensitivity-77% (58-90%); specificity-93% (87-97%); age> or =18 years: sensitivity-60% (39-78%), specificity-92% (87-96%); age<18: sensitivity-78 (65-87%), specificity-93% (87-95)%. Majority of errors in diagnosis (>85%) occurred at the ends-of-bones.

CONCLUSIONS

Clinicians with focused ultrasound training were able to diagnose fractures using point-of-care ultrasound with a high specificity rate. Specificity rates to rule-in fracture were similar for non-long bone and long bone fractures, as well as in skeletally mature young adults and children with open growth plates. Clinician-performed point-of-care ultrasound accuracy was highest at the diaphyses of long bones, while most diagnostic errors were committed at the ends-of-bones or near joints. Point-of-care ultrasound may serve as a rapid alternative means to diagnose midshaft fractures in settings with limited or no access to X-ray.

An Evidence-Based Approach for Integrating Bedside Ultrasound Into Routine Practice in the Assessment of Undifferentiated Shock

Undifferentiated hypotension remains a central diagnostic and therapeutic challenge in emergency and critical care medicine. Increasingly, bedside ultrasound conducted by intensivists and emergency medicine providers is assuming a central role in diagnosis and resuscitation of hypotension. This review discusses sample algorithms for the bedside ultrasonographic assessment of undifferentiated shock and outlines an evidence-based framework for the intensivist seeking to incorporate bedside ultrasound into daily clinical practice. The literature regarding specific applications including cardiac, thoracic, pulmonary, and vascular assessment is briefly reviewed, as is the evidence pertaining to effective implementation, training, credentialing, and ongoing quality assurance.

Management of bleeding following major trauma: an updated European guideline

INTRODUCTION

Evidence-based recommendations are needed to guide the acute management of the bleeding trauma patient, which when implemented may improve patient outcomes.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing a guideline for the management of bleeding following severe injury. This document presents an updated version of the guideline published by the group in 2007. Recommendations were formulated using a nominal group process, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) hierarchy of evidence and based on a systematic review of published literature.

RESULTS

Key changes encompassed in this version of the guideline include new recommendations on coagulation support and monitoring and the appropriate use of local haemostatic measures, tourniquets, calcium and desmopressin in the bleeding trauma patient. The remaining recommendations have been reevaluated and graded based on literature published since the last edition of the guideline. Consideration was also given to changes in clinical practice that have taken place during this time period as a result of both new evidence and changes in the general availability of relevant agents and technologies.

CONCLUSIONS

This guideline provides an evidence-based multidisciplinary approach to the management of critically injured bleeding trauma patients.

Ultrasound in trauma

Point-of-care ultrasound is well suited for use in the emergency setting for assessment of the trauma patient. Currently, portable ultrasound machines with high-resolution imaging capability allow trauma patients to be imaged in the pre-hospital setting, emergency departments and operating theatres. In major trauma, ultrasound is used to diagnose life-threatening conditions and to prioritise and guide appropriate interventions. Assessment of the basic haemodynamic state is a very important part of ultrasound use in trauma, but is discussed in more detail elsewhere. Focussed assessment with sonography for Trauma (FAST) rapidly assesses for haemoperitoneum and haemopericardium, and the Extended FAST examination (EFAST) explores for haemothorax, pneumothorax and intravascular filling status. In regional trauma, ultrasound can be used to detect fractures, many vascular injuries, musculoskeletal injuries, testicular injuries and can assess foetal viability in pregnant trauma patients. Ultrasound can also be used at the bedside to guide procedures in trauma, including nerve blocks and vascular access. Importantly, these examinations are being performed by the treating physician in real time, allowing for immediate changes to management of the patient. Controversy remains in determining the best training to ensure competence in this user-dependent imaging modality.

[Management of hemorrhage in patients with abdominal trauma: application of the European Guidelines for the management of bleeding following major trauma]

In patients with traumatic intraabdominal hemorrhage, urgent decisions must be made. Resuscitation measures must often be simultaneously combined with diagnostic actions and measures to control the source of the bleeding. Hemorrhages are usually complicated by coagulation disorders and the presence of acidosis and hypothermia. In these conditions, emergency measures are required that usually involve various specialists. However, given the paucity of the scientific evidence in this field, the intervention protocols differ from one center to another. The European Guidelines for the management of bleeding following major trauma has recently been published. These guidelines review aspects such as evaluation and initial management of bleeding, localization and control of the source of bleeding and replacement of blood products. In addition, recommendations based on the best available evidence to 2008 are made. This review describes the basic aspects of traumatic intraabdominal hemorrhage.

Ultrasound performed by radiologists-confirming the truth about FAST in trauma

BACKGROUND

For hemodynamically stable patients with suspected abdominal injuries, the diagnostic accuracy of computed tomographic scans remains unmatched. Focused assessment with sonography for trauma (FAST) is useful in trauma evaluation to identify intraabdominal fluid early in the unstable patient. In skilled hands, sensitivity is shown to be close to 100%. However, some recent studies have questioned its sensitivity in subgroups at risk of bleeding. In most studies, hemodynamic markers of instability have been limited to hypotension. The purpose of this study was to determine the sensitivity and specificity of initial FAST for detection of hemoperitoneum in the potentially unstable patient as judged by objective hemodynamic parameters available early during resuscitation.

METHODS

Prospective observational study at a major European trauma center. FAST was performed in trauma patients by the trauma team radiologist. The study population consisted of the subgroup deemed potentially unstable on arrival as defined by systolic blood pressure < or =90 mm Hg, pulse rate > or =120, or base deficit > or =8. Results were compared with one of the following reference standards: computed tomographic scan, diagnostic peritoneal lavage, exploratory laparotomy, or observation.

RESULTS

One hundred and four patients constituted the study group. There were 75 true-negative, 10 false-negative, 16 true-positive, and 3 false-positive FAST results. Sensitivity and specificity were 62% and 96%, positive and negative predictive values 84% and 89%, respectively, and overall accuracy was 88%.

CONCLUSION

A negative initial FAST in hemodynamically unstable patients, even in the hands of radiologists, cannot reliably exclude intraabdominal bleeding. These patients should undergo additional diagnostic tests to exclude intraperitoneal hemorrhage.

Blast injuries

Health-care providers are increasingly faced with the possibility of needing to care for people injured in explosions, but can often, however, feel undertrained for the unique aspects of the patient's presentation and management. Although most blast-related injuries (eg, fragmentation injuries from improvised explosive devices and standard military explosives) can be managed in a similar manner to typical penetrating or blunt traumatic injuries, injuries caused by the blast pressure wave itself cannot. The blast pressure wave exerts forces mainly at air-tissue interfaces within the body, and the pulmonary, gastrointestinal, and auditory systems are at greatest risk. Arterial air emboli arising from severe pulmonary injury can cause ischaemic complications-especially in the brain, heart, and intestinal tract. Attributable, in part, to the scene chaos that undoubtedly exists, poor triage and missed diagnosis of blast injuries are substantial concerns because injuries can be subtle or their presentation can be delayed. Management of these injuries can be a challenge, compounded by potentially conflicting treatment goals. This Seminar aims to provide a thorough overview of these unique primary blast injuries and their management.

[Training in emergency sonography for trauma. Concept of a 1-day course program]

In the last decade prehospital focused abdominal sonography for trauma (P-FAST) could be established as a valid on-site diagnostic tool for both air and ground rescue medical services in Germany. An appropriate use of P-FAST demands a standardized training concept. Therefore a 1-day training program was developed by the working group "emergency ultrasound" in Frankfurt/Main and was introduced in 2003. The training consists of lectures on general and specific aspects of emergency ultrasound techniques with demonstrations of numerous pathological findings, intensive hands-on training with patients and volunteers, as well as simulated on-site training. After completing the P-FAST course the participants gained competency to perform prehospital emergency ultrasound with high accuracy. Strict application of the exact technique as well as appropriate integration of the adjunct into the algorithm of prehospital care are the most important prerequisites for successful use of P-FAST. From February 2003 to March 2008 540 participants were trained in P-FAST in the 1-day course.

Prehospital and Emergency Department Ultrasound in Blunt Abdominal Trauma

Blunt abdominal trauma is a challenging aspect of trauma management. Early detection has a major impact on patient outcome. In contrast to physical examination, computed tomography is known to be a sensitive and specific test for blunt abdominal injuries. However, it is time-consuming and thus contraindicated in hemodynamically unstable patients. Therefore, focused assessment with sonography for trauma (FAST) offers a fast and easily applicable screening method to identify patients for urgent laparotomy without any further diagnostics. FAST detects, with high sensitivity, intraperitoneal fluid that accumulates in dependent areas indicating blunt abdominal trauma. FAST has been established as a gold standard early screening method for blunt abdominal trauma when performing trauma management in the emergency department (ED) based on the Advanced Trauma Life Support(®) algorithm. The development of hand-held ultrasound devices facilitated the introduction of FAST into prehospital trauma management. It was demonstrated that prehospital FAST (p-FAST) can be performed with high sensitivity and specificity, and can lead to significant changes in prehospital trauma therapy and management. Standardized training with both theoretical and hands-on modules is mandatory in order to gain the skills required to perform FAST or p-FAST well.

The clinical and technical evaluation of a remote telementored telesonography system during the acute resuscitation and transfer of the injured patient

BACKGROUND

Ultrasound (US) has an ever increasing scope in the evaluation of trauma, but relies greatly on operator experience. NASA has refined telesongraphy (TS) protocols for traumatic injury, especially in reference to mentoring inexperienced users. We hypothesized that such TS might benefit remote terrestrial caregivers. We thus explored using real-time US and video communication between a remote (Banff) and central (Calgary) site during acute trauma resuscitations.

METHODS

A existing internet link, allowing bidirectional videoconferencing and unidirectional US transmission was used between the Banff and Calgary ERs. Protocols to direct or observe an extended focused assessment with sonography for trauma (EFAST) were adapted from NASA algorithms. A call rota was established. Technical feasibility was ascertained through review of completed checklists. Involved personnel were interviewed with a semistructured interview.

RESULTS

In addition to three normal volunteers, 20 acute clinical examinations were completed. Technical challenges requiring solution included initiating US; audio and video communications; image freezing; and US transmission delays. FAST exams were completed in all cases and EFASTs in 14. The critical anatomic features of a diagnostic examination were identified in 98% of all FAST exams and a 100% of all EFASTs that were attempted. Enhancement of clinical care included confirmation of five cases of hemoperitoneum and two pneumothoraces (PTXs), as well as educational benefits. Remote personnel were appreciative of the remote direction particularly when instructions were given sequentially in simple, nontechnical language.

CONCLUSIONS

The remote real-time guidance or observation of an EFAST using TS appears feasible. Most technical problems were quickly overcome. Further evaluation of this approach and technology is warranted in more remote settings with less experienced personnel.

Focused abdominal sonography for trauma in the emergency department for blunt abdominal trauma

BACKGROUND

Blunt abdominal trauma (BAT) is a diagnostic challenge to the emergency physician (EP). The introduction of bedside ultrasound provides another diagnostic tool for the EP to detect intra-abdominal injuries.

AIMS

To evaluate the performance of EP in a local emergency department in Hong Kong to perform the 'focused abdominal sonography for trauma' (FAST) in BAT patients.

METHODS

This was a retrospective cohort study including all the trauma team cases in a 36-month period in the emergency department of a public hospital in Hong Kong. The results of FAST scans were analyzed and compared with CT scans when the FAST was positive or followed by a period of clinical observation when the FAST was negative. Descriptive statistics and sensitivity, specificity, and predictive values were calculated.

RESULTS

There was a total of 273 cases, and FAST scans were performed in 242 cases. The sensitivity and specificity were 86% and 99%, respectively. The negative predictive value was 0.98, while the positive predictive value was 0.94. The overall accuracy was 97%.

CONCLUSIONS

The performance of the EP in using FAST scans in BAT patients was encouraging. The high specificity (99%), positive predictive value (0.98), and likelihood ratio for positive tests (86) make it a good 'rule in' tool for BAT patients. The high negative predictive value also makes the FAST scan a useful screening tool. However, ultrasound examination is operator dependent, and FAST scan has its own limitations. For negative FAST scan cases, we recommend a period of monitoring, serial FAST scans, or further investigations, such as CT scan or peritoneal lavage.

Focused bedside ultrasonography by clinicians: experiences with a basic introductory course

OBJECTIVE

Ultrasonography (US) performed by clinicians might shorten workout time and diminish the workload of simple diagnostic procedures for physicians specialized in US. The purpose of this follow-up study was to evaluate the effect of an introductory course in US on participants' clinical behaviour and course compliance.

MATERIAL AND METHODS

The course consisted of a combined didactic, hands-on, one-day course including a skills test and a review of 20 still-pictures of pathological findings for final authorization. A questionnaire focusing on pre- and post-course activity and its impact on clinical behaviour was sent to 162 participants.

RESULTS

The response rate was 64% (103). Forty-eight (47%) participants changed their clinical approach, 45 (44%) their workout programme and 25 (24%) the pattern of referral. Eleven (10%) sent in the required pathological findings for final authorization. Thirty-four (33%) participants did not carry out US after the course; 19 did not have access to US apparatus, 7 claimed that they lacked the time, 6 lacked supervision and 1 participant cited insufficiency of the course. Clinical approach was changed by 48 (47%), acute workout by 45 (44%) and pattern of referral by 24 (23%).

CONCLUSIONS

Clinicians appear to be ready to change the patterns of their workout programmes and clinical approach after a combined didactic and hands-on introduction to US, but only 10% produced the recommended documentation for authorization. National guidelines need to be introduced for gastroenterologists and surgeons or the European Federation of Societies for Ultrasound in Medicine and Biology Guidelines should be implemented.

Current Role of Emergency US in Patients with Major Trauma

In patients with major trauma, focused abdominal ultrasonography (US) often is the initial imaging examination. US is readily available, requires minimal preparation time, and may be performed with mobile equipment that allows greater flexibility in patient positioning than is possible with other modalities. It also is effective in depicting abnormally large intraperitoneal collections of free fluid, which are indirect evidence of a solid organ injury that requires immediate surgery. However, because US has poor sensitivity for the detection of most solid organ injuries, an initial survey with US often is followed by a more thorough examination with multidetector computed tomography (CT). The initial US examination is generally performed with a FAST (focused assessment with sonography in trauma) protocol. Speed is important because if intraabdominal bleeding is present, the probability of death increases by about 1% for every 3 minutes that elapses before intervention. Typical sites of fluid accumulation in the presence of a solid organ injury are the Morison pouch (liver laceration), the pouch of Douglas (intraperitoneal rupture of the urinary bladder), and the splenorenal fossa (splenic and renal injuries). FAST may be used also to exclude injuries to the heart and pericardium but not those to the bowel, mesentery, and urinary bladder, a purpose for which multidetector CT is better suited. If there is time after the initial FAST survey, the US examination may be extended to extra-abdominal regions to rule out pneumothorax or to guide endotracheal intubation, vascular puncture, or other interventional procedures.

Prehospital ultrasound detects pericardial tamponade in a pregnant victim of stabbing assault

The development of handheld, portable ultrasound devices has enabled the use of this diagnostic tool also in the out-of-hospital environment. We report on a pregnant teenager who was found haemodynamically unstable after a stab assault. When she suffered cardiac arrest shortly thereafter, diagnosis of cardiac tamponade was made by portable ultrasound, and immediate pericardiocentesis was performed by the emergency physician. While her baby died after emergency Caesarean section, the teenager survived after thoracotomy and prolonged resuscitation without neurological sequelae.

How fast is the focused assessment with sonography for trauma examination learning curve?

OBJECTIVE

Although accuracy for focused assessment with sonography for trauma (FAST) examination interpretation has been widely reported, the learning curve for FAST interpretation by emergency medicine (EM) residents who are novice to ultrasound has not been well described. The present study's objective was to analyse EM resident FAST interpretation accuracy over 18 months.

METHODS

Prospective comparison of EM resident FAST interpretation accuracy for a class of nine EM residents at baseline after initial training, and then every 6 months over 18 months. Accuracy was scored after viewing the same 20 video clip images of the four anatomic views for five FAST examination cases. Three video clips had large anechoic stripe (AS) (>6 mm), four had moderate AS (6 mm > or = AS > or = 3 mm), two had small AS (<3 mm), and eleven had no AS (AS = 0 mm). A surgeon with 20 years of ultrasound experience confirmed the video clip interpretations. Data analysis used descriptive statistics with 95% confidence intervals.

RESULTS

For no AS views, EM resident accuracy was 79.8% (70.3-86.9%) baseline, 91.9% (84.2-96.2%) at 12 months, and 92.9% (85.5-96.9%) at 18 months. For small AS views, resident accuracy was 27.8% (10.7-53.6%) baseline, 66.7% (41.2-85.7%) at 12 months, and 72.2% (46.4-89.3%) at 18 months. For large AS views, resident accuracy was 77.8% (57.3-90.6%) baseline, 86.1% (69.7-94.8%) at 12 months, and 100.0% (84.5-100%) at 18 months.

CONCLUSION

Over 18 months, EM resident FAST interpretation accuracy steadily increased. By 12 months (or 35 examinations), the accuracy of EM residents novice to ultrasound approximated previously reported accuracy rates.

Operator confidence correlates with more accurate abdominal ultrasounds by emergency medicine residents

The purpose of this study was to assess whether greater operator confidence correlates with more accurate focused abdominal ultrasounds (FAUS) by residents. This was a prospective study of novice residents performing FAUS in patients with abdominal pain. FAUS included focused assessment with sonography for trauma, gall bladder, renal, and aortic examinations. Residents answered the question, "How confident are you of your findings?" using a visual scale from 1 (doubtful) to 5 (certain). The results of the resident-performed FAUS were compared to subsequent criterion evaluations. Thirty-eight residents with an average experience of 27 (95% confidence interval [CI] 18-36) prior US examinations evaluated 504 patients. Greater operator confidence correlated with improved accuracy of FAUS (R(2) = 0.858, p = 0.0369). Sensitivity and specificity were 14% (95% CI 4-37 %) and 71% (95% CI 48-88 %) with a confidence level of 2/5 but 85% (95% CI 73-93 %) and 100% (95% CI 97-100 %) with a confidence level of 5/5. Greater operator confidence correlates with improved accuracy in FAUS. This should be considered in the development of training guidelines.

Ultrasound-Guided Internal Jugular Access

In 2001, the Agency for Healthcare Research and Quality recommended the use of ultrasound for the placement of central venous catheters (CVCs) as one of their 11 practices to improve patient care. These recommendations were based on the results of several randomized clinical trials showing significantly improved overall success as well as reductions in complications. This article will describe the practical aspects of using ultrasound to guide placement of CVCs in the internal jugular vein in a "how I do it" approach, as well as review the practice management and training aspects related to incorporating ultrasound into daily practice.

Toward an ultrasound curriculum for critical care medicine

Accurate assessment and rapid decision-making are essential to save lives and improve performance in critical care medicine. Real-time point-of-care ultrasound has become an invaluable adjunct to the clinical evaluation of critically ill and injured patients both for pre- and in-hospital situations. However, a high level of quality is necessary, guaranteed by appropriate education, experience, credentialing, quality control, continuing education, and professional development. Although educational recommendations have been proposed by a variety of nonimaging specialties, to date they are still scattered and limited examples of standards for critical and intensive care professionals. The challenge of providing adequate specialty-specific training, as encouraged by major medical societies, is made even more difficult by the diversity of critical care ultrasound utilization by various subspecialties in a variety of settings and numerous countries. In order to meet this educational challenge, a standard core curriculum is presented in this manuscript. The proposed curriculum is built on a competence, performance, and outcomes-based approach that is tailored to setting-specific training needs and prioritized according to critical problem-based pathways, rather than traditional organ-based systems. A multiple goal-oriented style fully addresses the specialty-specific approach of critical and intensive care professionals, who typically deal with disease states in complex scenarios rather than individual organ complaints. Because of the variation in the concept of what constitutes critical care worldwide, and the rate of change of information and technology, this manuscript attempts to present a learning system addressing a variety of needs for a rapidly changing world.

Battling fire and ice: remote guidance ultrasound to diagnose injury on the International Space Station and the ice rink

BACKGROUND

National Aeronautical and Space and Administration (NASA) researchers have optimized training methods that allow minimally trained, non-physician operators to obtain diagnostic ultrasound (US) images for medical diagnosis including musculoskeletal injury. We hypothesize that these techniques could be expanded to non-expert operators including National Hockey League (NHL) and Olympic athletic trainers to diagnose musculoskeletal injuries in athletes.

METHODS

NHL and Olympic athletic trainers received a brief course on musculoskeletal US. Remote guidance musculoskeletal examinations were conducted by athletic trainers, consisting of hockey groin hernia, knee, ankle, elbow, or shoulder evaluations. US images were transmitted to remote experts for interpretation.

RESULTS

Groin, knee, ankle, elbow, or shoulder images were obtained on 32 athletes; all real-time US video stream and still capture images were considered adequate for diagnostic interpretation.

CONCLUSIONS

This experience suggests that US can be expanded for use in locations without a high level of on-site expertise. A non-physician with minimal training can perform complex, diagnostic-quality examinations when directed by a remote-based expert.

A bedside ultrasound curriculum for medical students: prospective evaluation of skill acquisition

OBJECTIVE

We conducted a study to evaluate the efficacy of an introductory ultrasound (US) curriculum for medical students rotating through our emergency department.

MATERIALS AND METHODS

Third- and 4th-year medical students indicated their previous US experience and were given a pretest consisting of static US images to assess baseline interpretation skills. They participated in a 45-min interactive didactic session followed by a 45-min session of hands-on experience practicing real-time US image acquisition on a normal model. After this session, we tested the timing and quality of their image acquisition skills on a separate normal model. Quality of images was based on a point value from 0 to 2 per image. This was followed by a posttest of static US images, which was graded in the same manner as the pretest.

RESULTS

Thirty-one students participated in the study. Median time to acquire 2 images was 112.5 sec (range = 15420 sec). Acquisition time was unaffected by previous experience (p = .97). The mean score on the quality of 2 images (maximum score = 4) was 3.84; median was 4 (range = 14). Image quality was significantly better in participants with previous US experience (p = .014). Scores on interpretation of static images improved significantly from pretest to posttest by a median of 8.25 points (p = .0001).

CONCLUSION

Our introductory US course is effective at significantly improving medical students' interpretation of static US images. The majority of students were able to acquire high quality images in a short period of time after this session.

The accuracy of focused assessment with sonography in trauma (FAST) in blunt trauma patients: experience of an Australian major trauma service

Focused assessment with sonography for trauma (FAST) is a method for detecting haemoperitoneum in trauma patients on initial assessment in the Emergency Department. The aim of this paper is to present an Australian trauma centre's experience with FAST as a tool to screen for intraabdominal free fluid in patient's sustaining blunt truncal trauma.

METHOD

Over a 63-month period, FAST scans were prospectively studied and compared with findings from a gold-standard investigation, either computed tomography (CT) or laparotomy.

RESULTS

463 FAST results were collected prospectively from 463 patients. 53 scans were excluded due to lack of a corresponding confirmatory gold-standard test. Overall sensitivity, specificity, positive and negative predictive values for FAST in detecting free fluid were 78%, 97%, 91%, 93%, respectively. Analysis of the credentialed operators demonstrated an improvement in accuracy (sensitivity 80%, specificity 100%, positive predictive value 100%, negative predictive value 94%). These findings are comparable with documented international experience.

CONCLUSION

The study demonstrates that the use of non-radiologist performed FAST in the detection of free fluid is safe and accurate within an Australian Trauma Centre.

Management of bleeding following major trauma: a European guideline

INTRODUCTION

Evidence-based recommendations can be made with respect to many aspects of the acute management of the bleeding trauma patient, which when implemented may lead to improved patient outcomes.

METHODS

The multidisciplinary Task Force for Advanced Bleeding Care in Trauma was formed in 2005 with the aim of developing guidelines for the management of bleeding following severe injury. Recommendations were formulated using a nominal group process and the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) hierarchy of evidence and were based on a systematic review of published literature.

RESULTS

Key recommendations include the following: The time elapsed between injury and operation should be minimised for patients in need of urgent surgical bleeding control, and patients presenting with haemorrhagic shock and an identified source of bleeding should undergo immediate surgical bleeding control unless initial resuscitation measures are successful. A damage control surgical approach is essential in the severely injured patient. Pelvic ring disruptions should be closed and stabilised, followed by appropriate angiographic embolisation or surgical bleeding control, including packing. Patients presenting with haemorrhagic shock and an unidentified source of bleeding should undergo immediate further assessment as appropriate using focused sonography, computed tomography, serum lactate, and/or base deficit measurements. This guideline also reviews appropriate physiological targets and suggested use and dosing of blood products, pharmacological agents, and coagulation factor replacement in the bleeding trauma patient.

CONCLUSION

A multidisciplinary approach to the management of the bleeding trauma patient will help create circumstances in which optimal care can be provided. By their very nature, these guidelines reflect the current state-of-the-art and will need to be updated and revised as important new evidence becomes available.