Prehospital point-of-care emergency ultrasound: a cohort study

A Qualitative Review of the Air Rescue One Rural Search and Rescue Program in British Columbia, Canada

INTRODUCTION

Rural emergency prehospital care in British Columbia is conducted primarily by the British Columbia Ambulance Services or ground search and rescue volunteers. Since 2014, the volunteer Air Rescue One (AR1) program has provided helicopter emergency winch rescue services to rural British Columbia. The aim of this research was to describe the activity of the AR1 program and to make recommendations to improve future operations.

METHODS

Data were collected retrospectively from September 2014 to May 2021, and parameters of emergency callout statistics from the organization's standard operating guidelines, rescue reports, and interviews were summarized and reviewed.

RESULTS

Of 152 missions within the study period, 105 were medically related rescues involving trauma or cardiac events. Snowmobiling, mountain biking, and hiking were the most common activities requiring rescue. The 38 medical callouts that were not completed by AR1 were reviewed for contributing factors. Response time varied due to the vast service area, but median time from request to takeoff was 55 min (interquartile range 47-69 min), and median on-scene time was 21 min (interquartile range 11-33 min).

CONCLUSIONS

AR1 provides advanced medical care into British Columbia's remote and difficult-to-access areas, minimizing delays in treatment and risk to patients and responders. Callout procedures should be streamlined enabling efficient AR1 activation. Collection of medical and flight information should be improved with standardized documentation, aiding in internal education and future research into the program's impact on emergency prehospital care. Future directions for improvement of care include the possibility of introducing portable ultrasound technology.

Diagnostic accuracy of prehospital lung ultrasound for acute decompensated heart failure: A systematic review and Meta-analysis

BACKGROUND

Lung ultrasound (LUS) reduces time to diagnosis and treatment of acute decompensated heart failure (ADHF) in emergency department (ED) patients with undifferentiated dyspnea. We conducted a systematic review to evaluate the diagnostic accuracy and clinical impact of LUS for ADHF in the prehospital setting.

METHODS

We performed a keyword search of multiple databases from inception through June 1, 2023. Included studies were those enrolling prehospital patients with undifferentiated dyspnea or suspected ADHF, and specifically diagnostic studies comparing prehospital LUS to a gold standard and intervention studies with a non-US comparator group. Title and abstract screening, full text review, risk of bias (ROB) assessments, and data extraction were performed by multiple authors. and adjudicated. The primary outcome was pooled sensitivity, specificity, and diagnostic likelihood ratios (LR) for prehospital LUS. A test-treatment threshold of 0.7 was applied based on prior ADHF literature in the ED. Intervention outcomes included mortality, mechanical ventilation, and time to HF specific treatment.

RESULTS

Eight diagnostic studies (n = 691) and two intervention studies (n = 70) met inclusion criteria. No diagnostic studies were low-ROB. Both intervention studies were critical-ROB, and not pooled. Pooled sensitivity and specificity of prehospital LUS for ADHF were 86.7% (95%CI:70.8%-94.6%) and 87.5% (78.2%-93.2%), respectively, with similar performance by physician vs. paramedic LUS and number of lung zones evaluated. Pooled LR+ and LR- were 7.27 (95% CI: 3.69-13.10) and 0.17 (95% CI: 0.06-0.34), respectively. Area under the summary receiver operating characteristic curve was 0.922. At the observed 42.4% ADHF prevalence (pre-test probability), positive pre-hospital LUS exceeded the 70% threshold to initiate treatment (post-test probability 84%, 80-88%).

CONCLUSIONS

LUS had similar diagnostic test characteristics for ADHF diagnosis in the prehospital setting as in the ED. A positive prehospital LUS may be sufficient to initiate early ADHF treatment based on published test-treatment thresholds. More studies are needed to determine the clinical impact of prehospital LUS.

Prehospital point-of-care ultrasound in ruptured abdominal aortic aneurysms-a retrospective cohort study

BACKGROUND

Patients with ruptured abdominal aortic aneurysm (rAAA) require immediate vascular treatment to survive. The use of prehospital point-of-care ultrasound (POCUS) may support clinical assessment, correct diagnosis, appropriate triage and reduce system delay. The aim was to study the process of care and outcome in patients receiving prehospital POCUS versus patients not receiving prehospital POCUS in patients with rAAA, ruptured iliac aneurysm or impending aortic rupture.

METHODS

We performed a retrospective cohort study in patients diagnosed with rAAA in the Central Denmark Region treated by a prehospital critical care physician from 1 January 2017 to 31 December 2021. Performance of prehospital POCUS was extracted from the prehospital electronic health records. System delay was defined as the time from the emergency phone call to the emergency medical service dispatch centre until the start of surgery. Data on patients primary hospital admission to a centre with/without vascular treatment expertise, treatments and complications including death were extracted from electronic health records.

RESULTS

We included 169 patients; prehospital POCUS was performed in 124 patients (73%). Emergency surgical treatment was performed in 71 patients. The overall survival in the POCUS group was 39% versus 16% in the NO POCUS group (hazard ratio (HR) (95% 0.60, 95% CI: 0.41-0.89, p = .011). In the POCUS group 99/124 (80%) were directly admitted to a vascular surgical centre versus 25/45 (56%) in the NO POCUS, RD 24% (95% CI: 8-40)), (p = .002). In the POCUS group, system delay was a median of 142 minutes (interquartile range (IQR) 121-189) and a median of 232 minutes (IQR 166-305) in the NO POCUS group (p = .006). In a multivariable analysis incorporating age, sex, previously known rAAA, and typical clinical symptoms of rAAA, the HR for death was 0.57, 95% CI 0.38-0.86 (p = .008) favouring prehospital POCUS.

CONCLUSIONS

Prehospital POCUS was associated with reduced time to treatment, higher chance of operability and significantly higher 30-day survival in patients with rAAA, ruptured iliac aneurysm or impending rupture of an AAA in this retrospective study. Residual confounding cannot be excluded. This study supports the clinical relevance of prehospital POCUS of the abdominal aorta.

Prehospital Extended FAST Exams Improve Clinical Decision Making by Helicopter EMS Crews: A Retrospective Case Series

Point of Care Ultrasound (POCUS) has seen increasing use in the prehospital environment over the last decade, primarily with the extended focused assessment with sonography in trauma (eFAST) exam. Previous studies have shown prehospital eFAST exams are feasible in the helicopter transport environment but have yet to demonstrate effects on clinical care. This retrospective case series identified 655 patients with blunt thoraco-abdominal trauma or concern for pneumothorax due to penetrating injury transported by a single helicopter EMS (HEMS) program over a two-year period after introducing POCUS. Of those patients, 258 received prehospital ultrasound which was reported to change clinical care in seven cases (2.7%, 95%-CI [1.1-5.5]). This was primarily through preventing unnecessary needle thoracostomy and initiating blood transfusion for treatment of hemorrhagic shock in cases where the degree of shock was unclear due to inconsistent vital signs. This study highlights the improvements in clinical care that may result from the introduction of eFAST exams in the prehospital environment.

Assessing the efficacy of simulation-based education for paramedics in extended focused assessment with sonography for trauma under physician guidance

We investigated the effectiveness of simulation-based education in Focused Assessment with Sonography for Trauma (FAST) to increase the number of Emergency Medical Technicians (EMTs) capable of performing ultrasound examinations in vehicles under the guidance of a physician. Twenty-eight paramedics watched a 14-min video on the features of the ultrasound system, its use, and the scanning method for each part of the body. Each participant performed four FAST examinations using a portable ultrasound device, and the task performance was rated using the Task Specific Checklist (TSC) and Global Rating Scale (GRS). The time required for visualizing each examination site and each FAST was assessed. The mean time required for the first and fourth FAST was 144.6 ± 52.4 s and 90.5 ± 31.0 s, respectively. The time required for each test significantly decreased with repeated testing (p < 0.001). The time to complete FAST was significantly shortened for the pericardial cavity (33.4 ± 23.1/15.3 ± 10.6 s, p < 0.01), right thoracic cavity (25.2 ± 11.8/12.1 ± 8.3 s, p < 0.01), Morrison fossa (19.1 ± 10.8/10.8 ± 6.3 s, p < 0.05), and left thoracic cavity (19.0 ± 8.3/15.6 ± 8.3 s, p < 0.05). TSC and GRS scores were elevated, and all EMTs could obtain valid images. The combination of a brief video lecture and hands-on training significantly reduced the time required for FAST performance. Moreover, repeated practice enabled the EMTs to efficiently obtain accurate and clinically useful images.

Suspension syndrome: a scoping review and recommendations from the International Commission for Mountain Emergency Medicine (ICAR MEDCOM)

BACKGROUND

Suspension syndrome describes a multifactorial cardio-circulatory collapse during passive hanging on a rope or in a harness system in a vertical or near-vertical position. The pathophysiology is still debated controversially.

AIMS

The International Commission for Mountain Emergency Medicine (ICAR MedCom) performed a scoping review to identify all articles with original epidemiological and medical data to understand the pathophysiology of suspension syndrome and develop updated recommendations for the definition, prevention, and management of suspension syndrome.

METHODS

A literature search was performed in PubMed, Embase, Web of Science and the Cochrane library. The bibliographies of the eligible articles for this review were additionally screened.

RESULTS

The online literature search yielded 210 articles, scanning of the references yielded another 30 articles. Finally, 23 articles were included into this work.

CONCLUSIONS

Suspension Syndrome is a rare entity. A neurocardiogenic reflex may lead to bradycardia, arterial hypotension, loss of consciousness and cardiac arrest. Concomitant causes, such as pain from being suspended, traumatic injuries and accidental hypothermia may contribute to the development of the Suspension Syndrome. Preventive factors include using a well-fitting sit harness, which does not cause discomfort while being suspended, and activating the muscle pump of the legs. Expediting help to extricate the suspended person is key. In a peri-arrest situation, the person should be positioned supine and standard advanced life support should be initiated immediately. Reversible causes of cardiac arrest caused or aggravated by suspension syndrome, e.g., hyperkalaemia, pulmonary embolism, hypoxia, and hypothermia, should be considered. In the hospital, blood and further exams should assess organ injuries caused by suspension syndrome.

Validation of secondary triage algorithms for mass casualty incidents : A simulation-based study-English version

BACKGROUND

In the event of a mass casualty incident (MCI), the situation-related shortage of medical resources does not end when the patients are transported from the scene of the incident. Consequently, an initial triage is required in the receiving hospitals. In the first step, the aim of this study was to create a reference patient vignette set with defined triage categories. This allowed a computer-aided evaluation of the diagnostic quality of triage algorithms for MCI situations in the second step.

METHODS

A total of 250 case vignettes validated in practice were entered into a multistage evaluation process by initially 6 and later 36 triage experts. This algorithm-independent expert evaluation of all vignettes-served as the gold standard for analyzing the diagnostic quality of the following triage algorithms: Manchester triage system (MTS module MCI), emergency severity index (ESI), Berlin triage algorithm (BER), the prehospital algorithms PRIOR and mSTaRT, and two project algorithms from a cooperation between the Federal Office of Civil Protection and Disaster Assistance (BBK) and the Hashemite Kingdom of Jordan-intrahospital Jordanian-German project algorithm (JorD) and prehospital triage algorithm (PETRA). Each patient vignette underwent computerized triage through all specified algorithms to obtain comparative test quality outcomes.

RESULTS

Of the original 250 vignettes, a triage reference database of 210 patient vignettes was validated independently of the algorithms. These formed the gold standard for comparison of the triage algorithms analyzed. Sensitivities for intrahospital detection of patients in triage category T1 ranged from 1.0 (BER, JorD, PRIOR) to 0.57 (MCI module MTS). Specificities ranged from 0.99 (MTS and PETRA) to 0.67 (PRIOR). Considering Youden's index, BER (0.89) and JorD (0.88) had the best overall performance for detecting patients in triage category T1. Overtriage was most likely with PRIOR, and undertriage with the MCI module of MTS. Up to a decision for category T1, the algorithms require the following numbers of steps given as the median and interquartile range (IQR): ESI 1 (1-2), JorD 1 (1-4), PRIOR 3 (2-4), BER 3 (2-6), mSTaRT 3 (3-5), MTS 4 (4-5) and PETRA 6 (6-8). For the T2 and T3 categories the number of steps until a decision and the test quality of the algorithms are positively interrelated.

CONCLUSION

In the present study, transferability of preclinical algorithm-based primary triage results to clinical algorithm-based secondary triage results was demonstrated. The highest diagnostic quality for secondary triage was provided by the Berlin triage algorithm, followed by the Jordanian-German project algorithm for hospitals, which, however, also require the most algorithm steps until a decision.

Ultrasound on the Frontlines: Empowering Paramedics with Lung Ultrasound for Dyspnea Diagnosis in Adults-A Pilot Study

Lung transthoracic ultrasound (LUS) is an accessible and widely applicable method of rapidly imaging certain pathologies in the thorax. LUS proves to be an optimal tool in respiratory emergency medicine, applicable in various clinical settings. However, despite the rapid development of bedside ultrasonography, or point-of-care (POCUS) ultrasound, there remains a scarcity of knowledge about the use of LUS in pre-hospital settings. Therefore, our aim was to assess the usefulness of LUS as an additional tool in diagnosing dyspnea when performed by experienced paramedics in real-life, pre-hospital settings. Participants were recruited consecutively among patients who called for an emergency due to dyspnea in the Warsaw region of Poland. All the enrolled patients were admitted to the Emergency Department (ED). In the prehospital setting, a paramedic experienced in LUS conducted an ultrasonographic examination of the thorax, including Bedside Lung Ultrasound in Emergency (BLUE) and extended Focused Assessment with Sonography for Trauma (eFAST) protocols. The paramedic's diagnosis was compared to the ED diagnosis, and if available, to the final diagnosis established on the day of discharge from the hospital. We enrolled 44 patients in the study, comprising 22 (50%) men and (50%) women with a median age of 76 (IQR: 69.75-84.5) years. The LUS performed by paramedic was concordant with the discharge diagnosis in 90.91% of cases, where the final diagnosis was established on the day of discharge from the hospital. In cases where the patient was treated only in the ED, the pre-hospital LUS was concordant with the ED diagnosis in 88.64% of cases. The mean time of the LUS examination was 63.66 s (SD: 19.22). The inter-rater agreement between the pre-hospital diagnosis and ER diagnosis based on pre-hospital LUS and complete ER evaluation was estimated at k = 0.822 (SE: 0.07; 95%CI: 0.68, 0.96), indicating strong agreement, and between the pre-hospital diagnosis based on LUS and final discharge diagnosis, it was estimated at k = 0.934 (SE: 0.03; 95%CI: 0.88, 0.99), indicating almost perfect agreement. In conclusion, paramedic-acquired LUS seems to be a useful tool in the pre-hospital differential diagnosis of dyspnea in adults.

The potential of point-of-care diagnostics to optimise prehospital trauma triage: a systematic review of literature

PURPOSE

In the prehospital care of potentially seriously injured patients resource allocation adapted to injury severity (triage) is a challenging. Insufficiently specified triage algorithms lead to the unnecessary activation of a trauma team (over-triage), resulting in ineffective consumption of economic and human resources. A prehospital trauma triage algorithm must reliably identify a patient bleeding or suffering from significant brain injuries. By supplementing the prehospital triage algorithm with in-hospital established point-of-care (POC) tools the sensitivity of the prehospital triage is potentially increased. Possible POC tools are lactate measurement and sonography of the thorax, the abdomen and the vena cava, the sonographic intracranial pressure measurement and the capnometry in the spontaneously breathing patient. The aim of this review was to assess the potential and to determine diagnostic cut-off values of selected instrument-based POC tools and the integration of these findings into a modified ABCDE based triage algorithm.

METHODS

A systemic search on MEDLINE via PubMed, LIVIVO and Embase was performed for patients in an acute setting on the topic of preclinical use of the selected POC tools to identify critical cranial and peripheral bleeding and the recognition of cerebral trauma sequelae. For the determination of the final cut-off values the selected papers were assessed with the Newcastle-Ottawa scale for determining the risk of bias and according to various quality criteria to subsequently be classified as suitable or unsuitable. PROSPERO Registration: CRD 42022339193.

RESULTS

267 papers were identified as potentially relevant and processed in full text form. 61 papers were selected for the final evaluation, of which 13 papers were decisive for determining the cut-off values. Findings illustrate that a preclinical use of point-of-care diagnostic is possible. These adjuncts can provide additional information about the expected long-term clinical course of patients. Clinical outcomes like mortality, need of emergency surgery, intensive care unit stay etc. were taken into account and a hypothetic cut-off value for trauma team activation could be determined for each adjunct. The cut-off values are as follows: end-expiratory CO2: < 30 mm/hg; sonography thorax + abdomen: abnormality detected; lactate measurement: > 2 mmol/L; optic nerve diameter in sonography: > 4.7 mm.

DISCUSSION

A preliminary version of a modified triage algorithm with hypothetic cut-off values for a trauma team activation was created. However, further studies should be conducted to optimize the final cut-off values in the future. Furthermore, studies need to evaluate the practical application of the modified algorithm in terms of feasibility (e.g. duration of application, technique, etc.) and the effects of the new algorithm on over-triage. Limiting factors are the restriction with the search and the heterogeneity between the studies (e.g. varying measurement devices, techniques etc.).

[Validation of secondary triage algorithms for mass casualty incidents-A simulation-based study-German version]

BACKGROUND

In the event of a mass casualty incident (MCI), the situation-related shortage of medical resources does not end when the patients are transported from the scene of the incident. Consequently, an initial triage is required in the receiving hospitals. In the first step, the aim of this study was to create a reference patient vignette set with defined triage categories. This allowed a computer-aided evaluation of the diagnostic quality of triage algorithms for MCI situations in the second step.

METHODS

A total of 250 case vignettes validated in practice were entered into a multistage evaluation process by initially 6 and later 36 triage experts. This algorithm-independent expert evaluation of all vignettes-served as the gold standard for analyzing the diagnostic quality of the following triage algorithms: Manchester triage system (MTS module MCI), emergency severity index (ESI), Berlin triage algorithm (BER), the prehospital algorithms PRIOR and mSTaRT, and two project algorithms from a cooperation between the Federal Office of Civil Protection and Disaster Assistance (BBK) and the Hashemite Kingdom of Jordan-intrahospital Jordanian-German project algorithm (JorD) and prehospital triage algorithm (PETRA). Each patient vignette underwent computerized triage through all specified algorithms to obtain comparative test quality outcomes.

RESULTS

Of the original 250 vignettes, a triage reference database of 210 patient vignettes was validated independently of the algorithms. These formed the gold standard for comparison of the triage algorithms analyzed. Sensitivities for intrahospital detection of patients in triage category T1 ranged from 1.0 (BER, JorD, PRIOR) to 0.57 (MCI module MTS). Specificities ranged from 0.99 (MTS and PETRA) to 0.67 (PRIOR). Considering Youden's index, BER (0.89) and JorD (0.88) had the best overall performance for detecting patients in triage category T1. Overtriage was most likely with PRIOR, and undertriage with the MCI module of MTS. Up to a decision for category T1, the algorithms require the following numbers of steps given as the median and interquartile range (IQR): ESI 1 (1-2), JorD 1 (1-4), PRIOR 3 (2-4), BER 3 (2-6), mSTaRT 3 (3-5), MTS 4 (4-5) and PETRA 6 (6-8). For the T2 and T3 categories the number of steps until a decision and the test quality of the algorithms are positively interrelated.

CONCLUSION

In the present study, transferability of preclinical algorithm-based primary triage results to clinical algorithm-based secondary triage results was demonstrated. The highest diagnostic quality for secondary triage was provided by the Berlin triage algorithm, followed by the Jordanian-German project algorithm for hospitals, which, however, also require the most algorithm steps until a decision.

Effectiveness of ultrasound screening in right upper quadrant pain: A comparative study in a basic emergency service

Background and Aims

The use of ultrasound screening is primarily facilitated by point-of-care ultrasound (POCUS) and its integration into healthcare systems is a result of the versatility of this imaging technique. This study intends to compare the accuracy and pertinence of sonographic findings obtained by a sonographer in a Basic Emergency Service (BES) with that of radiologists at referral hospital (RH) in Portugal.

Methods

Twenty patients with right upper quadrant (RUQ) pain and suspected cholecystitis or biliary pathology underwent sonography screening using POCUS in the BES. They were then forwarded to the RH where a radiologist performed a conventional ultrasound exam on the same patients. The results of both exams were compared to determine if the findings obtained in the BES were confirmed by the radiologist in the RH.

Results

In our sample, 60% of cases were related to biliary pathology, 20% were liver-related, 10% had hepatopancreatic biliary etiology, and 10% had unknown etiology. A strong association between the sonographic findings in the BES and the RH was found in the variables "Sonographic Murphy sign" (V = 0.859; p = 0.001), "Cholelithiasis/Gallbladder sludge" (V = 0.840; p = 0.001), and "Intrahepatic biliary tract dilatation" (V = 0.717; p = 0.006). Adequate measures of agreement between the findings of the radiographer and radiologist were obtained for the "Sonographic Murphy sign" (k = 0.664; p = 0.001) and the presence of "Cholelithiasis/Gallbladder sludge" (k = 0.712; p = 0.000).

Conclusion

Major biliary abnormalities were detected in patients with RUQ pain in BES using sonography. The correlation between the sonographic findings obtained by the sonographers at BES and those obtained by radiologists at the RH in Portugal was strong, showing that POCUS screening could be extended to other similar settings; however, more studies are needed.

Diagnostic accuracy for hemoperitoneum, influence on prehospital times and time-to-definitive treatment of prehospital FAST: A systematic review and individual participant data meta-analysis

BACKGROUND

Focused assessment sonography for trauma (FAST) performed in the prehospital setting may improve trauma care by influencing treatment decisions and reducing time to definitive care, but its accuracy and benefits remain uncertain. This systematic review evaluated the diagnostic accuracy of prehospital FAST in detecting hemoperitoneum and its effects on prehospital time and time to definitive diagnosis or treatment.

METHODS

We systematically searched PubMed, Embase, and Cochrane library up to November 11th, 2022. Studies investigating prehospital FAST and reporting at least one outcome of interest for this review were considered eligible. The primary outcome was prehospital FAST diagnostic accuracy for hemoperitoneum. A random-effect meta-analysis, including individual patient data, was performed to calculate the pooled outcomes with 95% confidence intervals (CI). Quality of studies was assessed using the QUADAS-2 tool for diagnostic accuracy.

RESULTS

We included 21 studies enrolling 5790 patients. The pooled sensitivity and specificity of prehospital FAST for hemoperitoneum were 0.630 (0.454 - 0.777) and 0.970 (0.957-0.979), respectively. Prehospital FAST was performed in a median of 2.72 (2.12 - 3.31) minutes without increasing prehospital times (pooled median difference of 2.44 min [95% CI: -3.93 - 8.81]) compared to standard management. Prehospital FAST findings changed on-scene trauma care in 12-48% of cases, the choice of admitting hospital in 13-71%, the communication with the receiving hospital in 45-52%, and the transfer management in 52-86%. Patients with a positive prehospital FAST achieved definitive diagnosis or treatment more rapidly (severity-adjusted pooled time ratio = 0.63 [95% CI: 0.41 - 0.95]) compared with patients with a negative or not performed prehospital FAST.

CONCLUSIONS

Prehospital FAST had a low sensitivity but a very high specificity to identify hemoperitoneum and reduced time-to-diagnostics or interventions, without increasing prehospital times, in patients with a high probability of abdominal bleeding. Its effect on mortality is still under-investigated.

Detection of pneumothorax on ultrasound using artificial intelligence

BACKGROUND

Ultrasound (US) for the detection of pneumothorax shows excellent sensitivity in the hands of skilled providers. Artificial intelligence may facilitate the movement of US for pneumothorax into the prehospital setting. The large amount of training data required for conventional neural network methodologies has limited their use in US so far.

METHODS

A limited training database was supplied by Defense Advanced Research Projects Agency of 30 patients, 15 cases with pneumothorax and 15 cases without. There were two US videos per patient, of which we were allowed to choose one to train on, so that a limited set of 30 videos were used. Images were annotated for ribs and pleural interface. The software performed anatomic reconstruction to identify the region of interest bounding the pleura. Three neural networks were created to analyze images on a pixel-by-pixel fashion with direct voting determining the outcome. Independent verification and validation was performed on a data set gathered by the Department of Defense.

RESULTS

Anatomic reconstruction with the identification of ribs and pleura was able to be accomplished on all images. On independent verification and validation against the Department of Defense testing data, our program concurred with the SME 80% of the time and achieved a 86% sensitivity (18/21) for pneumothorax and a 75% specificity for the absence of pneumothorax (18/24). Some of the mistakes by our artificial intelligence can be explained by chest wall motion, hepatization of the underlying lung, or being equivocal cases.

CONCLUSION

Using learning with limited labeling techniques, pneumothorax was identified on US with an accuracy of 80%. Several potential improvements are controlling for chest wall motion and the use of longer videos.

LEVEL OF EVIDENCE

Diagnostic Tests; Level III.

PrehospitaL Ultrasound in Undifferentiated DyspnEa (PreLUDE): a prospective, clinical, observational study

BACKGROUND

Diagnostic uncertainty in patients with dyspnea is associated with worse outcomes. We hypothesized that prehospital point-of-care ultrasound (POCUS) can improve diagnostic accuracy.

METHODS

Prospective observational study of adult patients suffering dyspnea. Prehospital critical care physicians registered a suspected diagnosis based on clinical examination alone, performed POCUS of the heart and lungs, and finally registered suspected diagnoses based on their clinical examination supplemented with POCUS. Pre- and post-POCUS diagnoses were compared to endpoint committee adjudicated diagnoses. The primary outcome was improved sensitivity for diagnosing acute heart failure. Secondary outcomes included other diagnostic accuracy measures in relation to acute heart failure and other causes of dyspnea.

RESULTS

In total, 214 patients were included. The diagnosis of acute heart failure was suspected in 64/214 (30%) of patients before POCUS and 64/214 (30%) patients after POCUS, but POCUS led to reclassification in 53/214 (25%) patients. The endpoint committee adjudicated the diagnosis of acute heart failure in 87/214 (41%) patients. The sensitivity for the diagnosis of acute heart failure was 58% (95% CI 46%-69%) before POCUS compared to 65% (95% CI 53%-75%) after POCUS (p = 0.12). ROC AUC for the diagnosis acute heart failure was 0.72 (95% CI 0.66-0.78) before POCUS compared to 0.79 (0.73-0.84) after POCUS (p < 0.001). ROC AUC for the diagnosis acute exacerbation (AE) of chronic obstructive pulmonary disease (COPD) or asthma was 0.87 (0.82-0.91) before POCUS and 0.93 (0.88-0.97) after POCUS (p < 0.001). A POCUS finding of any of severely reduced left ventricular function, bilateral B-lines or bilateral pleural effusion demonstrated the highest sensitivity for acute heart failure at 88% (95% CI 79%-94%), whereas the combination of all of these three findings yielded the highest specificity at 99% (95% CI 95%-100%).

CONCLUSION

Supplementary prehospital POCUS leads to an improvement of diagnostic accuracy of both heart failure and AE-COPD/-asthma overall described by ROC AUC, but the increase in sensitivity for the diagnoses of acute heart failure did not reach statistical significance. Tailored use of POCUS findings optimizes diagnostic accuracy for rule-out and rule-in of acute heart failure.

TRIAL REGISTRATION

Registered in Clinical Trials, 05.04.2019 (identifier: NCT03905460) https://clinicaltrials.gov/ct2/show/study/NCT03905460?term=NCT03905460&cond=Dyspnea&cntry=DK&draw=2&rank=1 .

New International Guidelines and Consensus on the Use of Lung Ultrasound

Following the innovations and new discoveries of the last 10 years in the field of lung ultrasound (LUS), a multidisciplinary panel of international LUS experts from six countries and from different fields (clinical and technical) reviewed and updated the original international consensus for point-of-care LUS, dated 2012. As a result, a total of 20 statements have been produced. Each statement is complemented by guidelines and future developments proposals. The statements are furthermore classified based on their nature as technical (5), clinical (11), educational (3), and safety (1) statements.

The Impact of Prehospital Point of Care Ultrasounds on Emergency Patients Length of Stay in Thailand

Purpose

Globally, emergency departments (ED) are faced with an overcrowding problem. This issue is further compounded due to the multitude of contributing factors. Point of Care ultrasound (POCUS), especially when performed in prehospital care, that is before the patient is admitted to the ED has a high potential to reduce time of diagnosis and time of investigation which leads to shorter ED length of stay (LOS). The primary focus was on variances in ED LOS between the prehospital POCUS group and the standard care group.

Patients and Methods

A cross-sectional study was conducted on prehospital patients who were admitted to the ED at Srinagarind Hospital, Thailand, from January to December 2021. We divided patients into two groups including patients who obtained prehospital POCUS (the prehospital POCUS group) and patients who received standard care treatment in which there was no prehospital POCUS performed (the standard care group). POCUS and ED medical records were documented and submitted for analysis.

Results

Of 1348 prehospital patients, 840 were enrolled in this study: 169 with prehospital POCUS and 671 with standard care. Median LOS in the prehospital POCUS group was 159 min (IQR 89,289) versus 165 (IQR 102,330) in the standard care group (p = 0.125). Further imaging diagnostic test which affected ED LOS more than four hours was lower in the prehospital POCUS group (adjusted odds ratio [OR], 0.92; 95% confidence intervals [CI], 0.729-1.666) than in the standard care group. The factor associated with increased odds of ED LOS more than four hour in the prehospital POCUS group was admission to hospital (adjusted OR 1.88; 95% CI, 1.230-2.239).

Conclusion

Patients evaluated with prehospital POCUS had a shorter LOS than the only standard care treatment without statistical significance.

Prehospital Ultrasound: A Narrative Review

Background: Point-of-care ultrasound is rapidly becoming more prevalent in the prehospital environment. Though considered a relatively new intervention in this setting, there is growing literature that aims to explore the use of prehospital ultrasound by EMS personnel.Methods: To better understand and report the state of the science on prehospital ultrasound, we conducted a narrative review of the literature.Results: Following a keyword search of MEDLINE in Ovid from inception to August 2, 2022, 2,564 records were identified and screened. Based on review of abstracts and full texts, with addition of seven articles via bibliography review, 193 records were included. Many included studies detail usage in air medical and other critical care transport environments. Clinicians performing prehospital ultrasound are often physicians or other advanced practice personnel who have previous ultrasound experience, which facilitates implementation in the prehospital setting. Emerging literature details training programs for prehospital personnel who are novices to ultrasound, and implementation for some study types appears feasible without prior experience. Unique use scenarios that show promise include during critical care transport, for triage in austere settings, and for thoracic evaluation of patients at risk of life-threatening pathology.Conclusion: There is a growing mostly observational body of literature describing the use of ultrasound by prehospital personnel. Prehospital ultrasound has demonstrated feasibility for specific conditions, yet interventional studies evaluating benefit to patient outcomes are absent.

[Initial preclinical assessment on-site]

Emergency personnel assess their patients as an essential part of their daily work in emergency settings. The clinical assessment can help differentiate between immediately life-threatening conditions and milder diseases in patients. This assessment is the basis for an adequate preclinical treatment and for a rational referral to the hospital providing further care. Carried out in a thoughtful manner it allows reasonable allocation of resources for inpatient care.Well-founded training, clinical experience, scores, and tools in the form of acronyms for assessing the patient lead to successful assessments according to quality standards.The preclinical initial assessment is crucial for ensuring appropriate care for patients on site with life-threatening conditions as well as those with minor problems. Prioritization of a treatment depends on the severity of the condition or injury.

Prehospital FAST reduces time to admission and operative treatment: a prospective, randomized, multicenter trial

BACKGROUND

The focused assessment with sonography in trauma (FAST) exam is an established trauma care diagnostic procedure. Ultrasound performed during prehospital care can improve early treatment and management of the patients. In this prospective randomized clinical trial, we wanted to assess whether a pre-hospital FAST (p-FAST) influences pre-hospital strategy and the time to operative treatment.

METHODS

We studied 296 trauma victims in a prehospital setting. Inclusion criteria were potential abdominal injuries identified either by clinical examination or suggested by the mechanism of injury. Physician-staffed helicopters and emergency ambulances were equipped with portable ultrasound devices. According to a scheme related to calendar weeks, a clinical exam only (CEX) or a clinical exam together with a p-FAST (CEX-p-FAST) was conducted. Outcome variables were prehospital diagnosis and strategy, the time to admission to the trauma room and to operation theater. The study was approved by the university ethical committee (REB#: 46/06).

RESULTS

CEX-p-FAST showed a high sensitivity (94.7%) and specificity (97.6%) in detection of free fluid compared to CEX-only (80.0%, 84.4%). The median time to admission was reduced significantly by 13 min and to operative treatment by 15 min after CEX-p-FAST. We observed a cross-over rate of 30.8% of p-FAST (n = 36) to CEX-p-FAST during the CEX-only weeks.

CONCLUSION

According to the experience of the principal investigators, CEX-p-FAST was superior to CEX-only. Despite the time needed for p-FAST, the relevant admission time was significantly shorter. Thus, p-FAST is recommended in addition to CEX if possible for decision-making in prehospital trauma care.

TRIAL REGISTRATION

German Clinical Trials Register #DRKS00022117-Registered 10 July 2020-Retrospectively registered, https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00022117 .

The Utilization of Handheld Ultrasound Devices in a Prehospital Setting

INTRODUCTION

Prehospital ultrasounds can be considered a new form of diagnostic tool when taking into account their small structure and due to the fact that nowadays, they are used in the care of emergency patients. However, at present, there is no study regarding the advantage of ultrasound usage in prehospital settings in Thailand.

STUDY OBJECTIVE

This study aims to determine the sonographic characteristics recorded by handheld ultrasounds used in prehospital care and the diagnostic accuracy of ultrasounds for prehospital patients.

METHODS

A cross-sectional study was conducted on prehospital patients who underwent point-of-care ultrasound (POCUS) examination on Emergency Medical Service (EMS) operations at Srinagarind Hospital, Thailand from January 2021 through December 2021. The ultrasound images, the electronic emergency department medical records, and the EMS database were recorded and reviewed by a team of emergency physicians. The quality of prehospital ultrasound examinations was assessed by comparing the diagnoses at the scene with those taken at the hospital.

RESULTS

One hundred sixty-nine prehospital patients who received POCUS examinations were examined over a one-year period. All (100.0%) of the scans were for medical cases. No ultrasound protocol was used in the prehospital care. Two hundred eight POCUS examinations were performed in this study. The most common POCUS indication was dyspnea (45.6%), followed by hypotension/shock (30.1%), and finally syncope (8.2%). The most common area where POCUS was performed was on the lung (37.0%), followed by the inferior vena cava (30.8%), and finally for cardiac cases (26.4%). This study found that 34.9% of sonographic findings could be considered abnormal. The diagnoses of prehospital patients were confirmed by using POCUS in 66 cases (39.1%) with the accuracy of prehospital diagnosis reaching a peak of 75.8%.

CONCLUSION

This study shows POCUS examinations can be effectively used in prehospital care. The prehospital diagnosis given by physicians administering treatment who used POCUS examinations correlated with the in-hospital diagnosis.

Overview of current implementation and limitations of point-of-care ultrasound in the emergency department: a nationwide survey in Belgium

OBJECTIVE

Giving an overview of the current implementation and limitations of point-of-care ultrasound (POCUS) in Belgian Emergency Departments (EDs).

METHODS

A survey, consisting of questions regarding demographics, practice patterns, policies, difficulties of implementing ultrasound (US) and training of emergency physicians was sent out to all Belgian EDs (n = 109).

RESULTS

Seventy-two percent of all the EDs responded. Eighty percent of these had an US device, 10% intended to have one in the near future whilst the remaining 10% had no intention of obtaining one. The main reasons for not having US were insufficient training (50%), no budget to purchase a device (31%), resistance from other specialties (31%), no return from investment (25%) and uncertainty about liability (19%).Eighty-four percent of the responding hospitals had a prehospital MUG (Mobiele Urgentiegroep) - team or SMUR (Service Mobile d'Urgence et de Réanimation). In 29% of these, prehospital US (PHUS) was used, 18% were in the process of purchasing a device whilst 53% had no intention of implementing PHUS. The main reasons for not implementing PHUS were short transfer times (38%), insufficient training (33%), the cost of a device (25%), no return from investment (19%), the assumption that PHUS delays administering urgent care (19%) and the uncertainty about liability (8%). Nationwide, 40% of all emergency physicians have had some form of US training.

CONCLUSIONS

POCUS is regularly used in Belgian EDs for diagnostic and management purposes. Further implementation of POCUS will depend on how barriers are being addressed in the near future.

Use of Point-of-Care Ultrasound by Non-Physicians to Assess Respiratory Distress in the Out-of-Hospital Environment: A Scoping Review

Background:

The use of ultrasound in the out-of-hospital environment is increasingly feasible. The potential uses for point-of-care ultrasound (POCUS) by paramedics are many, but have historically been limited to traumatic indications. This study utilized a scoping review methodology to map the evidence for the use of POCUS by paramedics to assess respiratory distress and to gain a broader understanding of the topic.

Methods:

Databases Ovid MEDLINE, EMBASE, CINAHL Plus, and PUBMED were searched from January 1, 1990 through April 14, 2021. Google Scholar was searched, and reference lists of relevant papers were examined to identify additional studies. Articles were included if they reported on out-of-hospital POCUS performed by non-physicians for non-traumatic respiratory distress.

Results:

A total of 591 unique articles were identified, of which seven articles met the inclusion criteria. The articles reported various different scan protocols and, with one exception, suffered from low enrolments and low participation. Most articles reported that non-physician-performed ultrasound was feasible. Articles reported moderate to high levels of agreement between paramedics and expert reviewers for scan interpretation in most studies.

Conclusion:

Paramedics and emergency medical technicians (EMTs) have demonstrated the feasibility of lung ultrasound in the out-of-hospital environment. Further research should investigate the utility of standardized education and scanning protocols in paramedic-performed lung ultrasound for the differentiation of respiratory distress and the implications for patient outcomes.

Remote real-time supervision of prehospital point-of-care ultrasound: a feasibility study

Background

Although prehospital point-of-care ultrasound (POCUS) is gaining in importance, its rapid interpretation remains challenging in prehospital emergency situations. The technical development of remote real-time supervision potentially offers the possibility to support emergency medicine providers during prehospital emergency ultrasound. The aim of this study was to assess the feasibility of live data transmission and supervision of prehospital POCUS in an urban environment and so to improve patients’ safety.

Methods

Emergency doctors with moderate ultrasound experience performed prehospital POCUS in emergency cases (n = 24) such as trauma, acute dyspnea or cardiac shock using the portable ultrasound device Lumify™. The ultrasound examination was remotely transmitted to an emergency ultrasound expert in the clinic for real-time supervision via a secure video and audio connection. Technical feasibility as well as quality of communication and live stream were analysed.

Results

Prehospital POCUS with remote real-time supervision was successfully performed in 17 patients (71%). In 3 cases, the expert was not available on time and in 1 case remote data transmission was not possible due to connection problems. In 3 cases tele-supervision was restricted to video only and no verbal communication was possible via the device itself due to power saving mode of the tablet.

Conclusion

Remote real-time supervision of prehospital POCUS in an urban environment is feasible most of the time with excellent image and communication quality.

Trial registration: ClinicalTrials Number NCT04612816.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00985-0.

Flight Teams' Learning Needs Assessment on Ultrasound: A Mixed Methods Approach

OBJECTIVE

The goal of this study was to understand flight clinicians' learning needs and attitudes with regard to a prehospital ultrasound curriculum.

METHODS

In this convergent mixed methods study, 21 prehospital clinicians completed a questionnaire, and 20 attended a 1-hour focus group to explore attitudes regarding learning ultrasound. These participants were from a single emergency medical service agency.

RESULTS

Five themes emerged from the focus group transcripts and were supported by the quantitative data: 1) theme 1, hands-on training in ultrasound is a highly preferred modality; 2) theme 2, emergency medical service providers desire learning integrated into shifts and real-life practice; 3) theme 3, prehospital providers express concerns about training and maintenance of competency; 4) theme 4, participants recognize the need for quality control during the training phase and after; and 5) theme 5, participants were enthusiastic about how ultrasound could help guide clinical decision making and potentially improve patient outcomes.

CONCLUSION

Those who participated in an evidence-based assessment of prehospital ultrasound needs and barriers were experienced flight clinicians who would use prehospital ultrasound if made available. These adult learners indicated their preferred learning method would be using standardized patients, simulators, and hands-on in the field with physicians. They preferred follow-up courses and simulators to maintain competency.

Helicopter Emergency Medical Services Performed Extended Focused Assessment With Sonography: Training, Workflow, and Sustainable Quality

The extended focused assessment of trauma (EFAST) examination is an invaluable tool for the initial evaluation of the trauma patient. Miniaturization of ultrasound has enabled helicopter emergency medical services (HEMS) to use point-of-care ultrasound to care for trauma patients on scene. Our study demonstrated that HEMS crews accurately performed EFAST examinations after the implementation of a novel HEMS EFAST workflow, multifaceted training, and ongoing quality assurance. The HEMS crews' overall sensitivity was 53%, and specificity was 98%. The obtained image quality was highest for the lung, cardiac, and right upper quadrant components of the EFAST. Our results suggest that with a structured multifaceted training program, user-friendly workflow, and ongoing quality assurance, HEMS crews can perform EFAST examinations safely and reliably in the field. This would allow HEMS crews to detect life-threatening, time-sensitive conditions such as a pneumothorax, pericardial effusion, and intraperitoneal hemorrhage. HEMS EFAST has the potential to triage certain trauma patients directly to the operating room or newly emerging hybrid suites, bypassing the emergency room and saving crucial time.

The impact of lung ultrasound on clinical-decision making across departments: a systematic review

Background

Lung ultrasound has established itself as an accurate diagnostic tool in different clinical settings. However, its effects on clinical-decision making are insufficiently described. This systematic review aims to investigate the impact of lung ultrasound, exclusively or as part of an integrated thoracic ultrasound examination, on clinical-decision making in different departments, especially the emergency department (ED), intensive care unit (ICU), and general ward (GW).

Methods

This systematic review was registered at PROSPERO (CRD42021242977). PubMed, EMBASE, and Web of Science were searched for original studies reporting changes in clinical-decision making (e.g. diagnosis, management, or therapy) after using lung ultrasound. Inclusion criteria were a recorded change of management (in percentage of cases) and with a clinical presentation to the ED, ICU, or GW. Studies were excluded if examinations were beyond the scope of thoracic ultrasound or to guide procedures. Mean changes with range (%) in clinical-decision making were reported. Methodological data on lung ultrasound were also collected. Study quality was scored using the Newcastle–Ottawa scale.

Results

A total of 13 studies were included: five studies on the ED (546 patients), five studies on the ICU (504 patients), two studies on the GW (1150 patients), and one study across all three wards (41 patients). Lung ultrasound changed the diagnosis in mean 33% (15–44%) and 44% (34–58%) of patients in the ED and ICU, respectively. Lung ultrasound changed the management in mean 48% (20–80%), 42% (30–68%) and 48% (48–48%) of patients in the ED, in the ICU and in the GW, respectively. Changes in management were non-invasive in 92% and 51% of patients in the ED and ICU, respectively. Lung ultrasound methodology was heterogeneous across studies. Risk of bias was moderate to high in all studies.

Conclusions

Lung ultrasound, exclusively or as a part of thoracic ultrasound, has substantial impact on clinical-decision making by changing diagnosis and management in the EDs, ICUs, and GWs. The current evidence level and methodological heterogeneity underline the necessity for well-designed trials and standardization of methodology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13089-021-00253-3.

Point-of-Care Ultrasound Use by EMS Providers in Out-of-Hospital Cardiac Arrest

AIM

Paramedics received training in point-of-care ultrasound (POCUS) to assess for cardiac contractility during management of medical out-of-hospital cardiac arrest (OHCA). The primary outcome was the percentage of adequate POCUS video acquisition and accurate video interpretation during OHCA resuscitations. Secondary outcomes included POCUS impact on patient management and resuscitation protocol adherence.

METHODS

A prospective, observational cohort study of paramedics was performed following a four-hour training session, which included a didactic lecture and hands-on POCUS instruction. The Prehospital Echocardiogram in Cardiac Arrest (PECA) protocol was developed and integrated into the resuscitation algorithm for medical non-shockable OHCA. The ultrasound (US) images were reviewed by a single POCUS expert investigator to determine the adequacy of the POCUS video acquisition and accuracy of the video interpretation. Change in patient management and resuscitation protocol adherence data, including end-tidal carbon dioxide (EtCO2) monitoring following advanced airway placement, adrenaline administration, and compression pauses under ten seconds, were queried from the prehospital electronic health record (EHR).

RESULTS

Captured images were deemed adequate in 42/49 (85.7%) scans and paramedic interpretation of sonography was accurate in 43/49 (87.7%) scans. The POCUS results altered patient management in 14/49 (28.6%) cases. Paramedics adhered to EtCO2 monitoring in 36/36 (100.0%) patients with an advanced airway, adrenaline administration for 38/38 (100.0%) patients, and compression pauses under ten seconds for 36/38 (94.7%) patients.

CONCLUSION

Paramedics were able to accurately obtain and interpret cardiac POCUS videos during medical OHCA while adhering to a resuscitation protocol. These findings suggest that POCUS can be effectively integrated into paramedic protocols for medical OHCA.

Helicopter emergency medical services use of thoracic point of care ultrasound for pneumothorax: a systematic review and meta-analysis

Background

Auscultating for breath sounds to assess for pneumothorax in the helicopter emergency medical services (HEMS) settings can be extremely challenging. Thoracic point of care ultrasound (POCUS) offers a seemingly more useful visual (rather than audible) alternative. This review critically and quantitatively evaluates the use of thoracic POCUS for pneumothorax in the HEMS setting.

Methods

A systematic literature review with meta-analysis was conducted. Only papers reporting on patients undergoing POCUS for pneumothorax in the helicopter or pre-hospital setting were included. Primary outcome was accuracy, focusing on sensitivity and specificity. Secondary outcome was practicality. PubMed, Embase and the Cochrane Library were searched. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) was used to assess validity of studies.

Results

Twelve studies reporting on n = 1,936 images from medical and trauma patients were included in qualitative synthesis. Studies were nearly all observational designs. Most images were acquired by nurses or paramedics who were previously novices to ultrasound. The reference standard was predominantly CT. Specificity results were unanimously precise and very high, whereas sensitivity results were imprecise and extremely variable. Meta-analysis of eight studies involving n = 1,713 images yielded pooled sensitivity 61% (95% CI: 27–87%; I² = 94%) and pooled specificity 99% (95% CI: 98–100%; I² = 89%). Six studies involving n = 315 images reported practicality. The highest or second highest categorisation of image quality was reported in around half of those images.

Conclusion

Thoracic POCUS is highly specific but has extremely variable sensitivity for pneumothorax when performed in the HEMS setting. This is from purely a diagnostic (not clinical) perspective. Sensitivity increases when only clinically significant pneumothoraces are considered. Case reports reveal thoracic POCUS can appropriately alter treatment and triage decisions, but only for a small number of patients. It appears predominantly useful in mitigating against unnecessary interventions. More research reporting patient focused outcomes is required. In the meantime, thoracic POCUS appears to offer a more appropriate visual alternative to auscultation for breath sounds when assessing for pneumothorax in the HEMS setting.

Point-of-care ultrasound (POCUS) practices in the helicopter emergency medical services in Europe: results of an online survey

Background

The extent to which Point-of-care of ultrasound (POCUS) is used in different European helicopter EMS (HEMS) is unknown. We aimed to study the availability, perception, and future aspects of POCUS in the European HEMS using an online survey.

Method

A survey about the use of POCUS in HEMS was conducted by a multinational steering expert committee and was carried out from November 30, 2020 to December 30, 2020 via an online web portal. Invitations for participation were sent via email to the medical directors of the European HEMS organizations including two reminding notes.

Results

During the study period, 69 participants from 25 countries and 41 different HEMS providers took part in the survey. 96% (n = 66) completed the survey. POCUS was available in 75% (56% always when needed and 19% occasionally) of the responding HEMS organizations. 17% were planning to establish POCUS in the near future. Responders who provided POCUS used it in approximately 15% of the patients. Participants thought that POCUS is important in both trauma and non-trauma-patients (73%, n = 46). The extended focused assessment sonography for trauma (eFAST) protocol (77%) was the most common protocol used. A POCUS credentialing process including documented examinations was requested in less than one third of the HEMS organizations.

Conclusions

The majority of the HEMS organizations in Europe are able to provide different POCUS protocols in their services. The most used POCUS protocols were eFAST, FATE and RUSH. Despite the enthusiasm for POCUS, comprehensive training and clear credentialing processes are not available in about two thirds of the European HEMS organizations. Due to several limitations of this survey further studies are needed to evaluate POCUS in HEMS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13049-021-00933-y.

Prehospital Echocardiogram Use in Identifying Massive Pulmonary Embolism in Unidentified Respiratory Failure

Medical transport teams often handle cases of complex, critically ill patients and are in need of rapid, bedside assessments to guide clinical decision making. The use of point-of-care ultrasound (POCUS) as a diagnostic indicator has gained increased acceptance in emergency medicine. Ultrasound devices have become increasingly portable, and numerous studies have demonstrated that use in the prehospital setting is feasible, accurate, and can have a dramatic impact on the care of patients. In this case report, we highlight the use of handheld ultrasound in the identification of right heart dilation in an unstable patient with respiratory failure in a rural emergency department, concerning for massive pulmonary embolism. The patient was given thrombolytic therapy with dramatic clinical improvement, ultimately surviving transport to the intensive care unit at a nearby tertiary care center.

Immediate Pneumothorax Diagnosis by Surgical Residents Using Portable Ultrasound

OBJECTIVE

Feasibility of diagnosis of pneumothorax using handheld ultrasound by non-radiologists shows inconsistent results. The aim of this study is to evaluate the feasibility and accuracy of portable ultrasound for immediate diagnosis of pneumothorax by general surgery residents who underwent short training.

METHODS

Patients who presented to the emergency department of a university hospital with suspected pneumothorax between 10/2018 and 12/2019 were included in the study. Patients underwent ultrasound in 2 points of each hemithorax. Sensitivity and specificity for pneumothorax diagnosis by ultrasound and physical examination were calculated and compared with chest computed tomography (CT). Patients in whom a chest tube was placed prior to ultrasound examination and those who did not undergo a CT scan were excluded from the study.

RESULTS

A total of 85 patients met the inclusion criteria. Mean age was 40.7 ± 20.2 years. Pneumothorax was found among 46 patients (54%) per chest CT, and of these, 21 (46%) underwent chest tube placement following imaging. Ultrasound showed the highest sensitivity and specificity (95.6% [95% confidence interval {CI} 85.16% to 99.47%] and 97.44% [95% CI 86.40% to 99.67%], respectively). Chest x-ray had the lowest sensitivity (47.8% [95% CI 32.89% to 63.05%]) for pneumothorax detection. Physical examination showed a moderate sensitivity and specificity (82.6% [95% CI 68.58% to 92.18%] and 77.89% [95% CI 60.67% to 88.87%], respectively) for the diagnosis of pneumothorax.

CONCLUSIONS

We found high accuracy rates of 2-point ultrasound in immediate pneumothorax diagnosis when performed by surgical residents who underwent a short ultrasound training. This is a fast and repeatable test, and has the potential for successful implementation in prehospital and military scenarios as well, minimizing unnecessary chest tube placements.

FAST Performance in a Stationary versus In-Motion Military Ambulance Utilizing Handheld Ultrasound: A Randomized Controlled Study

OBJECTIVE

On-scene prehospital conditions and patient instability may warrant a during-transport ultrasound (US) exam. The objective of this study was to assess the effect of ambulance turbulence on the performance of the Focused Assessment with Sonography in Trauma (FAST) with a handheld US device.

METHODS

This was a randomized controlled trial in which participants were randomized to perform a FAST in either a stationary or an in-motion military ambulance. Participants were physicians and physician assistants (PAs) with previous FAST training. All exams were performed on an US phantom model. The primary outcome was FAST completion time, reported as a mean, in seconds. Secondary outcomes included image acquisition score (range of 0-24, reported as a mean), diagnostic accuracy (reported as sensitivity and specificity), and a post-participation survey with five-item Likert-type scales.

RESULTS

Twenty-seven participants performed 27 FASTs, 14 in the stationary ambulance and 13 in the in-motion ambulance. All participants obtained the four requisite views of the FAST. A significant difference was detected in image acquisition scores in favor of the stationary ambulance group (19.4 versus 16.7 [95% CI for difference, 0.9-4.4]; P <.01). Significant differences in survey items between groups were related to obtaining and maintaining US images and the exam conditions. There was not a difference in FAST completion time between groups (98.5 seconds versus 78.7 seconds [95% CI for difference, -13.5 seconds to 53.1 seconds]; P = .23). Sensitivity and specificity of FAST in the stationary ambulance was 85.7% (95% CI, 67.3%-96.0%) and 96.4% (95% CI, 81.7%-99.9%) versus 96.2% (95% CI, 80.4%-99.9%) and 100.0% (95% CI, 86.8%-100.0%) in the in-motion ambulance group (P = .21).

CONCLUSION

Vehicular motion did not affect FAST completion time and diagnostic accuracy; however, it did reduce FAST image acquisition scores. The results suggest timely and diagnostically accurate FASTs may be completed by experienced sonographers during moderate levels of ambulance turbulence. Further investigation assessing the utility and limitations of newer handheld US devices in various prehospital conditions is warranted.

Ultrasound Use in the Prehospital Setting for Trauma: A Systematic Review

BACKGROUND

Trauma is a leading cause of death in the United States. Ultrasound use in the prehospital environment has the potential to change trauma management. Although ultrasound use for prehospital trauma is increasing, the role of this modality is not clearly defined.

OBJECTIVES

We examined the use of prehospital ultrasound (PHUS) for trauma patients and the use by different provider types. Specific factors of interest were if prehospital ultrasound has been shown to improve providers' ability to recognize conditions that can be managed in the prehospital setting, treat these conditions, change transport destination, or improve overall mortality rates for trauma patients.

METHODS

We searched MEDLINE/PubMed, EBSCOhost, Cochrane Library, and Embase medical literature databases for articles that addressed our outcomes. Abstracts and articles were examined and studies that did not specifically evaluate ultrasound in the prehospital setting for trauma and duplicates were eliminated. Studies included in this comprehensive review were assessed for the use of ultrasound in the prehospital setting to aid in the diagnosis, treatment, and transport of trauma patients. We also conducted an analysis of bias in the included articles. Due to the large heterogeneity in the included studies, no meta-analysis could be performed.

RESULTS

Sixteen studies were identified comprising 3,317 patients. One study evaluated Emergency Medical Services (EMS) professionals as the ultrasound operator while five studies involved mixed practitioners and ten studies involved only physicians. Diagnostic accuracy was similar amongst physicians and mixed practitioners with no studies reporting PHUS accuracy for EMS providers alone. Seven studies evaluated treatment and transport impact of PHUS though the variables measured were inconsistent and results varied by protocol and outcomes measured. There were no studies that evaluated PHUS and its impact on patient mortality.

CONCLUSION

Ultrasound use in the prehospital setting for trauma is feasible and demonstrates potential. However, the evidence in the medical literature mainly consists of prospective observational studies of physicians utilizing ultrasound for trauma in a HEMS setting. Further scientific research must be undertaken to firmly establish the role of prehospital ultrasound in trauma management by all types of EMS providers.

Recommendations for Lung Ultrasound in Internal Medicine

A growing amount of evidence prompts us to update the first version of recommendations for lung ultrasound in internal medicine (POLLUS-IM) that was published in 2018. The recommendations were established in several stages, consisting of: literature review, assessment of literature data quality (with the application of QUADAS, QUADAS-2 and GRADE criteria) and expert evaluation carried out consistently with the modified Delphi method (three rounds of on-line discussions, followed by a secret ballot by the panel of experts after each completed discussion). Publications to be analyzed were selected from the following databases: Pubmed, Medline, OVID, and Embase. New reports published as of October 2019 were added to the existing POLLUS-IM database used for the original publication of 2018. Altogether, 528 publications were systematically reviewed, including 253 new reports published between September 2017 and October 2019. The new recommendations concern the following conditions and issues: pneumonia, heart failure, monitoring dialyzed patients' hydration status, assessment of pleural effusion, pulmonary embolism and diaphragm function assessment. POLLUS-IM 2020 recommendations were established primarily for clinicians who utilize lung ultrasound in their everyday clinical work.

Prehospital point-of-care ultrasound: A transformative technology

Point-of-care ultrasound at the bedside has evolved into an essential component of emergency patient care. Current evidence supports its use across a wide spectrum of medical and traumatic diseases in a variety of settings. The prehospital use of ultrasound has evolved from a niche technology to impending widespread adoption across emergency medical services systems internationally. Recent technological advances and a growing evidence base support this trend. However, concerns regarding feasibility, education, and quality assurance must be addressed proactively. This topical review describes the history of prehospital ultrasound, initial training needs, ongoing skill maintenance, quality assurance and improvement requirements, available devices, and indications for prehospital ultrasound.

Prehospital ultrasound use among Canadian aeromedical service providers - A cross-sectional survey

OBJECTIVES

Evidence suggests that prehospital point of care ultrasound (POCUS) may change patient management. It serves as an aid in triage, physical examination, diagnosis, and patient disposition. The rate of adoption of POCUS among aeromedical services throughout Canada is unknown. The objective of this study was to describe current POCUS use among Canadian aeromedical services providers.

METHODS

This is a cross-sectional observational study. A survey was emailed to directors of government-funded aeromedical services bases in Canada. Data were analyzed using descriptive statistics.

RESULTS

The response rate was 82.3% (14/17 aeromedical services directors), representing 41 of 46 individual bases. POCUS is used by aeromedical services in British Columbia, Alberta, Saskatchewan, and Manitoba. New Brunswick, Nova Scotia, Prince Edward Island, and Yukon reported they are planning to introduce POCUS within the next year. Ontario and Newfoundland reported they are not using POCUS and are not planning to introduce it. British Columbia is the only province currently using POCUS on fixed-wing aircraft. Most commonly reported frequency of POCUS use on missions was <25%. Most useful applications are assessment for pneumothorax, abdominal free fluid, and cardiac standstill. The most common barrier to POCUS use is cost of training and maintenance of competence.

CONCLUSIONS

Prehospital POCUS is available in Western Canada with one third of the Canadian population having access to aeromedical services using ultrasound. The Maritimes and the Yukon Territory will further extend POCUS use on fixed-wing aircraft. While there are barriers to POCUS use, those bases that have adopted POCUS consider it valuable.

Too fast, or not fast enough? The FAST exam in patients with non-compressible torso hemorrhage

BACKGROUND

Focused assessment with sonography for trauma (FAST) performance metrics are unknown in patients with non-compressible torso hemorrhage (NCTH).

METHODS

Retrospective review of a dedicated NCTH database from four level 1 trauma centers (2008-2012). NCTH was defined as (1) named axial torso vessel disruption; (2) AIS chest or abdomen >2 with shock (base deficit < -4) or truncal operation in ≤ 90 min; or (3) pelvic fracture with ring disruption. Patients were grouped by cavity of hemorrhage source and by shock (SBP ≤ 90).

RESULTS

274 patients had a FAST prior to diagnosis of NCTH. FAST was positive in 51% of patients with abdominal/pelvic hemorrhage for a false negative rate (FNR) of 49%. FNR was higher for pelvic (61%) versus abdominal (43%) sources (p = 0.02). There was no difference between FAST negative or positive patients for ISS, shock, length of stay, or mortality (all p = NS). FNR was not improved among the subgroup of NCTH patients with shock (p = NS).

CONCLUSION

FAST identified abdominal/pelvic hemorrhage in approximately half of NCTH patients, and this was not improved among patients presenting with shock.