Prehospital lung ultrasound for the diagnosis of cardiogenic pulmonary oedema: a pilot study

Contribution of point-of-care ultrasound in the prehospital management of patients with non-trauma acute dyspnea: a systematic review and meta-analysis

Acute dyspnea is a common symptom whose management is challenging in prehospital settings. Point-of-care ultrasound (POCUS) is increasingly accessible because of device miniaturization. To assess the contribution of POCUS in the prehospital management of patients with acute nontraumatic dyspnea, we performed a systematic review on nontrauma patients of any age managed in the prehospital setting for acute dyspnea and receiving a POCUS examination. We searched seven databases and gray literature for English-language studies published from January 1995 to November 2023. Two independent reviewers completed the study selection, data extraction, and risk of bias assessment. The primary outcome was the assessment of the contribution of POCUS to feasibility, diagnostic, therapeutic, prognosis, patient referral, and transport vector modification. Twenty-three studies were included. The risk of bias assessment identified 3 intermediate-risk, 18 serious-risk, and 2 critical-risk studies. Three studies reported moderate to excellent feasibility for lung POCUS, and three studies reported poor to mediocre feasibility for cardiac POCUS. The median duration of the POCUS examination was less than 5 minutes (six studies). POCUS improved diagnostic identification (seven studies). The diagnostic accuracy of POCUS was excellent for pneumothorax (sensitivity = 100%, specificity = 100%, two studies), very good for acute heart failure (sensitivity = 71-100%, specificity = 72-95%, eight studies), good for pneumonia (sensitivity = 88%, specificity = 59%, one study), and moderate for pleural effusion (sensitivity = 26-53%, specificity = 83-92%, two studies). Treatment was modified in 11 to 54% of the patients (seven studies). POCUS had no significant effect on patient prognosis (two studies). POCUS contributed to patient referrals and transport vectors in 51% (four studies) and 25% (three studies) of patients, respectively. The evidence supports the use of POCUS for managing acute nontraumatic dyspnea in the prehospital setting in terms of feasibility, overall diagnostic contribution, and, particularly, lung ultrasound for acute heart failure diagnosis. Moreover, POCUS seems to have a therapeutic contribution. There is not enough evidence supporting the use of POCUS for pneumonia, pleural effusion, pneumothorax, chronic obstructive pulmonary disease, or asthma exacerbation diagnosis, nor does it support prognostic, patient referral, and transport vector contribution. A high level of evidence is lacking and needed.

[Prehospital ultrasound in emergency medicine]

Small, portable hand-held ultrasound devices nowadays enable a widespread use of prehospital point-of-care ultrasound (pPOCUS), which has so far only been used hesitantly, especially in ground-based emergency services. Many critical or even life-threatening conditions or internal injuries can often be better diagnosed or ruled out using pPOCUS, which can enable faster and more suitable goal-directed treatment and hospital transport. This article critically discusses relevant data, clinical benefits, limitations and challenges to be overcome when using pPOCUS for the most important life-threatening situations and aims to call for intensifying training and the extensive use of pPOCUS.

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.

Home Ultrasound: A Contemporary and Valuable Tool for Palliative Medicine

This narrative review explores the application of point-of-care ultrasound (POCUS) in palliative care and its feasibility in home care settings. POCUS has the potential to streamline diagnostic strategies without patient transfer to the hospital, expedite timely symptomatic relief, and reduce complications from specific palliative interventions. The advent of handheld ultrasound devices has made it an attractive diagnostic and interventional adjunct in acute palliative care. POCUS has gained widespread acceptance as part of routine care in emergency medicine and intensive care, guiding certain procedures and increasing their safety. The modernization and miniaturization of ultrasound equipment have made ultra-portable devices available, allowing for better-quality images at affordable prices. Handheld devices have the potential to revolutionize everyday clinical practice in home-based palliative care, contributing to important bedside clinical decisions. Palliative care patients often require diagnostic examinations in the last months of their lives, with CT being the most frequently performed imaging procedure. However, CT imaging is associated with high costs and burdens, leading to increased suffering and impaired quality of life. Clinical ultrasound, a dialogic imaging modality, offers a safer and more efficient approach to palliative care. POCUS applications, which are cost-effective, non-invasive, and well-tolerated, can be used to improve patient satisfaction and diagnostic understanding. POCUS is a valuable tool in palliative care, improving diagnostic accuracy and reducing the time to diagnosis for various pathologies. It is a standard of care for many procedures and improves patient safety. However, there are limitations to POCUS in palliative care, such as operator-dependent examination variability and limited availability of trained professionals. To overcome these limitations, palliative care physicians should receive mandatory training in POCUS, which can be incorporated into the core curriculum. Additionally, ultrasound teleconsulting can assist less experienced examiners in real-time examinations. The literature on POCUS in palliative care is limited, but research on patient-oriented outcomes is crucial. POCUS should be considered a supplement to good clinical reasoning and regulated radiological evaluations.

Lung Ultrasound and Pleural Artifacts: A Pictorial Review

Lung ultrasound is a well-established diagnostic approach used in detecting pathological changes near the pleura of the lung. At the acoustic boundary of the lung surface, it is necessary to differentiate between the primary visualization of pleural parenchymal pathologies and the appearance of secondary artifacts when sound waves enter the lung or are reflected at the visceral pleura. The aims of this pictorial essay are to demonstrate the sonographic patterns of various pleural interface artifacts and to illustrate the limitations and pitfalls of the use of ultrasound findings in diagnosing any underlying pathology.

Prehospital lung ultrasound in acute heart failure: Impact on diagnosis and treatment

OBJECTIVE

Patients with acute heart failure (AHF) are commonly misdiagnosed and undertreated in the prehospital setting. These delays in diagnosis and treatment have a direct negative impact on patient outcomes. The goal of this study was to determine the diagnostic accuracy of paramedics with and without the use of lung ultrasound (LUS) for the diagnosis of AHF in patients with dyspnea in the prehospital setting. Secondarily, we assessed LUS impact on rate of and time to initiation of HF therapies.

METHODS

This was a prospective interventional study on a consecutive sample of patients transported to the hospital by one emergency medical services agency. Adult patients (>18 years) with a chief complaint of dyspnea were included. LUS was performed by trained paramedics and was defined as positive for AHF if both anterior-superior lung zones had greater than or equal to three B-lines or bilateral B-lines were visualized on a four-view protocol. Paramedic diagnosis was compared to hospital discharge diagnosis which served as the criterion standard.

RESULTS

Of the 264 included patients, 94 (35%) had a final diagnosis of AHF. Forty total patients had a LUS performed; 17 of these patients had a final diagnosis of AHF. Sensitivity and specificity for AHF by paramedics were 23% (95% confidence interval [CI] 0.14-0.34) and 97% (95% CI 0.92-0.99) without LUS and 71% (95% CI 0.44-0.88) and 96% (95% CI 0.76-0.99) with the use of LUS. In the 94 patients with AHF, 14% (11/77) received HF therapy prehospital without the use of LUS and 53% (9/17) with the use of LUS. LUS improved frequency of treatment by 39%. Median time to treatment was 21 min with LUS and 169 min without.

CONCLUSIONS

LUS improved paramedic sensitivity and accuracy for diagnosing AHF in the prehospital setting. LUS use led to higher rates of prehospital HF therapy initiation and significantly decreased time to treatment.

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.

Objective structured clinical examination in basic thoracic ultrasound: a European study of validity evidence

BACKGROUND

Basic thoracic ultrasound is being used more frequently by clinicians in several settings due to its high diagnostic accuracy for many common causes of respiratory failure and dyspnoea. However, ultrasound examinations are operator-dependent, and sufficient competences are needed to obtain high sensitivity and specificity of examinations. Additionally, it is crucial for ultrasound operators to perceive the competence to interpret the images and integrate them into the patient history and other examinations. This study aims to explore and gather validity evidence for an objective structured clinical examination test of basic thoracic ultrasound competences and establish a pass/fail score.

METHODS

An expert panel created the test which included two theoretical and five practical stations representing cases with different diagnoses that cause respiratory symptoms and which are possible to establish by basic thoracic ultrasound. Twenty-five participants with different levels of experience in basic thoracic ultrasound completed the test. Data of the test scores were used for item analysis, and exploring validity evidence was done according to Messick's framework which is recommended. The contrasting groups' standard setting method was used to establish a pass/fail score.

RESULTS

The summarised internal consistency reliability was high with a Cronbach's alpha of 0.87. The novice group (n = 4) had a mean test score of 42 ± 10.1 points, the intermediate group (n = 8) scored 79.1 ± 8.1 points, and the experienced group (n = 13) 89.0 ± 6.2 points (one-way ANOVA, p < 0.001). A pass/fail score of 71 points was thus derived (maximum test score = 105 points).

CONCLUSION

We developed a test for the assessment of clinical competences in basic thoracic ultrasound with solid validity evidence, and a pass/fail standard with no false positives or false negatives.

Handheld Ultrasound (HHUS): Potential for Home Palliative Care

Due to the severity of their disease, palliative care patients often present complex clinical symptoms and complaints like pain, shortness of breath, nausea, loss of appetite, and fatigue. Solely relying on the information available from the history and physical examination often causes uncertainty among palliative care physicians regarding treatment decisions during home visits, potentially leading to unnecessary hospitalizations or transfer to cross-sectional imaging in radiological practices. A rational approach is essential to avoid diagnostic aggressiveness while still providing the imaging information required for optimal palliative care. Bedside use of handheld ultrasound (HHUS) has the potential to expand the diagnostic and therapeutic spectrum in the case of symptom exacerbation but is still underutilized. In this review, we evaluate the potential uses of HHUS in home care settings to provide a more accurate diagnosis of the most common symptoms in palliative patients and to guide bedside interventions such as bladder catheterization, thoracentesis, paracentesis, venous access, and regional anesthesia. Specific training programs for ultrasound in palliative care are currently not available. Adequate documentation is warranted but fraught with technological and privacy issues. Expert supervision and quality assurance are necessary. Despite its limitation and challenges, we suggest that HHUS leads to improved clinical decision-making, expedited symptom relief, and reduced complications without burdening of the patient and costly transfer to hospital or specialty consultations.

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.

Semi-quantitative lung ultrasound score during ground transportation of outborn neonates with respiratory failure

Lung ultrasound score (LUS) is increasingly diffused in neonatal critical care but scanty data are available about its use during transfer of severely ill neonates. We aimed to clarify the effect of ground transportation on LUS evolution, conformity of interpretation, and relationships with oxygenation and clinical severity. This is a single-center, blinded, observational, cross-sectional study. Neonates of any gestational age with respiratory distress appearing within 24 h from birth were transferred by a mobile unit towards neonatal intensive care unit (NICU) of a tertiary referral center. Calculation of LUS prior to the transportation (T1), in the mobile unit (T2), at the end of transportation (T3), and finally upon NICU admission. LUS in the mobile unit and in the NICU was performed by different physicians blinded to each other's results. LUS did not change overtime (T1: 6.3 (3.5), T2: 6.1 (3.5), T3: 5.8 (3.4); p = 0.479; adjusted for gestational or postnatal age or transport duration: p = 0.951, p = 0.424, and 0.266, respectively) but reliably predicted surfactant need (AUC at T1: 0.833 (95%CI: 0.72-0.92); AUC at T2: 0.82 (95%CI: 0.70-0.91); AUC at T3: 0.82 (95%CI: 0.70-0.90); p always < 0.0001). There were significant agreement (ICC = 0.912 (95%CI: 0.83-0.95); p < 0.001) and correlation (r = 0.905, p < 0.001) between LUS calculated during transportation and in the NICU. LUS during transportation was also significantly correlated with oxygenation index (r = 0.321, p = 0.026; standardized B = 0.397 (95%CI: 0.03-0.76), p = 0.048) and TRIPS-II score (r = 0.302, p = 0.008; standardized B = 0.568 (95%CI: 0.04-1.1), p = 0.037).

CONCLUSION

LUS during ground transportation of neonates with respiratory failure is suitable and not influenced by the transportation itself. It has a high agreement with that calculated in the NICU and correlates with patients' oxygenation and severity.

WHAT IS KNOWN

• Lung ultrasound is a part of the point-of-care ultrasound, which is becoming an essential tool, to manage critically ill neonates and children in an accurate, non-invasive and quick way.

WHAT IS NEW

• Lung ultrasound score (LUS) is suitable during transportation of critically ill neonates with respiratory failure and is not influenced by the transportation itself. • LUS has a high agreement with that calculated in the NICU and correlates with patients' oxygenation and severity of respiratory failure.

Lung ultrasound to quantitatively evaluate extravascular lung water content and its clinical significance

BACKGROUND

As we all know, pulmonary edema can be diagnosed by lung ultrasound (LUS), but how to accurately and quantitatively evaluate lung water content by ultrasound is a difficult problem that needs to be solved urgently. B-line assessment with LUS has recently been proposed as a reliable, noninvasive semiquantitative tool for evaluating extravascular lung water (EVLW). To date, however, there has been no easy quantitative method to evaluate EVLW by LUS.

OBJECTIVE

(1) To explore the feasibility of establishing a rabbit model with increased EVLW by injecting warm normal saline (NS) into the lungs via the endotracheal tube. (2) To establish a simple, accurate and clinically operable method for quantitative assessment of EVLW using LUS. (3) To develop LUS into a resource for guiding the clinical treatment of patients with increased EVLW.

METHODS

Forty-five New Zealand rabbits were randomized into nine groups (n = 5). After anesthesia, each group of rabbits was injected with different amounts of warm sterile NS (0 ml/kg, 2 ml/kg, 4 ml/kg, 6 ml/kg, 8 ml/kg, 10 ml/kg, 15 ml/kg, 20 ml/kg, 30 ml/kg) via the endotracheal tube. Each rabbit was examined by LUS before and after NS injection. At the same time, the spontaneous respiratory rate (RR, breaths per minute), heart rate (HR, bpm) and arterial blood gas (ABG) of the rabbits were recorded. Then, both lungs were dissected to obtain the wet and dry weight and conduct a complete histological examination.

RESULTS

Injecting NS into the lungs through a tracheal tube can successfully establish a rabbit model with increased EVLW. The extent of EVLW increase is related to the volume of NS injected into the lungs. As the EVLW increases, three different types of B-lines can be seen in the LUS. When the NS injection volume is 2-6 ml/kg, comet-tail artifacts and B-lines are the main patterns found on LUS; as additional NS is injected into the lungs, the rabbits' RR gradually increases, while their HR gradually decreases, ABG remains normal or shows mild metabolic acidosis (MA). Confluent B-lines grow gradually but significantly, reaching a dominant position when the NS injection volume reaches 6-8 ml/kg and predominating almost entirely when the NS injection volume is 8-15 ml/kg; at that time, rabbits' RRs and HRs decrease sharply, and the ABG indicated type I respiratory failure (RF).Compact B-lines occur and predominate almost entirely when the NS injection volume reaches 10 ml/kg and 15-20 ml/kg, respectively. At that time, rabbits begin to enter cardiac and respiratory arrest, and ABG shows type II RF and MA.

CONCLUSION

In this study, the establishment of an animal model with increased EVLW confirmed that different lung water content had corresponding manifestations in ultrasound and was associated with different degrees of clinical symptoms, and the study results can be used to guide clinical practice.

Prehospital Release of Patients After Treatment in an Anesthesiologist-Staffed Mobile Emergency Care Unit

IMPORTANCE

Prehospital treatment and release of patients may reduce unnecessary transports to the hospital and may improve patient satisfaction. However, the safety of patients should be paramount.

OBJECTIVE

To determine the extent of unplanned emergency department (ED) contacts, short-term mortality, and diagnostic patterns in patients treated and released by a prehospital anesthesiologist supervising a mobile emergency care unit (MECU).

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used a manual review of prehospital and in-hospital medical records to investigate all living patients who were treated and released by an MECU in Odense, Denmark, between January 1, 2011, and December 31, 2020. Patients were followed up for 30 days after initial contact with the prehospital service.

MAIN OUTCOMES AND MEASURES

Primary outcome measures included unplanned contacts with the emergency department less than 48 hours after prehospital treatment and prehospital assigned diagnosis. Secondary outcomes consisted of mortality at 48 hours and 7 and 30 days.

RESULTS

A total of 3141 patients were identified; 384 were excluded and 2757 were included in the analysis. The median patient age was 40 (IQR, 14-66) years; 1296 (47.0%) were female and 1461 (53.0%) were male. Two hundred thirty-nine patients (8.7% [95% CI, 7.6%-9.8%]) had unplanned contact with the ED within 48 hours; this rate was doubled for patients with respiratory diseases (37 of 248 [14.9% (95% CI, 10.7%-20.0%)]). Fifty-nine of 60 patients who died within 48 hours of release had terminal illness. Excluding these patients, the mortality rates were 0.04% at 48 hours, 0.8% at 7 days, and 2.4% at 30 days. Two thousand sixty-one patients (74.8%) had primarily nondefinitive observational diagnoses.

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that prehospital treatment and subsequent release at the scene is safe. One patient in 12 attended the ED within the ensuing 48 hours. However, for patients with respiratory diseases, this rate was doubled. Hospital admission could be avoided for some patients in the end stage of a terminal illness.

How and When to Use Lung Ultrasound in Patients with Heart Failure?

Pulmonary congestion is a critical finding in patients with heart failure (HF) that can be quantified by lung ultrasound (LUS) through B-line quantification, the latter of which can be easily measured by all commercially-available probes/ultrasound equipment. As such, LUS represents a useful tool for the assessment of patients with both acute and chronic HF. Several imaging protocols have been described in the literature according to different clinical settings. While most studies have been performed with either the 8 or 28 chest zone protocol, the 28-zone protocol is more time-consuming while the 8-zone protocol offers the best trade-off with no sizeable loss of information. In the acute setting, LUS has excellent value in diagnosing acute HF, which is superior to physical examination and chest X-ray, particularly in instances of diagnostic uncertainty. In addition to its diagnostic value, accumulating evidence over the last decade (mainly derived from ambulatory settings or at discharge from an acute HF hospitalisation) suggests that LUS can also represent a useful prognostic tool for predicting adverse outcome in both HF with reduced (HFrEF) and preserved ejection fraction (HFpEF). It also allows real-time monitoring of pulmonary decongestion during treatment of acute HF. Additionally, LUS-guided therapy, when compared with usual care, has been shown to reduce the risk of HF hospitalisations at short- and mid-term follow-up. In addition, studies have shown good correlation between B-lines during exercise stress echocardiography and invasive, bio-humoral and echocardiographic indices of haemodynamic congestion; B-lines during exercise are also associated with worse prognosis in both HFrEF and HFpEF. Altogether, LUS represents a reliable and useful tool in the assessment of pulmonary congestion and risk stratification of HF patients throughout their entire journey (i.e., emergency department/acute settings, in-hospital management, discharge from acute HF hospitalisation, monitoring in the outpatient setting), with considerable diagnostic and prognostic implications.

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.

A National Survey of Prehospital Care Services of United Kingdom for Use, Governance and Perception of Prehospital Point of Care Ultrasound

Introduction: Point of care ultrasound (POCUS) has become a common practice in prehospital care over the last 10 years. There is lack of literature on its use and governance structure in United Kingdom (UK) prehospital care services. We aimed to survey the use, governance of prehospital POCUS among UK prehospital services and perceptions of clinicians and services regarding its utility and barriers to its implementation. Methods: Four electronic questionnaire surveys were delivered to UK helicopter emergency medical service (HEMS) & clinicians, ambulance and community emergency medicine (CEM) services between 1^st of April and 31^st of July 2021 investigating current use, governance structure for POCUS and perception about its benefits and barriers. Invitations were sent via email to medical directors or research leads of services and using social media. Survey links remained live for two months each. Results: Overall, 90%, 62% and 60% of UK HEMS, ambulance and CEM services respectively, responded to surveys. Most of the services used prehospital POCUS, however only two HEMS organisations fulfilled the Royal College of Radiology governance criteria for POCUS. The most commonly performed POCUS modality was echo in cardiac arrest. Majority of clinicians judged POCUS to be beneficial and the common perceived benefit was promotion of enhanced and effective clinical care. Major barriers to its implementation included a lack of formal governance, limited literature supporting its use and difficulties in performing POCUS in prehospital environment. Conclusion: This survey demonstrates that prehospital POCUS is being provided by a majority of the prehospital care services and clinicians have found it beneficial in providing enhanced clinical care to their patients. However, the barriers to its implementation are relative lack of governance structure and supportive literature.

Prehospital emergency medical technicians can perform ultrasonography and blood analysis in prehospital evaluation of patients with chronic obstructive pulmonary disease: a feasibility study

INTRODUCTION

Crowding of the emergency departments is an increasing problem. Many patients with an exacerbation of chronic obstructive pulmonary disease (COPD) are often treated in the emergency departments for a very short period before discharged to their homes. It is possible that this treatment could take place in the patients' homes with sufficient diagnostics supporting the treatment. In an effort to keep the diagnostics and treatment of some of these patients in their homes and thus to reduce the patient load at the emergency departments, we implemented a prehospital treat-and-release strategy based on ultrasonography and blood testing performed by emergency medical technicians (EMT) or paramedics (PM) in patients with acute exacerbation of COPD.

METHOD

EMTs and PMs were enrolled in a six-hour educational program covering ultrasonography of the lungs and point of care blood tests. During the seasonal peak of COPD exacerbations (October 2018 - May 2019) all patients who were treated by the ambulance crews for respiratory insufficiency were screened in the ambulances. If the patient had uncomplicated COPD not requiring immediate transport to the hospital, ultrasonographic examination of the lungs, measurements of C-reactive protein and venous blood gases analyses were performed. The response to the initial treatment and the results obtained were discussed via telemedical consultation with a prehospital anaesthesiologist who then decided to either release the patient at the scene or to have the patient transported to the hospital. The primary outcome was strategy feasibility.

RESULTS

We included 100 EMTs and PMs in the study. During the study period, 771 patients with respiratory insufficiency were screened. Uncomplicated COPD was rare as only 41patients were treated according to the treat-and-release strategy. Twenty of these patients (49%) were released at the scene. In further ten patients, technical problems were encountered hindering release at the scene.

CONCLUSION

In a few selected patients with suspected acute exacerbations of COPD, it was technically and organisationally feasible for EMTs and PMs to perform prehospital POCT-ultrasound and laboratory testing and release the patients following treatment. None of the patients released at the scene requested a secondary ambulance within the first 48 h following the intervention.

Outcomes of Patients Treated with Prehospital Noninvasive Ventilation: Observational Retrospective Multicenter Study in the Northern French Alps

Noninvasive ventilation (NIV) improves the outcome of acute cardiogenic pulmonary edema (AcPE) and acute exacerbation of chronic obstructive pulmonary disease (aeCOPD) but is not recommended in pneumonia. The aim of this study was to assess the appropriateness of the use of NIV in a prehospital setting, where etiological diagnostics rely mainly on clinical examination. This observational multicenter retrospective study included all the patients treated with NIV by three mobile medical emergency teams in 2015. Prehospital diagnoses and hospital diagnoses were extracted from the medical charts. The appropriateness of NIV was determined by matching the hospital diagnosis to the current guidelines. Among the 14,067 patients screened, 172 (1.2%) were treated with NIV. The more frequent prehospital diagnoses were AcPE (n = 102, 59%), acute respiratory failure of undetermined cause (n = 46, 28%) and aeCOPD (n = 17, 10%). An accurate prehospital diagnosis was more frequent for AcPE (83/88, 94%) than for aeCOPD (14/32, 44%; p < 0.01). Only two of the 25 (8%) pneumonia cases were diagnosed during prehospital management. Prehospital NIV was inappropriate for 32 (21%) patients. Patients with inappropriate NIV had a higher rate of in-hospital intubation than patients with appropriate NIV (38% vs. 8%; p < 0.001). This high frequency of inappropriate NIV could be reduced by an improvement in the prehospital detection of aeCOPD and pneumonia.

Paramedic-performed Prehospital Point-of-care Ultrasound for Patients with Undifferentiated Dyspnea: A Pilot Study

INTRODUCTION

Thoracic ultrasound is frequently used in the emergency department (ED) to determine the etiology of dyspnea, yet its use is not widespread in the prehospital setting. We sought to investigate the feasibility and diagnostic performance of paramedic acquisition and assessment of thoracic ultrasound images in the prehospital environment, specifically for the detection of B-lines in congestive heart failure (CHF).

METHODS

This was a prospective observational study of a convenience sample of adult patients with a chief complaint of dyspnea. Paramedics participated in a didactic and hands-on session instructing them how to use a portable ultrasound device. Paramedics assessed patients for the presence of B-lines. Sensitivity and specificity for the presence of bilateral B-lines and any B-lines were calculated based on discharge diagnosis. Clips archived to the ultrasound units were reviewed and paramedic interpretations were compared to expert sonologist interpretations.

RESULTS

A total of 63 paramedics completed both didactic and hands-on training, and 22 performed ultrasounds in the field. There were 65 patients with B-line findings recorded and a discharge diagnosis for analysis. The presence of bilateral B-lines for diagnosis of CHF yielded a sensitivity of 80.0% (95% confidence interval [CI], 51.4-94.7%) and specificity of 72.0% (95% CI, 57.3-83.3), while presence of any B-lines was 93.3% sensitive (95% CI, 66.0-99.7%), and 50% specific (95% CI, 35.7-64.2%) for CHF. Paramedics archived 117 ultrasound clips of which 63% were determined to be adequate for interpretation. Comparison of paramedic and expert sonologist interpretation of images showed good inter-rater agreement for detection of any B-lines (k = 0.60; 95% CI, 0.36-0.84).

CONCLUSION

This observational pilot study suggests that prehospital lung ultrasound for B-lines may aid in identifying or excluding CHF as a cause of dyspnea. The presence of bilateral B-lines as determined by paramedics is reasonably sensitive and specific for the diagnosis of CHF and pulmonary edema, while the absence of B lines is likely to exclude significant decompensated heart failure. The study was limited by being a convenience sample and highlighted some of the difficulties related to prehospital research. Larger funded trials will be needed to provide more definitive data.

European Respiratory Society statement on thoracic ultrasound

Thoracic ultrasound is increasingly considered to be an essential tool for the pulmonologist. It is used in diverse clinical scenarios, including as an adjunct to clinical decision making for diagnosis, a real-time guide to procedures and a predictor or measurement of treatment response. The aim of this European Respiratory Society task force was to produce a statement on thoracic ultrasound for pulmonologists using thoracic ultrasound within the field of respiratory medicine. The multidisciplinary panel performed a review of the literature, addressing major areas of thoracic ultrasound practice and application. The selected major areas include equipment and technique, assessment of the chest wall, parietal pleura, pleural effusion, pneumothorax, interstitial syndrome, lung consolidation, diaphragm assessment, intervention guidance, training and the patient perspective. Despite the growing evidence supporting the use of thoracic ultrasound, the published literature still contains a paucity of data in some important fields. Key research questions for each of the major areas were identified, which serve to facilitate future multicentre collaborations and research to further consolidate an evidence-based use of thoracic ultrasound, for the benefit of the many patients being exposed to clinicians using thoracic ultrasound.

Utility of Different Lung Ultrasound Simulation Modalities Used by Paramedics during Varied Ambulance Driving Conditions

INTRODUCTION

Prehospital use of lung ultrasound (LUS) by paramedics to guide the diagnoses and treatment of patients has expanded over the past several years. However, almost all of this education has occurred in a classroom or hospital setting. No published prehospital use of LUS simulation software within an ambulance currently exists.

STUDY OBJECTIVE

The objective of this study was to determine if various ambulance driving conditions (stationary, constant acceleration, serpentine, and start-stop) would impact paramedics' abilities to perform LUS on a standardized patient (SP) using breath-holding to simulate lung pathology, or to perform LUS using ultrasound (US) simulation software. Primary endpoints included the participating paramedics': (1) time to acquiring a satisfactory simulated LUS image; and (2) accuracy of image recognition and interpretation. Secondary endpoints for the breath-holding portion included: (1) the agreement between image interpretation by paramedic versus blinded expert reviewers; and (2) the quality of captured LUS image as determined by two blinded expert reviewers. Finally, a paramedic LUS training session was evaluated by comparing pre-test to post-test scores on a 25-item assessment requiring the recognition of a clinical interpretation of prerecorded LUS images.

METHODS

Seventeen paramedics received a 45-minute LUS lecture. They then performed 25 LUS exams on both SPs and using simulation software, in each case looking for lung sliding, A and B lines, and seashore or barcode signs. Pre- and post-training, they completed a 25-question test consisting of still images and videos requiring pathology recognition and formulation of a clinical diagnosis. Sixteen paramedics performed the same exams in an ambulance during different driving conditions (stationary, constant acceleration, serpentines, and abrupt start-stops). Lung pathology was block randomized based on driving condition.

RESULTS

Paramedics demonstrated improved post-test scores compared to pre-test scores (P <.001). No significant difference existed across driving conditions for: time needed to obtain a simulated image; clinical interpretation of simulated LUS images; quality of saved images; or agreement of image interpretation between paramedics and blinded emergency physicians (EPs). Image acquisition time while parked was significantly greater than while the ambulance was driving in serpentines (Z = -2.898; P = .008). Technical challenges for both simulation techniques were noted.

CONCLUSION

Paramedics can correctly acquire and interpret simulated LUS images during different ambulance driving conditions. However, simulation techniques better adapted to this unique work environment are needed.

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.

From bedside to bench: lung ultrasound for the assessment of pulmonary edema in animal models

Traditionally, the lung has been excluded from the ultrasound organ repertoire and, hence, the application of lung ultrasound (LUS) was largely limited to a few enthusiastic clinicians. Yet, in the last decades, the recognition of the previously untapped diagnostic potential of LUS in intensive care medicine has fueled its widespread use as a rapid, non-invasive and radiation-free bedside approach with excellent diagnostic accuracy for many of the most common causes of acute respiratory failure, e.g., cardiogenic pulmonary edema, pneumonia, pleural effusion and pneumothorax. Its increased clinical use has also incited attention for the potential usefulness of LUS in preclinical studies with small animal models mimicking lung congestion and pulmonary edema formation. Application of LUS to small animal models of pulmonary edema may save time, is cost-effective, and may reduce the number of experimental animals due to the possibility of serial evaluations in the same animal as compared with traditional end-point measurements. This review provides an overview of the emerging field of LUS with a specific focus on its application in animal models and highlights future perspectives for LUS in preclinical research.

ERS statement on chest imaging in acute respiratory failure

Chest imaging in patients with acute respiratory failure plays an important role in diagnosing, monitoring and assessing the underlying disease. The available modalities range from plain chest X-ray to computed tomography, lung ultrasound, electrical impedance tomography and positron emission tomography. Surprisingly, there are presently no clear-cut recommendations for critical care physicians regarding indications for and limitations of these different techniques.The purpose of the present European Respiratory Society (ERS) statement is to provide physicians with a comprehensive clinical review of chest imaging techniques for the assessment of patients with acute respiratory failure, based on the scientific evidence as identified by systematic searches. For each of these imaging techniques, the panel evaluated the following items: possible indications, technical aspects, qualitative and quantitative analysis of lung morphology and the potential interplay with mechanical ventilation. A systematic search of the literature was performed from inception to September 2018. A first search provided 1833 references. After evaluating the full text and discussion among the committee, 135 references were used to prepare the current statement.These chest imaging techniques allow a better assessment and understanding of the pathogenesis and pathophysiology of patients with acute respiratory failure, but have different indications and can provide additional information to each other.

Diagnostic value of prehospital arterial blood gas measurements - a randomised controlled trial

Background

Arterial blood gas analysis is an important diagnostic tool in managing critically ill patients within the hospital. Whether prehospital application of this diagnostic modality contributes to more exact diagnoses and treatments in critically ill prehospital patients is unknown. The aim of this study was to establish whether access to arterial blood gas analysis increased the prehospital diagnostic accuracy of prehospital anaesthesiologists. Furthermore, we investigated whether prehospital blood gas analysis resulted in therapeutic interventions that would not have been carried out if the arterial blood gas analyser had not been available.

Methods

In a prospective randomised study, two groups of prehospital adult patients with acute critical illness were compared. All patients received standard prehospital care. In the intervention group, an arterial blood gas sample was analysed prehospitally. The primary outcome was the impact of blood gas analysis on the accuracy of prehospital diagnoses. Furthermore, we registered any therapeutic interventions that were carried out as a direct result of the blood gas analysis.

Results

A total of 310 patients were included in the study. Eighty-eight of these patients were subsequently excluded, primarily due to difficulties in obtaining post hoc consent or venous sampling or other technical difficulties. A total of 102 patients was analysed in the arterial blood gas group (ABG group), while 120 patients were analysed in the standard care group (noABG group). In 78 of the 102 patients in the ABG group, the prehospital physician reported that ABG analysis increased their perceived diagnostic precision. In 81 cases in the noABG group, the lack of arterial blood gas analysis was perceived to have decreased diagnostic accuracy. The claim that ABG analysis increased diagnostic accuracy could, however, not be substantiated as there was no difference in the number of un-specific diagnoses between the groups.

Blood gas analysis increased the probability of targeting specific prehospital therapeutic interventions and led to 159 interventions, including intubation, ventilation and/or upgrading the level of urgency, in 71 ABG-group patients (p < 0.001).

Conclusion

Although prehospital arterial blood gas analysis did not improve the accuracy of the prehospital diagnoses assigned to patients, it significantly increased the quality of treatment provided to patients with acute critical illness.

Trial registration

ClinicalTrials.gov, NCT03006692, retrospectively registered six months after first patient entry.

Pulmonary Ultrasound in Patients with Heart Failure - Systematic Review

Pulmonary congestion is an important clinical finding in patients with heart failure (HF). Physical examination and chest X-ray have limited accuracy in detecting congestion. Pulmonary ultrasound (PU) has been incorporated into clinical practice in the evaluation of pulmonary congestion. This paper aimed to perform a systematic review of the use of PU in patients with HF, in different scenarios. A search was performed in the MEDLINE and LILACS databases in February 2017 involving articles published between 2006 and 2016. We found 26 articles in the present review, 11 of which in the emergency setting and 7 in the outpatient setting, with diagnostic and prognosis defined value and poorly studied therapeutic value. PU increased accuracy by 90% as compared to physical examination and chest X-ray for the diagnosis of congestion, being more sensitive and precocious. The skill of the PU performer did not interfere with diagnostic accuracy. The presence of B-lines ≥ 15 correlated with high BNP values (≥ 500) and E/e' ratio ≥ 15, with prognostic impact in IC patients at hospital discharge and those followed up on an outpatient basis. In conclusion, when assessing pulmonary congestion in HF, PU has an incremental value in the diagnostic and prognostic approach in all scenarios studied.

Usefulness of ultrasound in the management of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening disease. Different imaging techniques have been used to diagnose and guide the ventilatory management of patients with ARDS. Chest ultrasound is a reliable tool to identify interstitial syndrome, lung consolidation, lung collapse, and pleural effusion. In addition, echocardiography is essential in the diagnosis of diastolic left ventricle dysfunction and the estimation of elevated ventricle filling pressures, which is necessary before diagnosing ARDS. Therefore, combining chest and heart ultrasound assessment is useful to diagnose ARDS and guide the ventilatory management of the disease. Available data in the literature suggest that protocol-based approaches should be implemented for the purposes of diagnosis and management.

Lung Ultrasound Is Accurate for the Diagnosis of High-Altitude Pulmonary Edema: A Prospective Study

Objective

The aim of this study was to assess the diagnostic accuracy of lung ultrasonography (LUS) for high-altitude pulmonary edema (HAPE).

Background

LUS has proven to be a reliable tool for the diagnosis of pulmonary diseases, including pneumonia, acute respiratory distress syndrome (ARDS), and pneumothorax. LUS also has potential for the diagnosis of HAPE. However, the actual diagnostic value of LUS for HAPE is still unknown. Our objective was to determine the feasibility of using LUS for the diagnosis of HAPE.

Materials and Methods

A prospective clinical research study of adult HAPE patients was conducted. LUS and chest X-ray (CXR) were performed in patients with suspected HAPE before and after treatment, and pulmonary moist rales were recorded concurrently. The diagnostic value of LUS, CXR, and moist rales for HAPE (i.e., their sensitivity, specificity, and positive and negative predictive values) were assessed, and the results were compared. The gold standard was the final diagnosis.

Results

In total, 148 patients were enrolled in the study, 126 of which were diagnosed with HAPE (85.14%). Before treatment, the diagnostic accuracy of LUS for HAPE was as follows: sensitivity, 98.41% (95% confidence interval (CI) 100.60-96.23%); specificity, 90.91% (95% CI 102.92-78.90%). LUS had higher sensitivity (0.98 vs. 0.81, P < 0.01 using the McNemar test) than moist rales for the diagnosis of HAPE. LUS also had higher sensitivity than CXR (0.98 vs. 0.93, P < 0.05 using the McNemar test). After treatment, LUS was consistent with CXR in 96.55% of HAPE patients, and the concordance between LUS and CXR was high (k statistic = 0.483 P ≤ 0.001; 95% CI -0.021 to -0.853).

Conclusion

The results indicate that LUS is a reliable method for the diagnosis and surveillance of HAPE. This trial is registered with Chinese Clinical Trial Registry (No. ChiCTR-DDD-16009841).

The role of point of care ultrasound in prehospital critical care: a systematic review

Background

In 2011, the role of Point of Care Ultrasound (POCUS) was defined as one of the top five research priorities in physician-provided prehospital critical care and future research topics were proposed; the feasibility of prehospital POCUS, changes in patient management induced by POCUS and education of providers. This systematic review aimed to assess these three topics by including studies examining all kinds of prehospital patients undergoing all kinds of prehospital POCUS examinations and studies examining any kind of POCUS education in prehospital critical care providers.

Methods and results

By a systematic literature search in MEDLINE, EMBASE, and Cochrane databases, we identified and screened titles and abstracts of 3264 studies published from 2012 to 2017. Of these, 65 studies were read in full-text for assessment of eligibility and 27 studies were ultimately included and assessed for quality by SIGN-50 checklists. No studies compared patient outcome with and without prehospital POCUS. Four studies of acceptable quality demonstrated feasibility and changes in patient management in trauma. Two studies of acceptable quality demonstrated feasibility and changes in patient management in breathing difficulties. Four studies of acceptable quality demonstrated feasibility, outcome prediction and changes in patient management in cardiac arrest, but also that POCUS may prolong pauses in compressions. Two studies of acceptable quality demonstrated that short (few hours) teaching sessions are sufficient for obtaining simple interpretation skills, but not image acquisition skills. Three studies of acceptable quality demonstrated that longer one- or two-day courses including hands-on training are sufficient for learning simple, but not advanced, image acquisition skills. Three studies of acceptable quality demonstrated that systematic educational programs including supervised examinations are sufficient for learning advanced image acquisition skills in healthy volunteers, but that more than 50 clinical examinations are required for expertise in a clinical setting.

Conclusion

Prehospital POCUS is feasible and changes patient management in trauma, breathing difficulties and cardiac arrest, but it is unknown if this improves outcome. Expertise in POCUS requires extensive training by a combination of theory, hands-on training and a substantial amount of clinical examinations – a large part of these needs to be supervised.

Electronic supplementary material

The online version of this article (10.1186/s13049-018-0518-x) contains supplementary material, which is available to authorized users.

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

Background

In the prehospital situation, the diagnostic armamentarium available to the rescue physician is limited. Emergency ultrasound has proven to be a useful diagnostic tool, providing crucial information for the management of critically ill and injured patients. The proportion of performed ultrasound scans in all patients attended to by the rescue service team, the quality of the findings and the ultrasound-related changes in management approach and patient transport were evaluated.

Methods

In this prospective 18-month observational study, we documented all missions performed by rescue physicians with special training in emergency ultrasound (expert standard). These data were than analysed with regard to the ultrasound examinations. The ultrasound protocols used comprised Focussed Assessment with Sonography for Trauma (FAST), Prehospital Lung Ultrasound (PLUS) and Focused Echocardiography in Emergency Life support (FEEL). The quality of prehospital examinations was assessed by comparing the findings and diagnoses at the emergency site with those established in hospital. The changes in patient management and transport were documented using a standardized protocol.

Results

A total of 99 (18.1%) emergency ultrasound examinations were performed during 546 callouts. The most common indications for prehospital emergency ultrasound were dyspnoea (n = 38; 38.4%), during cardiac arrest (n = 17/17.2%), fall (n = 12/12.1%) and high-speed trauma (n = 11/11.1%). The combinations of ultrasound examination protocols in the trauma group (n = 31; 31.3%) were: 1. FAST+FEEL+PLUS (n = 17; 54.8%). 2. FAST+PLUS (n = 11; 35.5%) 3. FAST alone (n = 3; 9.7%). In the non-trauma group (n = 68; 68.7%), the following combinations were used: 1. FEEL+PLUS (n = 36; 52.9%), 2. FEEL alone (n = 21/30.9%). 3. PLUS alone (n = 6/8.8%) 4. FAST alone (n = 2; 2.9%) 5. FAST+FEEL+PLUS (n = 2; 2.9%). 6. FAST+FEEL (n = 1/1.5%). The emergency ultrasound findings impaired left ventricular contractile function (sensitivity 89.4%), right ventricular stress (85.7%), lung interstitial syndrome (100%), ruling out pneumothorax (specificity 100%), ruling out intraabdominal fluid (97,1%) were verified at the receiving hospital using ultrasonography, CT scan or x-rays; the prehospital diagnosis was confirmed in 90.8% of cases, the difference between the prehospital and in-hospital findings were not significant(p-values from p = 0.688 to p = 0,99). Ultrasound-related changes in patient management occurred in 49.5% of patients; in 33.3%, these were transported-related.

Conclusions

Emergency ultrasound was as often used in the prehospital situation as it is in hospital. The ultrasound findings correlated well with in-hospital diagnostic results. Significant pathology changed patient-management, without prolonging the mission time.

Prehospital prognosis is difficult in patients with acute exacerbation of chronic obstructive pulmonary disease

Background

Patients with acute exacerbation of chronic obstructive pulmonary disease often require prehospital emergency treatment. This enables patients who are less ill to be treated on-site and to avoid hospital admission, while severely ill patients can receive immediate ventilatory support in the form of intubation. The emergency physician faces difficult treatment decisions, however, and prognostic tools that could assist in determining which patients would benefit from intubation and ventilator support would be helpful. The aim of the current study was to identify prehospital clinical variables associated with mortality from acute exacerbation of chronic obstructive pulmonary disease. As part of the study, we estimated the 30-day mortality for patients with this prehospital diagnosis.

Methods

A retrospective study was performed using data collected by the mobile emergency care unit in Odense, Denmark, combined with data from the patients’ medical records. Patients with the tentative diagnosis of acute exacerbation of chronic obstructive pulmonary disease between 1st July 2011 and 31st December 2013 were included in the study.

Results

Based on data from 530 patients, we found no statistically significant associations between prehospital clinical variables and mortality, apart from a minor association between older age and higher mortality. The overall 30-day mortality was 10%, while that for patients admitted to the intensive care unit was 30%.

Conclusion

No specific prehospital prognostic factors for mortality were identified. Prognostic assessment and the decision to withhold treatment for acute exacerbation of chronic obstructive pulmonary disease seem inadvisable in the prehospital setting.