Integrating Lung Ultrasound with Clinical Assessment to Improve Diagnosis of Acute Decompensated Heart Failure in Dyspneic Patients.

Matt Olson, DO | EMIM PGY3

The Article:

Lung ultrasound integrated with clinical assessment for the diagnosis of acute decompensated heart failure in the emergency department: a randomized control trial. Pivetta et al. (2018) European Journal of Heart Failure. 21, 754-766

The Idea:

To determine if using Lung ultrasound (LUS), in addition to clinical assessment, for patients with acute dyspnea can aid in the diagnosis of acute decompensated heart failure (ADHF).

The Study:

This was a randomized control trial that was conducted in two emergency departments from January 2014 to March 2015 on patients with acute dyspnea. 518 patients were enrolled in the study and randomized into one of two arms, the lung ultrasound arm and the CXR/Nt-proBNP arm. Every patient started with an initial clinical evaluation including history and physical exam. After the clinical exam the physician was asked to indicate a presumptive cause of the dyspnea. Afterwards the patients were separated into their arm (lung ultrasound vs. CXR/Nt-proBNP). Lung ultrasound was performed at bedside by the clinician with a curvilinear probe in eight zones looking for 3 or more B-lines to indicate a positive exam. After the lung ultrasound or CXR/Nt-proBNP a new presumptive diagnosis was recorded by the provider. Afterwards a CXR and Nt-proBNP were conducted on the lung ultrasound group. After hospital discharge two expert intensivists/emergency physicians (blinded to LUS results) reviewed the medical record and determined if the patient fit the diagnosis/definition of acute decompensated heart failure (based on European Society of Cardiology). 

The Findings:

The study found that the accuracy of clinical evaluation alone in the identification of acute decompensated heart failure was not significantly different in the groups. It also showed that combining CXR/Nt-proBNP with clinical evaluation was not statistically significant for sensitivity or specificity however the combined group with lung ultrasound was statistically significant. The lung ultrasound group also was showed to have a higher net reclassification improvement verses CXR/Nt-proBNP (8.9% vs. 4.5% for ADHF and non ADHF respectively). The median time needed to formulate the diagnostic hypothesis (measured from when the first diagnostic hypothesis was recorded to when the integrated diagnosis taking test results into account) was 104.5min in the CXR/Nt-proBNP group vs. 5min in the lung ultrasound group. The lung ultrasound arm was shown to be more sensitive (84.7 vs. 81.0), more specific (91.0 vs. 88.8) and had a higher positive predictive value (89.7 vs. 81.8) in the clinical evaluation along with the integrated evaluation. 

The Takeaway:

Overall this study demonstrated that in adult patients presenting to the emergency department with acute dyspnea, a diagnostic protocol based on integration of lung ultrasound and clinical assessment is more accurate than currently recommended CXR/NT-proBNP. Lung ultrasound can increase sensitivity and specificity of diagnosing acute decompensated heart failure. It can also improve time to diagnosis of acute decompensated heart failure when compared to only using CXR/NT-proBNP. 

A preliminary study on the ultrasonic manifestations of peripulmonary lesions of non-critical novel coronavirus pneumonia (COVID-19)

Andrew Lee, DO | EM PGY3

The Article: 

Huang, Yi, et al. “A Preliminary Study on the Ultrasonic Manifestations of Peripulmonary Lesions of Non-Critical Novel Coronavirus Pneumonia (COVID-19).” SSRN Electronic Journal, 2020, doi:10.21203/ssrn.3544750.

The Idea:

To observe the ultrasonic manifestations of peripulmonary lesions in non-critical COVID-19 so as to provide reference for clinical diagnosis and efficacy evaluation 

The Study:

A retrospective analysis of the color doppler ultrasound information of peripulmonary lesions in early and progressive COVID-19. Ultrasound findings of twenty patents (11 male, 9 female) who had the following criteria were involved in the analysis:

• history of travel in Wuhan, China or areas with COVID-19 transmission within 14 days of prior to onset of illness

• exposure to patients with fever or respiratory symptoms who were from Wuhan or other areas with COVID-19 transmission within 14 days prior to the onset of disease,

• Clusters or epidemiological associations with COVID-19 infections

• Fever

• Radiographic features of pneumonia with ground glass opacity or patchy consolidation in the lungs

• Normal or decreased WBC count

• Decreased lymphocyte count in the early stage of disease

• Positive nucleic acid of SARS-Cov-2 detected by real time fluorescence

• Highly homologous virus gene sequencing with SARS-Cov-2

Each lung was divided into six sonographic regions: an upper and lower anterior area, an upper and lower axillary area, and an upper and lower posterior area. The areas were scanned by two physicians, each with more than 5 years of ultrasound experience, with a linear array probe or with a convex array probe. They observed for:

• A smooth, continuous, or interrupted pleural line

• The distribution, number, and fusion of B lines in the peripulmonary area of both lungs

• The echo, location, shape and range of peripulmonary lesions

• The presence of absence of air bronchograms in the consolidation

• The presence of absence of blood flow in the consolidation

• The presence of absence of pleural effusion around the lesion

• The presence of absence of localized pleural thickening

The Findings:

Many of the sonographic manifestations seen with typical pneumonia were identified, such as interrupted pleural lines, B lines, air bronchograms, and subpleural consolidations. Peripulmonary lesions were mostly located in the posterior fields of both lungs. Multiple B lines under the pleural line were visible. Unique to COVID-19 patients, B lines could be discontinuous or continuous, however, they were more likely to be continuous, fixed and fused (waterfall sign) rather than discontinuous as is typically seen in cardiogenic pulmonary edema. Localized pleural thickening with a local pleural effusion around the subpleural lesion was identified. Also unique to COVID-19 patients, color doppler showed poor blood flow in the subpleural consolidation.

The Takeaway: 

Ultrasound can show typical findings associated with any pneumonia in COVID-19 pneumonia. However, if poor blood flow in the subpleural consolidation is found by doppler and B lines are fused, this may suggest atypical/COVID pneumonia. However, ultrasound is limited to evaluation of peripulmonary lesions, and cannot replace CT in evaluation of intrapulmonary and apical lesions.

Pre-hospital lung ultrasound for cardiac heart failure and COPD: is it worthwhile?

Jacob Finkle, DO | EM PGY 4 

The Article:  “Pre-hospital lung ultrasound for cardiac heart failure and COPD: is it worthwhile?” Mirko Zanatta* , Piero Benato, Sigilfredo De Battisti, Concetta Pirozzi, Renato Ippolito and Vito Cianci. Zanatta et al. Crit Ultrasound J (2018) 

The Idea 

Ultrasound is a known and proven useful commodity in the Emergency Department. It’s ability to rapidly diagnose and decrease length of stay in the Emergency Department is proven. Pre-hospital US is considered one of the top five research priorities according to the opinion of consensus meeting of a European expert panel to identify which US examinations can be reliably transferred to the pre hospital setting. Lung US has the ability to rapidly identify the lung profile - the identification of, interstitial edema, pleural effusions and the diagnosis of pneumothorax. Given that a rapid two point technique is often sufficient to rule in or rule out lung pathology, the use of Lung US could be extremely useful in the pre-hospital setting. 

The Study 

The study was a case controlled study in the pre hospital emergency setting in Italy performed between January 2016 and December 2016. The area included a major emergency department with 35,000 visits and a minor emergency department with 6,000 visits. Each of these hospitals had an emergency physician led advanced life support ambulance. The larger hospital’s ambulance contained a portable US sonosite. The smaller hospital was the control. The inclusion criteria was severe dyspnea as prevalent symptom most likely caused by CHF or COPD exacerbation and pulse oximetry was required to be less than 90%. The exclusion criteria were other causes of respiratory failure and patients less than 18 years old. Lung US was performed after clinical exam with a rapid two point technique in the upper anterior and basal lateral areas. The type of lung profile was recorded as type A - dry lung or type B - wet lung and the presence was noted as well. An interstitial syndrome was defined by the presence of > 3 B lines between two ribs in two or more regions bilaterally. The convex probe was used using the same US device. Sometimes a linear probe was used. In hospital assessment included a PE, lab work, blood gas, CXR, US, cardiac ECHO, and IVC evaluation. The in-hospital lung US was blinded with respect to the pre-hospital one and was performed early upon arrival. The study aimed to evaluate the feasibility of pre-hosptial lung US and improvement of both pharmacological and oxygen administration in the ambulance and of the blood gases analysis at arrival to the ED. The hospitalization rate and time spent in the ED between the two groups was also evaluated. 

The Findings 

A total of 30 patients were recruited affected by non traumatic respiratory failure. There were 12 subjects whose respiratory failure were caused by CHF and 18 by COPD who underwent US management. This was compared to 30 other subjects managed without ultrasound. The characteristics of the groups were all similar in terms of age, gender, type of respiratory failure, and pulse ox value. Pre hospital lung US was accurate for identifying the correct lung profile. B lines had a high sensitivity (100%) and specificity (94.4%), a high PPV and NPV (92.3 and 100%) for CHF. Pleural effusions diagnosis was not as accurate as B lines for CHF - sensitivity 83%, specificity 58.3 %, PPV 75%, NPV 70%. The number of patients who received an appropriate pharmacological treatment was higher in the US group, especially in those who were diagnosed with lung group A - dry lung indicating non cardiogenic cause of respiratory failure. The mean dose of furosemide was significantly lower than those in the non US group and those diagnosed with lung group B - wet lung the mean dosage of furosemide was large than the US group. Steroid administration was comparable between A and B lung groups. CPAP was used more in patients with an A profile and employed more in the US group. Blood gases analysis was not significantly different between the groups, nor were there any significant differences between the other lab work. The hospitalization rate was comparable between the 2 groups, however there was a reduction in overall time spent in the ED by the US group but the data didn ot reach a full statistical significance. 

The Takeaway 

Ultrasound in the pre-hospital setting has great potential and utility. Specifically relating to lung US it is easy and feasible. The learning curve is rapid. The differentiation between COPD and CHF can easily be made with the use of US and can help shed light on the etiology of the undifferentiated respiratory distress, potentially decrease harmful doses of non indicated medications in the field and reduce overall time spent in the ED. The study was small but promising, however larger studies should be performed to establish use of US in the pre hospital setting.