Thoracic ultrasound

Utilization of Point-of-Care Ultrasound as an Imaging Modality in the Emergency Department: A Systematic Review and Meta-Analysis

Point-of-care ultrasound (POCUS) is an imaging modality that has become a fundamental part of clinical care provided in the emergency department (ED). The applications of this tool in the ED have ranged from resuscitation, diagnosis, and therapeutic to procedure guidance. This review aims to summarize the evidence on the use of POCUS for diagnosis and procedure guidance. To achieve this, CrossRef, PubMed, Cochrane Library, Web of Science, and Google Scholar databases were extensively searched for studies published between January 2000 and November 2023. Additionally, the risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 (for studies on the diagnostic role of POCUS) and Cochrane Risk of Bias tool (for studies on the use of POCUS for procedure guidance). Furthermore, diagnostic accuracy outcomes were pooled using STATA 16 software (StatCorp., College Station, TX, USA), while outcomes related to procedure guidance were pooled using the Review Manager software. The study included 81 articles (74 evaluating the diagnostic application of POCUS and seven evaluating the use of POCUS in guiding clinical procedures). In our findings sensitivities and specificities for various conditions were as follows: appendicitis, 65% and 89%; hydronephrosis, 82% and 74%; small bowel obstruction, 93% and 82%; cholecystitis, 75% and 96%; retinal detachment, 94% and 91%; abscess, 95% and 85%; foreign bodies, 67% and 97%; clavicle fractures, 93% and 94%; distal forearm fractures, 97% and 94%; metacarpal fractures, 94% and 92%; skull fractures, 91% and 97%; and pleural effusion, 91% and 97%. A subgroup analysis of data from 11 studies also showed that the two-point POCUS has a sensitivity and specificity of 89% and 96%, while the three-point POCUS is 87% sensitive and 92% specific in the diagnosis of deep vein thrombosis. In addition, the analyses showed that ultrasound guidance significantly increases the overall success rate of peripheral venous access (p = 0.02) and significantly reduces the number of skin punctures (p = 0.01) compared to conventional methods. In conclusion, POCUS can be used in the ED to diagnose a wide range of clinical conditions accurately. Furthermore, it can be used to guide peripheral venous access and central venous catheter insertion.

Global Ultrasound Check for the Critically lll (GUCCI)-a new systematized protocol unifying point-of-care ultrasound in critically ill patients based on clinical presentation

Ultrasound technology is an essential tool in the management of critically ill patients. Point-of-care ultrasonography (POCUS) enables data collection from different anatomic areas to achieve the most probable diagnosis and administer the right therapy at the right time. Despite the increasing utilization of POCUS, there is still a lack of standards to establish how to use different bedside ultrasound protocols, and it is imperative to develop a unifying protocol. Thus, the aim of this paper is to establish a new systematized approach that can be adopted by all physicians to implement POCUS for critically ill patient management. To achieve this, we propose a new systematized approach—Global Ultrasound Check for the Critically Ill (GUCCI)—that integrates multiple protocols. This protocol is organized based on three syndromes (acute respiratory failure, shock, and cardiac arrest) and includes ultrasound-guided procedures.

Integrating point-of-care ultrasound in the ED evaluation of patients presenting with chest pain and shortness of breath

OBJECTIVE

The differential diagnoses of patients presenting with chest pain (CP) and shortness of breath (SOB) are broad and non-specific. We aimed to 1) determine how use of point-of-care ultrasound (POCUS) impacted emergency physicians' differential diagnosis, and 2) evaluate the accuracy of POCUS when compared to chest radiograph (CXR) and composite final diagnosis.

METHODS

We conducted a prospective observational study in a convenience sample of patients presenting with CP and SOB to the Emergency Department (ED). Treating physicians selected possible diagnoses from a pre-indexed list of possible diagnoses of causes of CP and SOB. The final composite diagnosis from a chart review was determined as the reference standard for the diagnosis. The primary analysis involved calculations of sensitivity and specificity for POCUS identifiable diagnoses in detecting cause of CP and SOB. Additional comparative accuracy analysis with CXRs were conducted.

RESULTS

128 patients with a mean age of 64 ± 17 years were included in the study. Using a reference standard of composite final diagnoses, POCUS had equal or higher specificity to CXR for all indications for which it was used, except for pneumonia. POCUS correctly identified all patients with pneumothorax, pleural effusion and pericardial effusion. In patients with a normal thoracic ultrasound, CXR never provided any actionable clinical information. Adding POCUS to the initial evaluation causes a significant narrowing of the differential diagnoses in which the median differential diagnosis from 5 (IQR 3-6) to 3 (IQR 2-4) p < 0.001.

CONCLUSION

In evaluation of patients with CP and SOB, POCUS is a highly feasible diagnostic test which can assist in narrowing down the differential diagnoses. In patients with a normal thoracic ultrasound, the added value of a CXR may be minimal.

Ultrasound in the management of pleural disease

INTRODUCTION

Pleural disease encompasses a large range of conditions, is a common presentation to the acute medical take and often requires comprehensive investigation and treatment. Ultrasound is well recognised as a useful investigative tool in pleural disease especially in the field of pleural effusion, pleural thickening and interventional procedures. Thoracic ultrasound (TUS) has gained widespread use by physicians as evidence has shown a reduced rate of complications when performing pleural procedures with ultrasound guidance. Areas covered: This article will review studies assessing the role of TUS in the management of pleural disease and examine ongoing research into how TUS could advance our knowledge and understanding over the next decade. Expert commentary: Physician lead thoracic ultrasound has become commonplace over the last decade, and now represents a minimum standard of safety in conducting the majority of 'bedside' pleural procedures. The current evidence points to important diagnostic and procedural roles of the use of bedside thoracic ultrasound. In the future, research developments are likely to lead to the use of thoracic ultrasound in prognostication, targeted treatment and understanding pathogenesis in pleural disease.

Incremental value of thoracic ultrasound in intensive care units: Indications, uses, and applications

Emergency physicians are required to care for unstable patients with life-threatening conditions, and thus must make decisions that are both quick and precise about unclear clinical situations. There is increasing consensus in favor of using ultrasound as a real-time bedside clinical tool for clinicians in emergency settings alongside the irreplaceable use of historical and physical examinations. B-mode sonography is an old technology that was first proposed for medical applications more than 50 years ago. Its application in the diagnosis of thoracic diseases has always been considered limited, due to the presence of air in the lung and the presence of the bones of the thoracic cage, which prevent the progression of the ultrasound beam. However, the close relationship between air and water in the lungs causes a variety of artifacts on ultrasounds. At the bedside, thoracic ultrasound is based primarily on the analysis of these artifacts, with the aim of improving accuracy and safety in the diagnosis and therapy of the various varieties of pulmonary pathologic diseases which are predominantly “water-rich” or “air-rich”. The indications, contraindications, advantages, disadvantages, and techniques of thoracic ultrasound and its related procedures are analyzed in the present review.

Emergency Thoracic US: The Essentials

Acute thoracic symptoms are common among adults visiting emergency departments in the United States. Adults with these symptoms constitute a large burden on the overall resources used in the emergency department. The wide range of possible causes can make a definitive diagnosis challenging, even after clinical evaluation and initial laboratory testing. In addition to radiography and computed tomography, thoracic ultrasonography (US) is an alternative imaging modality that can be readily performed in real time at the patient's bedside to help diagnose many thoracic diseases manifesting acutely and in the trauma setting. Advantages of US include availability, relatively low cost, and lack of ionizing radiation. Emergency thoracic US consists of two main parts, lung and pleura US and focused cardiac US, which are closely related. Acoustic mismatches among aerated lungs, pleura, chest wall, and pathologic conditions produce artifacts useful for diagnosis of pneumothorax and pulmonary edema and help in detection of subpleural, pleural, and chest wall pathologic conditions such as pneumonia, pleural effusion, and fractures. Visual assessment of cardiac contractility and detection of right ventricular dilatation and pericardial effusion at focused cardiac US are critical in patients presenting with acute dyspnea and trauma. Additional US examinations of the inferior vena cava for noninvasive volume assessment and of the groin areas for detection of deep venous thrombosis are often performed at the same time. This multiorgan US approach can provide valuable information for emergency treatment of both traumatic and nontraumatic thoracic diseases involving the lungs, pleura, chest wall, heart, and vascular system. Online supplemental material is available for this article. (©)RSNA, 2016.

[Basic lung ultrasound. Part 1. Normal lung ultrasound and diseases of the chest wall and the pleura]

Lung ultrasound has become part of the diagnostic armamentarium in Resuscitation and Recovery Units with an enormous potential due to its many advantages: capacity to diagnose more precisely than conventional radiology, earlier diagnosis, convenience due to being able to performed at the bedside, possibility of being performed by one person, absence of ionising radiation, and, due to its dynamic character, is capable of transforming into physiological processes that were once static images. However, lung ultrasound also has its limitations and has a learning curve. The aim of this review is to provide sufficient information that may help the specialist starting in this field to approach the technique with good possibilities of success. To do this, the review is structured into two parts. In the first, the normal ultrasound of the chest wall is presented, as well as the pleura, diaphragm, and lung parenchyma, and the most important pathologies of the chest wall (rib fractures and hematomas), the pleura (pleural effusion and its different types, and pneumothorax), and the diaphragm (hypokinesia and paralysis). In the second part, parenchymal diseases will be approached and will include, atelectasis, pneumonia and abscess, lung oedema, respiratory distress, and pulmonary thromboembolism.

Usefulness of lung ultrasound in the diagnosis of community-acquired pneumonia in children

BACKGROUND

Pneumonia is a life-threatening disease in children. With the current lack of universal diagnostic criteria, the diagnosis is usually made on clinical manifestations and findings from chest radiographs. Ultrasonography has recently been applied to the detection of pulmonary diseases. However, few data have been published showing its effectiveness in detecting pneumonia in children. The objective of this study was to determine the power of lung ultrasonography (LUS) for the diagnosis of pneumonia in children.

METHODS

This retrospective study was carried out by reviewing medical records. Patients admitted to a pediatric ward with a diagnosis of pneumonia from June 1, 2010 to December 31, 2012 were enrolled in this study. Personal information, laboratory data, characteristics on LUS scan, and the results of chest radiography and LUS were collected. We compared the detection rate of pneumonia by chest radiography and LUS. LUS scans were followed up in 23 patients during the progression of their disease.

RESULTS

A total of 163 patients was enrolled. Chest radiography was able to detect pneumonia in 152 patients, whereas LUS detected pneumonia in 159 patients. In LUS, the positive rates of the comet-tail sign, air bronchograms, fluid bronchograms, vascular pattern within the consolidation, and pleural effusion were 50.9%, 93.7%, 20.1%, and 28.9%, respectively. During follow up, the average size of the pneumonia patch in 23 patients decreased from 10.9 ± 8.7 cm(2) to 5.5 ± 8.2 cm(2), and finally to 2 ± 1.9 cm(2) on Day 1, Days 3-5 and Days 7-14, respectively.

CONCLUSION

LUS is a sensitive diagnostic tool with which to identify pneumonia in children. It is also useful in following up the progress of pneumonia. We suggest that LUS is a complementary tool to chest radiography in the diagnosis of pneumonia in children and that the follow up of pneumonia by LUS can reduce the exposure of children to ionizing radiation.

Can ultrasound guidance reduce the risk of pneumothorax following thoracentesis?

OBJECTIVE:

Thoracentesis is one of the bedside procedures most commonly associated with iatrogenic complications, particularly pneumothorax. Various risk factors for complications associated with thoracentesis have recently been identified, including an inexperienced operator; an inadequate or inexperienced support team; the lack of a standardized protocol; and the lack of ultrasound guidance. We sought to determine whether ultrasound-guided thoracentesis can reduce the risk of pneumothorax and improve outcomes (fewer procedures without fluid removal and greater volumes of fluid removed during the procedures). In our comparison of thoracentesis with and without ultrasound guidance, all procedures were performed by a team of expert pulmonologists, using the same standardized protocol in both conditions.

METHODS:

A total of 160 participants were randomly allocated to undergo thoracentesis with or without ultrasound guidance (n = 80 per group). The primary outcome was pneumothorax following thoracentesis. Secondary outcomes included the number of procedures without fluid removal and the volume of fluid drained during the procedure.

RESULTS:

Pneumothorax occurred in 1 of the 80 patients who underwent ultrasound-guided thoracentesis and in 10 of the 80 patients who underwent thoracentesis without ultrasound guidance, the difference being statistically significant (p = 0.009). Fluid was removed in 79 of the 80 procedures performed with ultrasound guidance and in 72 of the 80 procedures performed without it. The mean volume of fluid drained was larger during the former than during the latter (960 ± 500 mL vs. 770 ± 480 mL), the difference being statistically significant (p = 0.03).

CONCLUSIONS:

Ultrasound guidance increases the yield of thoracentesis and reduces the risk of post-procedure pneumothorax. (Chinese Clinical Trial Registry identifier: ChiCTR-TRC-12002174 [http://www.chictr.org/en/])

Ultrasound artifacts mimicking pleural sliding after pneumonectomy

STUDY OBJECTIVE

To determine the presence of pleural sliding on chest ultrasonography (US) in a series of patients admitted to a surgical intensive care unit (SICU).

DESIGN

Prospective, observational study.

SETTING

16-bed SICU of a University hospital.

PATIENTS

8 patients (7 men, 1 woman), aged 64 - 73 years (mean 67.5 yrs). Seven patients underwent pneumonectomy for pulmonary neoplasms; one patient underwent an atypical lung resection after having undergone a pneumonectomy one year before.

INTERVENTIONS

None.

MEASUREMENTS

Chest ultrasounds were performed during mechanical ventilation and spontaneous ventilation after endotracheal tube removal. In both examinations, pleural sliding was searched bilaterally in brightness mode (B-mode) and motion mode (M-mode) on the anterior thoracic wall in the least gravitationally dependent areas.

RESULTS

During mechanical ventilation, pleural sliding was always absent on the side of the pneumonectomy and present on the other side. During spontaneous ventilation, some artifacts mimicking pleural sliding were noted on the side of the pneumonectomy both in B-mode and M-mode (presence of the seashore sign) in all patients, except for the one patient who had undergone a pneumonectomy one year earlier. Those artifacts became more pronounced during deep breaths.

CONCLUSIONS

Ultrasound artifacts mimicking pleural sliding may be observed in the absence of the lung and may originate from the activity of intercostal muscles since they become more evident during deep breathing.

Ultrasound for the Detection of Pleural Effusions and Guidance of the Thoracentesis Procedure

Objective. To review the use of ultrasound for the detection of pleural effusions and guidance of the thoracentesis procedure. Methods. Two clinical cases will be presented in which ultrasound proved beneficial in guiding the diagnosis and management of patients with pleural effusions and respiratory distress. The ultrasound techniques for the evaluation of pleural effusions and performance of the thoracentesis procedure are discussed. A review of the most current literature follows to present the known diagnostic and safety benefits of ultrasound guidance for thoracentesis. Conclusions. Ultrasound improves the diagnostic accuracy for the detection of pleural effusions over standard chest radiographs. Ultrasound can also diagnose a complicated pleural effusion that may be at higher risk for an adverse outcome during a thoracentesis. Optimally, thoracentesis should be performed under direct ultrasound guidance to decrease the complication rate and improve patient safety.