Role of thoracic ultrasound in diagnosis of pulmonary and pleural diseases in critically ill patients

Advancement in pleura effusion diagnosis: a systematic review and meta-analysis of point-of-care ultrasound versus radiographic thoracic imaging

BACKGROUND

Pleural effusion is a fluid buildup in the pleural space that mostly result from congestive heart failure, bacterial pneumonia, malignancy, and pulmonary embolism. The diagnosis of this condition can be challenging as it presents symptoms that may overlap with other conditions; therefore, imaging diagnostic tools such as chest x-ray/radiograph (CXR), point-of-care ultrasound (POCUS), and computed tomography (CT) have been employed to make an accurate diagnosis. Although POCUS has high diagnostic accuracy, it is yet to be considered a first-line diagnostic tool as most physicians use radiography. Therefore, the current meta-analysis was designed to compare POCUS to chest radiography.

METHODS

n extended search for studies related to our topic was done on five electronic databases, including PubMed, Medline, Embase, Scopus, and Google Scholar. A quality assessment using the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) was performed on all eligible articles obtained from the databases. Moreover, the diagnostic accuracy of POCUS and CXR was performed using STATA 16 software.

RESULTS

Our search yielded 1642 articles, of which only 18 were eligible for inclusion and analysis. The pooled analysis showed that POCUS had a higher diagnostic accuracy compared to CXR (94.54% (95% CI 91.74-97.34) vs. 67.68% (95% CI 58.29-77.08) and 97.88% (95% CI 95.77-99.99) vs. 85.30% (95% CI 80.06-90.54) sensitivity and specificity, respectively). A subgroup analysis based on the position of patients during examinations showed that POCUS carried out in supine and upright positions had higher specificity than other POCUS positions (99%). In comparison, lateral decubitus CXR had higher sensitivity (96%) and specificity (99%) than the other CXR positions. Further subgroup analyses demonstrated that CXR had higher specificity in studies that included more than 100 patients (92.74% (95% CI 85.41-100). Moreover, CXR tends to have a higher diagnostic accuracy when other CXR positions are used as reference tests (93.38% (95% CI 86.30-100) and 98.51% (95% CI 94.65-100) sensitivity and specificity, respectively).

CONCLUSION

POCUS as an imaging modality has higher diagnostic accuracy than CXR in detecting pleural effusion. Moreover, the accuracy is still high even when performed by physicians with less POCUS training. Therefore, we suggest it is considered a first-line imaging tool for diagnosing pleural effusion at the patients' bedside.

Pleural effusion and thoracentesis in ICU patients: A longitudinal observational cross-sectional study

BACKGROUND

Pleural effusion is common among patients in the intensive care unit (ICU) but reported prevalence varies. Thoracentesis may improve respiratory status, however, indications for this are unclear. We aimed to explore prevalence, development, and progression of pleural effusion, and the incidence and effects of thoracentesis in adult ICU patients.

METHODS

This is a prospective observational study utilizing repeated daily ultrasonographic assessments of pleurae bilaterally, conducted in all adult patients admitted to the four ICUs of a Danish university hospital throughout a 14-day period. The primary outcome was the proportion of patients with ultrasonographically significant pleural effusion (separation between parietal and visceral pleurae >20 mm) in either pleural cavity on any ICU day. Secondary outcomes included the proportion of patients with ultrasonographically significant pleural effusion receiving thoracentesis in ICU, and the progression of pleural effusion without drainage, among others. The protocol was published before study initiation.

RESULTS

In total, 81 patients were included of which 25 (31%) had or developed ultrasonographically significant pleural effusion. Thoracentesis was performed in 10 of these 25 patients (40%). Patients with ultrasonographically significant pleural effusion, which was not drained, had an overall decrease in estimated pleural effusion volume on subsequent days.

CONCLUSION

Pleural effusion was common in the ICU, but less than half of all patients with ultrasonographically significant pleural effusion underwent thoracentesis. Progression of pleural effusion without thoracentesis showed reduced volumes on subsequent days.

EFSUMB Clinical Practice Guidelines for Point-of-Care Ultrasound: Part One (Common Heart and Pulmonary Applications) LONG VERSION

AIMS

 To evaluate the evidence and produce a summary and recommendations for the most common heart and lung applications of point-of-care ultrasound (PoCUS).

METHODS

 We reviewed 10 clinical domains/questions related to common heart and lung applications of PoCUS. Following review of the evidence, a summary and recommendation were produced, including assignment of levels of evidence (LoE) and grading of the recommendation, assessment, development, and evaluation (GRADE). 38 international experts, the expert review group (ERG), were invited to review the evidence presented for each question. A level of agreement of over 75 % was required to progress to the next section. The ERG then reviewed and indicated their level of agreement regarding the summary and recommendation for each question (using a 5-point Likert scale), which was approved if a level of agreement of greater than 75 % was reached. A level of agreement was defined as a summary of "strongly agree" and "agree" on the Likert scale responses.

FINDINGS AND RECOMMENDATIONS

 One question achieved a strong consensus for an assigned LoE of 3 and a weak GRADE recommendation (question 1). The remaining 9 questions achieved broad agreement with one assigned an LoE of 4 and weak GRADE recommendation (question 2), three achieving an LoE of 3 with a weak GRADE recommendation (questions 3-5), three achieved an LoE of 3 with a strong GRADE recommendation (questions 6-8), and the remaining two were assigned an LoE of 2 with a strong GRADE recommendation (questions 9 and 10).

CONCLUSION

 These consensus-derived recommendations should aid clinical practice and highlight areas of further research for PoCUS in acute settings.

COVID-19 in the radiology department: What radiographers need to know

OBJECTIVES

The aim is to review current literature related to the diagnosis, management, and follow-up of suspected and confirmed Covid-19 cases.

KEY FINDINGS

Medical Imaging plays an important auxiliary role in the diagnosis of Covid-19 patients, mainly those most seriously affected. Practice differs widely among different countries, mainly due to the variability of access to resources (viral testing and imaging equipment, specialised staff, protective equipment). It has been now well-documented that chest radiographs should be the first-line imaging tool and chest CT should only be reserved for critically ill patients, or when chest radiograph and clinical presentation may be inconclusive.

CONCLUSION

As radiographers work on the frontline, they should be aware of the potential risks associated with Covid-19 and engage in optimal strategies to reduce these. Their role in vetting, conducting and often reporting the imaging examinations is vital, as well as their contribution in patient safety and care. Medical Imaging should be limited to critically ill patients, and where it may have an impact on the patient management plan.

IMPLICATIONS FOR PRACTICE

At the time of publication, this review offers the most up-to-date recommendations for clinical practitioners in radiology departments, including radiographers. Radiography practice has to significantly adjust to these new requirements to support optimal and safe imaging practices for the diagnosis of Covid-19. The adoption of low dose CT, rigorous infection control protocols and optimal use of personal protective equipment may reduce the potential risks of radiation exposure and infection, respectively, within Radiology departments.

Assessing Extravascular Lung Water in Critically Ill Patients Using Lung Ultrasound: A Systematic Review on Methodological Aspects in Diagnostic Accuracy Studies

Lung ultrasound (LUS) is a non-invasive bedside method used to quantify extravascular lung water (EVLW). To evaluate the methodology and diagnostic accuracy of LUS in studies assessing EVLW in intensive care unit patients, PubMed and Embase were searched for studies comparing LUS with imaging modalities. In 14 relevant studies a wide variety of equipment used and training of examiners were noted. Four scoring systems were reported: (i) a binary score (the presence of three or more B-lines); (ii) a categorical score; (iii) a numerical score; (iv) a quantitative LUS score using software. The diagnostic accuracy of LUS varied: sensitivity ranged from 50%-98%, specificity from 76%-100% and r² from 0.20-0.91. Methodology and diagnostic accuracy varies substantially in published reports. Further research is needed to correlate methodological factors with diagnostic accuracy. Hospitals should standardize LUS methodology. Consensus is needed to harmonize LUS methodology for lung water assessment.

The lung ultrasound: facts or artifacts? In the era of COVID-19 outbreak

Ultrasound is the most disruptive innovation in intensive care life, above all in this time, with a high diagnostic value when applied appropriately. In recent years, point-of-care lung ultrasound has gained significant popularity as a diagnostic tool in the acutely dyspnoeic patients. In the era of Sars-CoV-2 outbreak, lung ultrasound seems to be strongly adapting to the follow-up for lung involvement of patients with ascertaining infections, till to be used, in our opinion emblematically, as a screening test in suspected patients at the emergency triage or at home medical visit. In this brief review, we discuss the lung ultrasound dichotomy, certainties and uncertainties, describing its potential role in validated clinical contexts, as a clinical-dependent exam, its limits and pitfalls in a generic and off-label clinical context, as a virtual anatomical-dependent exam, and its effects on the clinical management of patients with COVID-19.

Sonography of the Lungs: Diagnosis and Surveillance of Patients With COVID-19

The outbreak of a novel coronavirus (COVID-19) with symptoms that mimic bronchitis and other chest infections has created a need for quick diagnosis to prevent disease spread. Traditionally, computed tomography (CT) has been used as the primary method to identify infection and staging of the virus. While effective, repeated use of ionizing radiation, particularly in susceptible patient populations, can add risk as the disease is monitored through full recovery. Sonography of the chest may be a viable alternative for diagnosis and monitoring of COVID-19. In addition, new technology such as the remote robotic ultrasound equipment being used at Zhejiang Provincial People’s Hospital in Hangzhou, China, has the potential to facilitate sonographic evaluation with minimal disease exposure to the sonologist and to other patients by eliminating the need for patient transport to imaging facilities. Additional studies will need to be conducted to evaluate the effectiveness of sonography versus other imaging modalities in the diagnosis and treatment of COVID-19 and other novel diseases.