Pleural effusions

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.

Efficacy of Computed Tomography (CT) Attenuation Values and CT Findings in the Differentiation of Pleural Effusion

Background

The aim of this study was to investigate the efficacy of computed tomography (CT) findings for characterizing pleural effusions with the use of attenuation values.

Material/Methods

One hundred and twenty eight patients with pleural effusions on thoracic CT who underwent thoracentesisis within two weeks were studied. Pleural effusions were classified as exudates or transudates according to the Light’s criteria. A region of interest was placed for the measurement of Hounsfield Unit (HU) values in the area of the greatest amount of effusion on each slice of the three slices used. CT features that were evaluated for distinguishing pleural exudates from transudates included pleural nodules, pleural thickening and loculation.

Results

Thirty three (26%) of the 128 pleural effusions were transudates and 95 (74%) were exudates. The mean HU values of the exudates (8.82±7.04) were significantly higher than those of the transudates (2.91±8.53), (p<0.001). No statistically significant difference was found between transudate and exudate patients in terms of pleural thickness, pleural nodules and loculation (p>0.05).

Conclusions

HU values can help in differentiating exudative pleural effusions from transudative pleural effusions. Because of overlapping HU values, correlation with clinical findings is essential.

Differences Between Radiologically Confirmed Pneumonia With and Without Pleural Fluid in Hospitalized Children Younger Than 5 Years in Southern Israel

We compared demographic and clinical characteristics of pneumonia with and without pleural fluid (PF and Pn, respectively) in hospitalized children younger than 5 years in southern Israel, between 2002 and 2011. Overall, 108 PF and 5811 Pn episodes were recorded. Children with PF were older. Prematurity (6.6% vs 14.0%) and asthma (9.9% vs 23.5%) were less common in PF. Mean temperature and saturation were higher in PF while hemoglobin and sodium levels were lower in PF compared with Pn. Nasal washes were obtained in 30.6% and 39.9% of PF and Pn episodes, respectively, with respiratory syncytial virus identified more commonly in Pn (24.2% vs 42.3%). Streptococcus pneumoniae was identified in 5.2% and 0.9% of blood cultures in PF and Pn, respectively. In conclusion, PF differed from Pn in demographic and clinical characteristics, possibly due to differences in etiology. Although both diseases are considered bacterial, a high proportion of viral etiology was found in both, especially in Pn.

Frequency of pleural effusion in acute bronchiolitis and its effect on prognosis

AIM

To analyze the frequency of pleural effusion and the effect on prognosis in children with acute bronchiolitis.

METHODS

A total of 69 infants aged 1-24 months with acute bronchiolitis were studied between September 2009 and December 2010. All patients'age, sex, breastfeeding duration, exposure to smoking, history of using vitamin D, symptoms duration, physical examination and laboratory findings were recorded. Bronchiolitis score and predisposing factors that influence the disease process were determined. Thorax ultrasonography was carried out in all patients, who were evaluated on the 3rd and 7th day of the treatment.

RESULTS

Mean age of patients (43 boys, 26 girls) was 11.97 ± 0.69 months (median 11 months). Breastfeeding duration was 8.26 ± 0.56 months (median 8 months). According to bronchiolitis score, 52 patients (75.4%) had mild and moderate bronchiolitis and 17 (24.6%) had severe bronchiolitis; 34 patients (49.2%) had pleural effusion. There was no relation between pleural effusion and symptoms. Frequency of pleural effusion was significantly higher in patients with risk factors.

CONCLUSIONS

This study demonstrated that most of the acute bronchiolitis cases in the infants studied were accompanied by pleural effusion. Pleural effusion in acute bronchiolitis had no effects on prognosis.

A case of spontaneous chylothorax in an adolescent

We discuss an male adolescent who presented to the emergency department with fever and respiratory distress. He was subsequently diagnosed with spontaneous chylothorax. We review his clinical presentation and diagnostic and therapeutic interventions and provide a discussion of the subject.