In patients with unilateral pleural effusion, restricted lung inflation is the principal predictor of increased dyspnoea

[Diaphragmatic ultrasonography for the pulmonologist: Technique and clinical use]

INTRODUCTION

Ultrasonography is an emerging tool that helps to assess diaphragmatic function. It is now widely used in ICUs to predict weaning from mechanical ventilation. Ultrasonography is readily available, harmless (no radiation), and repeatable with good interoperator reproducibility. Over the past few years, ultrasonography has seen increasing use in patients with chronic pulmonary pathologies.

STATE OF THE ART

The aim of this review is (1) to describe the ultrasound techniques used to assess diaphragmatic excursion and thickening, (2) to indicate the expected, normal values in healthy patients, and (3) to summarize the main findings and clinical applications in treatment of chronic respiratory disorders.

CONCLUSIONS

Chronic pulmonary diseases are associated with diaphragmatic dysfunction that can be assessed with ultrasound. Diaphragmatic dysfunction is primary in neuromuscular disorders and secondary to respiratory disease in other chronic pulmonary conditions (COPD, ILD). Ultrasound is correlated with the severity of the underlying disease (functional and clinical parameters).

PERSPECTIVES

The prognostic interest of diaphragm ultrasonography remains to be established, after which its utilization should become routine.

Malignant pleural disease

Malignant pleural disease represents a growing healthcare burden. Malignant pleural effusion affects approximately 1 million people globally per year, causes disabling breathlessness and indicates a shortened life expectancy. Timely diagnosis is imperative to relieve symptoms and optimise quality of life, and should give consideration to individual patient factors. This review aims to provide an overview of epidemiology, pathogenesis and suggested diagnostic pathways in malignant pleural disease, to outline management options for malignant pleural effusion and malignant pleural mesothelioma, highlighting the need for a holistic approach, and to discuss potential challenges including non-expandable lung and septated effusions.

Breathlessness with Pleural Effusion: What Do We Know?

Breathlessness is the most common symptom in individuals with pleural effusion and is often disabling. The pathophysiology of breathlessness associated with pleural effusion is complex. The severity of breathlessness correlates weakly with the size of the effusion. Improvements in ventilatory capacity following pleural drainage are small and correlate poorly with the volume of fluid drained and improvements in breathlessness. Impaired hemidiaphragm function and a compensatory increase in respiratory drive to maintain ventilation appear to be an important mechanism of breathlessness associated with pleural effusion. Thoracocentesis reduces diaphragm distortion and improves its movement; these changes appear to reduce respiratory drive and associated breathlessness by improving the neuromechanical efficiency of the diaphragm.

Novel clinical biomarkers in blood and pleural effusion for diagnosing patients with tuberculosis distinguishing from malignant tumor

Pleural effusion (PE) is a common manifestation of tuberculosis (TB) and malignant tumors but tuberculous PE (TPE) is difficult to distinguish from malignant PE (MPE), especially by noninvasive detection indicators. This study aimed to find effective detection indices in blood and PE for differentiating TB from a malignant tumor. A total of 815 patients who were diagnosed with TB or cancer in Hubei Shiyan Taihe Hospital from 2014 to 2017 were collected. Amongst them, 717 were found to have PE by thoracoscopy. Clinical characteristics, patients' blood parameters and PE indicator information were summarized for analysis. Patients with MPE had higher percentages to be bloody and negative of Rivalta test in PE than those with TPE. For clinical indicators, comparison of the specific parameters in blood showed that 18 indicators were higher in the TPE group than in the MPE group. By contrast, 12 indicators were higher in the MPE group than in the TPE group (P < .01). In addition, in PE tests, 3 parameters were higher in the TPE group, whereas other 4 parameters were higher in the MPE group (P < .01). Then, for clinical diagnosing practice, ROC analysis and principal component analysis were applied. The top 6 relevant indicators with area under curve over 0.70 were screened out as follows: hydrothorax adenosine dehydrogenase (pADA, 0.90), hydrothorax high-sensitivity C reactive protein (0.79), percentage of blood monocyte (sMONp, 0.75), blood high-sensitivity C reactive protein (sHsCRP, 0.73), erythrocyte sedimentation rate (0.71) and blood D-dimer (0.70). Moreover, logistic regression model revealed that a specific combination of 3 biomarkers, namely, pADA, sMONp and sHsCRP, could enhance the distinguishment of TB from malignant tumor with PE (area under curve = 0.944, 95% confidence interval = 0.925-0.964). The diagnostic function of the top single marker pADA in patients from different groups was analyzed and it was found to maintain high specificity and sensitivity. The 6 indicators, namely, pADA, hydrothorax high-sensitivity C reactive protein, sMONp, sHsCRP, sESR and blood D-dimer, showed significant diagnostic value for clinicians. Further, the combination of pADA, sMONp and sHsCRP has high accuracy for differential diagnosis for the first time. Most interestingly, the single marker pADA maintained high specificity and sensitivity in patients with different statuses and thus has great value for rapid and accurate diagnosis of suspected cases.

Ipsilateral and contralateral hemidiaphragm dynamics in symptomatic pleural effusion: The 2nd PLeural Effusion And Symptom Evaluation (PLEASE-2) Study

BACKGROUND AND OBJECTIVE

The pathophysiology of breathlessness in pleural effusion is unclear. In the PLEASE-1 study, abnormal ipsilateral hemidiaphragm shape and movement, assessed qualitatively, were independently associated with breathlessness relief after pleural drainage. Effects of pleural effusion on contralateral hemidiaphragm function are unknown. PLEASE-2, a prospective exploratory pilot study, assessed the effects of unilateral effusion and drainage on both hemidiaphragms using advanced quantitative bedside ultrasonography.

METHODS

Individuals with symptomatic unilateral pleural effusion undergoing therapeutic drainage were included. Measurements pre- and post-drainage included severity of breathlessness (visual analogue scale) and ultrasound measurements of diaphragm excursion and thickness, in addition to shape and movement. Diaphragm measurements were compared to published reference values.

RESULTS

Twenty participants were recruited (mean age 68.9 [SD 12.8] years, 12 females). During tidal breathing, contralateral hemidiaphragm excursion exceeded ipsilateral excursion and reference values (all p ≤ 0.001). Contralateral excursion was greatest in participants with abnormal ipsilateral hemidiaphragm movement and was inversely correlated with ipsilateral tidal excursion (r = -0.676, p = 0.001). Following drainage (mean volume 2121 [SD = 1206] ml), abnormal shape (n = 12) and paradoxical movement (n = 9) of the ipsilateral hemidiaphragm resolved in all participants, and tidal excursion of the contralateral hemidiaphragm normalized. Relief of breathlessness post-drainage correlated with improvement in ipsilateral hemidiaphragm excursion (r = 0.556, p = 0.031).

CONCLUSION

This pilot study suggests, for the first time, that unilateral pleural effusion not only impairs ipsilateral hemidiaphragm function but also causes compensatory hyperactivity of the contralateral hemidiaphragm, which resolves post-drainage. These findings provide a basis for detailed studies of diaphragmatic function and ventilatory drive in patients with symptomatic pleural effusion.

Anatomy and Applied Physiology of the Pleural Space

The unique anatomy and physiology of the pleural space provides tight regulation of liquid within the space under normal physiologic conditions. When this balance is disrupted and pleural effusions develop, there can be significant impacts on the respiratory system. Drainage of effusions can lead to meaningful improvement in symptoms, primarily owing to improvement in the length-tension relationship of the respiratory muscles. Ultrasound examination to evaluate the movement and function of the diaphragm, as well as pleural manometry, have provided a greater understanding of the impact of pleural effusion and thoracentesis.

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.

The Pleural Effusion And Symptom Evaluation (PLEASE) study of breathlessness in patients with a symptomatic pleural effusion

INTRODUCTION

Pathophysiology changes associated with pleural effusion, its drainage and factors governing symptom response are poorly understood. Our objective was to determine: 1) the effect of pleural effusion (and its drainage) on cardiorespiratory, functional and diaphragmatic parameters; and 2) the proportion as well as characteristics of patients with breathlessness relief post-drainage.

METHODS

Prospectively enrolled patients with symptomatic pleural effusions were assessed at both pre-therapeutic drainage and at 24-36 h post-therapeutic drainage.

RESULTS

145 participants completed pre-drainage and post-drainage tests; 93% had effusions ≥25% of hemithorax. The median volume drained was 1.68 L. Breathlessness scores improved post-drainage (mean visual analogue scale (VAS) score by 28.0±24 mm; dyspnoea-12 (D12) score by 10.5±8.8; resting Borg score before 6-min walk test (6-MWT) by 0.6±1.7; all p<0.0001). The 6-min walk distance (6-MWD) increased by 29.7±73.5 m, p<0.0001. Improvements in vital signs and spirometry were modest (forced expiratory volume in 1 s (FEV₁) by 0.22 L, 95% CI 0.18-0.27; forced vital capacity (FVC) by 0.30 L, 95% CI 0.24-0.37). The ipsilateral hemi-diaphragm was flattened/everted in 50% of participants pre-drainage and 48% of participants exhibited paradoxical or no diaphragmatic movement. Post-drainage, hemi-diaphragm shape and movement were normal in 94% and 73% of participants, respectively. Drainage provided meaningful breathlessness relief (VAS score improved ≥14 mm) in 73% of participants irrespective of whether the lung expanded (mean difference 0.14, 95% CI 10.02-0.29; p=0.13). Multivariate analyses found that breathlessness relief was associated with significant breathlessness pre-drainage (odds ratio (OR) 5.83 per standard deviation (sd) decrease), baseline abnormal/paralyzed/paradoxical diaphragm movement (OR 4.37), benign aetiology (OR 3.39), higher pleural pH (OR per sd increase 1.92) and higher serum albumin level (OR per sd increase 1.73).

CONCLUSIONS

Breathlessness and exercise tolerance improved in most patients with only a small mean improvement in spirometry and no change in oxygenation. Breathlessness improvement was similar in participants with and without trapped lung. Abnormal hemi-diaphragm shape and movement were independently associated with relief of breathlessness post-drainage.

Ultrasound Evaluation of Hemidiaphragm Function Following Thoracentesis: A Study on Mechanisms of Dyspnea Related to Pleural Effusion

BACKGROUND

Dyspnea is the major symptom caused by pleural effusion. The pathophysiological pathways leading to dyspnea are poorly understood. Dysfunction of respiratory mechanics may be a factor. We aimed to study the change in diaphragmatic function following thoracentesis.

METHODS

Patients undergoing thoracentesis at a highly specialized pleural center, underwent ultrasound evaluation of hemidiaphragm movement, before and after thoracentesis was performed. The change was compared to the reduction of dyspnea measured at the modified Borg scale.

RESULTS

Thirty-two patients were included. Dyspnea was reduced from 5.01 [95% confidence interval (CI): 4.12-6.04] to 2.6 (95% CI: 1.87-3.4, P<0.0001). Low hemidiaphragmatic movement before thoracentesis on the side of pleural effusion was improved by 17.4 cm (95% CI: 13.04-21.08), equalizing movement to the side without pleural effusion. On average, 1283 mL (SD: 469) fluid was drained. Multiple linear regression analysis showed that prethoracentesis ultrasound evaluation of hemidiaphragmatic function was correlated with successful thoracentesis.

CONCLUSION

Hemidiaphragm function is reduced on the side of pleural effusion, and thoracentesis restores function. Improvement in diaphragm movement is related to a reduction in dyspnea.

[Detection of carcinoembryonic antigen levels in pleural effusion and serum and their ratio for differential diagnosis of pleural effusion resulting from tuberculosis and lung cancer]

OBJECTIVE

To study the clinical value of detecting carcinoembryonic antigen levels in pleural effusion (PCEA) and serum (SCEA) and their ratio (P/S) in the differential diagnosis of pleural effusions resulting from tuberculosis and lung cancer.

METHODS

This retrospectively study was conducted among 82 patients with pleural effusion caused by pulmonary tuberculous (TB; control group) and 120 patients with pleural effusion resulting from lung cancer in our hospital between April, 2016 and March, 2018. PCEA, SCEA and P/S were compared between the two groups and among the subgroups of lung cancer patients with squamous cell carcinoma (SqCa), adenocarcinoma (ACA), small cell carcinoma (SCLC). The receiveroperating characteristic curve (ROC) analysis was used to confirm the optimal critical value to evaluate the diagnostic efficiency of different combinations of PCEA, SCEA and P/S.

RESULTS

PCEA, SCEA and P/S were significantly higher in the overall cancer patients and in all the 3 subgroups of cancer patients than in the patients with TB (P < 0.05). The areas under the ROC curve of PCEA, SCEA and P/S were 0.925, 0.866 and 0.796, respectively; PCEA had the highest diagnostic value, whose diagnostic sensitivity, specificity, accurate rate, and diagnostic threshold were 83.33%, 96.34, 88.61%, and 3.26 ng/ml, respectively; SCEA had the lowest diagnostic performance; the diagnostic performance of P/S was between that of SCEA and PCEA, but its combination with SCEA greatly improved the diagnostic performance and reduced the rates of misdiagnosis and missed diagnosis. Parallel tests showed that the 3 indexes combined had significantly higher diagnostic sensitivity than each or any two of the single indexes (P < 0.05), but the diagnostic specificity did not differ significantly. The area under the ROC curve of combined detections of the 3 indexes was 0.941 for diagnosis of lung cancer-related pleural effusion, higher than those of any other combinations of the indexes.

CONCLUSIONS

The combined detection of PCEA, SCEA and P/S has a high sensitivity for diagnosis of lung cancer-related pleural effusion and provides important information for rapid and accurate diagnosis of suspected cases.