Diagnostic work-up of pleural effusions

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.

Capillary leakage in travelers with dengue infection: implications for pathogenesis

Dengue hemorrhagic fever is characterized by the presence of a capillary leak syndrome. Its pathogenesis is presumed to differ from that of classical dengue fever (DF) and to be associated with secondary dengue infection. Returning travelers given a diagnosis of DF were evaluated for capillary leakage with abdominal sonography. Data were compared between travelers with primary/secondary infection defined by epidemiologic and serologic parameters. A total of 12 (34.3%) of 35 patients had sonographic signs of capillary leakage. Most (85%) patients with capillary leakage had classical DF. Capillary leak was diagnosed in 32% of primary dengue cases and in 40% of secondary dengue cases (P = 0.69). The two patients given a diagnosis of dengue hemorrhagic fever had primary infections. The high prevalence of capillary leakage among travelers, most of them with primary exposure to dengue, calls into question the importance of secondary infection in causing capillary leakage in dengue infection.

Perception versus reality: the measuring of pleural fluid pH in the United States

BACKGROUND

Pleural fluid pH measured by a blood gas analyzer is the only recommended method of pH measurement to guide management for patients with parapneumonic pleural effusions. Not all hospitals use blood gas analyzers for pleural fluid pH determination and it is unknown if physicians are aware of this problem.

OBJECTIVE

To determine if a discrepancy exists between the modality used for measuring pleural fluid pH and how physicians believe it is measured.

METHODS

We surveyed pulmonologists randomly across the USA by e-mail inquiring how they thought pleural fluid pH was measured at their laboratory. We then independently contacted the laboratory and asked how pleural fluid pH was actually measured.

RESULTS

Two hundred and sixty-seven pulmonologists completed the survey. Eighty-six percent of the pulmonologists use pleural fluid pH to manage complicated parapneumonic effusions. Forty-three percent did not recognize blood gas analyzer solely as the most accurate and validated method. Thirty-nine percent of the physicians who use pleural pH to manage effusions and believe that blood gas analyzers are the most accurate were wrong in their assumption that their laboratory was using this tool for pleural pH measurement.

CONCLUSIONS

Whether it is due to inaccurate knowledge or a perception of how pleural fluid pH is tested, a significant number of pulmonologists, when treating complicated parapneumonic effusions, may be making management decisions based on erroneous information.

Mechanisms of pleural involvement in orphan diseases

Over the past 10 years, the widespread clinical applicability of semi-invasive and noninvasive diagnostic tools including medical thoracoscopy and ultrasonography has expanded the occurrence of pleural effusions to include several rare diseases such as granulomatous, connective tissue and autoimmune disorders including sarcoidosis, granulomatosis with polyangiitis (Wegener's), systemic sclerosis, lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, amyloidosis, Langerhans cell histiocytosis, and others. The purpose of this review is to summarize the current state of the knowledge regarding pathogenetic mechanisms of pleural involvement in rare disease entities and to highlight the need for more efforts to understand the underlying mechanisms for a more effective therapy.

Pleural disease in the emergency department

Emergency department presentations of pleural-based diseases are common, with severity ranging from mild to life threatening. The acute assessment, diagnosis, and treatment of pleural disease are critical as urgent invasive maneuvers such as thoracocentesis and thoracostomy may be indicated. The emergency physician must have a systematic approach to these conditions that allows for rapid recognition, diagnosis, and definitive management. This article focuses on nontraumatic pleural disease, including diagnostic and treatment considerations of pleural effusion, empyema, primary spontaneous pneumothorax, secondary spontaneous pneumothorax, pediatric pneumothorax, spontaneous hemothorax, and spontaneous tension pneumothorax.

[Management of pleural disease]

In view of the presentations in the First National Forum of Trainee Pneumologists, the present article focuses on infectious pleural effusions and on the study of possible markers of malignant disease in asbestos-exposed individuals. The yield of the distinct techniques for the diagnosis of tuberculous pleural effusion is assessed, with emphasis on analysis of sputum and pleural samples (fluid and tissue) for Mycobacteriumtuberculosis. The utility of adenosine deaminase (ADA) (in the absence of empyema, ADA > 70 U/l is diagnostic of tuberculous pleurisy, while values of less than 40 U/l exclude this diagnosis) and interferon gamma in pleural fluid (cut off: 3.7 Ul/ml) is also discussed. The management of complicated parapneumonic pleural effusions is stratified in four categories, depending on the anatomical and morphological (size and eventual presence of loculations), bacteriological (positivity or negativity of pleural fluid culture) and biochemical (pH/glucose) characteristics of the effusion. Finally, recently developed markers for the evaluation and follow-up of asbestos-exposed individuals are described, with special emphasis on serum determination of mesothelin levels, which seem highly promising as a marker of the development of mesothelioma in these cases. A multicenter study currently being performed in Spain found that soluble mesothelin-related protein (SMRP) levels higher than 0.55 nmol/L showed a sensitivity and specificity of 72% for the diagnosis of epithelial malignant mesothelioma.

Diagnosis of pleural effusion: a systematic approach

In most diseases related to pleural effusion, the fluid analysis yields important diagnostic information, and in certain cases, fluid analysis alone is enough for diagnosis. The many important characteristics of pleural fluid are described, as are other complementary investigations that can assist with the diagnosis of common and rare pleural effusions. For a systematic review of pleural effusion, a literature search for articles on the practical investigation and diagnosis of pleural effusion was done. Articles included guidelines, expert opinion, experimental and nonexperimental studies, literature reviews, and systematic reviews published from May 2003 through June 2009. The search yielded 1 guideline, 2 meta-analyses, 9 literature reviews, 1 randomized control trial, and 9 clinical studies. On the basis of class IIa or class I evidence from these articles, a step by step approach is recommended for investigating a pleural effusion, beginning with assessment of the medical history, clinical examination, radiology, pleural fluid evaluation, and finally, if no diagnosis is forthcoming, a pleural biopsy under image guidance or thoracoscopy.

Biopsy techniques for the diagnosis of mesothelioma

The incidence of mesothelioma continues to increase in the Western world and is likely to do so until 2011-2015. It commonly presents with breathlessness secondary to a pleural effusion, and whilst guidelines still advise thoracocentesis as the first line investigation, the sensitivity of this is low and a tissue diagnosis is usually required. Abrams needle biopsy also has a low diagnostic yield and high complication rate and is not recommended in guidelines on the investigation of mesothelioma. Computed tomography-guided biopsy or thoracoscopy both have a comparable sensitivity and low complication rates. Local anaesthetic thoracoscopy is increasingly used by respiratory physicians and has a comparable diagnostic sensitivity to Video-Assisted Thoracoscopic Surgery (VATS) without the need for a general anaesthetic. The requirement for prophylactic radiotherapy after pleural procedures in cases of mesothelioma is contentious, as the results from early trials suggesting it reduces tract seeding have been disputed by more recent trials.

Intrapleural administration of lipoplatin in an animal model

BACKGROUND

Lipoplatin is a new liposomal cisplatin already tested in solid tumors with encouraging results. Little is known about the activity of lipoplatin administered intrapleurally (IP).

AIM

The aim of this study was to assess in an animal model the pharmacokinetics, and potentially induced histopathological lesions of lung and kidney after IP vs. IV injection of lipoplatin.

METHODS

15 male Wistar rats were assigned to an IV group at dose 10mg/kg of lipoplatin (group 1) and to IP groups at 10 (group 2) or 20mg/kg (group 3) equal to 60 and 120 mg/m(2) in humans respectively. After lipoplatin administration, serial plasma samples were analyzed by atomic absorption spectrometry for the maximum plasma concentration (C(max)), the area under the plasma concentration-time curve (AUC), and the total body clearance (CL). Pleura, lungs and kidneys of the rats were histologically examined for possible lesions.

RESULTS

The C(max) was significantly higher in groups 1 vs. 2 (p = 0.02) and vs. 3 (p = 0.01). The AUC of groups 3 vs. 1 was significantly higher (p = 0.028) but the AUC of groups 2 vs. 1 was significantly lower (p = 0.02). CL in IP rats did not differ considerably compared to the IV. Inflammatory changes were noted in the pleura of IP rats and mild kidneys lesions in IV group.

CONCLUSION

Compared to the IV route, IP20 administration of lipoplatin yielded higher AUC, equal CL, but a significantly lower C(max). As C(max) is a determinant of lipoplatin toxicity, IP administration might offer a more effective therapeutic index while improving tolerability. We noted fibrotic changes in the pleura of IP rats, and mild kidneys changes in IV rats, as expected.

Thyroid hormones, their carrier proteins, and thyroid antibodies in the pleural effusion of two patients with graves' disease-induced thyrotoxicosis

INTRODUCTION

Concentrations of thyroid hormones, their carrier proteins, and thyroid antibodies in plasma have been extensively investigated, but those in pleural effusion have not. PATIENTS AND MEDTHODS: In the present study, we report, for the first time, the concentrations of thyroid hormones, their carrier proteins, and thyroid antibodies in the pleural effusion of two thyrotoxicosis patients with Graves' disease.

RESULTS

The pleural effusions were transudates. The concentrations of thyroid hormone carrier proteins, such as thyroxine-binding globulin (TBG), thyroxine-binding prealbumin (TBPA), and albumin (Alb) were approximately 30-50% of the plasma. The concentrations of total triiodothyronine (TT3), total tetraiodothyronine (TT4), free triiodothyronine (FT3), and free tetraiodothyronine (FT4) were approximately 15-40%, 45-55%, 45-75%, and 80-85% of the plasma, respectively. The concentration of thyroid stimulating hormone receptor antibody (TRAb) (equal to TSH-binding inhibitory immunoglobulins%; TBII%) was approximately 90% of the plasma.

CONCLUSION

If the pleural effusions were treated with diuretics, substantial quantity of thyroid hormones and thyroid antibodies in the pleural effusion may have returned to the plasma, and might exacerbate thyrotoxicosis. For patients with thyrotoxicosis and pleural effusion, thoracentesis should be considered. The present findings will contribute to the understanding and treatment of hyperthyroidism-induced pleural effusion.