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 Table of Contents  
Year : 2018  |  Volume : 5  |  Issue : 2  |  Page : 110-113

Spectrum of pleural effusion etiology revisited in 18–70 years of age group: A tertiary care center-based study of 1000 patients

1 Department of Chest Diseases and Tuberculosis, Government Medical College, Jammu, Jammu and Kashmir, India
2 Department of Radiodiagnosis and Imaging, Government Medical College, Jammu, Jammu and Kashmir, India

Date of Web Publication9-Apr-2018

Correspondence Address:
Mohd Ilyas
Department of Radiodiagnosis and Imaging, Government Medical College, Jammu - 180 001, Jammu and Kashmir
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/cjhr.cjhr_109_17

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Objective: The main objective study was to evaluate the new-onset cases of pleural effusion with respect to etiology/causation. Materials and Methods: A total of 1000 patients were included in the study aged between 18 and 70 years. The patients with earlier diagnosis of pleural effusion or those who had undergone thoracocentesis were excluded from the study. All the patients were subjected to thorough clinical examination, chest radiography, chest and abdominal sonography, pleural fluid analysis, and pleural fluid cytology, and in select cases, pleural biopsy was done. The results were assimilated and tabulated, observations thereby drawn by. Results and Observations: Out of total 1000 patients, 69.5% had tuberculosis followed by malignancy (16%) with the systemic causes forming about 15% bulk of the patients with pleural effusion. It was found more in males, associated with smoking, and majority of patients had unilateral effusion. Eighty-nine percent of patients had exudative effusion. Conclusion: The results of the study revealed that tuberculosis is still the most common cause of pleural effusion and efforts need to be stepped up to control tuberculosis. The national programs for control of tuberculosis need to be revisited to assess the magnitude of the problem, and the patients need to be counseled for the compliance of the therapy. Furthermore, malignancy is trending upward in the etiology of pleural effusion.

Keywords: Cytology, malignancy, pleural effusion, pleural fluid analysis, tuberculosis

How to cite this article:
Gupta R, Gupta A, Ilyas M. Spectrum of pleural effusion etiology revisited in 18–70 years of age group: A tertiary care center-based study of 1000 patients. CHRISMED J Health Res 2018;5:110-3

How to cite this URL:
Gupta R, Gupta A, Ilyas M. Spectrum of pleural effusion etiology revisited in 18–70 years of age group: A tertiary care center-based study of 1000 patients. CHRISMED J Health Res [serial online] 2018 [cited 2022 May 23];5:110-3. Available from: https://www.cjhr.org/text.asp?2018/5/2/110/229579

  Introduction Top

The accumulation of fluid in the pleural cavity (potential space between the parietal and visceral pleura) is known as pleural effusion. The causes may be pleural, diseased surrounding lung parenchyma, or systemic. It is one of the major causes of pulmonary morbidity and mortality. It can be classified as transudative or exudative based on the modified Light's criteria.[1] Transudative pleural effusion is commonly due to systemic illnesses, which results in altered hydrostatic or oncotic pressures in the pleural space, such as congestive heart failure, hypoalbuminemia, nephrotic syndrome, and hepatic disorders (cirrhosis). Exudative pleural effusion commonly occurs due to the local pleural or lung parenchymal pathology. The common causes of exudative pleural effusion include pleural or pulmonary tuberculosis, pneumonia, malignancy, and inflammatory disorders such as rheumatoid arthritis, systemic lupus erythematosus, chylothorax (thoracic duct injury or lymphatic obstruction), postcardiac injury syndrome, hemothorax (posttrauma), and asbestosis. Less common causes of pleural effusion include pulmonary embolism, drug-induced (e.g., amiodarone, methotrexate), postradiotherapy, esophageal rupture, and ovarian hyperstimulation syndrome. In these cases, it may be transudative or exudative.[2]

  Materials and Methods Top

The prospective, observational study was carried out in the Department of Chest Diseases and Tuberculosis of our institute over a period of 1 year (April 2016–March 2017). A total of 1000 patients with newly diagnosed pleural effusion were included in the study.

Inclusion criteria

  1. All patients above 18 years and below 70 years of age with the new-onset radiographic or sonographic evidence of pleural effusion
  2. Patients with clinical evidence of pleural effusion. In these patients, the clinical suspicion was confirmed by radiography or sonography.

Exclusion criteria

  1. Patients with below 18 years or above 70 years of age
  2. Patients already diagnosed with pleural effusion and patients on the treatment for pleural effusion
  3. Patient who already had undergone pleurocentesis.

A detailed history with regard to symptoms, contact history, travel history, and smoking was elicited followed by thorough clinical examination involving the general physical examination and respiratory examination. The systemic disease component-related history and clinical examination were also done.

The clinical component was followed by the investigations. The investigations included sputum examination, posteroanterior (PA) chest radiograph, chest ultrasonography, abdominal ultrasonography, hemogram, coagulation profile, liver function tests, and renal function tests. The effusion was graded as mild, moderate, and severe based on chest radiographic and sonographic quantification. The sonographic quantification was done based on the formula: volume (mL) = 16 × parietal to visceral pleura distance (mm) at the mid-diaphragm.[3]

Thoracoscopic-based pleural biopsy was done in 36 willing patients.

This was followed by ultrasonography-guided aspiration of the pleural effusion. The aspirated fluid was sent for biochemical and cytological analysis to ascertain the type of effusion (exudative versus transudative based on modified Light's criteria) and the cause of effusion. The Adenosine deaminase (ADA) levels in the pleural fluid were measured using spectrophotometry with cutoff value of 36 IU/L. The patients with ADA levels more than this value were diagnosed to be having tuberculosis if other criteria were also met.

The diagnosis of tuberculosis was based on the detection of Mycobacterium tuberculosis in sputum, pleural fluid, and pleural biopsy specimens along with the demonstration of high ADA levels in the pleural fluid. It was based on the demonstration of acid-fast bacilli (AFB) on sputum smear in 561 patients. The GeneXpert (CBNAAT) was done in patients with strong suspicion of tuberculosis who had negative sputum smear (134 patients), and it was positive for M. tuberculosis in 115 patients. The rest of the 19 patients were diagnosed as having tuberculosis on the basis of AFB demonstration on thoracoscopic biopsy specimens (10 patients) and on pleural fluid smear (9 patients). The guidelines used were as per the recommendations of tuberculosis control program-2016 in India.

The malignancy was diagnosed based on the demonstration of malignant cells in the pleural fluid or on the histopathological examination of pleural biopsy specimens.

The final results were compiled in terms of gender distribution, age distribution, etiological profile, association with smoking, transudative versus exudative type, and laterality of the effusion.

  Observations and Results Top

The present study revealed that pleural effusion was more common in males following the earlier described trends in the literature. It revealed that majority of patients were between 31 and 40 years of age, there was a strong association with smoking, and 68% patients of pleural effusion were smokers. The major presenting symptoms included fever and dyspnea on exertion, with almost 56% having moderate effusion. Majority of the patients had right-sided effusion. Two most common causes of pleural effusion included tuberculosis and malignancy.

In patients with tuberculosis, only 10 had transudative effusion while 685 patients had exudative effusion. In malignant cases, only two patients had transudative effusion while 158 had exudative effusion. In cases having systemic diseases such as liver cirrhosis, congestive cardiac failure, and renal dysfunction, majority of them had transudative effusion (>90%) while those cases having pleural effusion associated with pancreatitis had exudative effusion (approximately 70%). When analyzed with respect to smoking, it was seen that most of the smokers had exudative effusion. Of the 70 patients with bilateral effusion, 56 had tuberculosis as the etiology.

In patients diagnosed as having malignancy on thoracoscopic biopsy, eight patients had adenocarcinoma, five had squamous cell carcinoma, and four had small cell carcinoma. In pleural fluid analysis, about 70% had raised ADA levels with majority of them having tuberculosis. The ADA levels were increased predominantly in exudative effusion (94.3%) and almost 99% of these patients had tuberculosis.

[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12], [Table 13] represent the data acquired in the study and analysis of the various attributes of the pleural effusion.
Table 1: Gender distribution of patients (n=1000)

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Table 2: Age distribution of patients (n=1000)

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Table 3: Association with smoking (n=1000)

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Table 4: Symptomology of patients (n=1000)

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Table 5: Distribution based on laterality of involvement (n=1000)

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Table 6: Severity based on radiographic and sonographic evidence (n=1000)

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Table 7: Pleural fluid analysis (n=1000)

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Table 8: Pleural fluid cytology analysis (n=1000)

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Table 9: Thoracoscopic pleural biopsy results (n=36)

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Table 10: Etiological distribution of patients based on pleural cytology and biopsy (n=1000)

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Table 11: Adenosine deaminase levels in pleural fluid (n=1000)

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Table 12: Adenosine levels with respect to exudative and transudative fluid (n=705)

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Table 13: Relationship of smoking to type of fluid (exudate vs. transudate)

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  Discussion Top

Pleural effusion is the most common pleural disease affecting a significant bulk of population in India. It can be a result of pleural, lung parenchymal, and systemic disease. The pleural effusion may be benign or malignant.

The pleural cavity is a potential space normally containing about 0.1–0.3 ml/kg of pleural fluid which is being exchanged constantly. The pleural fluid is produced by the parietal pleural vasculature and gets absorbed by the lymphatics in the mediastinal and diaphragmatic parietal pleura. If the pleural effusion is due to altered hydrostatic and oncotic pressures, the resultant is transudates, and if the effusion is due to increased mesothelial and capillary permeability, the resultant is exudates.[4]

The pleural fluid is characterized into transudate and exudate based on the modified Light's criteria.

Exudative pleural fluid has at least one of the following characteristics as per the Light's criteria:[5]

  1. Pleural fluid protein/serum protein ratio more than 0.5
  2. Pleural fluid lactate dehydrogenase (LDH)/serum LDH ratio more than 0.6
  3. Pleural LDH is more than two-thirds of the upper limits of normal laboratory value for serum LDH.

If these criteria are not met, then the fluid is considered as transudate.

The patients of pleural effusion may be asymptomatic or may present with exertional dyspnea. The most common presentations are cough, chest pain, and fever. Active inflammation may also give the picture of pleurisy. The clinical examination will be positive for fullness of intercostal spaces and dullness on percussion on the involved side. The detailed history with regard to the involvement of pulmonary or systemic disease is important in the diagnosis of pleural effusion.[6]

Chest radiographs are helpful in the confirmation of pleural effusion. In a standing PA view radiograph, it requires 200 ml to obscure the costophrenic angle displaying the meniscus sign, while on a lateral radiograph, 50 ml fluid can be appreciated. Sonography of the chest is more sensitive in the diagnosis of pleural effusion and also helps in the guidance of thoracentesis.[7]

Pleural fluid cytology is also important. It has 60% sensitivity in the detection of malignant cells with increase in yield by three attempts on different days to almost 95%. Pleural fluid can also be used for ADA levels (specific for tuberculosis), amylase levels (in esophageal rupture), NT-pro-BNP levels (heart failure), and triglyceride levels (>110 mg/dl in chylothorax).[8]

Once the diagnosis is made, the main aim of the treatment strategy is to treat the underlying cause. In India, the tuberculosis is treated as per the guidelines issued via the revised national tuberculosis program and WHO guidelines which are modified from time to time.

In a study by Mohan and Ravindran, they found tuberculosis as the most common cause of exudative pleural effusion followed by malignancy.[9] The same results are reflected in the present study.

The present study revealed that malignancy as a cause of pleural effusion has taken the second seat following tuberculosis. The pleural fluid analysis, pleural biopsy, and radiographic and sonographic analysis were used in the accurate diagnosis of these cases.

The results were also in conformity with the study done by Raghavan et al., who concluded that tuberculosis and malignancy form the bulk of the patients with pleural effusion.[10]

Malignant pleural effusion indicates an advanced malignancy as described by Dixit et al.[11] The similar results were obtained in the present study where almost 65% of patients with malignant effusion had advanced/unresectable malignancy.

Dhital et al., in their study, concluded that tuberculosis is the most common cause of unilateral effusions followed by synpneumonic effusions.[12] The present study revealed that tuberculosis as the most common cause of pleural effusion (unilateral as well as bilateral), but in contradiction, the second most common cause was found to be malignancy.

  Conclusion Top

The present study concludes that despite the revised national tuberculosis control program in India, the tubercular effusions are still at large. The cause is usually the noncompliance with antitubercular therapy. The malignant pleural effusion cases are far less than tuberculosis, but their incidence is rising as compared to previous studies. While evaluating a case of pleural effusion, a combined approach, involving clinical evaluation, radiographic and sonographic evaluation, pleural fluid analysis, pleural fluid cytology, and in cases where possible thoracoscopic pleural biopsy, must be utilized to fruitful and accurate diagnosis.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Akulian J, Feller-Kopman D. The past, current and future of diagnosis and management of pleural disease. J Thorac Dis 2015;7:S329-38.  Back to cited text no. 1
Yalcin NG, Choong CK, Eizenberg N. Anatomy and pathophysiology of the pleura and pleural space. Thorac Surg Clin 2013;23:1-10, v.  Back to cited text no. 2
Usta E, Mustafi M, Ziemer G. Ultrasound estimation of volume of postoperative pleural effusion in cardiac surgery patients. Interact Cardiovasc Thorac Surg 2010;10:204-7.  Back to cited text no. 3
Charalampidis C, Youroukou A, Lazaridis G, Baka S, Mpoukovinas I, Karavasilis V, et al. Physiology of the pleural space. J Thorac Dis 2015;7:S33-7.  Back to cited text no. 4
Light RW. The light criteria: The beginning and why they are useful 40 years later. Clin Chest Med 2013;34:21-6.  Back to cited text no. 5
Karkhanis VS, Joshi JM. Pleural effusion: Diagnosis, treatment, and management. Open Access Emerg Med 2012;4:31-52.  Back to cited text no. 6
Prina E, Torres A, Carvalho CR. Lung ultrasound in the evaluation of pleural effusion. J Bras Pneumol 2014;40:1-5.  Back to cited text no. 7
Ferreiro L, Toubes ME, Valdés L. Contribution of pleural fluid analysis to the diagnosis of pleural effusion. Med Clin (Barc) 2015;145:171-7.  Back to cited text no. 8
Mohan KM, Ravindran C. Etiology and clinical profile of pleural effusion in a teaching hospital of South India: A descriptive study. Pulmon 2012;14:89-96.  Back to cited text no. 9
Raghavan S, Jayachandran R, Mosses S. Clinical and etiological profile of patients with pleural effusion in a tertiary care centre. J Med Sci Clin Res 2017;5:23553-8.  Back to cited text no. 10
Dixit R, Agarwal KC, Gokhroo A, Patil CB, Meena M, Shah NS, et al. Diagnosis and management options in malignant pleural effusions. Lung India 2017;34:160-6.  Back to cited text no. 11
[PUBMED]  [Full text]  
Dhital KR, Acharya R, Bhandari R, Kharel P, Giri KP, Tamrakar R, et al. Clinical profile of patients with pleural effusion admitted to KMCTH. Kathmandu Univ Med J (KUMJ) 2009;7:438-44.  Back to cited text no. 12


  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9], [Table 10], [Table 11], [Table 12], [Table 13]


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