Diagnostic utility of pleural fluid/serum bilirubin ratio versus light’s criteria in differentiating exudative and transudative pleural effusions. A cross-sectional observational study.

Jonnalagadda  Monika; S Deepan  Raj; Nithin Joseph  Beera; Dr.Perapagu  Jhansi

doi:10.51168/sjhrafrica.v6i9.2154

Authors

Dr. Jonnalagadda Monika Associate Consultant in Pulmonary Medicine, Yashoda Hospital, Secunderabad, Telangana, India.
Dr. S Deepan Raj Assistant Professor, Department of Pulmonary Medicine, Arundhathi Institute of Medical Sciences, Dundigal, Medchal Malkajgiri District, Telangana, India
Dr. Beera Nithin Joseph Assistant Professor, Department of Pulmonary Medicine, Government Medical College, Suryapet, Telangana, India.
Dr.Perapagu Jhansi Senior Resident, Department of Pulmonary Medicine, Government Medical College, Suryapet, Telangana, India.

DOI:

https://doi.org/10.51168/sjhrafrica.v6i9.2154

Keywords:

Pleural effusion, Exudates, Transudates, Light’s criteria, Bilirubin ratio

Abstract

Background
Differentiation between exudative and transudative pleural effusions is fundamental for guiding clinical management. Light’s criteria remain the standard, though reports suggest misclassification in certain cases, necessitating exploration of alternative biochemical markers.

Objectives
To evaluate the efficacy of the pleural fluid/serum bilirubin ratio in differentiating exudative from transudative pleural effusions in comparison with Light’s criteria.

Methods
A cross-sectional observational study was conducted on 60 patients with pleural effusion at a tertiary care center from January 2021 to June 2022. Patients underwent detailed clinical evaluation, radiological assessment, and biochemical analysis of pleural fluid and serum for protein, lactate dehydrogenase (LDH), and bilirubin. Ratios of pleural fluid to serum concentrations were calculated. Exudates and transudates were classified using clinical criteria, and diagnostic performance of Light’s criteria and bilirubin ratio was compared.

Results
Of the 60 patients, 33 (55%) had exudative and 27 (45%) transudative effusions. Exudates were more common in males (57.5%) and in the age group 31–50 years, whereas transudates predominated among females and those aged 51–70 years. Tuberculosis (48.5%) and malignancy (36.4%) were the leading causes of exudates, while congestive cardiac failure (44.5%) and chronic liver disease (37%) were the main transudative etiologies. The mean pleural fluid/serum bilirubin ratio (0.74 vs. 0.32, p < 0.001) significantly differentiated exudates from transudates. Diagnostic accuracy was highest for the bilirubin ratio (96.67%) compared to Light’s criteria (95%), with superior specificity in identifying transudates.

Conclusion
The pleural fluid/serum bilirubin ratio is a simple, cost-effective, and reliable parameter, with diagnostic accuracy comparable to Light’s criteria.

Recommendations
The bilirubin ratio can be used as an adjunct or alternative to Light’s criteria, especially in resource-limited settings, to minimize misclassification. Larger multicentric studies are recommended to validate its clinical utility and establish standardized cut-off values.

Author Biographies

Dr. Jonnalagadda Monika , Associate Consultant in Pulmonary Medicine, Yashoda Hospital, Secunderabad, Telangana, India.

Associate Consultant, Department of Respiratory Medicine, Yashoda Hospital, Secunderabad, Telangana, India. Dr. Jonnalagadda Monika is presently serving as an Associate Consultant in the Department of Respiratory Medicine at Yashoda Hospital, Secunderabad. She completed her MBBS from Gandhi Medical College under Dr. NTR University of Health Sciences, Andhra Pradesh (Batch 2013–2014; graduated in 2018). She obtained her MD in Respiratory Medicine from Gandhi Medical College and Hospital, Secunderabad (Batch 2020–2021; completed in 2023).

Following her postgraduate training, she worked as a Senior Resident in the Department of Respiratory Medicine at Government Medical College, Nalgonda (September 2023–July 2024) and subsequently at Malla Reddy Institute of Medical Sciences, Suraram, Hyderabad.

Her clinical expertise includes the diagnosis and management of a broad spectrum of respiratory disorders such as bronchial asthma, chronic obstructive pulmonary disease, interstitial lung diseases, and pulmonary infections. She has a strong academic interest in critical care pulmonology, bronchoscopy, sleep-related breathing disorders, and advanced ventilatory support. Dr. Monika is deeply committed to evidence-based respiratory care, medical education, and clinical research aimed at improving outcomes in pulmonary medicine.ORCID iD: https://orcid.org/0009-0001-2865-2399

Dr. S Deepan Raj, Assistant Professor, Department of Pulmonary Medicine, Arundhathi Institute of Medical Sciences, Dundigal, Medchal Malkajgiri District, Telangana, India

MD Assistant Professor, Department of Respiratory Medicine, Arundhathi Institute of Medical Sciences, Dundigal, Telangana, India. Dr. Deepan Raj S is currently serving as an Assistant Professor in the Department of Respiratory Medicine at Arundhathi Institute of Medical Sciences, Dundigal. He completed his MBBS from Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth University, Puducherry (Batch 2013–2014; graduated 2017). He pursued his MD in Respiratory Medicine at Gandhi Medical College and Hospital, Secunderabad (Batch 2020–2021; completed 2023). Following his postgraduate training, he served as a Senior Resident in the Department of Respiratory Medicine at Government Medical College, Suryapet (September 2023–September 2024).

His professional expertise encompasses the management of a broad range of respiratory disorders, including bronchial asthma, chronic obstructive pulmonary disease, interstitial lung diseases, and pleural pathologies. His areas of academic interest include critical care pulmonology, bronchoscopy, pulmonary rehabilitation, and tuberculosis control strategies. Dr. Deepan Raj S is committed to advancing respiratory medicine through evidence-based clinical practice, active teaching, and collaborative research contributing to the improvement of pulmonary health care.ORCID iD:https://orcid.org/0009-0003-0578-107X

Dr. Beera Nithin Joseph , Assistant Professor, Department of Pulmonary Medicine, Government Medical College, Suryapet, Telangana, India.

MD Assistant Professor, Department of Pulmonology, Government Medical College, Suryapet, Telangana, India. Dr. Beera Nithin Joseph obtained his MBBS degree from Prathima Institute of Medical Sciences, Karimnagar (2009–2014), and completed his MD in Pulmonology at Mamata Medical College, Khammam (2018–2021). He is currently serving as an Assistant Professor in the Department of Pulmonology at Government Medical College, Suryapet. His professional interests include interventional pulmonology, sleep-related breathing disorders, tuberculosis and drug-resistant TB management, and chronic obstructive pulmonary disease. Dr. Joseph is dedicated to advancing pulmonary healthcare through evidence-based clinical practice, academic teaching, and collaborative research in respiratory medicine. ORCID iD:https://orcid.org/0009-0008-2826-1057

Dr.Perapagu Jhansi , Senior Resident, Department of Pulmonary Medicine, Government Medical College, Suryapet, Telangana, India.

MD Senior Resident, Department of Respiratory Medicine, Government Medical College, Suryapet, Telangana, India. Dr. P. Jhansi completed her MBBS from Gandhi Medical College, Secunderabad, in the batch of 2014. She pursued her postgraduate training (MD in Respiratory Medicine) at the same institution, graduating in the batch of 2021. She is presently serving as a Senior Resident in the Department of Respiratory Medicine at Government Medical College, Suryapet. Her clinical and research interests include pulmonary infections, obstructive airway diseases, interstitial lung disorders, and advancements in bronchoscopic diagnostic techniques. She is committed to evidence-based respiratory care and medical education, contributing actively to academic and clinical excellence in pulmonary medicine.ORCID iD:https://orcid.org/0009-0007-2780-4921

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