1Postgraduate PG, Department of Respiratory Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research (BIHER), Chrompet, Chennai - 600044, Tamil Nadu, India. Email: sidhu.eron@gmail.com ORCID: 0009-0007-5053-8625
2*Assistant Professor, Department of Respiratory Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research (BIHER), Chrompet, Chennai - 600044, Tamil Nadu, India. Email: ashwinkailash93@gmail.com ORCID: 0000-0001-9987-4987 (Corresponding Author)
3Associate Professor, Department of Respiratory Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research (BIHER), Chrompet, Chennai - 600044, Tamil Nadu, India. Email: drelenann153@gmail.com ORCID: 0009-0007-1510-0935
4Professor and Head, Department of Respiratory Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research (BIHER), Chrompet, Chennai - 600044, Tamil Nadu, India. Email: drgsverma@gmail.com ORCID: 0000-0001-7409-8133
5Postgraduate PG, Department of Respiratory Medicine, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research (BIHER), Chrompet, Chennai - 600044, Tamil Nadu, India. Email: pupa.preethi24@gmail.com ORCID: 0009-0004-6361-7021
Received: 15th Feb, 2026; Revised: 27th Feb 2026; Accepted: 20th Mar, 2026; Available Online: 5th Apr, 2026
Background: Accurate differentiation of pleural effusions into exudates and transudates is essential for appropriate clinical management. Although Light's criteria remain the standard diagnostic method, their specificity is limited in patients receiving diuretic therapy due to hemoconcentration, leading to misclassification. The DUETS score is a novel ultrasound-based tool designed to overcome these limitations by incorporating morphological features.
Methods: This prospective diagnostic accuracy study included 70 adult patients with undiagnosed pleural effusions. All participants underwent thoracic ultrasound using standardized BLUE protocol points, and the DUETS score (range 0–5) was calculated, with a cut-off ≥2 indicating exudate. Pleural fluid analysis was performed using Light's criteria. Discordant cases were adjudicated using the serum–pleural fluid albumin gradient, with a value >1.2 g/dL indicating transudate.
Results: Of the 70 patients, 42 (60%) had exudative and 28 (40%) had transudative effusions. Tuberculous pleuritis was the most common exudative etiology (38.1%). The DUETS score demonstrated a sensitivity and specificity of 100% for identifying exudates. In comparison, Light's criteria showed a sensitivity of 100% but a reduced specificity of 75%, misclassifying 7 of 28 (25%) transudates as exudates. All misclassified cases were patients with congestive heart failure receiving diuretics. The DUETS score correctly identified all discordant cases as transudates.
Conclusion: The DUETS score is a highly accurate, non-invasive diagnostic tool that matches the sensitivity of Light's criteria while providing superior specificity, particularly in diuretic-associated effusions. Its bedside applicability makes it especially valuable in resource-limited settings, where it may reduce the need for invasive procedures.
Keywords: Pleural effusion, DUETS score, Light's criteria, thoracic ultrasound, exudate, transudate, diagnostic accuracy, diuretic therapy, bedside imaging, non-invasive diagnosis
How to cite this article: Sidharthan M, Kailash A, Abraham EA, Verma G, Preethi P. Diagnostic Accuracy of the DUETS Pleural Ultrasound Score Versus Light's Criteria for Differentiating Exudative and Transudative Pleural Effusions in a Tertiary Care Setting. Int J Drug Deliv Technol. 2026;16(4): 1. DOI: 10.25258/ijddt.16.4.1
Source of support: Nil.
Conflict of interest: None