Clinicoradiological Spectrum and Predictors of Complicated Parapneumonic Effusion: A Prospective Observational Study from a Tertiary Care Center in India

Abstract

Background: Parapneumonic effusion (PPE) represents a spectrum ranging from simple exudative effusion to empyema. Early identification of severity is essential for timely intervention and improved clinical outcomes

Aim: To evaluate the clinicoradiological characteristics of parapneumonic effusion and identify independent predictors of complicated effusion

Methods: This prospective observational study was conducted over 18 months in a tertiary care center in India, including 42 adult patients with PPE. Clinical features, pleural fluid parameters, and radiological findings were analyzed. Effusions were classified as uncomplicated or complicated based on biochemical and ultrasonographic criteria. Variables with p <0.1 in univariate analysis were included in multivariate logistic regression to determine independent predictors. Model calibration was assessed using the Hosmer–Lemeshow test, and multicollinearity was evaluated using variance inflation factor (VIF).

Results: The mean age was 47.8 ± 14.2 years with male predominance (78.6%). Complicated PPE was present in 57.1% of patients. These patients had significantly higher pleural fluid LDH (1980 ± 850 vs 820 ± 310 IU/L, p<0.001) and lower glucose levels (36.2 ± 10.4 vs 72.4 ± 12.1 mg/dL, p<0.001). Loculations were significantly more frequent (58.3% vs 11.1%, p<0.001). Independent predictors included LDH >1000 IU/L (OR 5.8, 95% CI: 2.1–15.9), glucose <60 mg/dL (OR 6.5, 95% CI: 2.4–17.4), and presence of loculations (OR 7.4, 95% CI: 2.6–20.8). ROC analysis showed good discriminative ability (LDH AUC = 0.82; glucose AUC = 0.85). The model demonstrated good calibration (Hosmer–Lemeshow p>0.05) with no multicollinearity (VIF <2).

Conclusion: Combined biochemical and ultrasonographic parameters reliably predict complicated parapneumonic effusion and can guide early aggressive management.