Chest Ultrasonography vs. Chest X-rays for Diagnosing Pleural Effusion in Intensive Care Unit Patients

Background and objectives: The early detection of pleural effusion in intensive care unit patients is important since the pleura is vital for proper respiratory function. This study evaluates the accuracy of ultrasonography in early diagnosis of pleural effusion in intensive care unit patients, comparing it to chest X-rays, a less invasive and expensive alternative. Methods: A cross-sectional comparative study design included 338 patients from March to September 2023 at three intensive care units: the emergency hospital, the Azadi Teaching Hospital, and the heart center. These patients underwent chest ultrasonography and X-ray examinations to detect pleural effusion Both imaging modalities' diagnostic accuracy, sensitivity, specificity, and predictive values were evaluated. P value <0.05 is regarded as statistically significant. Results: The findings indicated that chest ultrasonography had a high level of sensitivity and specificity of up to 97% and 99.7% respectively with overall accuracy of 93.2%. A sensitivity and specificity of up to 90.1%, and 97.9% respectively, with an overall accuracy of 97%, were obtained from the chest X-rays. Ultrasound has higher positive and negative predictive values compared to chest X-rays, with a positive and negative predictive value of 96% and 99.7% respectively. In all cases, the statistical analysis results showed no significant difference in the diagnostic capabilities of ultrasonography and X-rays. Conclusions: The findings demonstrate that ultrasound is a reliable tool with a kappa value of 0.738 for detecting pleural effusion at the bedside.