Background: Pneumothorax is a prevalent critical condition in the intensive care unit, which ranges according to its clinical manifestations from asymptomatic to life-threatening, so early detection is essential. This study aims to evaluate the diagnostic role of chest ultrasonography (U/S) in identifying pneumothorax (PNX) in ICUs patients.

Patients and methods: This cross-sectional study was performed in ICUs at Zagazig University Hospitals. The study included thirty critically ill cases admitted to ICUs from January to December 2023.Using Sony LOGIQ P7 < made in Korea. All studied populations had the following: Detailed history taking from patients or relatives, clinical examination, laboratory investigations, and radiological evaluation, including chest x-ray, chest U/S, and CT chest.

Results: The most common U/S findings in pneumothorax on the first day of admission were lung point (63.3%), absent lung sliding presented (20%), and barcode sign (13.3%), while lung pulse could be detected in only one case (3.3%). On the third day, follow-up of the study, 30% of pneumothorax cases showed complete resolution, while on the seventh day, it reached 60%. .chest ultrasound showed good agreement with CT chest (kappa = 0.723); it could detect 23 positive cases out of 27 confirmed with CT and exclude two negative cases out of three truly negative confirmed by CT Chest. pneumothorax in ICU patients, as it is simple, portable, affordable, bedside, safe, and has higher sensitivity than chest X-rays. Among sonographic findings, the Lung point sign has the highest sensitivity, specificity, and overall accuracy in the detection of pneumothorax