Tension Gastrothorax in a Child With Undiagnosed Congenital Diaphragmatic Hernia: A Case Report and Proposed Emergency Management Algorithm.

Background: Tension gastrothorax is a rare but life-threatening pediatric emergency that most commonly results from herniation of the stomach through an unrecognized congenital diaphragmatic defect, followed by progressive intrathoracic gastric distension and compression of intrathoracic structures. Because its clinical presentation often mimics tension pneumothorax, delayed diagnosis, or inappropriate management may rapidly lead to obstructive shock, respiratory failure, and cardiac arrest. Prompt recognition and timely intervention are therefore essential to prevent fatal outcomes. Case Presentation: We report the case of a previously healthy 3-year-old boy who presented with abdominal pain, recurrent vomiting, fever, and rapidly progressive respiratory distress. Shortly after admission, he developed severe respiratory compromise, hemodynamic instability, and altered mental status, raising initial suspicion of tension pneumothorax. However, chest radiography demonstrated a large air-fluid level occupying the left hemithorax with marked mediastinal shift, consistent with tension gastrothorax. Initial nasogastric decompression was unsuccessful, due to distortion of the gastroesophageal junction. Owing to the patient's critical condition, emergency transthoracic needle decompression followed by drain placement into the distended intrathoracic stomach was performed, resulting in immediate hemodynamic and respiratory improvement. Computed tomography subsequently confirmed a left-sided Bochdalek congenital diaphragmatic hernia with intrathoracic herniation of the stomach, spleen, small bowel, and part of the colon. Definitive surgical repair was undertaken on the same day after patient's stabilization. The postoperative course was complicated by acute lung injury and sepsis, but the child recovered fully and remained asymptomatic at follow-up. Conclusion: Tension gastrothorax should be considered in the differential diagnosis of any child presenting with sudden respiratory deterioration, unilateral absent breath sounds, and mediastinal shift, especially when preceded by vomiting or other events associated with increased intra-abdominal pressure. Recognition of the characteristic radiographic findings, prompt gastric decompression, and early multidisciplinary management are critical for preventing life-threatening cardiorespiratory compromise. This case highlights the importance of maintaining a high index of suspicion for this uncommon but potentially fatal condition in children with previously undiagnosed congenital diaphragmatic hernia.