Pitfalls in the diagnosis of blunt diaphragmatic injury.

BACKGROUND: Severe blunt trauma to the torso can result in diaphragmatic disruption. Prompt recognition of this potentially life-threatening injury is difficult when the initial chest roentgenogram is unrevealing and immediate thoracotomy or celiotomy is not performed. This retrospective study was undertaken to: (1) determine the incidence of missed diaphragmatic injuries on initial evaluation; (2) identify factors contributing to diagnostic delays; and (3) formulate a diagnostic approach that reliably detects diaphragmatic rupture following blunt trauma.

METHODS: Retrospective review of hospital records and radiographs from our 18-year experience with blunt diaphragmatic injuries.

RESULTS: Seven of 57 (12%) blunt diaphragmatic injuries were missed on initial evaluation. Recognition followed 2 days to 3 months later. Two (4%) isolated left-sided injuries initially presented with normal chest roentgenograms. Five patients (9%) (4 with right-sided ruptures) had abnormalities on chest roentgenogram or computed tomography (CT) initially attributed to chest trauma. They were diagnosed by radionuclide, ultrasound, or CT investigations of hemothorax, pulmonary sepsis, and right upper quadrant pain; and, in 1 case, at thoracotomy for a persistent right hemothorax. In the remaining 50 patients (88%), the diagnosis was established within 24 hours. In 21 (42%) of these, the problem was initially recognized at the time of celiotomy for accompanying injuries.

CONCLUSIONS: Blunt diaphragmatic injuries are easily missed in the absence of other indications for immediate surgery, since radiologic abnormalities of the diaphragm--particularly those involving the right hemidiaphragm--are often interpreted as thoracic trauma. In this setting, a high index of suspicion coupled with selective use of radionuclide scanning, ultrasound, and CT or magnetic resonance imaging is necessary for early detection of this uncommon injury.