Rigler’s triad consists of all except
**Core Concept**
Rigler's triad is a classic radiological finding associated with pneumomediastinum, pneumopericardium, and subcutaneous emphysema. This triad is often seen in cases of severe chest trauma or iatrogenic causes such as endotracheal intubation or positive pressure ventilation.
**Why the Correct Answer is Right**
Rigler's triad is a diagnostic hallmark of pneumomediastinum, which occurs when air enters the mediastinum through a tear in the esophagus or trachea. Pneumopericardium refers to the presence of air within the pericardial sac, which can compress the heart and compromise cardiac function. Subcutaneous emphysema is characterized by the presence of air in the subcutaneous tissue, often seen as a crepitus upon palpation. The combination of these three findings is highly suggestive of a severe underlying condition.
**Why Each Wrong Option is Incorrect**
**Option A:** Not relevant to Rigler's triad.
**Option B:** Not a component of Rigler's triad.
**Option C:** Actually a part of Rigler's triad.
**Clinical Pearl / High-Yield Fact**
Rigler's triad is a classic example of a "sentinel event" in critical care, indicating a high-risk patient who may require immediate intervention to prevent further complications.
**Correct Answer: C.**