What does Kehr's sign indicate?

Kehr's sign is a clinical indication of splenic rupture. It is characterized by referred pain in the left shoulder due to irritation of the diaphragm. The diaphragm is innervated by the phrenic nerve, and when the spleen ruptures, it can cause blood to irritate the diaphragm, leading to referred pain in that area. This is a classic symptom that healthcare providers recognize when assessing a patient who may have sustained trauma to the abdomen or who presents with significant abdominal pain.

In this context, the other conditions listed can have different presentations and symptoms. Myocardial infarction typically presents with chest pain that may radiate to the left arm or jaw, while appendicitis usually presents with pain in the right lower quadrant of the abdomen and may be accompanied by fever and nausea. Cholecystitis is associated with pain in the right upper quadrant, particularly after fatty meals, and may present with Murphy's sign, but does not typically cause referred pain to the shoulder in the manner of Kehr's sign. Therefore, the association of Kehr's sign with splenic rupture is what makes the identification of this symptom critical in emergency and critical care settings.