A nurse is providing care for a client experiencing obstructive shock. Which of the following diagnoses should the nurse expect?

The correct answer is A: Cardiac tamponade. In obstructive shock, there is impaired filling of the heart due to an obstruction preventing adequate cardiac output. Cardiac tamponade, where fluid accumulates in the pericardial sac, can lead to decreased cardiac output and contribute to obstructive shock. The other choices are incorrect because: B) Third spacing refers to fluid shifting from the intravascular space into the interstitial space, not directly related to obstructive shock. C) Ruptured aneurysm would lead to hypovolemic shock from sudden blood loss, not obstructive shock. D) Cardiomyopathy is a structural or functional abnormality of the heart muscle, which may lead to different types of shock, but not specifically obstructive shock.