P. T. is a 58-year-old female who is admitted with chest pain and shortness of breath and is found to have a large pulmonary embolus. Her systolic blood pressure is falling, and a diagnosis of obstructive shock is made. Cardiac pressure would likely demonstrate
Correct Answer: C
Rationale: The correct answer is C because in obstructive shock due to a large pulmonary embolus, there is increased resistance to blood flow out of the right ventricle, leading to elevated right ventricular pressure. This causes a backup of blood into the pulmonary circulation, increasing left ventricular pressure. The increased left ventricular pressure results in decreased cardiac output as the left ventricle struggles to pump against the increased resistance.
A: Elevated atrial and decreased ventricular pressures - This is incorrect as obstructive shock typically results in elevated ventricular pressures due to increased resistance.
B: Elevated right-sided and decreased left-sided pressures - This is partially true, but C is a more complete answer that explains the consequences of these pressures on cardiac output.
D: Elevated left ventricular pressure and decreased systemic vascular resistance - This is incorrect as obstructive shock leads to increased, not decreased, systemic vascular resistance due to the embolus obstructing blood flow.