American Board of Surgery Qualifying Exam (ABS QE) Practice Test

In the context of shock, high pulmonary capillary wedge pressure (PCWP) is indicative of the heart's inability to effectively pump blood, leading to fluid backing up into the lungs. This condition is primarily seen in cardiogenic shock, which arises from inadequate cardiac output due to heart failure, myocardial infarction, or any condition that directly affects the heart's ability to function.

In cardiogenic shock, the failing heart results in elevated pressures in the left atrium and subsequently in the pulmonary circulation, causing an increase in PCWP. This increase reflects the degree of left atrial pressure and provides insight into the fluid status of the lungs. Consequently, patients may experience pulmonary congestion and edema as a result.

In comparison, hypovolemic shock is characterized by a decrease in blood volume which typically leads to low PCWP. Distributive shock, often seen in conditions like septic shock, can also show low or normal PCWP due to peripheral vasodilation and relative hypovolemia. Neurogenic shock, a form of distributive shock, is similar in that it does not result in elevated PCWP due to the lack of fluid overload.

Thus, the recognition of high PCWP is vital in diagnosing cardiogenic shock, making it a key characteristic