Hemodynamics — Flashcards

Flashcard 131: One finding in the Cushing reaction is hypertension, which is caused by increased _____ tone

Answer: sympathetic

Extra: The Cushing reflex (or reaction) is a physiological response to increased intracranial pressure (ICP), resulting in the Cushing triad: hypertension, bradycardia, and irregular respirations. Increased ICP results in compressed cerebral arterioles → cerebral ischemia → sympathetic activation → hypertension to maintain cerebral perfusion pressure (CPP = MAP - ICP).

Flashcard 132: The _____ is the point at which the vascular function curve intersects the x-axis

Answer: mean systemic pressure

Flashcard 133: What is the effect of cardiac tamponade on cardiac output? _____

Answer: Decreased CO

Flashcard 134: In response to increased Pco2 in the brain, there is intense peripheral _____

Answer: vasoconstriction

Flashcard 135: A(n) decrease in TPR causes a(n) _____ rotation of the vascular function curve

Answer: clockwise

Flashcard 136: Eisenmenger Syndrome leads to a decreased O2 saturation in the _____

Answer: LV

Flashcard 137: An increase in mean systemic pressure is reflected in a shift of the vascular function curve to the _____

Answer: right

Flashcard 138: _____ pulse pressures are seen in conditions that decrease left ventricular stroke volume

Answer: Decreased

Flashcard 139: The blood volume contained in the veins is called the _____

Answer: unstressed volume

Flashcard 140: _____ is a good approximation of left atrial pressure

Answer: Pulmonary capillary wedge pressure (PCWP)

Extra: See right panel below. A catheter is inserted through the venous side to the right ventrical and then to a small pulmonary artery. A balloon is inflated to occlude blood flow and a sensor on the tip of the ballon senses the pressure behind the balloon. This pressure is effectively the pressure of the capillaries behind the balloon. This capillary pressure is a proxy for the pressure in the left atrium (there should be no theoretical increase or decrease in pressure between the capillaries and the left atrium). This avoids having to go into the arterial side to meaure the left atrial pressure, which would be much more invasive.