Ch 22 Flashcards
At what point in cardiac failure does fluid retention begin? Make it make sense physiologically, briefly
- Heart’s pumping capability is reduced to a point
- Insufficient blood flow to the kidneys
- Kidneys cannot excrete enough salt and water to equal salt and water intake
- fluid retention begins
What are the detrimental effects of excess fluid retention in severe cardiac failure?
- Increased workload on the damaged heart
- Overstretching the heart
- Filtration of fluid through the lungs leading to pulmonary edema and deoxygenation of the blood
- Extensive edema develops elsewhere in the body
In a sentence, what is decompensated heart failure?
When cardiac output and right atrial pressure diverge (CO decr, RA incr) because of reduced cardiac pumping ability coupled with fluid retention that still will not deliver adequate blood volume to the kidneys
Name two drugs (or categories) that would slow decompensation
Cardiotonic drugs like digoxin, and diuretics
What is the mechanism of action of digoxin?
-Increase amt of calcium in muscle fibers
-Inhibits the Na/K ATP pump, increasing intracellular sodium and slowing the Na/Ca exchange pump
-This increases the calcium ion concentration in the cardiac muscle
What is the mechanism of action of digoxin?
-Increase amt of calcium in muscle fibers
-Inhibits the Na/K ATP pump, increasing intacellular sodium and slowing the Na/Ca exchange pu
Briefly, what are the consequences of unilateral heart failure?
-Usually this is L sided
-L side cannot pump blood out of pulmonary and into systemic circulation effectively
-Mean pulmonary filling pressure rises
-Pulmonary capillary pressure increases until it equals colloid osmotic pressure
-Pulmonary edema
Why do the kidneys produce less urine in cardiac failure?
-. Decreased glomerular filtration rate
- Activation of the RAAS and increased reabsorption of water and salt by the renal tubules
- Increased aldosterone secretion
- Activation of the SNS
