Perfusion Part 6 - Flashcards
Why is chronic stress an issue?
Chronic stress = chronic cortisol secretion = no purpose for extra cortisol = adrenal insufficiency (overall depletion due to perceived overproduction).
Cortisol _____ _____ glycogen to prevent ______.
breaks down; starvation.
What are 4 common signs & symptoms of adrenal insufficiency?
- Salt cravings due to a excess Na+ excretion.
- Fatigue due to lack of glycogen breakdown.
- Hypoglycemia (post-exercise) due to lack of refill mechanism.
- Hyponatremia.
What is the danger of a non-physician monitored Keto diet?
Metabolic acidosis: breakdown of adipose tissue for energy > triglycerides > fatty acids > decline in cellular function/necrosis
Why are diabetics prone to metabolic acidosis?
They lack insulin to break down glucose, so fatty acids are used for energy.
What’s the difference between primary and secondary pulmonary hypertension?
Primary: related to organ function.
Secondary: due to diagnosed disease.
What do we use to treat pulmonary hypertension? What route of admin is used?
Nipride (DAV): endotracheal for pulmonary vasodilation.
What is a potential secondary injury that can result from pulmonary hypertension?
Cor pulmonale (right-sided heart failure) due to backlog affecting the heart.
What is the difference between an MI and heart failure (HF)?
MI: injury to cardiac cells due to lack of O2.
HF: ANY condition decreasing the heart’s ability to pump enough blood to meet metabolic demands.
What’s the difference between systolic & diastolic HF?
Systolic: contraction is affected due to muscle atrophy.
Diastolic: filling is affected due to hypertrophy decreasing chamber space.
List some major risk factors for HF.
Basically anything that can lead to decreased functional ability. CAD HTN Large MI Cardia tamponade Electrolyte imbalance (K+, Ca2+ for contraction) Arrhythmias (a. fib, bradycardia) Cardiomyopathy Diabetes Vascular dysfunction
What regulates HR, CO & BP? (4)
CNS
ANS (peripheral vascular resistance & BV)
Baroreceptors
Hormonal regulation of BP (ex: aldosterone, ADH, renin-angiotensin)
Where does the back-up occur in right-sided heart failure?
Systemic circulation (specifically: venous system).
Right-sided heart failure causes ______ pressure to build, leading to fluid shifting _________.
capillary; into cells.
What are 3 symptoms of right-sided heart failure?
- Peripheral edema (pitting due to fluid accumulation)/weight gain.
- Organ congestion: liver, renal, GI.
- Ischemia: LoC changes, fatigue.
Where does the back-up occur in left-sided heart failure?
Pulmonary circulation.
What are 3 signs & symptoms of left-sided heart failure?
- Pulmonary edema: hypoxia, hypoxemia, cyanosis.
- SoB, crackles on auscultations & coughing.
- Exercise intolerance.
Briefly describe how SNS activation leads to compensation and ultimately, worsening of CO.
Induces muscle hypertrophy of surrounding smooth muscle/fibroblast (not heart cells) > decrease in ventricle volume > CO decreases more.
What 2 substances does the SNS release to initiate compensation?
- Endothelial enzymes.
2. Cytokines (inflammatory mediators).
What are our 3 goals for pharmacotherapy of HF?
- Decrease cardiac workload.
- Increase O2 supply.
- Increase contractility.
What are 3 ways to either decrease cardiac workload or increase O2 supply?
- Decrease preload/afterload (decrease blood volume & vasodilate).
- Decrease HR.
- Oxygenate the patient.
Which 5 classes of drugs can we use to decrease preload/afterload or decrease HR to targets?
- Diuretics (ex: Spironalactone): decreases preload.
- ACE inhibitors.
- Adrenergic antagonists (receptor-specific).
- DAVs.
- Calcium channel agonists/blockers.
Besides decreasing preload/afterload, what is another benefit of using diuretics to treat HF?
Decreases sodium retention.
Which 3 drug classes are used to increase contractility?
- Cardiac glycosides.
- P inhibitors.
- Adrenergic agonists.
What is the mechanism of action of cardiac glycosides?
Affects electrolyte transport: blocks exit of Na+ > high intracellular Na+ prompts NA+/Ca2+ exchanger > brings in Ca2+ > increased contractility.
If a patient is on cardiac glycosides, we should prioritize monitoring their ____ because:
HR; cardiac glycosides slow conduction pathway at AV node.
Name 2 cardiac glycosides.
Digoxin (Lanoxin) & Digitoxin.
What is notable about Digoxin/Digitoxin in terms of ADME?
Narrow TI.
What is the mechanism of action for phosphodiesterase (P) inhibitors?
Block phosphodiesterase (PDE) > increases cAMP activity
Normally, what is the role of phosphodiesterase?
Breaks down ATP & recycles its byproducts to create more ATP.
What do we consider a “bonus” side effect of phosphodiesterase inhibitors?
Vasodilation.
Phosphodiesterase inhibitors should only be used for _____/_____ treatments.
Acute CHF/short-term.
Name 2 meds considered phosphodiesterase inhibitors.
Milrinone; amrinone.
What 3 things should we monitor for patients taking phosphodiesterase inhibitors?
ECGs, HR, BP.
Name 2 “rescue meds” considered adrenergic agonists.
- Dobutamine.
2. Dopamine HCL.
Which receptors does Dobutamine affect?
Generally: B1 specific.
Some B2 binding, but lower affinity.
Why can’t we use epinephrine as a chatacholamine (adrenergic agonist) to treat HF?
Generic: affects both alpha & beta 1 + 2.
Will increase afterload.
What are 4 things we monitor for patients on adrenergic agonists?
- Vitals.
- Angina.
- Tachycardia.
- ECGs: watch for arrhythmias.
Which 3 classes of drugs should be used to treat acute heart failure?
- Loop diuretics.
- DAVs/organic nitrates.
- B1 agonists - catacholamines.
List some risk factors for dilated cardiomyopathy.
Genetics Gender (males) Age (20-50 years old) HTN Diabetes Cardiac infection (ex: bacterial endocarditis) MI CAD Drugs (ex: cocain, ETOH)
In chronic heart failure, which parts of the acute treatment regimen should be subbed out? For what?
B1 agonists subbed out for cardiac glycosides.
DAVs subbed out for ACE/ARBs.
List 4 factors that affect AV node dysfunction.
- Ischemia.
- Drugs (ex: Digoxin, calcium channel blockers).
- Electrolytes (K+).
- Inflammation (ex: scar tissue, cardiac surgery).
How does PNS stimulation affect cardiac rhythm?
Vagus nerve stimulated > bradycardia.
What are 2 ways that we can treat arrhythmia?
- Decrease SA-AV node conduction.
2. Depress ectopy at ventricular level to enhance normal AV conduction.
Which drug will decrease SA-AV node conduction?
Digoxin.
Which 2 drugs will depress ectopy at the ventricular level in treatment of arrhythmia?
- Lidocaine (Na+ channel blocker).
2. Amiodarone (K+ channel blocker).
