Congestive Heart Failure: Take Home Exam Anp 201

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6. Describe the mechanism of action of digoxin on the heart. Digoxin is an inotrope, a medication that increases the strength of heart contraction.

How will the medication help cardiac output in this patient?

When on digoxin, patients are contraindicated for any IV calcium treatment. Can you explain the dangers?

Answer part 1: According to my drug book it states that Digoxin inhibits sodium-potassium activated adenosine triphosphates, which promotes movement of calcium from extracellular to intracellular cytoplasm and strengthen myocardial contraction. By giving this medication it would promote the strengthen of the contraction where the CHF and hypertension has weaken it.

Answer part 2: According to my drug book any to pay attention to calcium levels because the digoxin can cause hypercalcemia. Which hypercalcemia is an excess of calcium in the blood. This is caused because the drug is promoting the movement of calcium, so it could get to the point where too much calcium is being pushed through the extracellular and intracellular cytoplasm.

7. Normally, when the kidneys sense a decrease in flow, they release a hormone that causes the body to retain sodium. How will this feedback mechanism affect blood pressure? Will this feedback response help the CHF?

Because of their role in the feedback mechanisms of blood flow and pressure, the kidneys are a target for medications prescribed to heart patients. Lasix is a commonly used diuretic. Explain its mechanism of action and the results for the patient.

Answer: When a patient has CHF it causes the kidney to retain more water and salt. That then causes the body to swell up. Which would cause higher amount of blood flow, which in return would be a higher blood pressure. The reason they give Lasix is to get you to pee and not hold that fluid in your kidneys or bladder. When you have diabetes and CHF it puts a higher risk of having swelling or not being able to urinate. According to my drug book Lasix inhibits sodium and chloride reabsorption. Which helps keeping the sodium out of the kidneys and expelling it through your urine.

B.

A 42 year old executive is beginning his daily workout at the local gym when he notices a slight tightness in his chest. As he continues riding the exercise bike, the pain becomes more severe and radiates to his left shoulder and jaw. He decides he is overdoing it and heads for the showers and then back to work. Ten minutes after he returns, his secretary finds him unconscious and calls an ambulance.

The paramedics arrive and they find the patient is not breathing, is pale and clammy. They begin CPR and administer TPA (tissue plasminogen activator) and take him to the hospital. They direct him to chew an aspirin and get the following vital signs.

Heart rate = 50 beats per minute/ irregular

BP = 74/48

Respiratory rate = 16 breaths per minute/ shallow

- Explain the action of the TPA and aspirin. How will they help the patient?

Answer: TPA is a molecule that promotes dissolution of blood clots. Aspirin in low doses can interfere with clotting by keeping a platelet aggregating substance from forming. Both of these medicine would help when a patient is having a heart attack by preventing and help break up blood clots in the heart where the clot is preventing the heart to pump blood effectively like it should be.

- Blood tests show:

pH of 7.18,

Lactate levels of 42 mEq/L,

Creatine Kinase of 82 IU/L,

Lactate Dehydrogenase = 130 IU/L.

How have the serum Lactate and Lactate Dehydrogenase become elevated?

Why is the pH low?

Answer : Serum lactate and Lactate Dehydrogenase have become elevated because the patient has had a heart attack and the damaged heart muscle cells have released enzymes into blood, which is why the levels were high.

- The patient is given propanolol and nitroglycerin. Explain the mechanism of action of each and why these were given.

Answer: According to my drug book propranolol is given to reduce cardiac oxygen demand by blocking catecholamine-induced increases in heartrate, BP, and force of MI contraction. Drug depresses renin secretion and prevents vasodilation of cerebral arteries. Nitroglycerin is given to reduce cardiac oxygen demand by decreasing left ventricular end-diastolic pressure and to a lesser extent, systemic vascular resistance, and also increases blood flow through the collateral coronary vessels. The two medicines given together were to help bring the blood pressure back up to normal and help the heart rate return to normal with a regular rhythm.

Reference Page

Normal ECG picture:

ECG with MI picture:

ECG with bundle branch block:

Sound of heart with CHF:

Sound of heart with Mitral Valve Stenosis:

Nursing 2016 DRUG HANDBOOK, Abramovitz, Jay, 2016