HESI Pharmacology Practice Exam

Correct Answer B: 100 ml/hour

Explanation:

To determine the infusion rate in ml/hour, we need to calculate the total volume to be infused and the time over which it will be infused.

Step 1: Given information.

The total volume to be infused is 50 ml.

The solution is to be infused over 30 minutes.

Step 2: Convert the infusion time to hours.

30 minutes = 0.5 hours.

Step 3: Calculate the infusion rate in ml/hour.

Infusion rate (ml/hour) = Total volume (ml) ÷ Time (hours).

Infusion rate = 50 ml ÷ 0.5 hours = 100 ml/hour.

Explanation of Incorrect Options:

A. 80 ml/hour – This would deliver 80 ml over 30 minutes, which is too low.

C. 120 ml/hour – This would deliver 120 ml over 30 minutes, which is too high.

D. 150 ml/hour – This would deliver 150 ml over 30 minutes, which is much too high.

Summary:

The nurse should program the infusion pump to deliver 100 ml/hour, which is B. 100 ml/hour.

Correct Answer C: Informing the client that this is normal

Explanation:

Mafenide acetate (Sulfamylon) is a topical antimicrobial agent commonly used to treat burn injuries. One of the well-known side effects of Mafenide acetate is local discomfort and a burning sensation upon application. These symptoms are normal and typically occur due to the penetrating effect of the medication on the damaged tissue. This sensation is often temporary and subsides as the medication takes effect and begins its antimicrobial action.

The nurse's role is to inform the client that this reaction is common and should not cause alarm unless it persists or worsens.

The nurse should reassure the client that the discomfort is part of the healing process and that the medication is working to prevent infection, a critical concern in burn injuries.

Mafenide acetate is highly effective at preventing infection in burn wounds, and the local irritation is generally short-lived and part of its mechanism of action.

Explanation of Incorrect Options:

A. Notifying the registered nurse:

While it's always good practice to communicate with the registered nurse, this particular reaction is a known side effect of Mafenide acetate. The discomfort is not indicative of a problem that requires immediate notification unless it is severe or persists.

B. Discontinuing the medication:

This is not necessary unless the discomfort becomes severe or intolerable, which would be an exceptional case. For most patients, the discomfort is a mild and temporary reaction that should not lead to discontinuation.

D. Applying a thinner film than prescribed to the burn site:

Reducing the amount of medication applied may lead to decreased effectiveness. The prescribed amount is designed to ensure adequate coverage and proper infection prevention. Applying a thinner layer is not appropriate and may compromise the treatment's efficacy.

Summary:

When applying Mafenide acetate (Sulfamylon) for burn injuries, the nurse should inform the client that the local discomfort and burning are normal side effects of the medication (option C). This sensation is generally temporary and part of the medication's mechanism of action to prevent infection. The nurse should monitor for any other adverse effects but reassure the client that this discomfort is expected.​​​​​​​

Correct Answer D: Withhold the medication and call the HCP if the pulse is less than 60 beats per minute.

Explanation of Correct Answer:

Digoxin (Lanoxin) is a cardiac glycoside used to treat heart failure and certain arrhythmias by increasing the force of contraction and slowing the heart rate. One of the most important nursing considerations when administering digoxin is to monitor the heart rate. Bradycardia (a heart rate of less than 60 beats per minute) is a known adverse effect of digoxin and may indicate digoxin toxicity or that the medication is affecting the heart too strongly. If the pulse is less than 60 beats per minute, the nurse should withhold the medication and contact the healthcare provider to ensure the safety of the client.

Why the Other Options Are Incorrect:

A. Count the radial and carotid pulses every morning.

While it is important to monitor pulse rates before administering digoxin, checking both the radial and carotid pulses every morning is not necessary. The nurse should focus on counting the radial pulse as it is more accessible. It is also essential to note that carotid pulses should be avoided in some situations, such as in patients with cervical spine issues or those prone to carotid sinus hypersensitivity, where pressure on the carotid artery could trigger bradycardia or syncope.

B. Check the blood pressure every morning and evening.

While it is important to monitor blood pressure, it is not a specific requirement when taking digoxin. Digoxin primarily affects the heart rate and contractility rather than blood pressure. However, in cases where the client also has hypertension or hypotension, it is reasonable to monitor blood pressure, but it is not the most critical action related to digoxin therapy.

C. Stop taking the medication if the pulse is higher than 100 beats per minute.

A pulse greater than 100 beats per minute does not necessarily require stopping digoxin. In fact, tachycardia is more commonly treated with digoxin, as it helps to slow the heart rate in cases of atrial fibrillation or other arrhythmias. Therefore, if the pulse is above 100 beats per minute, the medication should not be stopped, and the nurse should consult with the healthcare provider regarding any changes in treatment.

Summary:

The nurse should withhold digoxin and contact the healthcare provider if the pulse is less than 60 beats per minute, as this may indicate digoxin toxicity or excessive heart rate suppression. Monitoring pulse rate is a critical aspect of care, but checking blood pressure or stopping the medication for a pulse over 100 beats per minute is not the appropriate action.

Correct Answer A: Tinnitus

Explanation:

Salicylic acid, commonly used for conditions like psoriasis, can lead to systemic toxicity, especially when used in excessive amounts or when the medication is absorbed through the skin over a prolonged period. The primary indicator of systemic toxicity from salicylic acid is tinnitus, which is a ringing or buzzing in the ears. This symptom is a hallmark of salicylate toxicity and should be closely monitored.

Salicylic acid can be absorbed into the bloodstream when applied over large areas of the skin, potentially causing salicylate toxicity. The symptoms of salicylate toxicity are often related to high blood levels of salicylates, and tinnitus is one of the first signs that systemic levels are rising to dangerous levels. The presence of tinnitus indicates that the medication is affecting the central nervous system and may require dose adjustments or discontinuation.

Explanation of Incorrect Options:

B. Diarrhea:

While diarrhea can occur as a side effect of many medications, it is not a typical sign of systemic toxicity from salicylic acid.

C. Constipation:

This is not a common symptom associated with salicylic acid toxicity. In fact, constipation is more likely to be associated with other medications or conditions.

D. Decreased respirations:

While respiratory depression can occur in cases of severe toxicity with certain substances (such as opioids or sedatives), it is not a characteristic symptom of salicylate toxicity. Instead, salicylate toxicity typically causes hyperventilation, not decreased respirations.

Summary:

The nurse should monitor for tinnitus (option A), as it is a key sign of systemic toxicity from salicylic acid. Other symptoms of salicylate toxicity can include nausea, vomiting, confusion, and hyperventilation. If tinnitus occurs, the nurse should reassess the dosage and consult with the healthcare provider to avoid further complications.

Correct answer B: 1

Detailed explanation of the correct answer:

To calculate the volume of bumetanide to administer, we use the formula:

Volume (mL) = Desired dose (mg) ÷ Concentration (mg/mL)

Given:

Desired dose = 0.25 mg

Concentration = 1 mg/4 mL

Now, calculate the volume:

Volume = 0.25 mg ÷ (1 mg/4 mL) = 0.25 mg × (4 mL/1 mg) = 1 mL

Thus, the nurse should administer 1 mL of bumetanide.

Explanation of why the other options are incorrect:

A. 0.5 is incorrect because it underestimates the required volume based on the given concentration and dose.

C. 2 is incorrect because it overestimates the required volume for the desired dose.

D. 4 is incorrect because it is the concentration in the vial and does not correspond to the correct amount needed for 0.25 mg.

Summary:

The nurse should administer 1 mL of bumetanide

Correct Answer D: Provides adequate oxygen saturation and maintains cardiac output

Explanation:

D. Provides adequate oxygen saturation and maintains cardiac output

Prostaglandin E1 (PGE1) is used in infants with transposition of the great arteries (TGA) to maintain a patent ductus arteriosus (PDA), a vessel that allows blood to bypass the lungs in fetal circulation. After birth, the PDA usually closes, but in TGA, the blood flow needs to be maintained to ensure proper oxygenation. Prostaglandin E1 helps to keep the ductus arteriosus open, allowing for mixing of oxygenated and deoxygenated blood and increasing oxygen saturation and cardiac output until surgery can correct the anatomical defect.

Why the Other Options Are Incorrect:

A. Prevents hypercyanotic (blue or tet) spells

While prostaglandin E1 can help improve oxygenation by keeping the PDA open, it does not specifically prevent hypercyanotic spells (also known as tet spells) in TGA. These spells occur due to decreased blood flow to the lungs. The treatment for hypercyanotic spells includes knee-to-chest position, oxygen, and medications such as morphine, but PGE1 primarily ensures oxygenation by maintaining the PDA, rather than directly preventing tet spells.

B. Maintains an adequate hormone level

Prostaglandin E1 does not function to maintain hormone levels. It is used to maintain the patency of the ductus arteriosus in certain congenital heart conditions, including TGA. Hormonal regulation is not a primary effect of this medication.

C. Maintains the position of the great arteries

Prostaglandin E1 does not affect the position of the great arteries. In TGA, the great arteries are positioned incorrectly (the aorta arises from the right ventricle and the pulmonary artery from the left ventricle), and surgical correction is needed to repair this defect. PGE1 helps by keeping the PDA open but does not address the positional relationship of the great arteries.

Summary:

The purpose of Prostaglandin E1 (D) in a child with transposition of the great arteries is to maintain the patency of the ductus arteriosus, improving oxygenation and cardiac output. This is crucial for ensuring adequate oxygen saturation until surgical intervention can be performed. Other options, such as preventing hypercyanotic spells, maintaining hormone levels, or affecting the position of the great arteries, are not the functions of PGE1.

Correct Answer B: Uric acid level

Explanation:

Busulfan (Myleran) is an alkylating agent used to treat conditions such as acute myelocytic leukemia. One of the significant adverse effects of busulfan is the potential for hyperuricemia, or an elevated uric acid level in the blood. Uric acid is a byproduct of purine metabolism, and chemotherapy agents like busulfan can cause the rapid destruction of cancer cells, releasing large amounts of purines. This leads to increased levels of uric acid, which may crystallize and deposit in the kidneys or joints, causing gout or renal damage (uric acid nephropathy). To avoid these complications, the nurse must closely monitor the client’s uric acid levels during treatment.

Uric acid levels can be controlled or prevented by administering medications such as allopurinol, which reduces uric acid production, or by encouraging hydration to help flush the uric acid from the body. Monitoring the uric acid level is essential to prevent these complications from occurring, as they can result in significant renal issues and painful joint inflammation.

Explanation of Incorrect Options:

A. Clotting time – Clotting time refers to the period it takes for blood to clot. While certain chemotherapy agents can affect blood clotting, busulfan is not specifically known to cause significant changes in clotting time. Therefore, this is not the primary laboratory value to monitor during busulfan treatment.

C. Potassium level – Potassium levels are typically monitored when chemotherapy agents have a direct effect on the kidneys or electrolyte balance, such as with cisplatin or certain diuretics. Busulfan, however, is not primarily associated with causing abnormal potassium levels.

D. Blood glucose level – Busulfan does not directly affect blood glucose levels in a way that would necessitate routine monitoring. While some chemotherapy agents may cause hyperglycemia due to stress or steroid use, this is not a concern specific to busulfan.

Summary:

The primary laboratory value to monitor during busulfan treatment is the uric acid level due to the risk of hyperuricemia, which can cause gout and renal complications. Correct answer: B. Uric acid level.

Correct Answer A: The client should reschedule the appointment.

Why this answer is correct:

Fexofenadine (Allegra) is a second-generation antihistamine, which works by blocking histamine receptors to reduce allergy symptoms. However, it can interfere with allergy skin testing because it blocks the histamine response that is essential for accurate testing. To ensure the results of the skin test are reliable, antihistamines, including fexofenadine, should be discontinued for several days before the test. Therefore, the client should reschedule the allergy skin testing for a time when the medication is no longer in their system.

Why the other options are incorrect:

B. A lower dose of allergen will need to be injected.

This option is incorrect because fexofenadine inhibits the body’s normal allergic reaction to the skin test. Therefore, a lower dose of allergen would not compensate for the interference caused by the antihistamine.

C. A higher dose of allergen will need to be injected.

This is incorrect because the presence of fexofenadine prevents the body from reacting appropriately to the allergen, regardless of the dose. Increasing the allergen dose would not yield a correct result and may lead to inaccurate testing.

D. The client should have the skin test read a day later than usual.

This is incorrect because the issue with fexofenadine is that it interferes with the initial allergic response, not just the reading of the test. Therefore, reading the test a day later would not resolve the issue of the medication affecting the test’s outcome.

Summary:

Since fexofenadine can interfere with allergy skin testing, the client should reschedule the appointment to allow the medication to leave their system, ensuring accurate results.

Correct Answer B: 4 ml

Explanation:

To determine the volume of Cephalexin (Keflex) to administer, we use the formula:

Volume to administer (ml) = Dose (mg) ÷ Concentration (mg/ml)

Given:

Ordered dose = 100 mg

Concentration = 125 mg in 5 ml

Step 1: Find the concentration in mg/ml:

125 mg ÷ 5 ml = 25 mg/ml

Step 2: Calculate the volume to administer:

100 mg ÷ 25 mg/ml = 4 ml

So, the nurse should administer 4 ml of the Cephalexin suspension.

Explanation of Incorrect Options:

A. 3.5 ml – This is incorrect as the correct volume is 4 ml based on the given concentration.

C. 5 ml – This would administer more than the required 100 mg.

D. 6 ml – This would administer more than the required 100 mg.

Summary:

The nurse should administer 4 ml of the Cephalexin suspension, which is B. 4 ml.