A nurse is caring for a client admitted to the intensive care unit for a cardiac dysrhythmia. The nurse understands the prescribed calcium channel blocker has which of the following mechanisms of action?
Acts on the beta cells within the heart and lungs to regulate cardiac rhythm
Increases heart rate and increases myocardial contractility
Reduces the contractility and conductivity of the heart
Increase oxygen to the systemic circulation
The Correct Answer is C
A) "Acts on the beta cells within the heart and lungs to regulate cardiac rhythm.": This statement is incorrect because calcium channel blockers do not primarily act on beta cells. Instead, they block calcium channels in cardiac and smooth muscle, which affects heart contractility and conductivity.
B) "Increases heart rate and increases myocardial contractility.": Calcium channel blockers typically do the opposite; they decrease heart rate and myocardial contractility by inhibiting calcium entry into the heart muscle cells. Therefore, this statement does not accurately describe their mechanism of action.
C) "Reduces the contractility and conductivity of the heart.": This statement accurately reflects the action of calcium channel blockers. By blocking calcium entry, these medications decrease myocardial contractility and slow down electrical conduction through the heart, which can help manage dysrhythmias.
D) "Increase oxygen to the systemic circulation.": While calcium channel blockers can improve blood flow and reduce myocardial oxygen demand by decreasing heart workload, their primary action does not directly focus on increasing oxygen delivery to systemic circulation. Their primary role is in managing heart contractility and rhythm.
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Correct Answer is A
Explanation
A) Heparin induced thrombocytopenia (HIT): Argatroban is an indirect thrombin inhibitor specifically used for anticoagulation in patients with HIT. This condition involves a significant drop in platelet counts due to heparin therapy, and argatroban is an appropriate alternative for preventing thrombosis in these patients.
B) Ventricular Dysfunction: While managing anticoagulation may be important in patients with ventricular dysfunction, this condition does not specifically necessitate the use of argatroban. Other anticoagulants may be used based on the clinical situation.
C) Myocardial infarction: Although anticoagulation may be warranted in the setting of a myocardial infarction, argatroban is not specifically indicated for this condition. Other antithrombotic therapies, such as aspirin or heparin, are more commonly used.
D) Hepatotoxicity: Argatroban is metabolized in the liver, so caution is warranted in patients with liver dysfunction. Hepatotoxicity itself would not be a reason to use argatroban; rather, it may require close monitoring or adjustment of dosage.
Correct Answer is ["C","D","E","F"]
Explanation
A) Constipation: While constipation can occur with digoxin use, it is not a classic sign of digoxin toxicity. Therefore, it is less critical for the client to monitor this symptom specifically in relation to toxicity.
B) Dark red urine: Dark red urine is not typically associated with digoxin toxicity. This symptom could indicate other conditions, such as blood in the urine or issues with the kidneys, but it is not a direct manifestation of digoxin toxicity.
C) Bradycardia: Digoxin toxicity can lead to bradycardia, characterized by a slower than normal heart rate. The client should be instructed to monitor their pulse and report any significant changes, especially if the heart rate drops below 60 beats per minute.
D) Nausea: Nausea is a common symptom of digoxin toxicity. Clients should be aware of this and report any persistent or severe nausea, as it may indicate that the digoxin levels in their system are too high.
E) Vomiting: Vomiting is another classic sign of digoxin toxicity. Clients should be instructed to report any episodes of vomiting, as this can further complicate their condition and may require adjustment of their medication.
F) Anorexia: Anorexia, or loss of appetite, can also occur with digoxin toxicity. Clients should be advised to monitor their appetite and report any significant changes, as this can be an early indicator of toxicity.