Dobutamine:

Correct Answer: D

Rationale: Dobutamine, a β1-selective agonist, can cause arrhythmias, so no arrhythmogenic effect is false. It increases myocardial oxygen consumption by enhancing contractility, not decreases it. It's selective, not non-selective, targeting cardiac β1 receptors. It doesn't act on CNS D2 dopamine receptors but on peripheral β1. It's used in heart failure to boost cardiac output, a true statement, making it valuable in acute settings. This inotropic effect distinguishes it from non-selective agents, critical for managing cardiogenic shock.

Correct Answer: C

Rationale: Levetiracetam treats post-stroke focal seizures by modulating SV2A, offering efficacy, minimal hepatic metabolism, and low interaction risk, ideal for an elderly patient with likely polypharmacy. Phenytoin, a sodium channel blocker, controls seizures but has nonlinear kinetics and P450 induction, risking toxicity. Oxcarbazepine, similar to carbamazepine, has hyponatremia risks, concerning in the elderly. Phenobarbital sedates and interacts via P450. Levetiracetam's safety, renal clearance, and effectiveness in stroke-related epilepsy, per guidelines, make it the most appropriate here.

Correct Answer: A

Rationale: The correct way to teach a new staff nurse to obtain a blood sample from a patient with a Portacath is to provide step-by-step instructions and demonstration. Using a Portacath requires specific knowledge and technique to prevent complications such as clot formation or infection. It is important for the preceptor nurse to properly guide and supervise the new staff nurse to ensure patient safety and accurate sample collection.

Correct Answer: A

Rationale: Metoclopramide, a D2 antagonist, causes acute dystonia (e.g., oculogyric crisis). Procyclidine, an anticholinergic, rapidly reverses this IV, relaxing muscles, a suitable treatment. Benzhexol (trihexyphenidyl) works orally but is slower. Levodopa and bromocriptine, dopamine agonists, treat Parkinson's, not dystonia from dopamine blockade. Risperidone worsens it. IV procyclidine's speed is critical in acute settings, restoring normal movement effectively.

Correct Answer: D

Rationale: The statement "Dextran therapy can cause anaphylaxis or renal failure" is true. Dextran is a type of colloid solution that can cause allergic reactions such as anaphylaxis in some individuals. It can also lead to kidney damage, which is why monitoring for signs of renal failure is crucial when administering Dextran. As a result of these potential risks, dextran therapy should be used cautiously and patients should be closely monitored for adverse reactions.