In assessing a patient before administration of a cardiac glycoside, the nurse knows that which lab result can increase the toxicity of the drug?

Correct Answer: A

Rationale: The correct answer is A: Potassium level 2.8 mEq/L. Low potassium levels can increase the toxicity of cardiac glycosides as they compete for the same binding sites on cardiac cells leading to enhanced drug effects. Potassium plays a crucial role in cardiac function, and low levels can potentiate the risk of cardiac glycoside toxicity. This can result in serious cardiac arrhythmias and even cardiac arrest. Summary: - Choice B: Potassium level 4.9 mEq/L is within normal range and would not increase toxicity. - Choice C: Sodium level 140 mEq/L is not directly related to cardiac glycoside toxicity. - Choice D: Calcium level 10 mg/dL is not typically associated with increased toxicity of cardiac glycosides.

Correct Answer: D

Rationale: The correct answer is D because active transport involves the movement of molecules against their concentration gradient, requiring energy expenditure. This process is crucial for maintaining cellular homeostasis and ensuring proper functioning of cells. Options A, B, and C are incorrect because active transport is not based on diffusion, does require energy consumption, and does not involve engulfing of molecules by vesicle formation. It is important to understand the fundamental concept of active transport to differentiate it from passive transport mechanisms.

Correct Answer: B

Rationale: The increase of second messengers concentration, such as cAMP, cGMP, and Ca2+, leads to the activation of protein kinases and subsequent protein phosphorylation. This is because second messengers act as signaling molecules that trigger a cascade of intracellular events, including the activation of protein kinases. Protein kinases then phosphorylate target proteins, modulating their activity and initiating various cellular responses. Therefore, choice B is correct as it accurately describes the downstream effect of increased second messengers' concentration. Choices A, C, and D are incorrect because they do not align with the established signaling pathway involving second messengers and protein kinases.

Correct Answer: D

Rationale: The correct answer is D: Spinal anesthesia. Spinal anesthesia involves injecting local anesthetics directly into the subarachnoid space, which is within the spinal canal. This allows for the anesthetic to block sensation in the lower part of the body. Topical anesthesia (A) is applied to the surface of the skin, infiltrative anesthesia (B) involves injecting local anesthetics into tissues surrounding the surgical site, and regional anesthesia (C) includes nerve blocks to numb specific areas. Spinal anesthesia is distinct as it targets the spinal nerves directly within the epidural or subarachnoid spaces.

Correct Answer: D

Rationale: The correct answer is D: Weakness of all skeletal muscles. Excessive stimulation of muscarinic receptors would not lead to weakness of skeletal muscles because muscarinic receptors are mainly found in smooth muscles and glands, not skeletal muscles. A: Abdominal cramps, diarrhea, B: Increased salivation, excessive bronchial secretion, and C: Miosis, bradycardia are all symptoms of excessive muscarinic receptor stimulation as these receptors are involved in various functions in the body such as gastrointestinal motility, salivation, bronchial secretions, pupil constriction, and heart rate regulation.