Nurse Pat promised to a post- surgical patient, that she would come back to assist in his ambulation after carrying out the physician's order. This follows the principle of

Correct Answer: D

Rationale: Fidelity is a principle of ethics that relates to being faithful or loyal to one's commitments and responsibilities. When Nurse Pat promises to assist the post-surgical patient with ambulation after carrying out the physician's order, she is demonstrating fidelity by honoring her commitment to the patient. This principle highlights the importance of keeping promises, being reliable, and maintaining trust in the nurse-patient relationship.

Correct Answer: C

Rationale: Humoral immunity is primarily responsible for protecting against infections by pathogens like viruses. In the case of the hepatitis B virus (HBV), the individual is exposed to the virus and develops immunity, which is typically mediated by antibodies produced by B cells. These antibodies circulate in the blood and can neutralize the virus, preventing future infections. This type of immunity is known as humoral immunity, as it involves the production of antibodies that target specific antigens, such as those present on the surface of the hepatitis B virus. In contrast, passive immunity is when antibodies are transferred from an external source, innate immunity provides immediate, non-specific defenses against pathogens, and cell-mediated immunity involves the activation of T cells to combat intracellular pathogens.

Correct Answer: C

Rationale: In a pregnant patient with suspected pulmonary embolism (PE), the most appropriate imaging modality for evaluation is contrast-enhanced computed tomography (CT) pulmonary angiography. This imaging technique has been shown to be safe for the fetus when necessary, especially if the benefits of making a diagnosis outweigh the minimal risks associated with radiation exposure. It provides quick and accurate detection of PE with high sensitivity and specificity.

Correct Answer: D

Rationale: The symptoms described by the patient indicate a potential transfusion reaction, such as a hemolytic reaction or allergic reaction. The immediate action the nurse should take in such a situation is to stop the infusion of the packed red blood cells. This will help prevent further complications and ensure the safety of the patient. After stopping the infusion, the nurse should assess the patient's condition, monitor vital signs, and inform the healthcare team, including the physician, regarding the situation. Once the patient is stable, further investigations can be conducted to determine the cause of the reaction.

Correct Answer: B

Rationale: The patient's presentation with recurrent episodes of vertigo, nausea, and nystagmus triggered by head movements, along with a positive Dix-Hallpike maneuver eliciting positional vertigo and rotary nystagmus, is classic for Benign Paroxysmal Positional Vertigo (BPPV). BPPV is the most common cause of vertigo due to a mechanical problem in the inner ear. In BPPV, brief episodes of vertigo are typically triggered by specific head movements, such as rolling over in bed or looking up. The characteristic rotary nystagmus observed in BPPV is consistent with the brief, intense episodes of vertigo that patients experience. The Dix-Hallpike maneuver, commonly used to diagnose BPPV, involves moving the patient from sitting to a supine head-hanging position and can induce vertigo and nystagmus in affected