Correct Answer: A

Rationale: The clinical presentation of recurrent fever, sore throat, cervical lymphadenopathy, leukocytosis with atypical lymphocytes, and positive heterophile antibody test (Monospot test) is highly indicative of infectious mononucleosis caused by the Epstein-Barr virus (EBV). EBV is a member of the herpesvirus family and is a common cause of infectious mononucleosis. The atypical lymphocytes seen on peripheral blood smear are reactive T lymphocytes responding to the EBV infection. The Monospot test detects heterophile antibodies produced in response to EBV infection.

Correct Answer: D

Rationale: It is NOT recommended to use the same syringe and needle in administering two different vaccines. This is to prevent contamination or mixing of different vaccines, which could potentially affect their effectiveness or pose a risk to the individual receiving the vaccines. It is important to use separate syringes and needles for each vaccine to ensure proper administration and prevent any adverse reactions.

Correct Answer: C

Rationale: In a primiparous patient who complains of unrelieved perineal pain on the first postpartum day, Nurse Kayla should assess for a perineal hematoma. A perineal hematoma is a collection of blood in the perineal tissues and can cause significant pain and discomfort. It can be a result of trauma during delivery or due to a blood vessel rupture. This condition requires prompt assessment and intervention to prevent complications such as infection or excessive bleeding. Vaginal laceration would typically be identified during the delivery process and would have been repaired by the healthcare provider. History of drug abuse, while important to know for overall patient care, is not as relevant in this immediate postpartum pain assessment. Puerperal infection usually presents with other signs such as fever, foul-smelling discharge, and uterine tenderness, which are not mentioned in this scenario.

Correct Answer: D

Rationale: The clinical presentation of chest pain, dyspnea, and a friction rub heard on auscultation is suggestive of pericarditis. The diffuse ST-segment elevation seen on the electrocardiogram (ECG) is a classic finding in pericarditis, known as the "universal sign." In contrast, stable angina typically presents with chest pain on exertion that is relieved by rest or nitroglycerin, while unstable angina presents with chest pain at rest or with minimal exertion. Acute myocardial infarction would typically present with ST-segment elevation in specific leads correlating with the area of myocardial ischemia/infarction. However, in the context of diffuse ST-segment elevation and symptoms suggestive of inflammation (friction rub), the most likely diagnosis is pericarditis.

Correct Answer: C

Rationale: In a missed abortion, the embryo has died, but the products of conception remain in the uterus, leading to the visualization of a gestational sac without an embryo on ultrasound. This is a type of missed miscarriage where the woman may not have any symptoms initially and the diagnosis is made during a routine ultrasound. The most common presenting symptom is painless vaginal bleeding. The absence of an embryo within the gestational sac can be confirmed through serial ultrasound examinations showing no fetal growth or cardiac activity. It is important for healthcare providers to provide appropriate counseling and management options to support the patient through this emotional experience.