What is the most appropriate nursing action when a patient on anticoagulant therapy develops sudden, severe back pain?

Correct Answer: C

Rationale: When a patient on anticoagulant therapy experiences sudden, severe back pain, the priority nursing action is to assess for signs of internal bleeding. Severe back pain in this context could be indicative of internal bleeding, such as a retroperitoneal bleed, which is a critical condition requiring immediate attention. Administering pain medication or applying a cold compress may mask or delay the identification of a potentially life-threatening situation. Repositioning the patient for comfort is not the priority when internal bleeding needs to be ruled out.

Correct Answer: B

Rationale: Verifying the blood type and patient identity with another nurse is crucial before administering a blood transfusion. This step helps prevent transfusion reactions and ensures that the correct blood is given to the right patient. Checking the patient's blood pressure, although important, is not directly related to verifying blood type and patient identity. Flushing the IV line with saline is a good practice but is not as critical as confirming the blood type and patient identity. Administering pre-transfusion medications would come after verifying the blood type and patient identity.

Correct Answer: B

Rationale: Administering oxygen and obtaining an ECG are crucial initial steps when managing a suspected myocardial infarction (MI). Oxygen helps improve oxygenation to the heart muscle, while an ECG is essential to diagnose an MI promptly. Applying a cold compress, encouraging the patient to walk, or providing a high-carbohydrate meal are not appropriate actions in the initial management of a suspected MI. Applying a cold compress can delay necessary interventions, encouraging the patient to walk may worsen the condition, and providing a high-carbohydrate meal is irrelevant to the immediate needs of a patient with a suspected MI.

Correct Answer: A

Rationale: The primary function of surfactant in the lungs is to reduce surface tension in the alveoli. This reduction in surface tension prevents lung collapse and allows for easier breathing. It is particularly crucial in premature infants to help with lung expansion. Choice B is incorrect because surfactant primarily affects surface tension, not oxygen absorption. Choice C is incorrect because surfactant's main role is not in facilitating carbon dioxide release. Choice D is incorrect because surfactant does not directly increase lung volume; its main role is in reducing surface tension.

Correct Answer: A

Rationale: The correct answer is A: Pacemaker of the heart. The SA node, known as the natural pacemaker, initiates the electrical impulses that set the rhythm for the heartbeat. It is responsible for coordinating the heart's contractions by generating electrical signals at regular intervals. Choice B is incorrect as the SA node's primary function is not related to blood pressure regulation. Choice C is incorrect as the SA node does not cause electrical conduction delay but rather initiates and conducts the electrical impulses. Choice D is incorrect as the SA node does not directly stimulate muscle contraction but rather initiates the electrical events that lead to muscle contraction.