Correct Answer: A

Rationale: A nurse should contact the healthcare provider immediately to report a critically low potassium level of 2 mEq/L. Potassium levels below the normal range can lead to life-threatening complications such as cardiac arrhythmias. Prompt notification is essential to ensure timely intervention and prevent harm to the patient. Option B is incorrect as delaying reporting such a critical value can jeopardize patient safety. Option C is not the priority in this situation; the focus should be on patient care. Option D is dangerous and inappropriate as administering a potassium supplement without healthcare provider's guidance can be harmful, especially with a critically low level.

Correct Answer: C

Rationale: Obtaining an electrocardiogram (ECG) is the first priority in assessing for ischemia or infarction in a client with chest pain and a history of myocardial infarction. This diagnostic test provides crucial information about the heart's electrical activity and helps in identifying any acute cardiac changes. Administering oxygen therapy and nitroglycerin can be important interventions, but obtaining an ECG takes precedence as it directly assesses the client's cardiac status. Assessing the client's level of consciousness is also essential, but in this scenario, assessing for cardiac indications through an ECG is the initial step.

Correct Answer: A

Rationale: The correct answer is A: Stridor. Stridor indicates bronchospasm, a serious reaction that can compromise the client's airway. Immediate intervention is crucial to prevent further respiratory distress. Nausea, headache, and pruritus are potential side effects of ceftriaxone but are not as immediately life-threatening as airway compromise indicated by stridor.

Correct Answer: D

Rationale: The correct answer is to obtain an arterial blood gas (ABG) sample. In a client with severe hypertension, it is essential to assess for metabolic or respiratory acidosis which can be done through an ABG sample. Administering antihypertensive medication without assessing the acid-base status of the client can lead to potential complications. Monitoring urine output and administering oxygen therapy are important interventions but are not the priority in this situation where the focus should be on assessing acidosis.

Correct Answer: B

Rationale: The most important instruction for a client who recently underwent a tracheostomy is to teach tracheal suctioning techniques. Suctioning helps clear secretions and maintain an open airway, which is critical for the client's respiratory function and overall well-being. While communication tools, self-care, and cleaning the tracheostomy site are important aspects of care, ensuring proper suctioning techniques is crucial for preventing complications and ensuring the client's safety.