A patient is admitted to the emergency department (ED) for shock of unknown etiology. The first action by the nurse should be to

Assessing the patient's level of consciousness is a critical initial step in evaluating a patient with shock. Altered mental status or decreased level of consciousness can be indicative of inadequate cerebral perfusion and may require immediate interventions to address compromised brain function and ensure patient safety.
While all the options mentioned are important in the assessment and management of a patient in shock, checking the level of consciousness takes priority as it provides essential information about the patient's neurological status and helps guide further interventions.
A. Obtaining the blood pressure in (option A) is incorrect because Assessing blood pressure is crucial in evaluating a patient in shock, but it can be done in conjunction with checking the level of consciousness and other vital signs.
C. Administering oxygen in (option C) is incorrect because: Administering oxygen is important in managing shock, as tissue hypoxia is a key concern. However, it can be done simultaneously with assessing the level of consciousness and initiating other interventions.
D. Obtaining a 12-lead electrocardiogram (ECG) in (option D) is incorrect because While an ECG may provide valuable information about the patient's cardiac function, it is not the first priority in a patient with shock of unknown etiology. Assessing the level of consciousness and vital signs takes precedence.

In this scenario, the patient's signs and symptoms suggest a state of shock, which can be caused by various factors, such as hypovolemia, cardiac dysfunction, or systemic vasodilation. The first priority in managing a patient in shock is to ensure adequate oxygenation and tissue perfusion. Administering oxygen at 100% per non-rebreather mask helps improve oxygen delivery to the tissues and supports vital organ function.
A. Placing the patient on a continuous cardiac monitor in (option A) is incorrect because it is an important step to monitor the patient's heart rhythm and identify any abnormalities. However, providing oxygen should take priority to address the potential hypoxemia and tissue hypoperfusion.
C. Inserting two 14-gauge IV catheters in (option C) is incorrect because it is crucial for establishing large-bore access for fluid resuscitation and medication administration. While it is an important step, addressing oxygenation takes precedence.
D. Drawing blood to type and crossmatch for transfusions in (option D) is incorrect because it is an important step in managing a patient in shock who may require blood products. However, ensuring adequate oxygenation through oxygen administration is the immediate priority.
Therefore, the nurse should act first on the order to administer oxygen at 100% per non-rebreather mask to support the patient's oxygenation and tissue perfusion.