The client has been hospitalized after a severe head injury. The nurse recognizes that the client's difficulty in maintaining a normal body temperature when there is no infection present can be the result of which of these?

A. The patient's blood pressure must remain elevated during several separate assessments in order to make a diagnosis of hypertension. Hypertension is diagnosed based on persistently elevated blood pressure readings across multiple visits, rather than a single elevated measurement.
B. The patient appeared extremely stressed and the health care provider decided not to inform the patient of the diagnosis at that appointment. While stress can temporarily elevate blood pressure, a diagnosis should be based on multiple readings rather than withholding information from the patient.
C. The patient's primary health care provider must consult with a cardiologist in order to make a diagnosis of hypertension. A cardiology consult is not required to diagnose hypertension; primary care providers can diagnose and manage hypertension independently.
D. The patient's blood pressure must be at least 180/100 during a single assessment in order for a diagnosis of hypertension to be made. A reading of 180/100 mmHg indicates hypertensive crisis, but hypertension is diagnosed when blood pressure is consistently ≥140/90 mmHg on multiple occasions.

A. Errors by the nurse assistant in measuring temperature. While improper technique can lead to inaccurate readings, consistent temperature fluctuations in a head injury patient are more likely due to hypothalamic dysfunction.
B. Increased vasodilatation of the superficial vessels contributing to excess heat losses. Vasodilation can play a role in heat loss, but it does not fully explain difficulty maintaining body temperature, which is primarily regulated by the hypothalamus.
C. The client's head injury causing interference with the function of the hypothalamus. The hypothalamus regulates body temperature, and a severe head injury can disrupt this function, leading to temperature instability (neurogenic fever or hypothermia) despite the absence of infection.
D. Choosing the wrong time of day to obtain vital signs. While body temperature naturally fluctuates throughout the day, major instability in temperature regulation is not due to the timing of measurement but rather an issue with the hypothalamus.