An older adult is admitted to the hospital following a closed head injury from a fall that resulted in a 5-minute period of unconsciousness. Which priority nursing assessment indicates neurological deterioration in the patient?

Choice A reason: This is incorrect. After the age of 60, the plasma volume decreases and there is a decreased ability to fight infections. The decrease in plasma volume reduces the blood flow and oxygen delivery to the tissues, which impairs the immune function.

Choice B reason: This is correct. Healthy bone marrow function decreases with aging, which lowers the immune response to infection. The bone marrow produces fewer white blood cells, which are essential for fighting infections. The older adult also has a reduced response to vaccines, which makes them more susceptible to infections.

Choice C reason: This is incorrect. Older adults have an underactive antibody response to vaccines. This means that they do not produce enough antibodies to protect themselves from the pathogens that the vaccine is supposed to prevent.

Choice D reason: This is incorrect. An older person's blood is more prone to clotting, but this does not affect the infection-fighting cells. The infection-fighting cells can still travel through the blood vessels and reach the source of infection. However, the increased risk of clotting can lead to other complications such as stroke or heart attack.

Choice A reason: Completing a halo test with the fluid is the initial intervention that the nurse should perform, as it can help to determine if the fluid is cerebrospinal fluid (CSF) or not. CSF is the fluid that surrounds and protects the brain and spinal cord, and it can leak from the nose or ears after a head injury. A halo test involves placing a drop of the fluid on a piece of filter paper or gauze and observing the color and shape of the stain. If the fluid is CSF, it will form a yellowish ring around a central blood spot, creating a halo effect.

Choice B reason: Taping a sterile gauze pad under the nose and monitoring the amount of fluid is not the initial intervention that the nurse should perform, as it does not help to identify the type of fluid. It may also increase the risk of infection or pressure on the brain if the fluid is CSF.

Choice C reason: Documenting the presence of rhinorrhea is not the initial intervention that the nurse should perform, as it does not help to diagnose or treat the condition. Rhinorrhea is the medical term for a runny nose, which can have many causes, such as allergies, colds, or sinus infections. It is not a specific sign of a head injury or CSF leakage.

Choice D reason: Informing the physician of the assessment is an important intervention that the nurse should perform, but not the initial one. The nurse should first confirm if the fluid is CSF or not, as this can affect the management and prognosis of the patient. The nurse should then report the findings and the patient's vital signs, neurological status, and other relevant information to the physician.