An emergency room nurse initiates care for a patient with a spinal cord injury at their cervical 5 vertebra after a motor vehicle accident. Select the nurse's critical focus of care:

Choice A reason: This is not a correct explanation for the large number of leukemic white cells. Leukemic white cells are abnormal white blood cells that do not function properly. They do not attempt to take over the function of the abnormal white blood cells, but rather crowd out the normal ones.

Choice B reason: This is also not a correct explanation for the large number of leukemic white cells. Leukemic white cells do not help to protect against infection, but rather increase the risk of infection. They impair the immune system's ability to fight off bacteria, viruses, and other pathogens.

Choice C reason: This is a partially correct explanation for the large number of leukemic white cells. Leukemic white cells are larger in size than normal white blood cells, and they can clog the bone marrow. This can interfere with the production of other blood cells, such as red blood cells and platelets. However, this is not the only reason for the large number of leukemic white cells.

Choice D reason: This is the best explanation for the large number of leukemic white cells. Leukemic white cells are not as effective as normal white cells to protect against infection, because they are immature and dysfunctional. They do not respond to signals from the immune system, and they do not recognize or destroy foreign invaders. They also prevent the normal white cells from doing their job.

Choice A reason: Assessment of arms and legs movement is an important part of the neurological assessment, but it is not the critical focus of care for a patient with a spinal cord injury at the cervical 5 vertebra. This level of injury affects the phrenic nerve, which controls the diaphragm and breathing. The patient may have difficulty breathing or require mechanical ventilation.

Choice B reason: Evaluation of knee jerk reflex is not the critical focus of care for a patient with a spinal cord injury at the cervical 5 vertebra. The knee jerk reflex is controlled by the spinal cord segments L2-L4, which are below the level of injury. The patient may have normal or exaggerated reflexes, depending on the extent of the spinal cord damage.

Choice C reason: Measurement of vital signs is a routine part of the nursing care, but it is not the critical focus of care for a patient with a spinal cord injury at the cervical 5 vertebra. The patient may have abnormal vital signs due to the injury, such as low blood pressure, slow heart rate, or irregular temperature. However, these are not as life-threatening as respiratory failure.

Choice D reason: Evaluation of respiratory status is the critical focus of care for a patient with a spinal cord injury at the cervical 5 vertebra. The patient is at high risk of respiratory compromise due to the impairment of the phrenic nerve and the diaphragm. The nurse should monitor the patient's oxygen saturation, respiratory rate, depth, and rhythm, and provide oxygen therapy or mechanical ventilation as needed. The nurse should also assess the patient for signs of respiratory infection, such as fever, cough, or sputum.