In neurogenic shock, vasodilation occurs as a result of a loss of sympathetic tone. This can be caused by spinal cord injury, spinal anesthesia, or nervous system damage. It can also result from the depressant action of medications or lack of glucose (eg, insulin re-action or shock).
Neurogenic shock may have a prolonged course (spinal cord injury) or a short one (syncope or fainting). It is characterized by dry, warm skin rather than the cool, moist skin seen in hypo-volemic shock. Another characteristic is bradycardia, rather than the tachycardia that characterizes other forms of shock.
Treatment of neurogenic shock involves restoring sympathetic tone either through the stabilization of a spinal cord injury or, in the instance of spinal anesthesia, by positioning the patient prop-erly. Specific treatment of neurogenic shock depends on its cause. If hypoglycemia (insulin shock) is the cause, glucose is rapidly administered.
It is important to elevate and maintain the head of the bed at least 30 degrees to prevent neurogenic shock when a patient is receiv-ing spinal or epidural anesthesia. Elevation of the head of the bed helps to prevent the spread of the anesthetic agent up the spinal cord. In suspected spinal cord injury, neurogenic shock may be prevented by carefully immobilizing the patient to prevent further damage to the spinal cord.
Nursing interventions are directed toward supporting cardio-vascular and neurologic function until the usually transient episode of neurogenic shock resolves. Applying elastic compression stock-ings and elevating the foot of the bed may minimize pooling of blood in the legs. Pooled blood increases the risk for thrombus formation. Therefore, the nurse needs to check the patient daily for any redness, tenderness, warmth of the calves, and positive Homans’ sign (calf pain on dorsiflexion of the foot). To elicit Homans’ sign, the nurse lifts the patient’s leg, flexing it at theknee and dorsiflexing the foot. If the patient complains of pain in the calf, the sign is positive and suggestive of deep vein thrombosis.
Administering heparin or low-molecular-weight heparin (Lovenox) as prescribed, applying elastic compression stockings, or initiating pneumatic compression of the legs may prevent thrombus formation. Performing passive range of motion of the immobile extremities helps promote circulation.
Patients who have experienced a spinal cord injury may not report pain caused by internal injuries. Therefore, in the imme-diate postinjury period, the nurse must monitor the patient closely for signs of internal bleeding that could lead to hypo-volemic shock.