5-19. COMPLICATIONS OF SPINAL CORD INJURY

a. Impaired Breathing as a Result of Spinal Cord Injury.

(1) Why this happens. High in the neck (at C3, C4, and C5), motor nerves to the diaphragm branch off the spinal cord. These cervical nerves are not usually injured by fractures or dislocations of the cervical spine. If the spinal cord is damaged at the mid-cervical or upper thoracic level, the corresponding motor nerves will be paralyzed, causing paralysis of the muscles of the abdomen, arms, and legs. Injury to the mid-cervical and/or upper thoracic motor nerves can interrupt or diminish normal respiratory muscle innervation (nerve supply to a structure or area). A severe injury prevents supporting muscles from assisting with breathing (the higher the injury, the greater the disability). Less severe upper-cord injuries may diminish respiratory drive, possibly causing atelectasis (a shrunken and airless state of the lung or a portion of the lung) and pneumonia.

(2) Effect on breathing. The patient may appear to be panting and having respiratory insufficiency. That is, he is not taking in enough oxygen for his body's needs. What has happened is that the spinal cord injury in paralyzing the chest wall muscles and the abdominal muscles has caused the patient to breathe only with his diaphragm. The motion of the diaphragm causes the abdomen to move in and out with each respiration. If the diaphragm cannot take in enough oxygen, the patient may pant in order to take in more air.

(3) Treatment. Monitor the patient's respirations. Give oxygen-enriched air to a patient with weak respirations.

b. Neurogenic Shock.

(1) Description. Neurogenic shock is the result of paralysis of the nerves that control the size of the blood vessels. A paralyzed patient's arteries and veins dilate (increase in size), especially in the abdomen and the lower extremities. Bigger arteries and veins allow more blood to move through the circulatory system, decreasing the patient's blood pressure. If not enough blood is returned to the heart, the patient's circulatory system may fail.

(2) Treatment. Follow this treatment:

(a) Splint the patient's spine by placing him on a long spine board.

(b) Put the patient in the shock position (Trendelenburg position). In this position, the foot of the long spine board is elevated about 12 inches. This elevation helps blood drain from the enlarged blood vessels in the abdomen and the lower extremities, returning the blood to the heart for circulation.

CAUTION: DO NOT elevate the foot of the spine board too much. If the board is elevated too much, the patient's bowels and other abdominal viscera may fall against the underside of the diaphragm and compromise the patient's breathing mechanism.