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.
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.