Hemodynamic responses to penetrating spinal cord injuries

Although the hemodynamic response to blunt spinal cord injury has been well described, much less is known about the responses to penetrating spinal cord injuries. In order to elucidate any differences, we reviewed the last 75 patients treated over the past 12 years with penetrating spinal cord injuries. There were 67 men and eight women; the mean age was 26.2 years (range, 15-59 years); 73 patients suffered 120 gunshot wounds; one patient was injured with an ice pick; one was stabbed twice. The offending missile causing spinal cord injury entered the neck in 24%, the thorax in 56%, and the abdomen in 20%. Nine patients (12%) were complete quadriplegics and 49 patients (65%) were complete paraplegics; 69 patients (92%) had no rectal tone; 17 patients (22%) had incomplete injuries. Despite the high proportion of complete spinal injury (78%), only 18 patients (24%) were hypotensive in the field. Five additional patients became hypotensive in the ED. Of the 23 patients with hypotension, 18 (74%) had significant blood loss to explain their low blood pressure. The mean HR was 100 beats/minute in the field (range, 50-130 beats/minute) and 90 beats/minute in the ED. Only five patients (7%) demonstrated the classic presentation of neurogenic shock (hypotension and bradycardia). This classic presentation of neurogenic shock is rare following penetrating spinal cord injury. Despite evidence of a complete spinal cord injury on initial physical examination, hypotension is usually secondary to blood loss in these patients. A careful search for sources of blood loss is mandatory before ascribing hypotension to spinal injury.