The Nervous Factor in Burns

Abstract

While evidence has been accumulating concerning the importance of a nervous factor in the etiology of traumatic shock,1-3 similar studies of the problem of burns have not been carried out.

A comparison was made of the effects of thermal trauma to one hind leg in control cats and in spinal animals. Transection of the spinal cord at L₁ or T₁₁ effectively eliminated the influence of afferent nerve impulses from the burned leg but left the major vasoconstrictor outflow from the spinal cord intact.

The experiments were performed on 83 adult cats, anesthetized throughout the procedure with pentobarbital sodium. One hind leg was burned with a Bunsen flame for 10 or 15 minutes. The spinal cord was transected about 30 niiiiutes preceding application of thermal trauma. Observations were made of blood pressure (carotid cannula), hemoglobin and specific gravity of whole venous blood, (falling drop technique), respiration, body temperature, survival, local fluid loss in the burned limb and pathology.

In control cats, burning resulted in an abrupt rise in arterial pressure from 120 to 160 mm Hg. The blood pressure remained high and only reached the original level after 10 hours. On the other hand, arterial pressure fell sharply in spinal cats during thermal trauma from an initial 90 mm Hg to 60 mm Hg; it was restored in the course of 1.5 hours and then maintained between 100 and 80 mm Hg. While arterial pressure fell quickly to 90 mm Hg as a result of spinal transection alone, without burning it remained at about this level for many hours. The rise in blood pressure from burns in control cats is thus apparently reflex and masks an initial sharp fall due to non-nervous factors.