The prognostic value of the brain sodium-potassium ATPase enzyme concentration in head injury.

Sodium-potassium adenosine triphosphatase (ATPase) enzyme was determined in the brain tissue of 11 patients with head injury and 6 control patients. Patients with head injury included in this study were selected from two categories: (a) patients in deep coma due to severe head injury [Glasgow Coma Scale (GCS) less than 8; 6 cases]; (b) patients with depressed skull fractures with dural tears who were conscious and able to give an adequate verbal response (GCS greater than 10; 5 cases). The level of the enzyme was significantly reduced in comatose patients with severe head injury as compared to the controls (P less than 0.001) or to conscious patients with depressed fractures (P less than 0.001). In the group of conscious patients with depressed fractures, the enzyme level was no different from that of the controls (P = 0.4215). All comatose patients with severely reduced enzyme levels subsequently died, whereas those with depressed fractures with normal enzyme levels survived. The relationship between a low enzyme level and brain edema in severe head injury is discussed.