Delayed intracranial hypertension: Relationship to leukocyte count

Objective: Secondary intracranial hypertension has been linked to leukocyto sis. We examined our data bank containing physiologic recordings and outcom e data of severely head injured patients to investigate the relationship be tween delayed increases in intracranial pressure (ICP), defined as occurrin g after a 12-hr period of normal ICP values, and leukocytosis. Design: A retrospective study of observational data. Setting: Regional neurosurgical unit and intensive care unit. Patients: Sixty-four patients suffered increased ICP >20 mm Hg. Thirty-five patients fulfilled selection criteria for delayed increases in ICP (group 1). Twenty-nine patients with increased ICP with no preceding or intervenin g periods of normal ICP were selected as a comparison group (group 2). Measurements and Main Results: Comparison of 12-month outcome revealed that 11% of group 1 patients died, with 49% remaining severely disabled, in con trast to group 2, where 35% of patients died and 14% were left severely dis abled (p =.021). The pattern of outcome was independent of monitoring time, or injury severity. Regression modeling was performed for prediction of de layed increase in ICP. Of 46 patients with an initial increase then decreas e in leukocyte count in the first 48 hrs, 65% experienced delayed increases in ICP, as compared with 18% of the 11 patients without this pattern (p =. 011). Conclusions: Patients with delayed increases have a significantly different pattern of outcome. Change in leukocyte count from admission to day 2 is a significant predictor of such a delayed increase.