Incidence of post burn hypertensive crisis in patients admitted to two burn centers and a community hospital in the United States.

Fortynine patients of 193 admitted (25%) with second and third degree burns to 3 hospitals in different geographical areas of the United States developed a hypertensive crisis within three to four days after admission. The crisis usually lasted from 5 days to about two weeks. Serum sodium levels decreased significantly in hypertensive patients one or two days before the peak of the hypertensive crisis and, in the Center where it was measured, plasma renin activity increased in an opposite trend to the fall of sodium. BUN and creatinine reached their highest levels in hypertensive patients two days after the peak of the crisis. Autopsies were performed on 23 patients who succumbed to the injury: eleven of them (48%) were hypertensive and had marked hypertrophy of left and right heart ventricles and of the adrenal glands when compared to the normotensive burn subjects. The cells of the zona fasciculata and the zona glomerulosa of the adrenal glands were very compact at histologic examination thus suggesting hyperactivity. This data shows that the incidence of hypertension in burn subjects is twice as high as that of the US population. Further studies of the renin-angiotensin-aldosterone system and the adrenal cortical function are indicated by the changes in plasma renin activity and the glandular weight and morphology seen at autopsy.