Cerebral Apoplexy (Stroke) Treated With or Without Prolonged Artificial Hyperventilation: 1. Cerebral Circulation, Clinical Course, and Cause of Death

Fifty patients with severe cerebral apoplexy were treated with artificial hyperventilation of three days' duration facilitated by general anesthesia (barbiturates and muscle relaxants) and instituted within the first day after onset of the attack. After a classification according to carotid angiographical findings, degree of consciousness and focal symptoms, a random allocation was performed so that 24 patients were subjected to moderate hypocapnia (Part,, about 25 mm Hg) and 26 patients to normocapnia (Pa-CO2 about 40 mm Hg). Afterward, 21 comparable patients not receiving ventilatory treatment were studied. The clinical course and the mortality rate showed no statistically significant differences between the three groups. All patients studied disclosed a longstanding (12 days) spontaneous hyperventilation. The ventilation treatment was followed by a low cerebral perfusion pressure and a high rate of pulmonary complications. Autopsies from all groups studied typically showed tentorial herniation and pathological lung changes. In 32 of the patients without occlusion of the carotid artery the regional cerebral blood flow was measured before hyperventilation treatment was applied. A low mean flow and focal abnormalities (ischemia, hyperemia, vasoparalysis) typically were found and in good correlation to the autopsy findings, In six of 13 patients tested an "inverse steal syndrome" following aminophylline was disclosed.