Abstract
In the Emergency and Critical Care Center, there were many subarachnoid hemorrhages (SAH) in cardiopulmonary arrest (CPA) patients detected by CT or autopsy. We thought that not all of these were caused by rupture of an aneurysm. So to determine the etiology of SAH in CPA patients, we conducted experiments using Wistar rats (200g) in cardiac arrest after apnea. Thirty-eight rats anesthetized with Eter were intubated after receiving a muscle relaxant and under mechanical ventilation. In 17 rats in which cardiac arrest was induced by ventilation-off, cardiopulomary resuscitation (CPR) with catecholamine was attempted as soon as possible. In 8 of these rats CPR was successuful, All rats were examined at autopsy. In macroscopic changes, SAH was detected in 5 rats with successuful CPR and in 1 rat with non-cariac arrest. According to Fisher's analysis, there was a close relationship between successuful CPR and SAH in the 17 cardiac arrest cases. In microscopic changes, there was no aneurysm or thrombosis of the vessel, and we thought the rupture of a venule on the surface of the cortex was the bleeding point of SAH. We suspected that the etiology of SAH in cardiac arrest is, first, vasoparalysis after recirculation ohe cerebral blood and, second, increased venous pressure due to increased intrathoracic pressure caused by cardiomassage and positive pressure ventilation.
