Abstract
We developed an experimental model of brain death using dogs. Brain death was induced by increasing the intracranial pressure (ICP) gradually by continuous Infusion of saline through an epidural Foley catheter in 5 mongrel dogs (weight, 18~22kg). Hemodynamic and electrocardiographic changes were evaluated continuously during the process of brain death and obtained the following results. 1. The average volume and time required to induce brain death was 4.8$\pm$1.0ml and 143.0$\pm$30.9minutes respectively. 2. There was a steady rise of the ICP after starting the constant infusion of saline, and ICP rised continuously until the brain death (122.0$\pm$62.5mmHg). After reaching to the maximal value (125.0$\pm$47.7mmHg) at 30 minutes after brain death, the ICP dropped and remained approximately constant at the slightly higher level than the mean arterial pressure (MAP). 3. MAP showed no change until the establishment of brain death and it declined gradually. The peak heart rate reached to 172.6$\pm$35.3/min at 30 minutes after the brain death. 4. Even though the body temperature and all hemodynamic variables, such as cardiac output, mean pulmonary arterial pressure, left ventricular (LV) end-diastolic pressure and LV maximum + dp/dt, were slightly greater than those of basal state, at the point of brain death, there was no statistically significant change during t e process of brain death. 5. There was no remarkable arrhythmias during the experiment except ventricular premature beats which was observed transiently in one dog at the time of brain death. Hemodynamic changes in the brain death model induced by gradual ICP increment were inconspicuous, and arrhythmias were rarely seen. Hyperdynamic state, which was observed at the point of brain death in another brain death model caused by abrupt ICP increase, was not observed.
5마리의 잡견(18~22kg)을 이용하여, 경막외강에 생리식염수를 연속 점적하여 뇌사를 유발시킨다. 뇌사발생시 점의 뇌압은 122.0$\pm$6.25mmHg이며 뇌사후 30분 최고치에 도달하였다. 뇌사를 유발시키는데 필요한 생리식염수의 양은 4.8$\pm$1.0ml이었고, 143.0$\pm$30.9분이 필요하였다. 뇌사가 올때까지 동맥압은 변하지 않지만 그후 점차 떨어지고, 맥박수는 뇌사 30분 후 안정시 보다 50% 정도 증가한 최고치에 달한다. 체온, 심박출량, 폐동맥압, 좌심실 이완말기압등의 혈역학적 지표는 뇌사진행 중에는큰 변화가 없었고, 심실 기외수축이 일시적으로 나타난 이외에는 부정맥도 관찰되지 않았다. 급작스러운 뇌압 상승 모델에서 보였던 혈역학적 변화는 관찰되지 않았다.
