Radioisotopic bolus technique as a test to detect circulatory deficit associated with cerebral death. 142 studies on 80 patients demonstrating the bedside use of an innocuous IV procedure as an adjunct in the diagnosis of cerebral death.

A portable radioisotopic technique was developed to demonstrate cerebral circulatory deficit, as part of a collaborative study to define and diagnose cerebral death simply and rapidly, in comatose, apneic patients with electrocerebral silence. The method involves an intravenous injection of 2mCi of 99mTcO4, and recording time/activity curves over the cranial cavity and a femoral artery simultaneously, using twin probe radioisotope detector equipment. Eight comatose, apneic patients had 142 studies in conjunction with clinical electroencephalographic and other laboratory evaluations. The results indicate that the absence of a bolus tracing from the head, as contrasted to the usual bolus seen is indicative of significant circulatory deficit to the cerebrum. This test may be used as an adjunct in confirming the diagnosis of cerebral death. A normal bolus tracing should be simultaneously observed over a femoral artery and this is used as a control. The method is safe and simple and offers significant information about the irreversibility of cerebral blood flow. Although further studies are indicated, the method appears to be most promising as a fundamental bedside laboratory test in the diagnosis of cerebral death in conjunction with other clinical and laboratory criteria.