Utility of Transcranial Doppler in the Coordination of Transplants: 10 Years of Experience

Abstract

Transcranial Doppler (TCD) integrated to multimodal neuromonitoring of neurocritical patients is a useful tool in the clinical follow-up. A retrospective and descriptive study of 194 patients who were admitted into the intensive care unit (ICU) was carried out from December 2007 to February 2017. We analyzed the distribution of study frequencies with respect to the pathologies that motivated them, the characteristics of patients who evolved to brain death (BD), and most frequent patterns of cerebral circulatory arrest. Ninety-four of the patients that evolved to BD required 126 studies during their follow-up. The insonation of the 2 middle cerebral arteries and the basilar artery was the most frequent combination (30%). Most frequent reasons of request for a TCD included apnea test intolerance and reduction of waiting time and sedation analgesia. These 10 years of experience have enabled a deeper understanding of the cerebral hemodynamics and the identification of common patterns of high resistance to different pathologies (subarachnoid hemorrhage, severe skull trauma, anoxic ischemia, ammonia encephalopathy) that explain the severity of the acute brain injury, related to the increase of brain volume and its deleterious consequence: the elevation of intracranial pressure (ICP). In the same way, because invasive ICP monitoring is not available in all cases, with a tomographic scan of the skull we have been able to observe a correlation of some imaging signs suggestive of intracranial hypertension with patterns of high resistance obtained by the TCD in the pathologies mentioned. We recommend that each ICU that assists neurocritical patients should have TCD equipment and the skilled personnel to carry out the technique.