Prediction of the Evolution to Brain Death in the Neurocritical Patient: SPN Model Showed Better Performance Than Simplified Acute Physiology Score II and Acute Physiology and Chronic Health Evaluation II.

The detection of brain death (BD) plays a fundamental role in the management of hospital donation. Delayed diagnosis of BD is the main cause of donor loss. A tool for monitoring and prognosis in the neurocritical patient is essential to meet these objectives. The most used prognostic scores in intensive care units are Simplified Acute Physiology Score (SAPS) II and Acute Physiology and Chronic Health Evaluation (APACHE) II. A predictive model of good performance (ModSPN) in predicting BD in neurocritical patients with Glasgow Coma Scale score < 8 was published in 2014. With the objective of analyzing the predictive capacity of ModSPN and comparing it with SAPS II and APACHE II, 2307 patients admitted to the neurocritical patient monitoring (SPN) program of the INDT were analyzed. The predictive capacity for death and brain death of SAPS II, APACHE II, and ModSPN was compared using receiver operating characteristic curves. The area under the curve showed a better APACHE II performance for the prediction of death and the ModSPN being a better predictor of the probability of dying in BD. Therefore, for the prediction of death in the neurocritical patient, APACHE II was superior, but for the prediction of encephalic death, the ModSPN presented the best predictive power for all causes of brain injury.

Addressing a Diagnosis of Brain Death in Hypernatremia Situation.

Hypernatremia and the state of plasma hypertonia are part of the alterations of insipid diabetes that are integrated to the brain death (BD) syndrome. Hypernatremia should be corrected as early as possible to make the clinical diagnosis of BD and to avoid its potential deleterious effect on the subsequent operation of the liver graft. Transcranial Doppler is a very valuable tool for the diagnosis of cerebral circulatory arrest associated with BD. The correction of natremia is made through the use of hypotonic solutions, and using of pyrogen-free distilled water intravenously in special cases, which controls the possibility of hemolysis in the donor. In our study, isolated severe hypernatremia corrected before ablation was not associated with liver graft failure in the recipient.

Organ Donation and Primary Central Nervous System Tumors.

Primary central nervous system tumors can be the cause of brain death. Not all of them contraindicate the donation of organs and tissues for transplant. A survey of cases was carried out in our country in which it was observed that the number of brain deaths caused by primary tumors was low, of the order of 2%, with an x (media) of 3 by year, which would increase the potential for donation. Medical records, an anatomopathologic study, and a detailed physical examination will be fundamental when applying the donor selection criteria. Nuclear magnetic resonance in expert hands has a sensitivity of 96% to catalog the benignity or malignancy of this type of tumors.

Intensive Care Unit Approach to the Diagnosis of Brain Death in Infratentorial Neurologic Pathology: Case Reports.

The ischemic and primary vascular injury of the brainstem (BS) can determine, among other serious conditions, the brain death (BD) of the individual. We present 2 cases of individuals with primary ischemic vascular disease of the BS who evolved to BD and were donors of solid organs and tissues. In both cases, the clinical examination was positive for the diagnosis of BD, and transcranial Doppler did not confirm the pattern of cerebral circulatory arrest that accompanies BD. The magnetic resonance angiography performed on 1 patient confirmed the lesion etiology and the presence of vascular obstruction. Both patients were real and effective organ and tissue donors. In these cases, we suggest not to resort to transcranial Doppler as an auxiliary diagnostic test.

Does Traumatic Brain Injury by Firearm Injury Accelerates the Brain Death Cascade? Preliminary Results.

Brain death (BD) triggers a series of pathophysiological events similar to multiple-organ dysfunction. Traumatic brain injury (TBI) due to firearm injury (FAI) causes lesions that could lead to BD. Patients admitted to the ICU due to severe TBI that evolved to BD were studied, including those caused by FAI; the 2 groups were compared with the objective of demonstrating that the support of the deceased donor by TBI due to FAI is more unstable and of shorter duration than the one related to TBI by another cause. Preliminary results demonstrated that the individuals with TBI by FAI died in BD in a higher percentage than the individuals with TBI caused by accidents (83% vs 41%). The donor treatment period was lower in individuals who presented TBI by FAI. These individuals needed higher doses of noradrenaline as vasopressor support for their treatment, without showing a statistically significant difference (P = .15), compared with individuals whose BD cause was TBI caused by accident.

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

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.

Systodiastolic Separation Expresses Cerebral Circulatory Arrest?

There is a situation before the cerebral circulatory cessation phase, the systodiastolic separation in transcranial Doppler (TCD), which may raise doubts to the operator technician who performs it. A total of 266 studies were performed in 188 neurocritical patients over a 9-year period: 88 cases (77%) corresponded to cerebral circulatory arrest (CCA) which accompanies brain death (BD); 9 (5%) presented the systodiastolic separation pattern. In 1 of those 9 there was persistence of cough reflex and spontaneous breathing; in 5, CCA was not reached; only 3 evolved to CCA. The finding of a minimal persistent neurologic semiology is a categoric fact that would rule out the clinical correlation between this pattern and BD diagnosis.

Transcranial Doppler in the diagnosis of cerebral circulatory arrest: cases of the National Institute of Donation and Transplantation of Uruguay.

BACKGROUND: Transcranial Doppler (TCD) is an auxiliary method for the diagnosis of cerebral circulatory arrest (CCA). The objective of this work was to appreciate the efficiency of the method in the diagnosis of the CCA and its outcome in situations such as decompressive craniectomy (DC). METHODS: In this descriptive, retrospective study, conducted between 2000 and 2012, variables considered were causes of brain death (BD), age, sex, application reason, CCA patterns, and CCA patterns in DC. As a statistical approach, Pearson χ(2) distribution was used. A total of 522 cases were analyzed; mean patient age was 30 ± 19 years, and 61% were men. RESULTS: The principal causes of BD were traumatic brain injury, 44%; subarachnoid hemorrhage, 20%; and post-cardiac arrest anoxic ischemic injury, 17%. TCD was requested by contraindication to apnea testing in 84% of cases, and it diagnosed CCA in 79%. The most frequent pattern of CCA was the systolic spike (70%). CCA was diagnosed in patients with DC in 43% (23/54) compared with 79% (369/468) in those patients without this procedure (P = .0001), with the systolic spike being the most frequent pattern (48%). CONCLUSIONS: TCD is a useful and highly specific tool for the diagnosis of CCA that occurs with BD, diminishing its performance significantly in patients with DC.