Schmidt J Michael
Department of Neurology, Columbia University Medical Center, New York, New York, U.S.A.
J Clin Neurophysiol. 2016 Jun;33(3):268-74. doi: 10.1097/WNP.0000000000000286.
Delayed cerebral ischemia is considered the leading cause of death or major disability in subarachnoid hemorrhage after the impact of the initial event and rebleeding. Waiting to treat patients until they exhibit clinical symptoms of ischemia is too late to prevent cerebral infarction for more than 60% of patients, and transcranial Doppler ultrasonography has not proven to be a reliable screening tool to identify high-risk patients. Continuous heart rate variability monitoring may provide an alternative screening strategy to identify patients at high risk for delayed cerebral ischemia. Heart rate variability is a composite reflection of autonomic outflow, neuroendocrine influences, and autonomic responsiveness. Most importantly, heart rate variability is responsive to changes in systemic inflammation, which evidence suggests is important to the causal pathway of delayed cerebral ischemia. The clinical application of continuous heart rate variability monitoring in critical care is relatively recent despite its existence for more than 50 years. Initial studies suggest promise for heart rate variability monitoring as a delayed cerebral ischemia screening tool, but significant research is still required before this approach may achieve clinical applicability and bring benefit to patients.
迟发性脑缺血被认为是蛛网膜下腔出血在初始事件和再出血影响后导致死亡或严重残疾的主要原因。等到患者出现缺血临床症状时才进行治疗，对于超过60%的患者来说，预防脑梗死为时已晚，而且经颅多普勒超声检查尚未被证明是识别高危患者的可靠筛查工具。持续心率变异性监测可能提供一种替代筛查策略，以识别迟发性脑缺血的高危患者。心率变异性是自主神经输出、神经内分泌影响和自主神经反应性的综合反映。最重要的是，心率变异性对全身炎症的变化有反应，有证据表明全身炎症对迟发性脑缺血的因果途径很重要。尽管心率变异性监测已经存在了50多年，但在重症监护中的临床应用相对较新。初步研究表明心率变异性监测作为迟发性脑缺血筛查工具具有前景，但在这种方法实现临床适用性并给患者带来益处之前，仍需要大量研究。
