To know or not to know: does EEG monitoring in the paediatric intensive care unit add anything besides cost?
To know or not to know: does EEG monitoring in the paediatric intensive care unit add anything besides cost?
复制标题
是否知道:儿科重症监护病房的脑电图监测除了成本之外还会增加什么吗?
DOI:
10.1093/brain/awu080
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发表时间:
2014
期刊:
影响因子:
--
通讯作者:
Holmes,GregoryL
中科院分区:
文献类型:
--
作者:
Holmes,GregoryL
You are called to the intensive care unit to see a 6-year-old girl admitted with encephalitis. The child presented with 2 days of fever, confusion and lethargy and was admitted following a generalized tonic-clonic seizure lasting 8min, which was treated with intravenous lorazepam followed by levetiracetam. When you see the child she is stuporous and does not respond to verbal commands but shows no clinical signs of ongoing seizures. The staff in the intensive care unit wish to know whether they should call in a technician to obtain an EEG. In a child who has already had a convulsive seizure, is on antiepileptic therapy and is showing no signs of ongoing seizure activity, will EEG monitoring add anything to her management? In the current issue of Brain, Payne et al.(2014) provide evidence to suggest that it might. There is a long-standing controversy as to whether seizures, either clinical or subclinical, are harmful in critically ill children. Many clinicians are of the mindset that the aetiology of seizures is the determinant of outcome and that seizures themselves are simply a reflection of the severity of the underlying condition. In a condition such as encephalitis, it is argued, children with more severe disease are more likely to have seizures than children with milder forms. In other words, seizures are a marker of a severe encephalopathy but do not cause additional brain damage. As the presence or absence of seizures has no bearing on outcome, why perform expensive testing that does not alter the clinical course? According to this viewpoint, the emphasis should be on treating the cause of the seizures, not the seizures themselves. The counter-argument is that seizures, even if electrographic and without clinical manifestations, are harmful and need to be identified quickly and treated aggressively. Knowing whether seizures are harmful in the context of a severe illness is therefore of critical importance. Payne and colleagues (2014) have now provided an answer to this contentious question. The investigators prospectively evaluated 259 children who underwent continuous video-EEG monitoring upon admission to the paediatric and cardiac intensive care units at the Hospital for Sick Children in Toronto. Strikingly, seizures occurred in 36% of the children with 9% experiencing status epilepticus. To determine whether seizures had an impact on neurological function, the investigators used a Paediatric Cerebral Performance Category (PCPC) score to estimate neurological status before and after hospitalization. Neurological decline was seen in 67% of this group of critically ill children. Moreover, neurological decline was clearly related to seizures; in the children with PCPC worsening the mean seizure burden (calculated as the maximum percentage of any given hour occupied by electrographic seizures) was 15.7% compared to 1.8% for those without PCPC worsening. Using multivariable analysis, which adjusted for diagnosis and illness severity, Payne et al.(2014) show that seizures, independent of illness severity, result in increased morbidity, but not mortality. The finding that seizures, whether clinically evident or not, are associated with poor outcomes would not be surprising to basic science investigators who demonstrated decades ago in animals that electrographic seizures can result in substantial brain damage, even in the absence of seizure-induced systemic changes in oxygenation, temperature or blood pressure, or seizure-induced electrolyte abnormalities or hypoglycaemia. Meldrum and colleagues (1973) and Brierley et al.(1972) compared the brain damage caused by convulsive and non-convulsive seizures in adolescent baboons. Prolonged …