「SCAN」规则可以减少轻微中风病患的ICH误诊


  【24drs.com】March 22, 2010 — 包含「严重高血压(severe hypertension[S])、意识混乱(confusion[C])、抗凝血剂(anticoagulation[A])以及恶心呕吐(nausea and vomiting[N]);简称SCAN规则」等四项症状的规则,在轻微中风病患的颅内出血(intracerebral hemorrhage[ICH])辨识上似乎具有特定性与敏感度。
  
  SCAN 规则指出,如果轻微中风病患出现至少一项这四种预测变项,该病患可能会有ICH。相较于已经有ICH或者在治疗前需要进一步脑部影像检查(磁振造影[MRI]或计算机断层[CT])者,这项规则有助于确认哪里些病患可以安全地立即使用抗血小板制剂治疗。
  
  之前任职于英国牛津John Radcliffe医院,目前任职于伦敦St. George's医院医学中心神经科的Caroline E. Lovelock医师(MBChB, DPhil, FRACP)与研究伙伴在3月份的神经学、神经外科学与精神医学期刊(Journal of Neurology, Neurosurgery & Psychiatry)中发表他们的研究发现。
  
  Lovelock医师向Medscape Neurology表示,因为CT脑部影像对于发作几天后的急性出血较不敏感,SCAN规则对于需要优先接受MRI的迟发型病患的辨识特别有用,如此可以使ICH的误诊风险降到最低。
  
  研究者试图藉由334名轻微中风病患(定义为美国国卫院脑中风评估表分数小于等于3分)辨识出与ICH有关的临床因素,将获自此一世代的预测模式运用在另一个有280名病患的世代上加以验证,在最初世代和确认世代中,约5%的病患有ICH。
  
  研究作者写道,在医院门诊确认世代中,约24%病患有至少一种临床预测因子,但是ICH病患则有93%出现这些因子之一,如果出现两种以上临床预测因子,扫描时有25%病患发现ICH的证据。
  
  汇整最初世代和确认世代的资料后,SCAN规则侦测ICH的敏感度为97%(95%信心区间[CI]为84% – 99%)、专一度为74%(95% CI,70% – 77%)。
  
  【运用于各种健康照护环境】
  Lovelock医师表示,使用于迟发型轻微中风病患的SCAN规则,可以运用于美国和英国的健康照护体系,她指出,即使在有高度资源的健康照护体系中,轻微中风病患仍旧较慢受到注意,特别是社会弱势或地处偏远者。
  
  根据Lovelock医师表示,SCAN规则也可运用于较贫穷的国家,用来辨识哪里些轻微中风病患优先需要接受初步CT检查来排除ICH,不过,还需要先在其它健康照护环境中进行确认。
  
  Lovelock医师指出,但是,SCAN规则不可以取代脑部影像检查用来诊断ICH,它只是一种帮助拟定轻微中风患者之适当检查与治疗计画的指引,用于那些最可能有ICH之患者时的考量。
  
  【并非取代脑部影像检查】
  根据英国爱丁堡大学Enda Kerr和Rustam Al-Shahi Salman两位医师的编辑评论,SCAN规则最有用的贡献是,它的阴性预测价值达99.8%(95% CI,99% – 100%)。
  
  他们指出,对于SCAN分数0分的那70%轻微中风病患,几乎可以完全排除ICH。
  
  但是,虽然SCAN规则可以排除SCAN 分数0分者的ICH,它还不足以取代即时且适当地脑部影像检查的需要。
  
  他们指出,脑部影像检查可以藉由辨识缺血性中风的血管范围,以排除出血,排除假性中风、影响预后估计以及处置策略,所以,当有脑部影像检查设备时,对各个中风案例立即进行脑部扫描依旧是最有成本效益的策略,且可以获得最大的调整质量后存活人年。
  
  Lovelock医师、Kerr医师以及Al-Shahi Salman医师皆宣告没有相关财务关系,该研究使用的资料来自「Oxford Vascular Study」这项由英国医学研究委员会、Dunhill医学信托基金、中风协会、BUPA基金会、国家健康研究中心(NIHR)、Thames Valley Primary Care Research Partnership以及NIHR牛津生医研究中心等资助的研究。

SCAN Rule May Reduce Misdiagnosis of ICH in Patients With Minor Stroke

By Emma Hitt, PhD
Medscape Medical News

March 22, 2010 — A rule involving 4 symptoms — severe hypertension (S), confusion (C), anticoagulation (A), and nausea and vomiting (N) — appears to be specific and sensitive at identifying intracerebral hemorrhage (ICH) in patients with minor stroke.

The SCAN rule states that if at least 1 of these 4 predictive variables is present in a patient with minor stroke, the patient is likely to have ICH. The rule may help determine which patients can be safely treated immediately with antiplatelet agents compared with those who might have ICH and would need further brain imaging (magnetic resonance imaging [MRI] or computed tomography [CT]) before treatment.

Caroline E. Lovelock, MBChB, DPhil, FRACP, formerly with the John Radcliffe Hospital in Oxford, United Kingdom, and now with the Department of Neurology at St. George's Hospital Medical School in London, United Kingdom, and colleagues published their findings in the March issue of Journal of Neurology, Neurosurgery & Psychiatry.

"Because CT brain imaging becomes insensitive to an acute bleed after only a few days, the SCAN rule is particularly useful for identifying which late-presenting patients need priority access to MRI brain imaging so that the risk of misdiagnosing an ICH can be minimized," Dr. Lovelock told Medscape Neurology.

The researchers sought to identify clinical factors associated with ICH in 334 consecutive patients with minor stroke, defined as a National Institutes of Health Stroke Scale score of 3 or less. The predictive model derived in this cohort was then further validated in a separate cohort of 280 patients. Approximately 5% of patients in the initial and validation cohorts had ICH.

"In the hospital clinic validation cohort, at least 1 clinical predictor was present in 24% of patients but in 93% of patients with ICH," the study authors write. "If 2 or more clinical predictors were present, 25% of patients had evidence of ICH on scan."

Data pooled from the derivation and validation cohorts indicated that the SCAN rule had a sensitivity of 97% (95% confidence interval [CI], 84% – 99%) and a specificity of 74% (95% CI, 70% – 77%) for the detection of ICH.

Utility in Various Healthcare Settings

The SCAN rule, which is applicable to late-presenting patients with minor stroke, should be useful in both the US and UK healthcare systems, Dr. Lovelock said. Even in a highly resourced healthcare system, she noted, "patients with minor stroke may still present late to medical attention, particularly if they are relatively socially or geographically isolated."

According to Dr. Lovelock, the SCAN rule may also be useful in poorer countries, "where it can be used to identify which patients with minor stroke need priority access to early CT imaging to rule out ICH," although it still requires validation in different healthcare settings.

Dr. Lovelock noted, though, that the SCAN rule should not be used as an alternative to brain imaging to diagnose ICH. "Instead it is a guide to help plan appropriate investigations and treatment for patients with minor stroke, in whom the possibility of an underlying ICH always needs to be considered."

Not an Alternative to Brain Imaging

According to a related editorial by Enda Kerr and Rustam Al-Shahi Salman with the University of Edinburgh, United Kingdom, "the most useful attribute of the SCAN rule might be its negative predictive value of 99.8% (95% CI, 99% – 100%).

"For the 70% of patients with minor stroke who had a SCAN score of zero, ICH was almost completely ruled out," they point out.

Still, although the SCAN rule almost "rules out ICH in patients with minor strokes and a SCAN score of zero, it is insufficient to completely refute the need for timely and appropriate brain imaging."

Brain imaging can also do more than exclude hemorrhage by identifying the vascular territory of an ischemic stroke, ruling out stroke "mimics" and potentially influencing prognosis estimates or management strategies, they add. "So, where brain imaging facilities permit, immediate brain scanning for all strokes remains the policy that is most cost-effective and results in the greatest gain in quality-adjusted life-years."

Dr. Lovelock, Dr. Kerr, and Dr. Al-Shahi Salman have disclosed no relevant financial relationships. The study used data from the Oxford Vascular Study, which is funded by the UK Medical Research Council, the Dunhill Medical Trust, the Stroke Association, the BUPA Foundation, the National Institute for Health Research (NIHR), the Thames Valley Primary Care Research Partnership, and the NIHR Oxford Biomedical Research Centre.

J Neurol Neurosurg Psychiatry. 2010;81:271-275, 239.

    
相关报导
治疗高血压之关键在于改善精神分裂症患者之认知?
2016/8/4 上午 10:42:14
代谢症候群盛行率稳定但仍影响约50%的年长者
2015/5/28 上午 09:17:19
抗凝血剂相关颅内出血处置的新版指引
2015/3/9 上午 11:55:43

上一页
   1   2   3   4   5   6   7   8   9   10  




回上一页