Zandbergen E G J, Hijdra A, de Haan R J, van Dijk J G, Ongerboer de Visser B W, Spaans F, Tavy D L J, Koelman J H T M
Department of Neurology and Clinical Neurophysiology, Academic Medical Centre/University of Amsterdam, P.O. Box 22660, 1100 DD Amsterdam, and Department of Clinical Neurophysiology, Maastricht University Hospital, The Netherlands.
Clin Neurophysiol. 2006 Jul;117(7):1529-35. doi: 10.1016/j.clinph.2006.03.018. Epub 2006 May 11.
To study interobserver variation in the interpretation of median nerve SSEPs in patients with anoxic-ischaemic coma.
SSEPs of 56 consecutive patients with anoxic-ischaemic coma were interpreted independently by 5 experienced clinical neurophysiologists using guidelines derived from a pilot study. Interobserver agreement was expressed as kappa coefficients.
Kappa ranged from 0.20 to 0.65 (mean 0.52, SD 0.14). Disagreement was related with noise level and failure to adhere strictly to the guidelines in 15 cases. The presence or absence of N13 and cortical peaks caused disagreement in 5 cases each. For recordings with a noise level of 0.25 microV or more, mean kappa was 0.34; for recordings with a noise level below 0.25 microV mean kappa was 0.74.
Interobserver agreement for SSEPs in anoxic-ischaemic coma was only moderate. Since the noise level strongly influenced interobserver variation, utmost attention should be given to its reduction. If an artefact level over 0.25 microV remains, absence of N20 cannot be judged with sufficient certainty and the SSEP should be repeated at a later stage.
Because of its moderate interobserver agreement, great care has to be given to accurate recording and interpretation of SSEPs before using the recordings for non-treatment decisions.
研究缺氧缺血性昏迷患者正中神经体感诱发电位（SSEP）解读中的观察者间差异。
5名经验丰富的临床神经生理学家依据一项初步研究得出的指南，对56例连续的缺氧缺血性昏迷患者的SSEP进行独立解读。观察者间的一致性用kappa系数表示。
kappa值范围为0.20至0.65（平均0.52，标准差0.14）。15例中，差异与噪声水平及未严格遵循指南有关。N13和皮层波峰的有无在各5例中导致了差异。对于噪声水平为0.25微伏或更高的记录，平均kappa值为0.34；对于噪声水平低于0.25微伏的记录，平均kappa值为0.74。
缺氧缺血性昏迷患者SSEP的观察者间一致性仅为中等。由于噪声水平强烈影响观察者间差异，应极其注意降低噪声水平。如果伪迹水平超过0.25微伏，无法足够确定地判断N20缺失，应在后期重复进行SSEP检查。
由于其观察者间一致性中等，在将SSEP记录用于非治疗决策之前，必须非常谨慎地进行准确记录和解读。
