Chen R, Bolton C F, Young B
Department of Clinical Neurological Sciences, University of Western Ontario, Victoria Hospital, London, Canada.
Crit Care Med. 1996 Apr;24(4):672-8. doi: 10.1097/00003246-199604000-00020.
To evaluate and compare the predictive powers of clinical examination, electroencephalography (EEG), and studies of short-latency somatosensory evoked potentials in determining the prognosis in anoxic coma.
Prospective case series of patients in anoxic coma, whose prognoses were uncertain based on previously established clinical criteria. The clinical features, EEG, and somatosensory evoked potentials results were correlated with outcome.
A 40-bed intensive care unit in a university teaching hospital.
Thirty-four consecutive patients admitted over a 2-yr period with anoxic coma as the principal diagnosis.
None.
Twenty-seven (79%) patients never recovered consciousness and seven (21%) patients made a good recovery. One of six patients whose pupillary reflexes were present but whose other cranial nerve reflexes were absent on day 1 recovered, but none of the seven patients with these features still present on day 3 survived. None of the patients with motor responses of extension to painful stimuli or worse on days 1 or 3 recovered. The EEGs were classified into benign, uncertain, and malignant categories. The results of both EEG and somatosensory evoked potentials studies were strongly associated with outcome. With malignant EEG, the sensitivity was 74%, the specificity was 71%, and the positive predictive value was 90% [corrected] for the prediction of no recovery (death or persistent vegetative state). However, two patients with an initially malignant EEG eventually made a good recovery. The sensitivity for low amplitude or absent somatosensory evoked potentials for prediction of no recovery was 66%. There were no falsely pessimistic predictions with somatosensory evoked potentials, as all 18 patients with absent or low-amplitude responses had no recovery (specificity and positive predictive value were 100%). EEG and somatosensory evoked potentials studies were complementary to clinical examination in the determination of prognosis. Using a combined clinical and electrophysiologic approach, 63% of patients who had no recovery could be identified by day 3. Repeat EEG and somatosensory evoked potentials studies were of value in patients whose prognoses were uncertain, as their evolution invariably correlated with outcome.
Based on the present data and a literature review, we propose that clinical examination combined with the results of EEG and somatosensory evoked potentials can be used to establish an early, definitive prognosis in a significant proportion of patients in anoxic coma. On day 3 or thereafter, patients with motor response of extension to pain or worse and malignant EEG, or those patients with flexor posturing or worse and bilaterally absent cortical somatosensory evoked potentials invariably have poor outcome. However, some patients with initially malignant EEG and normal somatosensory evoked potentials may recover and should be supported until their prognoses become more definitive.
评估并比较临床检查、脑电图（EEG）及短潜伏期体感诱发电位研究在判定缺氧性昏迷预后方面的预测能力。
针对缺氧性昏迷患者的前瞻性病例系列研究，这些患者基于先前既定的临床标准，预后尚不确定。将临床特征、EEG及体感诱发电位结果与预后情况进行关联分析。
一所大学教学医院的40张床位的重症监护病房。
在2年期间连续收治的34例以缺氧性昏迷为主要诊断的患者。
无。
27例（79%）患者未恢复意识，7例（21%）患者恢复良好。6例在第1天瞳孔反射存在但其他脑神经反射缺失的患者中有1例恢复，但在第3天仍有这些特征的7例患者无一存活。在第1天或第3天对疼痛刺激有伸展性运动反应或更差反应的患者无一恢复。EEG被分为良性、不确定和恶性三类。EEG和体感诱发电位研究结果均与预后密切相关。对于预测无恢复（死亡或持续性植物状态），恶性EEG的敏感度为74%，特异度为71%，阳性预测值为90%[校正后]。然而，2例最初EEG为恶性的患者最终恢复良好。低波幅或体感诱发电位缺失对预测无恢复的敏感度为66%。体感诱发电位没有出现假阴性预测，因为所有18例反应缺失或波幅低的患者均未恢复（特异度和阳性预测值均为100%）。在判定预后方面，EEG和体感诱发电位研究与临床检查具有互补性。采用临床和电生理联合方法，在第3天可识别出63%无恢复的患者。对于预后不确定的患者，重复进行EEG和体感诱发电位研究具有价值，因为其变化始终与预后相关。
基于现有数据及文献综述，我们提出临床检查结合EEG和体感诱发电位结果可用于在相当比例的缺氧性昏迷患者中建立早期明确的预后判断。在第3天或之后，对疼痛有伸展性运动反应或更差反应且EEG为恶性的患者，或有屈肌姿势或更差反应且双侧皮质体感诱发电位缺失的患者，预后往往较差。然而，一些最初EEG为恶性但体感诱发电位正常的患者可能恢复，应给予支持直至其预后更加明确。
