接上篇：临床脑电图操作的最低技术要求之记录（一）

 

3.8 记录期间若仪器设定（灵敏度、滤波、走纸速度、图像）有改变，则应在改变时将之清楚地标注在记录上。如果技术上可行，则最终的标准应包括在记录中所用的每个灵敏度和滤波的设定。在高灵敏度时记下用过的校正信号是很重要的。对于一些数字系统，增益也许就是唯一能提供的评估手段，用以评估模拟系统的功能。在一些广泛使用的校正标准，诸如上述所提到的那些都是被鼓励使用的。

 

3.9 基线记录应包含至少20min技术上令人满意的记录。记录越长久，其所包含的信息也越丰富。尽管重置数字脑电图可以让所有的记录都在一张纸上，但这种做法往往使不提倡的。仅仅只观察一幅图像往往不足以判断电极是否连接牢固，同时也会影响操作者对一些异常现象的评估，这些细微异常现象往往需要一些特殊的技术支持才能探测到（例如额外加装电极）。脑电图仅能记录患者生活中的一个小片段，在合理的限定下记录时间越长，越有可能记录到异常情况的异常状态。许多实验中心的经验显示20分钟的一段小小的无伪迹的记录对于评估脑电活动的基线状态是很有必要的。附加实验如闪光刺激、过度通气和特殊睡眠测定——如果有可能，这些均应完成并记录。

 

3.10 记录应包含患者睁眼闭眼时的脑电活动，恰当的脑电图记录要求检查刺激对于脑电图的影响，睁闭眼试验时一种很重要的评估方法。正常情况下一些被α活动掩盖的脑电节律会在睁眼时α节律减弱的情况下显现出来。某些形式的眼动可能会表现为额叶的δ或θ活动，而睁眼试验有利于这种鉴别。一些阵发性的脑电活动可能仅在睁眼或闭眼时出现，也可能在睁闭眼交替时出现，所以，如果未将睁闭眼试验作为常规脑电图测定方法就有可能会错过一些有用的信息，这项检查非常简单，所以，只要病人可以合作都应该进行，或者若患者自身不能完成这项动作，我们可以手动帮助他们完成睁闭眼动作以利检查。

 

3.11 除非用药的关系或有其他合理的原因而禁忌此项检查，否则过度通气也应作为一项常规的检测项目（特殊情况下例如近期有急性脑出血、明显的心肺疾病、镰刀状红细胞贫血，患者不能或不愿合作进行此项检查）。记录时间应不少于3min，且此中必须有至少1min的记录是在过度通气停止后记录的。有时为了获取更充分的脑电活动波形会需要患者进行一端长时间的过度通气。为了更好地评估过度通气的效果，常常需要在过度通气开始前有至少1min的脑电记录。记录中应包含有对患者过度通气努力程度评估。在记录的各个部分通过一个心电图导联记录心电活动是很有帮助的，特别是在波峰很高尖，或有脉冲波产生或有心电伪迹时，这种方法是很有帮助的。用一个额外的导联（例如第17导联），就可以继续监测心电图。

 

3.12 如果可能的话应该同时记录做睡眠脑电图和清醒脑电图，越来越多的证据表明昏迷，昏昏沉沉状态下或睡眠时记录的脑电图能够提供更多的信息。一些实验室甚至将睡眠脑电图作为常规检查项目。对于可疑抽搐或已确定抽搐情况的患者，睡眠脑电图往往是不可或缺的。

 

3.13 患者的意识水平（清醒、昏沉、睡眠或昏迷）和由此而来的一些改变，操作者都应记录在脑电图记录纸上，在记录的过程中我们要求患者做了什么动作，给了患者什么信号，以及患者有什么动作或临床痫间性活动或没有动作，我们都应在记录纸上有所记录。对患者细观察勤记录是很有必要的，特别是在有不常见的波形出现时，这种细微的工作就更为必要，缩写的使用必须规范化，以使用读者能很快明白它的含义。对于失去知觉或昏迷的病人或那些脑电图始终无变化的患者，我们应记录期间对之施之以视觉、听觉、感觉等各种刺激，这些加诸于患者的刺激以及患者对刺激的反应（无论是有还是无）均应记在脑电图记录单上尽可能近的标注刺激发生的位点上。识别出与不同意识状态相关的脑电图模式往往使脑电图仪操作者的责任，但这种操作员员对于患者临床状态的判断只能对医生提供参考，特别是当脑电图与临床情况出现矛盾或有异常相关性时，就更不能只依赖操作者的判断了。操作者确认患者处于非常清醒的状态或至少在记录时处于非常清醒的状态对于有效评价清醒的背景活动是非常重要的。

 

3.14 在对患者实施一些有一定风险性操作时必须要有合格的内科医生在场，同时配备足够的复苏设施。当然，患者本人或重要亲属或法定监护人的知情同意也是不可或缺的。

 

3.15 脑电图对于脑功能中断的评价（“脑死亡”），要求一些特别的程序和准备（具体见指南3：脑电图用于可疑死亡患者的最低基数标准）

 

 

英文原文

 

3.8 When instrument settings (sensitivities, filters, paper speed, montage) are changed during the recording, the settings should be clearly identified on the record at the time of the change. If technologically feasible, the final calibration(s) should include each sensitivity and filter settings used in the recording, and should include calibration voltages appropriate to the sensitivities actually used. It is especially important to record calibration signals at very high sensitivities when these settings have been used. With some digital systems, a gain factor display may be the only available assessment for function of the analog system. More comprehensive calibrations, such as those described above, are encouraged.

 

3.9 The baseline record should contain at least 20 min of technically satisfactory recording. Longer recordings are often more informative. Although the possibility of reformatting digital EEG allows the entire recording to be performed in a single montage, this is not acceptable practice. Observing only one montage may prevent recognition of poor connections in electrodes that happen not to be included, and also prevent appreciation of subtle abnormalities that require special technical maneuvers (such as placement of additional electrodes.)

 

The EEG is a short sample in time from the patient’s life. Within reasonable limits, the longer the recording, the better the chance of recording an abnormality or abnormalities demonstrating the variability of these. Experience in many centers shows that a very minimum of 20 min of artifact-free recording is necessary to assess baseline waking EEG activity. The addition of photic stimulation, hyperventilation, and especially sleep—which should be recorded whenever possible—often requires an increase of recording time.

 

3.10 The recordings should include periods when the eyes are open and when they are closed.

 

Proper EEG recordings requires examining the effect of stimuli upon the EEG. A comparison between the eyes-open and eyes-closed condition constitutes one important means for assessment. Some rhythms can be masked by the alpha activity and are visible only when the alpha rhythm has been attenuated by eye-opening. Certain forms of eye movement may appear to be frontal delta or theta activity but eye-opening and closing helps in differentiation. Finally, paroxysmal activity may appear only when the eyes are opened or only when the eyes are closed or at the times these conditions change. Thus, failure to record with eye-opening and closing as a routine procedure can reduce chances of obtaining potentially important information. This procedure is so simple that it is unjustifiable not to request eye-opening and closure whenever patient cooperation per-mits, or to manually open and close the eyes when it does not.

 

3.11 Hyperventilation should be used routinely unless medical or other justifiable reasons (e.g., a recent intracranial hemorrhage, significant cardiopulmonary disease, sickle cell disease or trait, or patient inability or unwillingness to cooperate) contraindi-cate it. It should be performed for a minimum of 3 min with continued recording for at least 1 min after cessation of overbreathing. At times, hyperventilation must be performed for a longer period in order to obtain adequate activation of the EEG. To evaluate the effects of this activation technique, at least 1 min of recording with the same montage should be obtained before overbreathing begins. The record should contain an assessment of the quality of patient effort during hyperventilation. It is often helpful to record electrocardiographic (ECG) activity directly on one EEG channel during this and other parts of the recording, particularly if spikes and sharp waves, or pulse or ECG artifact, are in question. With an additional (e.g., 17th) channel, the ECG can be monitored continuously.

 

3.12 Sleep recordings should be taken whenever possible but not to the exclusion of the waking record.

 

It is increasingly evident that considerable additional information can be obtained by recording during drowsiness and sleep. Some laboratories use sleep recording routinely. Sleep recording is usually essential for patients with suspected or known convulsive disorders.

 

3.13 The patient’s level of consciousness (awake, drowsy, sleeping, or comatose), and any change thereof, should be noted by the technologist on the EEG recording. Any commands or signals to the patient, and any movement or clinical seizure activity or absence thereof, should also be noted on the recording. Careful observation of the patient with frequent notations is often essential, particularly when unusual waveforms are observed in the tracing. Abbreviations used should be standardized, with their definitions readily available to the reader.

 

In stuporous or comatose patients and those showing invariant EEG patterns of any kind, visual, auditory, and somatosensory stimuli should be applied systematically during recording. The stimuli and the patient’s responses or failure to respond should be noted on the recording paper as near as possible to their point of the occurrence.

 

It is the responsibility of the electroencephalographer to recognize the patterns usually associated with different states of consciousness. However, observations by the technologist about the patient’s clinical status can be of considerable interpretative value, particularly when discrepancies or unusual correlations occur.

 

To facilitate assessing awake background activity, it is important for the technologist to ascertain that the patient is maximally alert for at least a portion of the record.

 

3.14 Special procedures that are of some risk to the patient should be carried out only in the presence of a qualified physician, only in an environment with adequate resuscitating equipment, and with the informed consent of the patient or responsible relative or legal guardian.

 

3.15 EEGs for the evaluation of cessation of cerebral function (“cerebral death”) require special procedures and extraordinary precautions (see Guideline 3: Minimum Technical Standards for EEG Recording in Suspected Cerebral Death).

 

翻译：陈文娟

编辑：格格