Wang B, Bai Q, Jiao X, Wang E, White P F
Department of Anesthesiology, Beijing Tiantan Hospital, Capital University of Medical Sciences, Beijing, People's Republic of China.
J Neurosurg Anesthesiol. 1997 Oct;9(4):335-40. doi: 10.1097/00008506-199710000-00008.
Propofol is alleged to possess both pro- and anticonvulsant properties, leading to controversy regarding its use in patients with a history of seizures. Since propofol is administered for both sedation and hypnosis, it is important to understand the effects of low (0.5-1.0 mg/kg) and high (2-2.5 mg/kg) doses of propofol on the electroencephalogram (EEG). In this study, the hemodynamic and EEG effects of cumulative doses of propofol from 0.5 to 2.5 mg/kg i.v. were studied in 30 neurosurgical patients with or without a history of seizure disorders. While continuously recording from scalp EEG electrodes (F3, F4, C3, C4, P3, P4, O1, and O2), propofol 0.5 mg/kg was infused intravenously over 20 s. The same dose of propofol was reinjected four times at 2-min intervals, until a total dose of 2.5 mg/kg had been administered. The number and average amplitude of the EEG waves were counted and measured manually, respectively, from 80 to 90 s after beginning the injection of each dose of propofol. After lower propofol doses (0.5-1 mg/kg), the number of beta-waves increased, while alpha- and theta-waves decreased significantly in all patients. However, with larger doses of propofol (total dose of 2-2.5 mg/kg), the number of beta-waves decreased and delta-waves appeared. The amplitudes of all EEG waves increased and were maintained at a higher level after administration of propofol. Spike (or sharp) waves appeared in 33% of the control patients and in 40% of the epileptic group after propofol 0.5 mg/kg and in 73% of the control and 67% of the epileptic patients after the 1.5-mg/kg dose. In the majority of patients, the spike waves disappeared when additional doses of propofol were administered. One patient in the epileptic group had an EEG-recorded and clinical grand mal seizure after propofol 1 mg/kg, but the seizure disappeared after an additional 0.5-mg/kg bolus dose was administered. The propofol-induced EEG changes appeared initially at the frontal and central EEG electrodes and subsequently at the other EEG electrodes. Overall, there were no significant differences in the spectrum of EEG changes between the two patient populations. It is concluded that propofol produces similar dose-dependent effects on EEG activity in patients with or without a history of seizure disorders. While induction of anesthesia with higher doses of propofol (> 1.5 mg/kg) in neurosurgical patients with well controlled seizure disorder is safe, smaller sedative doses should be administered with caution to epileptic patients.
丙泊酚据称兼具促惊厥和抗惊厥特性，这导致其在有癫痫病史患者中的使用存在争议。由于丙泊酚用于镇静和催眠，了解低剂量（0.5 - 1.0毫克/千克）和高剂量（2 - 2.5毫克/千克）丙泊酚对脑电图（EEG）的影响很重要。在本研究中，对30例有或无癫痫病史的神经外科患者静脉注射累积剂量从0.5至2.5毫克/千克的丙泊酚，研究其对血流动力学和脑电图的影响。在持续记录头皮脑电图电极（F3、F4、C3、C4、P3、P4、O1和O2）的同时，将0.5毫克/千克丙泊酚在20秒内静脉输注。每隔2分钟重复注射相同剂量的丙泊酚4次，直至总剂量达到2.5毫克/千克。在每次注射丙泊酚后80至90秒，分别手动计数和测量脑电图波的数量和平均振幅。较低剂量的丙泊酚（0.5 - 1毫克/千克）注射后，所有患者的β波数量增加，而α波和θ波显著减少。然而，使用较大剂量的丙泊酚（总剂量2 - 2.5毫克/千克）时，β波数量减少且出现δ波。注射丙泊酚后，所有脑电图波的振幅均增加并维持在较高水平。在注射0.5毫克/千克丙泊酚后，33%的对照组患者和40%的癫痫组患者出现棘波（或尖波）；在注射1.5毫克/千克丙泊酚后，73%的对照组患者和67%的癫痫组患者出现棘波。在大多数患者中，追加丙泊酚剂量后棘波消失。癫痫组中有1例患者在注射1毫克/千克丙泊酚后出现脑电图记录的临床大发作，但在追加注射0.5毫克/千克推注剂量后发作消失。丙泊酚引起的脑电图变化最初出现在额叶和中央脑电图电极，随后出现在其他脑电图电极。总体而言，两组患者脑电图变化的频谱无显著差异。结论是，丙泊酚对有或无癫痫病史患者的脑电图活动产生相似的剂量依赖性影响。对于癫痫得到良好控制的神经外科患者，使用较高剂量的丙泊酚（> 1.5毫克/千克）诱导麻醉是安全的，但对癫痫患者应谨慎给予较小的镇静剂量。
