The use of propofol in status epilepticus]

Three cases of status epilepticus not responsive to an aggressive treatment are described. The seizures and EEG activity were rapidly brought under control with a continuous infusion of propofol (3-6 mg/kg/hour), maintained between 21 hours and 7 days. Patient awakening at the end of the infusion period was rapid and without sequelae.     

Effect of propofol on visual evoked potentials during neurosurgery

BACKGROUND: Evoked potentials are used to monitor the central nervous system during neurosurgery and it is well known that they are affected by the depth of anesthesia. Many studies on the evoked potential like somatosensory evoked potential (SEP) and auditory brain stem response (ABR) are reported, but studies on visual evoked potential (VEP) are few. We investigated the influence of the propofol concentration on VEP in neurosurgical patients. METHODS: Seven patients scheduled for neurosurgery, three with cranial aneurysm and four with brain tumor, were studied. Anesthesia was maintained with intravenous propofol using target controlled infusion (TCI). We measured the change of amplitude and latency of VEP at three propofol concentrations (effect site concentrations of 1.5, 2.0 and 3.0 microg x ml(-1)), and also evaluated bispectral index (BIS) at each propofol concentration. RESULTS: Amplitude of VEP at 3.0 microg x ml(-1) propofol concentration decreased significantly compared with the amplitude at 1.5 microg x ml(-1) concentration. No significant change was observed with the latency of VEP. The value of BIS at 3.0 microg x ml(-1) propofol concentration also decreased significantly compared with 2.0 microg x ml(-1) concentration. CONCLUSIONS: Amplitude of VEP is strongly affected by the concentration of propofol. Caution should be taken in evaluating VEP in patients undergoing propofol anesthesia.     

Lactic acidosis associated with propofol during general anaesthesia for neurosurgery

Propofol infusion syndrome (PRIS) is a new clinical entity reported in critically ill patients. Lactic acidosis, cardiac failure and rhabdomyolysis are the features. Lactic acidosis related to short-term propofol administration has been described during general anaesthesia. Lactic acidosis could be an early marker of PRIS. We report here a case of very early lactic acidosis in a 66-year-old-man receiving propofol during a neurosurgery. The outcome was good after discontinuation of propofol.     

General anesthesia during neurosurgery in sitting position]

Sitting position during surgery of the posterior fossa is very convenient for the neurosurgeon but can be dangerous, specially concerning the risk of air-embolism. We discuss the major problems of this special position, and the modifications of respiratory and hemodynamic functions from our experience on 84 cases. We study the monitoring of these patients during surgery, with special emphasis on prevention and detection of air-embolism with the capnograph. With the protocol suggested we can avoid major risk in this position.     

Cerebrospinal fluid and blood propofol concentration during total intravenous anaesthesia for neurosurgery

Background. The aim of this paper is to compare the propofolconcentration in blood and cerebrospinal fluid (CSF) in patientsscheduled for different neurosurgical procedures and anaesthetizedusing propofol as part of a total intravenous anaesthesia technique. Methods. Thirty-nine patients (ASA I–III) scheduled forelective intracranial procedures, were studied. Propofol wasinfused initially at 12 mg kg^–1 h^–1 and thenreduced in steps to 9 and 6 mg kg^–1 h^–1. Duringanaesthesia, bolus doses of fentanyl and cis-atracurium wereadministered as necessary. After tracheal intubation the lungswere ventilated to achieve normocapnia with an oxygen-air mixture(FI_O2=0.33). Arterial blood and CSF samples for propofol examinationwere obtained simultaneously directly after intracranial drainageinsertion and measured using high-performance liquid chromatography.The patients were divided into two groups depending on the typeof neurosurgery. The Aneurysm group consisted of 13 patientswho were surgically treated for ruptured intracranial aneurysm.The Tumour group was composed of 26 patients who were undergoingelective posterior fossa extra-axial tumour removal. Results. Blood propofol concentrations in both groups did notdiffer significantly (P>0.05). The propofol concentrationin CSF was 86.62 (SD 37.99) ng ml^–1 in the Aneurysm groupand 50.81 (26.10) ng ml^–1 in the Tumour group (P<0.005). Conclusions. Intracranial pathology may influence CSF propofolconcentration. However, the observed discrepancies may alsoresult from quantitative differences in CSF composition andfrom restricted diffusion of the drug in the CSF. Br J Anaesth 2003; 90: 84–6     

异丙酚对颅内压的影响

目的：评价异丙酚对神经外科病人颅内压的影响。方法：１３例颅内胶质瘤成年病人ＡＳＡⅠ～Ⅱ级，择期行开颅手术。在麻醉诱导时，静注异丙酚２ｍｇ／ｋｇ。分别于注药前、后１、２、３、５、７、１０、１５和２０分钟，观察收缩压（ＳＰ），舒张压（ＤＰ），平均动脉压（ＭＡＰ），心率（ＨＲ），脑灌注压（ＣＰＰ），颅内压（ＩＣＰ）的变化。颅内压监测采用腰蛛网膜下腔置管直接测压。结果：静注异丙酚后ＳＰ，ＭＡＰ，ＣＰＰ显著降低（１５．１８±２．２１ｋＰａ降至１３．４４±１．５６ｋＰａ，１１．３３±２．１４ｋＰａ降至９．５４±１．７０ｋＰａ，９．０５±２．４６ｋＰａ降至７．９７±２．１４ｋＰａ）但是随着时间的延长在２０分钟内恢复至基础水平，ＤＰ、ＨＲ给药前后无明显变化，ＩＣＰ给药后明显下降且在观察期内无回升趋势。结论：异丙酚能降低病人的颅内压，适用于神经外科麻醉，对颅内压增高病人应适当调整用量。     

右美托咪定或丙泊酚复合瑞芬太尼用于功能神经外科术中唤醒的比较

目的比较右美托咪定(Dex)或丙泊酚复合瑞芬太尼用于功能神经外科术中唤醒的效果。方法功能神经外科需术中唤醒的患者48例,ASAⅠ或Ⅱ级,男21例,女27例,年龄12~65岁,随机均分为Dex复合瑞芬太尼组(D组)和丙泊酚复合瑞芬太尼组(P组),分别以Dex复合瑞芬太尼和丙泊酚复合瑞芬太尼维持麻醉实施术中唤醒。记录两组血流动力学、苏醒时间、自主呼吸恢复时间、唤醒成功率及唤醒期间的呛咳、躁动、呼吸抑制等不良事件发生率。结果两组唤醒成功率相似。D组苏醒更快,自主呼吸恢复时间短,且呛咳、躁动显著低于P组(P<0.05)。D组用药初期血压升高,心率减慢(P<0.05),但唤醒期间组间差异无统计学意义。结论与丙泊酚复合瑞芬太尼相比,右美托咪定复合瑞芬太尼麻醉下能有效实施术中唤醒,唤醒期间血流动力学平稳,不良事件发生率更低。     

The use of an antigravity suit in neurosurgery

Some neurosurgeons prefer to perform certain operations with the patient in the sitting position. Owing to the hydrostatic pressure, the missing muscle pump function and the obstruction of the regulation of the circulation, this position impedes the circulation in causing pooling of blood in the lower extremities.
To meet these difficulties, the author has employed an anti-g suit, which, inflated with air, exerts a pressure on the patient's legs and lower part of the abdomen. The suit renders it possible to maintain constant values for pulse rate and blood pressure and thereby maintain optimum conditions for the circulation.     

The use of the Nd-YAG laser in neurosurgery

Whereas the focused CO2 laser may be used as a cutting instrument in less vascularized tissue with limited trauma to the surrounding tissue, use of the defocused Nd-YAG laser results in homogeneous coagulation with an energy-dependent depth effect. Thus, residual tumor tissue may be cauterized selectively with a depth effect which can be predicted with satisfactory precision. Tumor shrinkage and demarcation based on different absorption properties facilitates dissection and, moreover, allows the preservation of healthy tissue. The excellent coagulating properties of the Nd-YAG laser render it especially effective in cases of highly vascularized meningeal tumors.     

YAG laser in neurosurgery]

The authors try to answer to some practical questions concerning Yag Lasers in neurosurgery. The aim of this work is to determine the main data useful for the choice of a YAG-Laser. Are considered: the wavelengths which can be bought on the international market (1.06 microns or 1.32 microns for instance), the peripherics at disposal, the tissular effects due to the different lasers, the surgical applications and indications. The Laser unit which will be chosen should be a compromise between the different advantages and inconveniences of a particular laser, its tissular effects, its price. The multi-wavelengths units appear to be, at the present time, interesting compromises (such as 1.32 + 1.06 microns, CO2 + 1.06 microns).     

Trephine craniotomy in neurosurgery]

For three years, we have performed craniotomy with a 5 cm diameter trephine through a linear incision. 53 craniotomies were done in 49 patients. This simple and time-saving method produced little bleeding and slight injury to the brain. The technique allowed the surgeon to spend most of his time at the management of lesion. Healing of wound was rapid and brain edema was minimal.     

丙泊酚麻醉对急性颅脑外伤手术患者血清S100B的影响

目的研究急性颅脑外伤手术前和手术期间丙泊酚对血清S100B的影响,以评价丙泊酚的脑保护作用。方法急症颅脑外伤手术患者30例。随机分为丙泊酚（A）组和异氟醚（B）组,每组15例。另10例泌尿系统手术的非颅脑损伤患者的血清作空白对照（C）组。酶联免疫吸附法测定C组及A、B组颅脑手术前、手术开始2h、手术结束时血清S100B含量。对急症颅脑外伤手术患者进行格拉斯哥（Glasgow）评分。结果A、B组患者手术前S100B显著高于C组（P〈0．01）;Glasgow评分越低的患者术前S100B越高（r=-0．446,P〈0．05）。手术结束时A组S100B显著低于B组（P〈0．05）。开颅手术2h和手术结束时两组S100B均较术前有升高。结论急性颅脑外伤时患者血清S100B升高,Glasgow评分越低,血清的S100B浓度也越高。提示临床剂量丙泊酚可以抑制血清S100B的升高,减轻继发性脑损害,具有脑保护作用。