Riker Richard R, Fraser Gilles L, Wilkins Micheline L
Department of Critical Care, Maine Medical Center, Portland 04102, USA.
Pharmacotherapy. 2003 Sep;23(9):1087-93. doi: 10.1592/phco.23.10.1087.32766.
The bispectral index (BIS), a processed variable derived from the raw electroencephalogram (EEG) used to guide sedation in the intensive care unit (ICU), has not been tested during barbiturate therapy for elevated intracranial pressure. We determined the BIS and suppression ratio (SR) values during traditional burst monitoring of the raw EEG during pentobarbital infusions.
Prospective, observational cohort study.
A 42-bed multidisciplinary ICU in a tertiary care medical center.
Twelve consecutive patients with elevated intracranial pressure treated with pentobarbital infusions.
All patients were monitored continuously with the Aspect Medical Systems A-1050 bedside EEG monitor using a bilateral referential montage. Pentobarbital doses were titrated based on the raw EEG to attain a burst-suppression pattern with a goal of 3-5 bursts/minute. Drug dosage, intracranial pressure, cerebral perfusion pressure values, EEG bursts/minute, BIS version 3.2, and SR were recorded daily.
The 12 patients were monitored for 62 patient-days. Mean +/- SD age was 32 +/- 15 years, seven (58%) patients were male, mean Acute Physiology and Chronic Heath Evaluation II score was 17.0 +/- 5.0, and hospital mortality was 42%. The mean pentobarbital infusion rate was 124 +/- 49 mg/hour or 2.3 +/- 1.3 mg/kg/hour, and mean pentobarbital serum concentration was 29.7 +/- 13 microg/ml. The mean BIS value was 18 +/- 14, mean SR 56% +/- 36%; BIS correlated well with SR (r=-0.99, p<0.001). For patient-days with a burst-suppression pattern, BIS 3.2 (r=0.90, p<0.001) and SR (r=-0.89, p<0.001) strongly correlated with the number of bursts/minute. The mean BIS value corresponding to 3-5 bursts/minute was 15 (95% confidence interval [CI] 10-20); SR value was 71 (95% CI 61-80).
The Aspect A-1050 applied to patients and monitored by nurses and physicians works well as a bedside EEG monitor, providing a raw EEG signal to titrate barbiturate therapy. The continuous data trend and real-time digital output for the BIS and SR quantify the degree of EEG suppression well and may prove helpful in facilitating titration of barbiturate infusions.
脑电双频指数（BIS）是一种从原始脑电图（EEG）得出的处理变量，用于指导重症监护病房（ICU）的镇静治疗，但尚未在巴比妥类药物治疗颅内压升高时进行测试。我们测定了戊巴比妥输注期间原始EEG传统爆发监测时的BIS和抑制率（SR）值。
前瞻性观察队列研究。
一家三级医疗中心的拥有42张床位的多学科ICU。
连续12例接受戊巴比妥输注治疗的颅内压升高患者。
所有患者均使用Aspect Medical Systems A - 1050床边EEG监测仪，采用双侧参考导联连续监测。根据原始EEG滴定戊巴比妥剂量，以达到爆发抑制模式，目标是每分钟3 - 5次爆发。每天记录药物剂量、颅内压、脑灌注压值、EEG每分钟爆发次数、BIS 3.2版和SR。
12例患者共监测62个患者日。平均年龄±标准差为32±15岁，7例（58%）为男性，急性生理与慢性健康状况评分II平均为17.0±5.0，医院死亡率为42%。戊巴比妥平均输注速率为124±49毫克/小时或2.3±1.3毫克/千克/小时，戊巴比妥血清平均浓度为29.7±13微克/毫升。平均BIS值为18±14，平均SR为56%±36%；BIS与SR相关性良好（r = - 0.99，p < 0.001）。对于呈爆发抑制模式的患者日，BIS 3.2（r = 0.90，p < 0.001）和SR（r = - 0.89，p < 0.001）与每分钟爆发次数密切相关。对应每分钟3 - 5次爆发的平均BIS值为15（95%置信区间[CI] 10 - 20）；SR值为71（95% CI 61 - 80）。
应用于患者并由护士和医生监测的Aspect A - 1050作为床边EEG监测仪效果良好，可提供原始EEG信号以滴定巴比妥类药物治疗。BIS和SR的连续数据趋势及实时数字输出能很好地量化EEG抑制程度，可能有助于促进巴比妥类药物输注的滴定。
