Liu Shao-hua, Wei Wei, Ding Guan-nan, Ke Jing-dong, Hong Fang-xiao, Tian Ming
Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
Chin Med J (Engl). 2009 Apr 20;122(8):935-40.
There are few studies to assess whether the effect-site concentration of propofol can predict anesthetic depth during the target-controlled infusion (TCI) induction in elderly patients. This study aimed to evaluate the relationship between effect-site concentration of propofol and depth of anesthesia during the TCI induction in elderly patients.
Ninety patients (60 - 80 years) with an American Society of Anesthesiologists (ASA) physical status of 1 - 3, undergoing scheduled abdominal and thoracic surgery under general anesthesia were randomly allocated into one of three groups, Group S1, S2 and S3 (30 patients in each group). The patients in Group S1 received propofol with a target plasma concentration of 4.0 microg/ml; patients in Group S2 received propofol with an initial target plasma concentrations of 2.0 microg/ml that was raised to 4.0 microg/ml 3 minutes later; patients in Group S3 received an infused scheme of 3 steps; starting from a target plasma concentration of 2.0 microg/ml that was increased stepwised by 1 microg/ml until a target plasma concentration of 4.0 microg/ml was achieved, the interval between the two steps was 3 minutes. When an Observer's Assessment of Alertness/Sedation (OAA/S) score of 1 was achieved, remifentanil (effect-site concentration (Ce) of 4.0 ng/ml) and rocuronium 0.9 mg/kg were administered. Tracheal intubation was started 2 minutes after rocuronium injection. Changes of propofol Ce, blood pressure (BP), heart rate (HR), and bispectral index (BIS) were recorded.
When an OAA/S score of 1 was achieved, Ce of propofol were (1.7 +/- 0.4) microg/ml, (1.9 +/- 0.3) microg/ml, (1.9 +/- 0.4) microg/ml and the BIS values were 64 +/- 5, 65 +/- 8, and 62 +/- 8 in Groups S1, S2 and S3. Before intubation, Ce of propofol was (2.8 +/- 0.2) microg/ml, (2.8 +/- 0.3) microg/ml, (2.7 +/- 0.3) microg/ml, and the BIS values were 48 +/- 7, 51 +/- 7, and 47 +/- 5 in Groups S1, S2 and S3. By linear regression analysis, a significant correlation between Ce of propofol and BIS values was found (r = -0.580, P < 0.01). Systolic blood pressure (SBP) before intubation was significantly lower in Group S1 than in Groups S2 and S3. SBP and HR after intubation in the three groups were significantly increased when compared with pre-intubation values, but they did not exceed baseline values.
During the TCI induction, Ce of propofol with (1.9 +/- 0.3) microg/ml may make the elderly patients unconscious. When remifentanil with a Ce of 4.0 ng/ml is added a Ce of propofol with (2.8 +/- 0.3) microg/ml is suitable for intubation. The Ce of propofol has a close correlation with the BIS values. Also, a two-step TCI technique seems to be a more suitable method of anesthesia induction in elderly patients compared with the no-stepwise TCI technique and three-step TCI technique.
很少有研究评估丙泊酚效应室浓度能否预测老年患者靶控输注（TCI）诱导期间的麻醉深度。本研究旨在评估老年患者TCI诱导期间丙泊酚效应室浓度与麻醉深度之间的关系。
90例年龄60 - 80岁、美国麻醉医师协会（ASA）身体状况分级为1 - 3级、拟行全身麻醉下腹部和胸部手术的患者被随机分为三组，即S1组、S2组和S3组（每组30例）。S1组患者接受丙泊酚靶血浆浓度为4.0μg/ml；S2组患者接受丙泊酚初始靶血浆浓度为2.0μg/ml，3分钟后升至4.0μg/ml；S3组患者接受三步输注方案，从靶血浆浓度2.0μg/ml开始，每步增加1μg/ml直至达到靶血浆浓度4.0μg/ml，两步之间间隔3分钟。当警觉/镇静观察评分（OAA/S）达到1分时，给予瑞芬太尼（效应室浓度（Ce）为4.0ng/ml）和罗库溴铵0.9mg/kg。罗库溴铵注射后2分钟开始气管插管。记录丙泊酚Ce、血压（BP）、心率（HR）和脑电双频指数（BIS）的变化。
当OAA/S评分达到1分时，S1组、S2组和S3组丙泊酚的Ce分别为（1.7±0.4）μg/ml、（1.9±0.3）μg/ml、（1.9±0.4）μg/ml，BIS值分别为64±5、65±8、62±8。插管前，S1组、S2组和S3组丙泊酚的Ce分别为（2.8±0.2）μg/ml、（2.8±0.3）μg/ml、（2.7±0.3）μg/ml，BIS值分别为48±7、51±7、47±5。通过线性回归分析，发现丙泊酚Ce与BIS值之间存在显著相关性（r = -0.580，P < 0.01）。S1组插管前收缩压（SBP）显著低于S2组和S3组。与插管前值相比，三组插管后SBP和HR均显著升高，但未超过基线值。
在TCI诱导期间，丙泊酚Ce为（1.9±0.3）μg/ml可能使老年患者意识消失。当添加Ce为4.0ng/ml的瑞芬太尼时，丙泊酚Ce为（2.8±0.3）μg/ml适合插管。丙泊酚Ce与BIS值密切相关。此外，与非逐步TCI技术和三步TCI技术相比，两步TCI技术似乎是更适合老年患者的麻醉诱导方法。
