Lee Jung-Man, Bahk Jae-Hyon, Lim Young-Jin, Lee Jiwon, Lim Leerang
Department of Anesthesiology and Pain Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, 20, Boramae-ro 5-gil, Dongjak-gu, Seoul, 07061, Republic of Korea.
Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
BMC Anesthesiol. 2017 Oct 10;17(1):136. doi: 10.1186/s12871-017-0426-z.
Head fixation can induce hemodynamic instability. Remifentanil is commonly used with propofol for total intravenous anesthesia (TIVA) during neurosurgery. This study investigated the 90% effective concentration (EC) of remifentanil for blunting of cardiovascular responses to head fixation during neurosurgery via bispectral index (BIS) monitoring.
Fifty patients undergoing neurosurgery requiring head fixation were enrolled. This study was performed using the biased coin up-and-down design sequential method (BCD). After tracheal intubation, the effect-site target concentration (Ce) of remifentanil was adjusted to achieve hemodynamic stability and reset to the level preoperatively assigned to each patient, according to the BCD method, approximately 10 min before head fixation. Baseline hemodynamic values were recorded before head fixation. An ineffective response was defined as a case with a > 20% increase in hemodynamic values from baseline. Otherwise, the response was determined to be effective. The EC of remifentanil was calculated as a modified isotonic estimator.
Forty-three patients completed this study. The EC of remifentanil for blunting cardiovascular responses to head fixation was estimated to be 6.48 ng/mL (95% CI, 5.94-6.83 ng/mL).
Adjustment of the Ce of remifentanil to approximately 6.5 ng/mL before head fixation could prevent noxious cardiovascular responses in 90% of neurosurgical ASA I-II patients aged 20 to 65 years old during propofol target-controlled infusion titrated to maintain BIS between 40 and 50.
ClinicalTrials.gov Identifier NCT01489137 , retrospectively registered 5 December 2011.
头部固定可诱发血流动力学不稳定。瑞芬太尼在神经外科手术的全凭静脉麻醉（TIVA）中常与丙泊酚联合使用。本研究通过脑电双频指数（BIS）监测，探讨瑞芬太尼抑制神经外科手术中头部固定引起的心血管反应的90%有效浓度（EC）。
纳入50例需要进行头部固定的神经外科手术患者。本研究采用偏倚硬币上下设计序贯法（BCD）。气管插管后，根据BCD方法，在头部固定前约10分钟，调整瑞芬太尼的效应室靶浓度（Ce）以实现血流动力学稳定，并重置为术前为每位患者设定的水平。记录头部固定前的基线血流动力学值。无效反应定义为血流动力学值较基线增加>20%的情况。否则，判定反应有效。瑞芬太尼的EC采用改良等渗估计器计算。
43例患者完成本研究。瑞芬太尼抑制头部固定引起的心血管反应的EC估计为6.48 ng/mL（95%CI，5.94 - 6.83 ng/mL）。
在年龄20至65岁的神经外科ASA I-II级患者中进行丙泊酚靶控输注并将BIS维持在40至50之间时，头部固定前将瑞芬太尼的Ce调整至约6.5 ng/mL可预防90%的有害心血管反应。
ClinicalTrials.gov标识符NCT01489137，于2011年12月5日进行回顾性注册。
