Department of Anesthesiology, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara-City, Chiba 299-0111, Japan.
Br J Anaesth. 2013 Aug;111(2):235-41. doi: 10.1093/bja/aet058. Epub 2013 Mar 21.
Hypotension during spinal anaesthesia for Caesarean delivery is a result of decreased vascular resistance due to sympathetic blockade and decreased cardiac output due to blood pooling in blocked areas of the body. Change in baseline peripheral vascular tone due to pregnancy may affect the degree of such hypotension. The perfusion index (PI) derived from a pulse oximeter has been used for assessing peripheral perfusion dynamics due to changes in peripheral vascular tone. The aim of this study was to examine whether baseline PI could predict the incidence of spinal anaesthesia-induced hypotension during Caesarean delivery.
Parturients undergoing elective Caesarean delivery under spinal anaesthesia with hyperbaric bupivacaine 10 mg and fentanyl 20 μg were enrolled in this prospective study. The correlation between baseline PI and the degree of hypotension during spinal anaesthesia and also the predictability of spinal anaesthesia-induced hypotension during Caesarean delivery by PI were investigated.
Baseline PI correlated with the degree of decreases in systolic and mean arterial pressure (r=0.664, P<0.0001 and r=0.491, P=0.0029, respectively). The cut-off PI value of 3.5 identified parturients at risk for spinal anaesthesia-induced hypotension with a sensitivity of 81% and a specificity of 86% (P<0.001). The change of PI in parturients with baseline PI ≤ 3.5 was not significant during the observational period, while PI in parturients with baseline PI>3.5 demonstrated marked decreases after spinal injection.
We demonstrated that higher baseline PI was associated with profound hypotension and that baseline PI could predict the incidence of spinal anaesthesia-induced hypotension during Caesarean delivery.
剖宫产术中脊麻引起的低血压是由于交感神经阻滞导致血管阻力降低和身体阻滞区域的血液淤积导致心输出量降低的结果。由于妊娠，基线外周血管张力的变化可能会影响这种低血压的程度。脉搏血氧仪得出的灌注指数 (PI) 已用于评估由于外周血管张力变化引起的外周灌注动力学。本研究旨在探讨基线 PI 是否可以预测剖宫产术中脊麻引起的低血压的发生率。
本前瞻性研究纳入了接受布比卡因 10mg 和芬太尼 20μg 腰麻下择期剖宫产的产妇。研究了基线 PI 与脊麻期间低血压程度之间的相关性，以及 PI 对剖宫产脊麻引起的低血压的预测能力。
基线 PI 与收缩压和平均动脉压降低的程度相关（r=0.664，P<0.0001 和 r=0.491，P=0.0029）。PI 的截断值为 3.5 可识别出有脊麻引起的低血压风险的产妇，其敏感性为 81%，特异性为 86%（P<0.001）。基线 PI≤3.5 的产妇在观察期间 PI 变化不明显，而基线 PI>3.5 的产妇在脊麻注射后 PI 明显下降。
我们证明较高的基线 PI 与严重的低血压相关，且基线 PI 可以预测剖宫产术中脊麻引起的低血压的发生率。
