Flexibility Of Pleth Variability Index Predicting Hypotension After Spinal Anesthesia For Cesarean Delivery

BackgroundHypotension due to vasodilation after subarachnoid block (SAB) can not be ignored. As tissue perfusion is so important both for mother and child in cesarean delivery, we design this research to investigate whether pleth variability index (PVI) could predict hypotension following systolic blood pressure (SBP), and thereby reducing the dangers from inadequate perfusion.MethodsNinety ASA Ⅰ or Ⅱ pregnant women were scheduled for cesarean delivery. PVI and perfusion index (PI) were collected at arriving at operating room (T1) and within5minutes after head-up tilt (T2～T6).Women were classified into three groups depending on the proportional decrease from baseline SBP after SAB:A (lowest SBP>80%of baseline), B (lowest SBP70%～80%of baseline), and C (lowest SBP<70%of baseline). Person correlation was used to demonstrate relationship between degree of hypotension and PVI (T1-T6), as well as some other factors. Receiver operating characteristic curve was used to evaluate the accuracy of relative factors.ResultsCompared with group A, PVIT1and PVIn in group C significantly increased (P<0.05). Compared with PVIT1, PVIT2in group C also significantly increased(P<0.05). Degree of hypotension was significantly correlated to SBPT1, diastolic blood pressure at T1, PVIT1and PVIn (P<0.01). A receiver operator characteristic curve analysis showed that sensitivity and specificity of PVIn>22%to predict20%decrease of SBP following SAB were96.2%and50.8%.ConclusionsPVI, especially at1minute after head-up tilt, is able to predict hypotension with acceptable sensitivity and specificity, which is a tool to detect patients at high risk of hypotension following SAB.