Predictive effect of the difference of brachial artery peak velocity during the valsalva maneuver in different positions on supine hypotension syndrome of parturient after spinal anesthesia

Abstract BACKGROUND:The effectiveness of predicting the incidence of supine hypotension syndrome (SHS) after spinal anesthesia was measured by ultrasonic measurement of the variation of brachial artery peak velocity in different positions of parturient. METHODS: Parturient scheduled for elective cesarean section. ASAI or Ⅱ, were divided into SHS group and no SHS group (SBP in the upper extremity decreased by>30 mmHg or decreased to<80 mmHg) after spinal anesthesia. To record HR, SBP, DBP, MAP of supine position and left lateral position before anesthesia, and to measure brachial artery peak velocity during the Valsalva maneuver by Ultrasonic. Calculate the differences of the above indexs before and after the transformation position. The receiver operating characteristic (ROC) curve was plotted to evaluate the predictive effect of each index on SHS after spinal anesthesia. RESULTS:Among the 84 patients, 41 cases (48.81%) developed SHS after spinal anesthesia. brachial artery peak velocity maximum (Vpmax), brachial artery peak velocity minimum (Vpmin) and brachial artery peak velocity variation (ΔVp) were different before and after the transformation position. The difference in SHS group is significantly greater than non SHS group (P<0.05). The areas under ROC curve (AUC) of ΔVpmin, ΔΔVp, ΔVpmax, were 0.859, 0.794，0.614, 95%CI were 0.776～0.941, 0.689～0.899, 0491～0.736, and the cut-off values were 10.55cm/s, 5.98%, 8.40cm/s. CONCLUSION:The difference of brachial artery peak velocity measured by ultrasonic in different positions of parturient during the Valsalva maneuver can effectively predict the occurrence of SHS, in which ΔVpmin≥10.55cm/s has better predictive effect.Trial registration: China Clinical Trial Register ChiCTR1900022704, prospective registered on 23. April 2019.