RESUMO
Objective To assess the accuracy and feasibility of respirophasic variation in carotid artery blood flow peak velocity (△Vpeak-CA) as predictors of fluid responsiveness in laparoscopic surgery.Methods Fifty-five patients undergoing laparoscopic surgeries,29 males and 26 females,aged 45-75 years,ASA physical status Ⅰ-Ⅲ,with body mass index 20-24 kg/m2,were enrolled.When intra-abdominal pressure was steady at the level of 13-15 mm Hg,6％ hydroxyethylstarch (HES 130/0.4) 500 ml was infused at the speed of 7 ml/kg within 20 minutes.After volume expansion,subjects were classified as responders (group R,n =32) if cardiac index increased (△CI) was≥ 15％ and no responders (group NR,n =23) as △CI＜15％.The receiver operating characteristic curve (ROC) curve for △Vpeak-CA in determining the volume expansion responsiveness was plotted,and the diagnostic threshold was determined.The area under curve (AUC) and 95 ％ confidence interval (CI) was calculated.Cardiac index (CI),△Vpeak-CA and stroke volume variation (SW) were independently recorded at 5 minutes after induction (T1),5 minutes after intra-abdominal pressure were stable at the level of 13-15 mm Hg (T2) and 5 minutes after volume expansion (T3).Results △Vpeak-CA is highly negatively correlated with CI (r=-0.843,P＜0.001).The results of ROC curve analysis showed,△Vpeak-CA threshold discriminated between responders and non-responders with a sensitivity of 81.3％ and a specificity of 91.3％,and the AUC was 0.884 (95％ CI 0.793-0.975).Conclusion △Vpeak-CA seems to be a highly feasible and reliable predictor for fluid responsiveness in laparoscopic surgery patients.