Role of mean arterial pressure and urine parameter as an indicator of fluid responsiveness in patients during general anesthesia

Objective To explore the indicate role of urine index or MAP of fluid responsiveness for patients during general anesthesia. Methods Fifty-six patients with ASA physical status Ⅰ-Ⅱ scheduled for gastro intestinal (GI) cancer surgery.Three times of bolus infusion (3 ml/kg) were administered 10 min after induction of anesthesia.Responsiveness was defined if stroke volume inder (SVI) increased by ≥ 10% from the bolus infusion;while SVI<10% was unresponsiveness.And according to the numbers of boluses warranted,all patients were divided into two groups:Group Ⅰ(one bolus warranted) and Group Ⅱ(two-three boluses warranted). Results Patients in Group Ⅱ have higher urinary osmolality,creatinine (Cr) concentration,and specific gravity at baseline compared with those in Group Ⅰ(P<0.05).MAP in baseline,during induction anesthesia and intubation,and during 3 boluses of fluid was nearly identical between two groups (P>0.05).The receiver-operating characteristic (ROC) curve demonstrated that the threshold value of urinary Cr ≥ 12 mmol/L for prediction of fluid responsiveness revealed the area under the curve (AUC) of 0.69(P=0.021),and cardiac inder (CI of ≤ 3.5 L/(min·m²) revealed AUC of 0.65(P=0.027).Urinary Cr in combination with CI for prediction of fluid responsiveness showed an AUC of 0.85(P=0.001) with a sensitivity of 86% and a specificity of 91%. Conclusion Urinary parameters can be used as an indicator of fluid responsiveness in patients during general anesthesia.Combination of both criteria of Cr and Urinary CI improve the accuracy of prediction,but MAP cannot be used as an indicator of fluid responsiveness.