The predictive value of PPV and SVV after tidal volume challengeon volumetric responsiveness in patients with ARDS / 重庆医学

ABSTRACT

Objective To explore the predictive value of pulse pressure variation(PPV),stroke volume variation(SVV)and their changing values after tidal volume increase from 6 mL/kg to 8 mL/kg predicted body weight(PBW)on the volumetric responsiveness in the patients with acute respiratory distress syndrome(ARDS).Methods A prospective study was conducted.Twenty-three ARDS patients with acute circulatory failure treated in the intensive care unit(ICU)of this hospital from January 2021 to December 2022 were se-lected.The indicators such as PPV,SVV and cardiac index were recorded at the tidal volume of 6 mL/kg PBW,1 min after tidal volume challenge(tidal volume instantly increased to 8 mL/kg PBW),the tidal volume re-reduced to 6 mL/kg PBW,and after fluid bolus(FB),respectively.The cardiac index increase(ΔCI)≥15％served as the volumetric responsiveness positive when the tidal volume was re-reduced to 6 mL/kg PBW and after giving FB.The receiver operating characteristic(ROC)curve was used to evaluate the predictive value of PPV,SVV and their changing values for the volumetric responsiveness after the tidal volume increase from 6 mL/kg to 8 mL/kg PBW.Results A total of 42 measurements were performed in 23 patients.Among them,24 set of measurements were volumetric responsiveness positive(group R),and 18 set of measurements were volumetric responsiveness negative(group NR).The absolute values(ΔPPV6-8,ΔSVV6-8)and percentage(％ΔPPV6-8,％ΔSVV6-8)of PPV and SVV in tidal volume increase from 6 mL/kg to 8 mL/kg PBW had statisti-cal differences between the two groups(P＜0.05).ΔPPV6-8 and ΔSVV6-8 could predict the volumetric respon-siveness in the patients with ARDS.The area under the ROC curve(AUC)and its 95％CI were 0.92(0.84-1.00)and 0.90(0.81-0.99),and the optimal cut off values were 2.5％and 3.5％,respectively.When the tid-al volume was 6 mL/kg PBW,the PPV,SVV and central venous pressure(CVP)could not effectively predict the volumetric responsiveness in the patients with ARDS.Conclusion The efficiency of PPV or SVV changing values after tidal volume challenge for predicting the volumetric responsiveness of ARDS patients during low tidal volume ventilation is superior to PPV and SVV.