Assessment of fluid treatment in elderly patients with severe sepsis guided by monitoring the variation of stroke volume

Objective To assess the effect of fluid treatment in elderly patients with severe sepsis under mechanically ventilation(MV) guided by monitoring the stroke volume variation(SVV).Methods Forty-two MV elderly patients with severe sepsis or septic shock,enrolled in ICU of Zhejiang Hospital from May 2005 to August 2008,were randomly divided into central venous pressure(CVP) group and SVV group(21 each).Fluid treatment was given to the patients in CVP group monitored by CVP.The treatment target was CVP≥12mmHg.Patients in SVV group were monitored by consecutive PiCCO combined with the changes in SVV.The APACHE II score,SOFA score,MODS scores,24-hour total infusion amount and central venous O2 saturation(ScvO2) of patients in the two groups were recorded.HR,mean arterial pressure(MAP),CVP,ScvO2,cardiac index(CI),system vascular resistance index(SVRI),internal thoracic blood volume index(ITBVI),extra-vascular lung water index(EVLWI) and SVV in SVV group were recorded before and after the treatment in both groups.The levels of plasma brain natriuretic peptide(BNP) and 28-day mortality in both groups were also recorded after the treatment.Results Two patients in SVV group were excluded due to the presence of complicating paroxysmal atrial fibrillation.There was no difference in all indices at the beginning and 28-day mortality between the two groups(47.6% in CVP group,31.6% in SVV group,P0.05).After the treatment,HR,MAP and CVP were increased in CVP group(P0.05 or P0.01),while ScvO2 showed no difference(P0.05);ScvO2,MAP,CVP were increased(P0.05 or P0.01) in SVV group,while HR showed no difference(P0.05).Plasma level of BNP was decreased in SVV group [256.0(78.0-510.0) pg/ml] compared with that in CVP group [437.0(279.5-1055.0) pg/ml] after therapy(P=0.034).After fluid treatment,CI,ITBVI,EVLWI were increased and SVV decreased significantly in SVV group(P0.05 or P0.01),while SVRI showed no change(P0.05).Changes in cardiac index(△CI) were correlated to baseline values of SVV(r=0.624,P=0.040),but not to CVP(P0.05).Conclusions Fluid therapy guided by functional hemodynamic index SVV in elderly patients with severe sepsis under MV is safe and more effective than that guided by CVP.SVV is valuable in prodicting the response to fluid treatment in elderly patients with severe sepsis.