Aortic Valve Velocity Time Integral Variation In The Assessment Of Fluid Responsiveness In Septic Shock

ObjectiveSeptic shock is a relatively common critical diseases and a serious threat to human health illness, it is still a difficult diseases with poor prognosis and high mortality. Volume resuscitation of septic shock is an important circulatory support means, the aim is to improve hemodynamics and reversal of organ dysfunction. At this point it should assess fluid responsiveness in patients, clear of volume therapy in patients with tolerance, clear whether patients can increase the effective circulating blood volume by expansion and improve tissue perfusion. This study intends to investigate the ability of aortic valve velocity time integral variation(ΔVTI)combined with passive leg raising trial predicting volume responsiveness in septic shock.MethodsThe prospective and observational cohort study, the choice of Tianjin First Central Hospital intensive care unit(ICU) treated 34 patients with septic shock between January 2014 and October 2014, record the general clinical data, has carried out PLR and volume expansion(VE) successively. Respectively, in front of the PLR(baseline), during the period of PLR and after VE using echocardiography measure aortic velocity time integral(VTI) and stroke volume(SV) and heart rate(HR), mean arterial pressure(MAP),central venous pressure(CVP), cardiac output(CO) and other hemodynamic changes. According to the responsiveness of volume expansion(Responders were defined by the appearance of an increase in SV ≥15% after VE),patients were divided into responders and nonresponders. Compared two groups of observed indices, receiver operating characteristic curve(ROC curve) analysis aortic valve velocity time integral variation(ΔVTI) assessment of volume responsiveness in patients with septic shock.Results1. A total of 34 septic shock patients were evaluated and resulting in 16 responders(47%) and 18 non-responders(53%). The patients in the two groups throughout the study period, no significant changes in heart rate and mean arterial pressure difference( P>0.05). Responders were significantly higher in PLR and after VE, CVP, CO, VTI and SV compared with baseline( P<0.05), but the four indicators pairwise comparisons showed no significant difference in the PLR and after VE( P > 0.05). No response group PLR and after VE, SV and CVP increased significantly when compared with baseline(P<0.05), but the SV and CVP pairwise comparisons showed no significant difference in the PLR and after VE(P> 0.05), in PLR and after VE, although CO, VTI increased compared with baseline, but the difference was not statistically significant( P> 0.05).2. VE and PLR induced Δ CVP in both groups was no statistically significant differences between the responsive patients. There was a positive correlation between ΔSV caused by VE and PLR, Person correlation coefficient of 0.630, P=0.000; PLR caused by ΔSV and ΔVTI also exist positive correlation, Person correlation coefficient of 0.946, P=0.000.3. Area under the ROC curve(AUC) of PLR-induced ΔSV, ΔVTI and ΔCVP predicting volume responsiveness in septic shock were 0.866 ± 0.064﹝95% CI 0.741 ~ 0.992, P = 0.000﹞, 0.872±0.061﹝95% CI 0.752~0.992,P=0.000﹞and 0.306±0.091﹝95% CI 为0.127~0.485,P=0.053﹞。The △VTI ≥14.74% during PLR was found to predict volume responsiveness with a sensitivity of 81.3%,specificity of 83.3%.Conclusions1. At the time of septic shock patients with volume resuscitation, HR, MAP and CVP are not accurate guide fluid therapy.2. The passive leg raising test can alternative volume expansion test to predict the volume responsiveness in septic shock patients.3. The variation of aortic velocity time integral(△VTI) has good predictive value in the evaluation of volume responsiveness in patients with septic shock.