Changes of operative performance of pulse pressure variation as a predictor of fluid responsiveness in endotoxin shock

Abstract

Several limitations regarding pulse pressure variation (PPV) use have been reported. Our aim was to describe changes in the PPV operative performance as a predictor of fluid responsiveness during the development of a swine endotoxin shock model and to assess hemodynamic variables associated with PPV changes. A swine porcine endotoxin shock model was established (Escherichia Coli 055:B5 endotoxin) in 7 pigs, and 3 pigs were included in the control group. The endotoxin was infused until the mean arterial pressure (MAP) dropped below 50 mmHg (TH0); then, the model animal was reanimated with fluids and vasopressors. We performed fluid challenges every hour for 6 h. ROC curve analysis and a linear mixed model were performed. The area under the curve of PPV decreased from 0.95 (0.81–1.00) to 0.60 (0.17–1.00) at TH0. Its cutoff increased from 10.5 to 22.00% at TH0. PPV showed an inverse relationship with stroke volume, mean systemic filling pressure, MAP, and systemic vascular resistance (SVR) (p < 0.001, AIC = 111.85). The PPV operative performance as a predictor of fluid responsiveness decreased with the progression of shock. This could lead to an inverse association between PPV and the following variables: MAP and SVR.