Changes of Operative Performance of Pulse Pressure Variation As A Predictor of Fluid Responsiveness in a Swine Model of Endotoxin Shock

Background: 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. Methods A swine porcine endotoxin shock model was established ( E. 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 hours. ROC curve analysis was conducted. Additionally, a linear mixed model was performed. Results The area under the curve (AUC) of PPV decreased from 0.95 (0.81–1.00) to 0.60 (0.17–1.00) at TH0. Its cutoff increased from 10.5–22.00% at TH0. PPV showed an inverse relationship with stroke volume, mean systemic filling pressure (MSFP), MAP, and systemic vascular resistance (SVR) (p < 0,001, AIC = 111.85). Conclusions The PPV operative performance as a predictor of fluid responsiveness decreased with the progression of endotoxic shock. This result could be due to the inverse association with MAP and SVR.