Vascular dysfunction and autonomic failure are associated in a porcine model of septic shock and resuscitation

Acute inflammation and sepsis are known to impair endothelial functions and autonomic nervous system (ANS)-based regulatory mechanisms. Our objective is to assess the effectiveness of standard resuscitation at vascular level and to investigate if there is any association between vascular and autonomic alterations. Six pigs underwent to a protocol of polymicrobial septic shock and resuscitation (fluids and noradrenaline). The characteristic arterial time constant $\tau$ was computed in aorta and in the femoral artery, together with estimates of total arterial compliance and peripheral resistance. Baroreflex sensitivity was computed to assess ANS functionality. Septic shock induced a severe vascular disarray and ANS dysfunction, which resulted correlated. This compromised condition was not resolved by resuscitation. Measures of vascular function and ANS activity may represent useful end-points to guide the resuscitation, in combination with standard hemodynamic and clinical markers.