Peripheral Perfusion Versus Lactate Targeted Fluid Resuscitation in Septic Shock

Persistent hyperlactatemia has been traditionally considered as representing tissue hypoxia, and lactate normalization is recommended as a resuscitation target by the Surviving Sepsis Campaign (SSC). However, other sources contribute to hyperlactatemia such as sustained adrenergic activity and impaired lactate clearance. Only hypoperfusion-related hyperlactatemia might be reversed by optimizing systemic blood flow. Fluid resuscitation (FR) is used to improve cardiac output (CO) in septic shock to correct hypoperfusion. Nevertheless, if persistent hyperlactatemia is not hypoxia-related, excessive FR could lead to flow overload. In addition, kinetics of recovery of lactate is relatively slow, and thus it might be a suboptimal target for FR. Peripheral perfusion appears as a promising alternative target. Abnormal capillary refill time (CRT) is frequently used as trigger for FR in septic shock. Studies demonstrated the strong prognostic value of persistent abnormal peripheral perfusion, and some recent data suggest that targeting FR on CRT normalization could be associated with less fluid loading and organ dysfunctions. The excellent prognosis associated with CRT recovery, the rapid-response time to fluid loading, its simplicity, and its availability in resource-limited settings, constitute a strong background to promote studies evaluating its usefulness to guide FR . The study hypothesis is that a CRT-targeted FR is associated with less positive fluid balances, organ dysfunctions, and at least similar improvement of tissue hypoperfusion or hypoxia, when compared to a lactate-targeted FR. To test this hypothesis, the investigators designed a clinical physiological, randomized controlled trial in septic shock patients. Recruited patients will be randomized to FR aimed at normalizing CRT or normalizing or decreasing lactate \>20% every 2 h during the study period. Fluid challenges (500 ml in 30 min intervals) will be repeated until perfusion target is achieved, or dyna