Physiological response to fluid resuscitation with Ringer Lactate versus Plasmalyte in critically ill burn patients.

Abstract : The metabolic consequences in vivo of various balanced solutions are poorly known in critically ill patients. The main objective of this study was to describe the metabolic consequences of Plasmalyte® versus Ringer lactate (RL) in critically ill burn patients, with a special focus on the plasma clearance of buffer anions (i.e. gluconate, acetate and lactate). We conducted a randomized trial between August 2017 and October 2018 in a tertiary teaching hospital in Paris, France. Patients with burn total body surface area >30% were randomized to receive Plasmalyte® or RL. The primary endpoint was the base excess (BE) 24 hours after inclusion. The secondary endpoints were acetate, gluconate and lactate plasma concentration, the strong ion difference (SID). Twenty-eight patients were randomized. Twenty-four hours after inclusion, plasma BE was not significantly different in the Plasmalyte® and RL groups (-0.9 [CI95% -1.8-0.9] vs -2.1 [CI95% -4.6-0.6] mmol/L respectively, p=0.26). Plasma gluconate concentration was higher in the Plasmalyte® group (p<0.001) with a maximum level of 1.86 (CI95% 0.98-4.0) mmol/L vs 0 (IC95% 0-0.15) mmol/L. Plasma acetate and lactate were not significantly different. Ionized calcium level was lower in the Plasmalyte® group (p=0.002). Hemodynamics did not differ between groups. To conclude, alkalinizing effect of Plasmalyte® was less important than expected with no difference in base excess compared to RL, in part due to gluconate accumulation. Acetate and lactate did not significantly accumulate. Plasmalyte® led to significantly lower ionized calcium levels.