Minimal haemodilution after rapid high-volume crystalloid infusion in healthy volunteers

Dear Editor, Intravenous fluid therapy remains one of the most common interventions in acute and emergency medicine [1]. Although the haemodynamic effects of fluid therapy have been widely studied, the short-term biochemical effects such as electrolyte and plasma dilution remain less well defined. In a recent randomized crossover trial, Biesenbach et al. [2] investigated the effects of administering 30 mL/kg of Ringers lactate at 15°C and 37°C on blood pressure in healthy volunteers. The study demonstrated that cold fluids produced a greater and more prolonged increase in mean arterial pressure, an effect associated with increased systemic vascular resistance and endogenous noradrenaline release. The present study represents a secondary post-hoc analysis of data obtained during the original trial. In addition to the results reported in the primary publication, arterial blood gas analyses were obtained in a subset of nine participants at baseline and every 30 min during the 120-min observation period. We conducted a post-hoc analysis of electrolyte and hemoglobin concentration changes collected through these blood gas samples.