Short summary

The study aims to investigate the effect of respectively 10°C and 22°C Ringer's lactate solution on the physiological response in healthy adults, through a single center crossover study. Each participant will receive 1 liter of Ringer Lactate either cold (10°C), or at room temperature (22°C), at an infusion rate of 100 ml/minute via a peripheral venous catheter. After a minimum "washout period" of 24 hours, subjects are switched to receive infusion at the other aforementioned temperature.

Rationale

Intravenous fluid bolus therapy (FBT) is the most common treatment in the emergency, perioperative and critical care setting. Fluids are routinely administered to treat hypotension, hypovolemia, and low urinary output. The rationale is to increase mean arterial pressure (MAP) and cardiac index (CI). However, these hemodynamic changes are limited in duration and scope and overall, evidence is scarce or inconclusive regarding timing, amount, and type of FBT. Especially the aspect of FBT temperature has been largely ignored. A trademark of FBT is that it is given at room temperature, unless used in specific situations, such as inducing hypothermia after cardiac arrest. However, previous data suggest that the hemodynamic effects are more pronounced and potentially long-lasting when fluids are given at lower temperatures. Recent, still unpublished data (18) from our group, have shown a significant increase in MAP when administering a 30 mL/kg Ringer´s lactate solution bolus at 15°C compared to a 37°C solution. The infusion, given over 30 minutes, was associated with a slight decrease in core temperature but otherwise an acceptable level of discomfort. These findings suggest that temperature, rather than volume, is responsible for the increase in MAP. However, no studies have compared cold fluids at 10°C with the current standard care of room temperature, which severely limits the clinical applicability of all previous studies. Therefore this study will test the hypothesis, that an even colder, 10°C, Ringer's lactate solution, can result in a more pronounced, and prolonged increase of blood pressure compared to a Ringer's lactate solution at room temperature (22°C) in healthy volunteers.

Description of the cohort

We will include 25 healthy volunteers between the age of 18-64. The study will be conducted at the Emergency Department at Odense University Hospital.

Data and biological material

We will measure and collect data of core temperature, vital signs, blood tests, diuresis and discomfort over a 2-hour period.

Collaborating researchers and departments

Emergency Medicine Research Unit, Emergency Department, Odense University Hospital

Emergency Medicine Research Unit, Emergency Department,University Hospital of Southern Denmark, Esbjerg Hospital