Thirst-guided participant-controlled intravenous fluid rehydration: a single blind, randomised crossover study

Area of Science:

• Physiology
• Clinical Research

Background:

• Dehydration is a common hospital issue linked to poor outcomes.
• Current methods for assessing and diagnosing dehydration are unreliable.
• Investigated self-controlled intravenous rehydration guided by thirst.

Purpose of the Study:

• To explore if individuals can regulate their own intravenous fluid intake based on thirst.
• To assess the reliability of thirst as a guide for rehydration.

Main Methods:

• A single-blind, randomized cross-over trial with 10 healthy males.
• Volunteers were dehydrated by 3-5% body mass through exercise in heat.
• Participants controlled intravenous fluid intake (4% dextrose in 0.18% saline) based on thirst over 4 hours, with two bolus volume conditions (50ml vs 200ml).

Main Results:

• Thirst intensity strongly correlated with plasma osmolality (pOsm).
• Fluid demand decreased as pOsm normalized.
• In the high-volume condition, participants achieved normal body mass and pOsm levels.

Conclusions:

• Healthy individuals can effectively use thirst to guide their intravenous fluid intake.
• Patient-controlled intravenous fluids may offer a new approach to managing hydration in hospitals.