Intravenous Fluid Resuscitation Capabilities in Simulated Reduced Gravity

Area of Science:

• Space Medicine
• Physiology
• Biomedical Engineering

Background:

• Critical care for space exploration missions may necessitate intravenous (IV) fluid resuscitation.
• Resource limitations in space may restrict the use of standard Earth-based infusion technologies.
• Investigating the impact of variable acceleration on IV fluid infusion rates is crucial for mission planning.

Purpose of the Study:

• To investigate the effect of variable acceleration on intravenous fluid infusion rates using simple resuscitation supplies.
• To determine if standard fluid resuscitation protocols can be maintained in simulated reduced gravity environments.
• To provide data for refining fluid resuscitation protocols for space exploration.

Main Methods:

• Infusions of water and a blood analog (40% glycerol) were conducted using IV bags with pressure bag augmentation (0, 150, 300 mmHg).
• Simulated gravitational accelerations included 1 G, Martian G, lunar G, and 0 G by adjusting the solution bag's height.
• Flow rates were measured using an in-line flow probe with 14- or 20-gauge angiocaths.

Main Results:

• Temporal flow rate data exhibited a one-phase exponential decay across all conditions.
• At 300 mmHg, maximum infusion rates for water ranged from 92-222 mL/min, and for the blood analog, from 21-49 mL/min.
• Reduced gravity conditions significantly increased infusion times compared to 1 G for both solutions.

Conclusions:

• Reduced acceleration significantly impacts fluid resuscitation flow rates and infusion durations.
• Infusion pressure bag augmentation alone can achieve target resuscitation rates (e.g., 20-30 mL/min) in simulated reduced gravity.
• This study provides essential data for adapting and optimizing IV fluid resuscitation protocols for long-duration space missions.