Inhaled Epoprostenol Augments Cold-Induced Vasodilation: A Double-Blind Crossover Trial

Area of Science:

• Physiology
• Pharmacology

Background:

• Cold exposure causes peripheral vasoconstriction, followed by cold-induced vasodilation (CIVD).
• Enhanced CIVD response may reduce frostbite risk and improve dexterity.
• Intravenous prostacyclin (PGI2) analogs are used for severe frostbite; inhaled options are unexplored.

Purpose of the Study:

• To investigate the effect of inhaled epoprostenol, a PGI2 analog, on CIVD response.
• To assess continuous finger temperature changes during cold water immersion with inhaled epoprostenol versus placebo.

Main Methods:

• Double-blind, crossover study design.
• Fourteen healthy volunteers underwent cold water immersion.
• Continuous finger temperature measurement was used to assess CIVD response.

Main Results:

• Inhaled epoprostenol significantly increased mean finger temperature (9.16°C vs 8.34°C, p=0.027).
• Higher mean maxima (10.86°C vs 9.88°C, p=0.045) and mean minima (7.45°C vs 6.80°C, p=0.024) finger temperatures were observed with epoprostenol.
• No significant differences in CIVD cycle count; no adverse events like hypotension or hypothermia were reported.

Conclusions:

• Inhaled epoprostenol augmented the CIVD response, significantly increasing finger temperatures.
• Nebulized PGI2 analog delivery suggests potential for early frostbite intervention in remote settings.
• Further research is required to confirm epoprostenol's efficacy in frostbite management.