Residual levels and biochemical changes after ventilation with perfluorinated liquid.

Area of Science:

• Biomedical Engineering
• Toxicology
• Respiratory Physiology

Background:

• Liquid ventilation offers potential for respiratory support in critical conditions.
• Perfluorinated liquids are candidates for liquid ventilation due to their oxygen-carrying capacity and inertness.
• Long-term effects and tissue retention of perfluorinated compounds require thorough investigation.

Purpose of the Study:

• To evaluate the safety and physiological effects of liquid ventilation with perfluoro-1-isopropoxy-hexane (Caroxin-F) in beagle dogs.
• To assess the recovery of spontaneous gaseous breathing and blood gas exchange post-liquid ventilation.
• To determine the long-term tissue retention and potential histopathological consequences of Caroxin-F.

Main Methods:

• Twenty-three beagle dogs underwent 1-hour liquid ventilation with Caroxin-F.
• Hematologic and biochemical parameters were monitored in five dogs for up to 1 year.
• Tissue samples from all dogs were analyzed for Caroxin-F presence using chromatography for up to 3 years.

Main Results:

• Dogs successfully transitioned from liquid Caroxin-F ventilation to spontaneous gaseous breathing within 24-72 hours, with normal blood gas exchange.
• Transient increases in serum alkaline phosphatase, cholesterol, and white blood cell count were observed but normalized within a week.
• Trace amounts of Caroxin-F were detected in all tissues up to 3 years, primarily in lungs and lymph nodes, with minimal histopathological findings (vacuolated macrophages).

Conclusions:

• Liquid ventilation with Caroxin-F is feasible and allows for rapid recovery of spontaneous respiration.
• While Caroxin-F is retained in tissues long-term, it appears to be well-tolerated without significant residual deleterious effects.
• Further research into the long-term biological interactions of retained perfluorinated compounds is warranted.