Partial perfusion in awake neonatal lambs: a comparison of three methods

Area of Science:

• Biomedical Engineering
• Cardiovascular Surgery
• Perfusion Technology

Background:

• Extended partial perfusion is crucial in cardiovascular surgery.
• Choosing the appropriate oxygenator and anticoagulant is vital for patient outcomes.
• Previous methods have limitations in prolonged procedures.

Purpose of the Study:

• To compare the efficacy of a silicone-tube membrane oxygenator versus a bubble oxygenator for extended perfusion in conscious lambs.
• To evaluate the suitability of Ancrod as an anticoagulant during membrane oxygenation.
• To establish optimal conditions for long-term perfusion in a conscious animal model.

Main Methods:

• Conscious lambs underwent extended partial perfusion using either a silicone-tube membrane oxygenator or a bubble oxygenator (Infant Temptrol).
• A separate group assessed Ancrod (Malayan Pit Viper venom extract) as an anticoagulant with a membrane oxygenator.
• Survival times, bleeding complications, packed cell volume (PCV), and hematocrit were monitored.

Main Results:

• Bubble oxygenator use resulted in markedly shortened survival times and uncontrollable bleeding with rapid PCV decline.
• Ancrod as an anticoagulant led to significant bleeding from cannulation sites, difficult to control.
• Both bubble oxygenator and Ancrod groups showed a rapid fall in hematocrit, exceeding expected loss.
• Successful 96-hour perfusion was achieved using the silicone-tube membrane oxygenator with heparin anticoagulation.

Conclusions:

• Silicone-tube membrane oxygenators, when used with heparin, are suitable for extended perfusion in conscious lambs.
• Bubble oxygenators and Ancrod present significant challenges, including bleeding and hematocrit instability, limiting their use in prolonged perfusion.
• Heparin remains a reliable anticoagulant for long-term membrane oxygenation in this model.