Low-dose ketamine combined with pentobarbital in a miniature porcine model for a cardiopulmonary bypass procedure: a randomized controlled study.
Porcine anaesthesia remains a great problem for cardiac surgery research and especially with cardiopulmonary bypass procedures. This study was designed to develop a suitable anaesthesia model in which miniature pigs could be induced smoothly and be maintained stably during and after a cardiopulmonary bypass procedure. Thirty-one miniature pigs were randomly divided into two groups and induced using ketamine and pentobarbital (K-P group, n = 15) or pentobarbital (P group, n = 16) alone, respectively. Animals in group K-P were induced with intramuscular injections of ketamine 5 mg kg and pentobarbital 20 mg kg body weight, and those in group P were induced with pentobarbital 30 mg kg alone. After intubation and intravenous catheterization, group K-P was maintained by continuous infusion of ketamine and pentobarbital, and pentobarbital was withdrawn after cardiopulmonary bypass started. Group P received a continuous infusion of pentobarbital throughout the operation. In addition, both groups were injected hourly with midazolam and pipecuronium bolus to achieve optimal surgical conditions. All of the group K-P animals survived for 24 h postoperatively. Five of the group P animals died from anaesthesia-related respiratory and cardiac arrest: three after induction and two after extubation. The animals in group K-P had more stable haemodynamics and arterial blood gas indices than animals in group P. Furthermore, the percentage of animals achieving satisfactory anaesthetic effects was significantly higher in group K-P than in group P. Combination anaesthesia with low-dose ketamine and pentobarbital demonstrated superior haemodynamic and respiratory indices in comparison with pentobarbital. The combination regimen can achieve both hypnosis and analgesia effects with stable circulatory parameters.
PubMed Abstracts
PubMed Abstracts