Nitrous oxide improves cardiovascular, respiratory, and thermal stability during prolonged isoflurane anesthesia in juvenile guinea pigs

Anesthesia is frequently used to facilitate physiological monitoring during interventional animal studies. However, its use may induce cardiovascular (central and peripheral), respiratory, thermoregulatory depression, confounding results in anesthetized animals. Despite the wide utility of guinea pigs as a translational platform, anesthetic protocols remain unstandardized for extended studies this species. Therefore, optimizing an protocol that balances stable anesthesia with intact cardiorespiratory metabolic function crucial. To achieve this, 12 age sex-matched juvenile Dunkin Hartley underwent (≤150 min) either (a) isoflurane (ISO: 1.5%), or (b) + N2O (ISO+ N2O: 0.8% +70%), randomized cross-over designed study. Cardiovascular (HR, SBP, peripheral microvascular blood flow), respiratory (respiratory rate, SpO2), thermal (Tre Tsk) measures were recorded continuously throughout anesthesia. Blood gas pre- post- performed. Incorporation 70% allowed significant reductions (to 0.8%) while maintaining effective depth prolonged noninvasive examination pigs. ISO+N2O maintained heart flow, at levels closest those conscious animals, especially females; however, it did not fully rescue anesthesia-induced hypotension. These suggest requiring pigs, adjuvant provides adequate anesthesia, minimizing associated depression. The preservation status most marked first hour