Normal physiologic values of neonatal pigs and the effects of isoflurane and pentobarbital anesthesia.

The newborn piglet is becoming increasingly popular as a model for neonatal studies. However, data on normal physiologic baseline values and the influence of anesthesia on these values are scarce. In this study, we describe husbandry, surgical, and experimental methods used to establish a conscious, chronically catheterized neonatal piglet model, which enabled study of unrestrained piglets recovered from surgery and anesthesia, for up to 10 days after separation from the sow. Chronic catheterization allowed repeated experiments to be performed in the same animals, reducing the number of animals needed for study. Presented herein are baseline resting hemodynamic and blood chemistry data and circulating hormone measurements of vasopressin, plasma renin activity, adrenocorticotrophic hormone, cortisol, epinephrine, norepinephrine, and dopamine for piglets in the first 2 weeks of life. Also, in two series of experiments, the effects of the gas anesthetic isoflurane and the injectable anesthetic pentobarbital on these baseline values were investigated. Results indicate that both pentobarbital and isoflurane elicit changes in blood pressure, heart rate, vasopressin, plasma renin activity and ventilatory drive that should be considered when using either of these anesthetic agents in acute studies.