Physiological impact of prolonged anesthesia in P7 neonatal mice.

(A) Experimental anesthesia setup. P7 neonatal mice were exposed to 1.5% isoflurane in 100% oxygen humidified air in a Plexiglass chamber, with gasses and chamber maintained at 38° C. (B) Respiratory rate in P7 mice as a function of time exposed to 1.5% isoflurane. Error bars depict standard error of the mean (SEM), dotted center lines depict non-linear best fit curve, dashed outer lines depict 95% confidence intervals (see Methods). n = 16 and 3 for 1.5% isoflurane and 1% isoflurane, respectively. (C) Comparison of respiratory rates in unexposed mice and mice anesthetized with 1.5% isoflurane for 2 or 4 hours ANOVA p-valueD) P7 mouse blood glucose concentration at baseline and at 2 or 4 hours of anesthesia with 1.5% isoflurane ANOVA p-valueE) P7 mouse blood ß-hydroxybutyrate concentration at baseline and at 2 or 4 hours of anesthesia with 1.5% isoflurane. ANOVA p-valueF) P7 mouse lactate concentration at baseline and at 2 or 4 hours of anesthesia with 1.5% isoflurane. ANOVA p-value = 0.0007; ***p = 0.0002, ****pG) P7 mouse blood pH at baseline and at 2 or 4 hours of anesthesia with 1.5% isoflurane. ANOVA p-value = 0.0007; *** = pC-G) Each data-point represents an individual animal. Error bars depict SEM. (H) Fraction of P7 mice surviving recovery period following exposure to 1.5% isoflurane for 4 hours. Data-points represent individual litters exposed for 4 hours, error bars represent SEM. Data represents a total of 6 litters (individual data-points) containing 4, 9, 3, 7, 7, and 5 pups, respectively. Total n = 35. *p = 0.0057 by one-sample t-test compared to a hypothetical value of zero.