Background Morbid obesity affects the pharmacokinetics and pharmacodynamics of anesthetics, which may result in inappropriate dosing. We hypothesized that obesity significantly alters the minimum alveolar concentration (MAC) for isoflurane and sevoflurane. In order to test this hypothesis, we used a rodent model of human metabolic syndrome developed through artificial selection for inherent low aerobic capacity runners (LCR) and high aerobic capacity runners (HCR). The LCR rats are obese, display phenotypes homologous to those characteristic of human metabolic syndrome, and exhibit low running endurance. In contrast, HCR rats have high running endurance and are characterized by improved cardiovascular performance as well as overall health. Methods Male and female LCR (n=10) and HCR (n=10) rats were endotracheally intubated and maintained on mechanical ventilation with either isoflurane or sevoflurane. A bracketing design was used to determine MAC; sensory stimulation was induced by tail-clamping. An equilibration period of 30 minutes was provided before and between the consecutive tail clamps. Two-tailed parametric (unpaired t-test) and nonparametric (Mann-Whitney test) statistical tests were used for the comparison of MAC between LCR and HCR rats. The data are reported as mean ± standard deviation along with the 95% confidence interval. A p-value of <0.05 was considered statistically significant. Results The MAC for isoflurane in LCR rats (1.52% ± 0.13) was similar to previously reported isoflurane-MAC for normal rats (1.51% ± 0.12). The HCR rats showed a significantly higher isoflurane-MAC (1.90% ± 0.19) as compared to the LCR rats (1.52% ± 0.13) (p = 0.0001). The MAC for sevoflurane was not significantly different between LCR and HCR rats and was similar to the previously published sevoflurane-MAC for normal rats (2.4% ± 0.30). There was no influence of sex on the MAC of either isoflurane or sevoflurane. Conclusion Obesity and associated co-morbidities do not affect anesthetic requirements as measured by MAC in a rodent model of metabolic syndrome. By contrast, high aerobic capacity is associated with a higher MAC for isoflurane and may be a risk factor for subtherapeutic dosing.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.