Introduction: There are few reports of in vivo muscle strength measurements in animal models of ICU-acquired weakness (ICU-AW). In this study we investigated whether the Escherichia coli (E. coli) septic peritonitis mouse model may serve as an ICU-AW model using in vivo strength measurements and myosin/actin assays, and whether development of ICU-AW is age-dependent in this model.
Methods: Young and old mice were injected intraperitoneally with E. coli and treated with ceftriaxone. Forelimb grip strength was measured at multiple time points, and the myosin/actin ratio in muscle was determined.
Results: E. coli administration was not associated with grip strength decrease, neither in young nor in old mice. In old mice, the myosin/actin ratio was lower in E. coli mice at t = 48 h and higher at t = 72 h compared with controls.
Conclusions: This E. coli septic peritonitis mouse model did not induce decreased grip strength. In its current form, it seems unsuitable as a model for ICU-AW.
Keywords: animal model; critical illness myopathy; critical illness polyneuropathy; grip strength; intensive care unit-acquired weakness.
© 2015 The Authors. Muscle & Nerve Published by Wiley Periodicals, Inc.