SESSION TYPE: Pharmacology in the ICU Posters
PRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PM
PURPOSE: Animal models of disease often use anesthesia, which can influence hemodynamics and cardiac function. Our purpose was to compare cardiac function in mice under light isoflurane anesthesia with cardiac function in unanesthetized mice.
METHODS: Wild type C57BL/6 mice (n=13) were anesthetized with isoflurane, via nose cone, titrated to the lowest dose necessary to achieve non-response to distal tail pinch; doses ranged from 0.75% - 1.75% isoflurane. High-frequency echocardiography with a 30Mhz ultrasound transducer was used to measure cardiac function, with M-mode for fractional shortening and aortic outflow tract PW Doppler for stroke volume. Control images were obtained under light anesthesia. Isoflurane anesthesia was then stopped while maintaining 100% oxygen flow. M-Mode and PW Doppler images continued to be captured until the mice emerged from anesthesia. The measurements collected at emergence from anesthesia were used to calculate unanesthetized cardiac function.
RESULTS: Temperature in anesthetized mice was 38.1±0.4°C vs. 38.0±0.4°C (p=0.73). Heart rate was 449±26 BPM vs. 423±24 BPM (p=0.16). Stroke volume was 49.2±6.1 μL vs. 50.5±6.3 μL (p=0.76). Cardiac output was 22.1±3.1 mL/min vs. 21.4±3.0 mL/min (p=0.74). Ejection fraction was 67.5±6.4% vs. 66.9±6.5% (p=0.90). Fractional shortening was 37.5±5.0% vs. 37.1±5.1% (p=0.92).
CONCLUSIONS: The data suggest that carefully titrated light isoflurane anesthesia does not have a significant effect on cardiac function. Cardiac function data measured under light isoflurane anesthesia can be assumed to be very close or equivalent to measurements in the unanesthetized mouse.
CLINICAL IMPLICATIONS: The need for anesthesia is one of the limitations in translating findings from animal models to the clinical setting. These findings suggest that hemodynamic observations in our murine model of sepsis may be relevant to clinical sepsis.
DISCLOSURE: The following authors have nothing to disclose: Edward Sawey, Steven Hollenberg, Sergio Zanotti
No Product/Research Disclosure InformationCooper University Hospital, Camden, NJ