Abstract
OBJECTIVE: To investigate whether changes in muscle tissue perfusion measured with positron emission tomography would be reflected by parallel changes in muscle tissue oxygen saturation (StO2) measured using near-infrared spectroscopy during high and low blood flow levels achieved using cardiopulmonary bypass (CPB) in an animal model.
DESIGN: A prospective, randomized study.
SETTING: Research laboratory, single institution.
PARTICIPANTS: Eight pigs (69-71 kg).
INTERVENTIONS: In anesthetized pigs, normothermic CPB was established with a blood flow of 60 mL/kg/min for 1 hour. Thereafter, a low blood flow of either 47.5 or 35 mL/kg/min was applied for 1 hour followed by a blood flow of 60 mL/kg/min for an additional hour. Regional StO2 was measured continuously by placing a near-infrared spectroscopy electrode on the skin above the gracilis muscle of the noncannulated back leg. Muscle tissue perfusion was measured using positron emission tomography with (15)O-labeled water during spontaneous circulation and the different CPB blood flows. Systemic oxygen consumption was estimated by measurement of venous saturation and lactate levels.
MEASUREMENTS AND MAIN RESULTS: The results showed profound systemic ischemia during low CPB blood flow. StO2 remained high until muscle tissue perfusion decreased to about 50%, after which StO2 paralleled the linear decrease in muscle tissue perfusion.
CONCLUSION: In an experimental CPB animal model, StO2 was stable until muscle tissue perfusion was reduced by about 50%, and at lower blood flow levels, there was almost a linear relationship between StO2 and muscle tissue perfusion.
Originalsprog | Engelsk |
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Tidsskrift | Journal of Cardiothoracic and Vascular Anesthesia |
Vol/bind | 31 |
Udgave nummer | 6 |
Sider (fra-til) | 2065-2071 |
Antal sider | 7 |
ISSN | 1053-0770 |
DOI | |
Status | Udgivet - 6 dec. 2017 |