BackgroundCardiopulmonary bypass is associated with microcirculatory disturbances which are reversible at the bypass weaning. Catecholamines have cardiac and peripheral vascular effects, which are difficult to separate. Previous studies have suggested that Dobutamine may have a direct peripheral vascular effect in septic shock patients. The aim of the present study is to investigate the effect of dobutamine in a model of impaired microcirculation and a fixed cardiac output.MethodsThe sublingual microcirculation in 40 patients undergoing elective cardiac surgery on normothermic cardiopulmonary bypass was measured using side-stream dark-field imaging. 20 patients received dobutamine for 30 minutes before having their microcirculation measured followed by 30 minutes saline. the other half of the group had or saline was Each patient was it's own control. Only vessels below 25 μm in diameter were studied and flow was categorized using a semi-quantitative approach. The total vessel length per microscope field was measured.ResultsAnesthesia induction was associated with an improvement of microcirculation with a decrease in intermittent and sluggishly perfused vessels. Cardio-pulmonary bypass is associated with a microcirculatory shut down with a 40% decrease in continuously perfused vessels. Dobutamine was associated with slight (NS) improvement of in the continuously perfused vessels but this still remain below pre-induction functional capillary density as shown in Table 1.Tabled 1ConclusionThis investigation showed that anesthesia induction improves micro-circulation, cardio-pulmonary bypass impairs micro-circulation and dobutamine administration partially improves this micro-circulatory shut down independently of a cardiac effect. The mechanism, effect on post-operative outcome and it's effect of other situations where microcirculation is impaired requires further studies. BackgroundCardiopulmonary bypass is associated with microcirculatory disturbances which are reversible at the bypass weaning. Catecholamines have cardiac and peripheral vascular effects, which are difficult to separate. Previous studies have suggested that Dobutamine may have a direct peripheral vascular effect in septic shock patients. The aim of the present study is to investigate the effect of dobutamine in a model of impaired microcirculation and a fixed cardiac output. Cardiopulmonary bypass is associated with microcirculatory disturbances which are reversible at the bypass weaning. Catecholamines have cardiac and peripheral vascular effects, which are difficult to separate. Previous studies have suggested that Dobutamine may have a direct peripheral vascular effect in septic shock patients. The aim of the present study is to investigate the effect of dobutamine in a model of impaired microcirculation and a fixed cardiac output. MethodsThe sublingual microcirculation in 40 patients undergoing elective cardiac surgery on normothermic cardiopulmonary bypass was measured using side-stream dark-field imaging. 20 patients received dobutamine for 30 minutes before having their microcirculation measured followed by 30 minutes saline. the other half of the group had or saline was Each patient was it's own control. Only vessels below 25 μm in diameter were studied and flow was categorized using a semi-quantitative approach. The total vessel length per microscope field was measured. The sublingual microcirculation in 40 patients undergoing elective cardiac surgery on normothermic cardiopulmonary bypass was measured using side-stream dark-field imaging. 20 patients received dobutamine for 30 minutes before having their microcirculation measured followed by 30 minutes saline. the other half of the group had or saline was Each patient was it's own control. Only vessels below 25 μm in diameter were studied and flow was categorized using a semi-quantitative approach. The total vessel length per microscope field was measured. ResultsAnesthesia induction was associated with an improvement of microcirculation with a decrease in intermittent and sluggishly perfused vessels. Cardio-pulmonary bypass is associated with a microcirculatory shut down with a 40% decrease in continuously perfused vessels. Dobutamine was associated with slight (NS) improvement of in the continuously perfused vessels but this still remain below pre-induction functional capillary density as shown in Table 1.Tabled 1 Anesthesia induction was associated with an improvement of microcirculation with a decrease in intermittent and sluggishly perfused vessels. Cardio-pulmonary bypass is associated with a microcirculatory shut down with a 40% decrease in continuously perfused vessels. Dobutamine was associated with slight (NS) improvement of in the continuously perfused vessels but this still remain below pre-induction functional capillary density as shown in Table 1. ConclusionThis investigation showed that anesthesia induction improves micro-circulation, cardio-pulmonary bypass impairs micro-circulation and dobutamine administration partially improves this micro-circulatory shut down independently of a cardiac effect. The mechanism, effect on post-operative outcome and it's effect of other situations where microcirculation is impaired requires further studies. This investigation showed that anesthesia induction improves micro-circulation, cardio-pulmonary bypass impairs micro-circulation and dobutamine administration partially improves this micro-circulatory shut down independently of a cardiac effect. The mechanism, effect on post-operative outcome and it's effect of other situations where microcirculation is impaired requires further studies.