RESUMEN
OBJECTIVE: The aim of this study was to investigate the effects of clinical dosages of norepinephrine and dobutamine on sublingual microcirculation during general anesthesia with sevoflurane in minor surgical procedures. DESIGN: This prospective study was performed on patients scheduled for breast cancer surgery. SETTING: Tertiary care university hospital. PARTICIPANTS: Twenty patients undergoing elective surgery. INTERVENTIONS: Patients received a continuous infusion of norepinephrine (0.1 µg/kg/min) and afterwards, following a 15-minute interval, a continuous infusion of dobutamine (5 µg/kg/min). Prior to and at the end of each drug infusion period, hemodynamic parameters were measured using an esophageal Doppler probe (ED), and 5 sidestream darkfield (SDF) sublingual microcirculation video recordings were taken. MEASUREMENTS AND MAIN RESULTS: No significant changes to total vessel density (TVD)(mm/mm(2)), perfused vessel density (PVD) (mm/mm(2)), proportion of perfused vessels (PPV) (percentage), or microvascular flow index (MFI) (arbitrary units) were measured at the end of each drug infusion period versus pre-infusion data and no differences were observed between the effects of norepinephrine versus dobutamine. Mean arterial pressure (APm) (mmHg) was significantly greater following both norepinephrine and dobutamine infusions compared to pre-infusion values, while peak velocity (PV) (cm/sec) and the stroke volume index (SVI) (mL/m(2)) only showed a significant increase following the dobutamine infusion. No change in corrected flow time (FTc) (msec) was observed. CONCLUSIONS: During general anesthesia with sevoflurane, the infusion of clinical dosages of norepinephrine and dobutamine did not alter sublingual perfusion, although the expected systemic hemodynamic alterations were induced.