['Low-dosage adrenaline contained in local anesthetics is commonly used for hemostasis during functional endoscopic sinus surgery (FESS), but often causes significant hemodynamic side effects that might be neglected. A randomized, controlled, prospective clinical trial was designed to find out these effects after local infiltration of different concentrations and/or different dosages of adrenaline during FESS under general anesthesia.', 'One hundred eight adult patients were randomized into one of four groups to receive 2 mL of 2% lidocaine and adrenaline 1:200,000 (group I), 4 mL of 1% lidocaine and adrenaline 1:400,000 (group II), 4 mL of 1% lidocaine and adrenaline 1:200,000 (group III), or 4 mL of 1% lidocaine (group IV) for local infiltration, respectively. Heart rate, systolic blood pressure (BP), diastolic BP, and mean arterial pressure were monitored continuously in radial artery.', 'Significant hemodynamic changes, particularly decrease of BP (p < 0.001) with slightly increased heart rate (p < 0.001) approximately 1.5 minutes after local infiltration, were observed in group I, group II, and group III compared with the baseline, but not in group IV. However, no significant hemodynamic changes were observed between group I, group II, and group III at the same time points (p > 0.05).'] Does low-dosage adrenaline induce transient marked decrease of blood pressure during functional endoscopic sinus surgery?