“…For these procedures, remifentanil as a single premedication is typically administered at doses ranging from 1 to 3 μg/kg administered over 60 s, with good quality of sedation and a lower rate of chest wall rigidity - between 0 and 13% [3,4,5,6]. In their study, de Kort et al [1] administered high cumulative doses of remifentanil for 9 patients (3 μg/kg for 6 patients, 4 μg/kg for 2 patients, and 5 μg/kg for 1 patient) in order to achieve effective sedation. The ineffectiveness of remifentanil at these doses is in contrast with the potent effect of this opioid described in previous studies [3,4,5,6].…”