Ellen de Kort

47 Remifentanil for INSURE in preterm newborns 3 DISCUSSION We aimed to evaluate the effectiveness of remifentanil premedication for the INSURE procedure in preterm neonates. However, the results of our observational study show that low doses (1 μg/kg) did not provide adequate sedation and rapidly administered remifentanil resulted in an unacceptable high incidence of chest wall rigidity following a high dose. Based on these results we conclude that remifentanil bolus infusion in 30 s is not suitable as premedication for neonatal intubation. Remifentanil as the single premedication drug has been investigated in three previous studies. Welzing et al. studied 2 μg/kg of remifentanil administered over 60 s in preterm infants undergoing the INSURE procedure. 6 A single dose provided adequate sedation in 81% of patients, with 19% needing a second dose and none of the patients requiring additional medication. Intubation was successful at the first attempt in 71% of patients, insufficient sedationwas never the reason for a second attempt and intubation conditions were excellent or good in all patients. No chest wall rigidity was reported. Avino et al. administered 1 μg/kg of remifentanil over 60 s to 36 preterm infants needing (semi-) elective intubation and reported similar results to the previous study. 7 Intubation was successful at the first attempt in 75% of patients but poor intubation conditions occurred in 24% of intubation attempts. Chest wall rigidity occurred in two patients (6%). Choong et al. also investigated remifentanil in elective intubation in neonates at a dose of 3 μg/ kg administered over 60 s. 8 They found less positive results, with additional medication needed in 26.7% of patients, failed first attempts in 60% of patients, and excellent or good intubation conditions in only 53.6% of patients. Chest wall rigidity was observed in 13% of patients. In our study, remifentanil was found to provide sufficient sedation in only a small number of patients. An explanation may be the faster infusion rate used in our study. Fast infusion is related to higher peak levels, and as a consequence increased side effects and shorter duration of effective sedation. 6,11 The window of opportunitymight have been too short to obtain an adequate sedation score and intubation procedure. We also found a significantly higher incidence of chest wall rigidity, most likely also attributable to the faster infusion rate of 30 s. In retrospect, the chosen duration of infusion was too fast in our study. We used an infusion rate of 30 s to flush the small volume of remifentanil because this is the standard way to administer many semi-acute cardiorespiratory drugs in our intensive care. The results of the current study underline the danger of such a routine way to administer drugs. Based on our results, this is obviously not appropriate and represents important knowledge for other clinicians and researchers who intend to use remifentanil in preterm neonates.