Ellen de Kort

32 Chapter 2 Remifentanil, a synthetic opioid, was introduced into clinical practice in 1996 and is therefore the newest opioid available. 28,29 Because of hydrolysis by nonspecific tissue and plasma esterases, metabolism is not dependent on liver and renal function, and it is also not age related. 30-34 Metabolism produces a metabolite known as remifentanil acid, which has no clinical significant activity. 29,31,32 This unique pharmacokinetic profile provides ultrashort action, high predictability, rapid onset and offset of action, immediate recovery of the clinical effect after interruption of the administration, a short context-sensitive half- life and short elimination time not influenced by the infusion time, and no accumulation of the drug. 30,31 These positive effects of remifentanil were evident in several reviewed studies. 32-39 Drug administration 1-2min Intubation and surfactant <10 min Recovery breathing Adequate sedation Inadequate sedation Time Level of sedation Figure 1. Ideal sedation model for the INSURE procedure Choong et al. investigated the effect of remifentanil as premedication in neonatal elective intubations. They found good intubation conditions (using a seven-point Likert scale) and few intubation attempts were needed. Mean time to return of spontaneous respiration in those patients who did not receive any additional drugs besides remifentanil was 210 seconds. 30 This finding supports our hypothesis that remifentanil is suitable for the INSURE procedure. In the study of Welzing et al. remifentanil was also found to be effective for neonatal intubation. Intubation conditions were good or excellent in all patients and the vast majority of patients were intubated at the first attempt. 16 However, the authors’ conclusions about the very short period of respiratory depression and early reinstitution of CPAP after surfactant treatment are debatable. The time to extubationwas rather long (42.4 minutes and still 16.9 minutes after excluding 3 patients on prolonged endotracheal CPAP for logistic reasons) and does not perfectly meet the criterion of