Ellen de Kort

62 Chapter 4 From 2016 onwards several reports have appeared in the literature using premedication during LISA. Although different strategies of sedative premedication were used, these reports unanimously showed better patient comfort in patients treated with premedication. 25-27 However, sedative premedication also has adverse effects. In one retrospective study and one randomized controlled trial, propofol as premedication for LISA has shown to increase the need for non-invasive intermittent positive pressure ventilation. 25,26 Although the need for endotracheal intubation was not increased in patients treated with propofol, the frequency of mechanical ventilation in the first 72 hours of lifewas higher compared to those that did not receive premedication. 20 Ketamine as premedication led to a relatively high need for endotracheal intubation. 27 Since LISA failure causes a higher median number of days on mechanical ventilation, a higher incidence of supplemental oxygen at day 28 and a 20% lower survival without serious adverse events, 31 it is important to use sedative premedication that has little to no effect on the respiratory drive in order to prevent LISA failure. Awake laryngoscopy has considerable effects on vital parameters such as oxygen saturation and heart rate. In our study population, oxygen desaturations <80% in the first 10 min from start of LISA occurred in 54% of patients. This percentage is lower compared to the studies using premedication prior to LISA. 25-28 The high incidence of oxygen desaturations in premedicated patients is most probably not due to laryngoscopy, but caused by a pronounced suppression in respiratory drive by the sedative premedication. Besides this, during LISA oxygen desaturations are not only an effect of laryngoscopy but are also caused by the administration of surfactant. The increase in heart rate found in our study is at least partly due to the administration of atropine prior to LISA and is therefore not a clear indicator of patient stress and discomfort. The administration of atropine did, however, prevent patients from developing bradycardia compared to the study of Dekker et al. who did not use atropine. 26 In endotracheal intubation, and presumably also in LISA, the use of premedication can decrease the number of attempts needed for success, 12,13,17 and improve the quality of technical condtions. 32,33 In half of all our LISA procedures more than one laryngoscopy episodewas needed for completion of the procedure. This success ratewas comparable to success rates in studies using premedication prior to LISA, 26,27 as well as studies using propofol as premedication before endotracheal intubation. 34,35 Inadequate quality assessment was found in 41% of procedures. Technical quality seems considerably better when ketamine is used prior to LISA. 27 To our opinion, the absence of improved success rate after premedication does not mean premedication should not be used. It indicates that we have to do better in premedicated LISA procedures and endotracheal intubation as well.