Ellen de Kort

121 Propofol for intubation in neonates 7 Propofol is known for its pronounced effect on blood pressure in the neonatal population. We found amedian decrease inMBPof 34%, which is in accordancewith other studies. 16,17,21 The incidence of hypotension of 59% was comparable to that reported by Smits et al. (64%), 21 but much higher than found by Welzing et al. (38%). 16 This could be explained by the much smaller study sample, the lower dosages, and the different definition of hypotension. 16 Ghanta et al. did not report hypotension. 18 This could be explained by the possibility that MBP measurements were not continued long enough to detect hypotension, as hypotension appears at a median of 10-20 min after propofol. 16,17 Because of the pronounced effect that propofol can have on blood pressure, the hemodynamic status of the patient should be carefully evaluated before propofol is administered. In case of (impeding) hemodynamic compromise, other premedication with less pronounced effects on blood pressure should be considered. Although blood pressure decrease after propofol is marked and there is a high incidence of hypotension, the implications for the short-term and long-term outcome are unclear. Blood pressure alone is a poor indicator of cardiovascular status. 27 In 95% of patients in the dose-finding study by Smits et al., cerebral autoregulation was intact during episodes of hypotension. 28 In the absence of clinical signs of shock, they labelled these episodes of hypotension as permissive. 21 Two other small studies on the cerebral effects of propofol in the neonatal population also showed no important correlation between blood pressure and cerebral oxygenation. 29,30 Although these findings are certainly reassuring, there is insufficient evidence on the short-term and long-term consequences of propofol- induced hypotension and blood pressure decrease to draw final conclusions. Until this is clarified in further studies, we should in our opinion be careful with designating propofol-induced hypotension and blood pressure decrease as permissive. On the other hand, the negative effects of propofol must be set against the negative effects of other premedication strategies. Almost all opioids, hypnotics and muscle relaxants also carry a risk of hypotension, and with fentanyl and remifentanil, there is also a risk of chest wall rigidity. 12 Our study has several limitations. First, we were unable to perform dose-finding as planned because patient inclusion in several groups proved to be very difficult. Reasons were insufficient time for achieving parental consent, and the very low incidence of endotracheal intubation in the higher gestational age groups. Second, we used a very strict definition of hypotension. Even a single measurement of MBP belowPMA in the first 60 min after propofol was marked as hypotension. It is questionable whether this single measurement of MBP below PMA has any clinical relevance. Adding a time element to the definition may better reflect the patients with clinically relevant hypotension. Unfortunately, we were unable to provide synchronized neuro-monitoring data, which