[Midazolam for anesthetic induction in neonates]

The purpose of this study is to evaluate the effects of midazolam on circulation, respiration, sedation, and liver function of the neonates. The study subjects are 27 neonates (body weight 2.1 to 3.8 kg, gestational age at birth 34 to 41 weeks) who underwent surgery in neonatal period. Of 27, 13 patients received lidocaine (1.5 mg.kg-1) immediately before tracheal intubation (group L), and 14 had midazolam (0.1 mg.kg-1) with lidocaine (group ML). We compared the effects of midazolam in the presence of lidocaine on the following parameters: (1) the incidence of hypotension (systolic blood pressure < 50 mmHg) and bradycardia (heart rate < 100 beats.min-1), (2) the incidence of apnea and desaturation of oxygen (< 80%), (3) the degree of sedation, and (4) the serum levels of bilirubin and unbound bilirubin after surgery. In group L, there were hypotension (1/13) and desaturation (1/13). In group ML, there were desaturation (1/14) and post-operative apnea (1/14). None in both groups developed bradycardia or intracranial hemorrhage. A single-dose of lidocaine induced sedation only in 4 neonates, while combination of midazolam and lidocaine in 11. None had elevation of either total or unbound bilirubin after surgery. In conclusion, the titrated dose of midazolam with lidocaine is useful for anesthetic induction of neonates, although cares should be taken on its adverse effects such as hypotension, desaturation, and post-operative apnea.