Midazolam sedation in mechanically ventilated newborns: a double blind randomized placebo controlled trial. Analgesia and sedation in preterm neonates who require ventilatory support: results from the NOPAIN trial. Neonatal Outcome and Prolonged Analgesia in Neonates. Placebo-controlled trial of midazolam sedation in mechanically ventilated newborn babies.
To determine efficacy of midazolam as a sedative in mechanically ventilated newborns.
                Double blind randomized placebo controlled trial.
                Neonatal Unit of Tertiary Hospital.
                Sedation over 48 h of observation.
                Neonates with birth weight less than 2000 g who were mechanically ventilated within 7 days of life were randomly assigned to midazolam and placebo group. Midazolam and placebo were administered as bolus (0.2 mg/kg) followed by continuous infusion (0.06 mg/kg/h). Both groups received morphine infusion (10 microg/kg/h). Sedation score was noted at 6 hourly intervals for 48 hours. Hemodynamic variables, ventilatory variables, complications and side effects of treatments were also recorded.
                Thirty-three neonates were enrolled (17 in midazolam, 16 in placebo group). The groups were comparable for birth weights and gestation. The midazolam group had significantly better sedation from 18-24 hours after enrollment compared to placebo group. At 48 h there were no significant differences in proportion of infants with adequate sedation between midazolam and placebo group. The two groups were comparable with respect to heart rate, perfusion, ventilatory indices and blood gas parameters. None of the infants were noted to have hypotension on loading with midazolam or placebo. Seizures were noted in 2 neonates in placebo group 24 hours after enrollment (insignificant statistically).
                Sedation provided by continuous infusion of midazolam and morphine appears to be comparable to morphine alone in newborn babies on mechanical ventilation, with no significant adverse effects. The course of mechanical ventilation is not influenced by use of midazolam. Preterm neonates are exposed to multiple painful procedures after birth and exhibit acute physiological responses to pain. Occurrence of early intraventricular hemorrhage within 24 to 72 hours after birth suggests a role of pain and stress in the multifactorial causation of severe intraventricular hemorrhage and periventricular leukomalacia. We proposed that such neurologic outcomes in preterm neonates who require ventilatory support may be reduced by morphine analgesia or midazolam sedation compared with a placebo.
                To define the incidence of clinical outcomes in the target study population, to estimate the effect size and adverse effects associated with analgesia and sedation, and to calculate the sample size for a definitive test of this hypothesis.
                Sixty-seven preterm neonates were randomized in a pilot clinical trial from 9 centers. Neonates of 24 to 32 weeks gestation were eligible if they had been intubated and required ventilatory support for less than 8 hours and if they were enrolled within 72 hours after birth. Exclusion criteria included major congenital anomalies, severe intrapartum asphyxia, and participation in other research studies. Severity of illness was assessed by the Clinical Risk Index for Babies, and neonates were randomized to receive continuous infusions of morphine sulfate, midazolam hydrochloride, or 10% dextrose (placebo). Masked study medications were continued as long as clinically necessary, then weaned and stopped according to predefined criteria. Levels of sedation (COMFORT scores) and responses to pain (Premature Infant Pain Profile scores) were measured before, during, and 12 hours after discontinuation of drug infusion. Cranial ultrasound examinations were performed as part of routine practice, and poor neurologic outcomes were defined as neonatal death, severe intraventricular hemorrhage (grade III or IV), or periventricular leukomalacia.
                No significant differences occurred in the demographic, clinical, and socioeconomic variables related to mothers and neonates in the 3 groups or in the severity of illness at birth as measured by Clinical Risk Index for Babies scores. Two neonates in the placebo group and 1 neonate in the midazolam group died; no deaths occurred in the morphine group. Poor neurologic outcomes occurred in 24% of neonates in the placebo group, 32% in the midazolam group, and 4% in the morphine group (likelihood ratio chi2 = 7.04, P = .03). Secondary clinical outcomes and neurobehavioral outcomes at 36 weeks' postconceptional age were similar in the 3 groups. Responses elicited by endotracheal tube suction (Premature Infant Pain Profile scores) were significantly reduced during the morphine (P<.001) and midazolam (P = .002) infusions compared with the placebo group.
                This pilot trial suggests that preemptive analgesia given by continuous low-dose morphine infusion may reduce the incidence of poor neurologic outcomes in preterm neonates who require ventilatory support. Limitations in the sample size of this pilot study suggest that these results should be confirmed in a large multicenter randomized trial. Although midazolam is used for sedation of mechanically ventilated newborn babies, this treatment has not been evaluated in a randomised trial. We have done a prospective placebo-controlled study of the effects of midazolam on haemodynamic variables and sedation as judged by a five-item behaviour score. 46 newborn babies on mechanical ventilation for respiratory distress syndrome were randomly assigned to receive midazolam (n = 24) or placebo (n = 22) as a continuous infusion. Doses of midazolam were calculated to obtain plasma concentrations between 200 and 1000 ng/mL within 24 h of starting treatment and to maintain these values throughout the study. Haemodynamic and ventilatory variables were noted every hour, as were complications and possible side-effects of treatment. Mean (SD) duration of inclusion was 78.7 (30.9) h. 1 patient in the treatment group and 7 in the placebo group were withdrawn because of inadequate sedation (p < 0.05). Midazolam gave a significantly better sedative effect than placebo, as estimated by the behaviour score (p < 0.05). Heart rate and blood pressure were reduced by treatment but remained within the normal range for gestational age and there was no effect on ventilatory indices. The incidence of complications was similar in the two groups. No midazolam-related side-effects were noted. Continuous infusion of midazolam at doses adapted to gestational age induces effective sedation in newborn babies on mechanical ventilation, with positive effects on haemodynamic variables. The course of the respiratory distress syndrome was not influenced by this treatment. Midazolam was given over only a few days and the limited effects on heart rate and blood pressure that we report should not encourage long-term administration.
There are insufficient data to promote the use of intravenous midazolam infusion as a sedative for neonates undergoing intensive care. This review raises concerns about the safety of midazolam in neonates. Further research on the effectiveness and safety of midazolam in neonates is needed.