Comparison of continuous drip of midazolam or lidocaine in the treatment of intractable neonatal seizures

Seizures constitute the most common neurological symptom in the neonatal period. Treatment usually involves the administration of intravenous benzodiazepines followed by either phenobarbital or phenytoin. For nonresponsive cases, continuous intravenous drip of either midazolam or lidocaine has been suggested for seizure control. Some reports suggest that seizures themselves may have a deleterious effect on long-term neurological outcome. Therefore, there is a need to find treatment regimens with better efficacy to provide maximum seizure control. The authors compared the effectiveness of lidocaine and midazolam in the treatment of intractable seizures in newborn infants born at or after 36 weeks of gestation who suffered from hypoxic-ischemic encephalopathy and who had their cerebral activity monitored. Thirty infants were included in the study: 22 received lidocaine, and 8 received midazolam. Seventeen (77%) infants had a good or partial response to lidocaine, and 4 (50%) had a partial response to midazolam. Of 20 infants diagnosed with hypoxic-ischemic encephalopathy grade 2, 18 (90%) responded to second-line treatment (14 [93%] of 15 to lidocaine and 4 [80%] of 5 to midazolam). Among 10 infants with hypoxic-ischemic encephalopathy grade 3, only 3 (30%) responded to second-line treatment (all 3 to lidocaine, none to midazolam). The findings suggest that lidocaine may be more effective than midazolam in reducing or controlling refractory neonatal seizures. The lower response rate to midazolam was more evident in infants with severe hypoxic-ischemic encephalopathy (grade 3).