Nitrous oxide anesthesia in children for MRI: a comparison with isoflurane and halothane

To compare the anesthetic effects of nitrous oxide, isoflurane, and halothane on hemodynamic stability and recovery characteristics in pediatric patients during magnetic resonance imaging (MRI). Materials and methods: The present study includes 60 ASA I-II children aged 1-12 years undergoing MRI. After endotracheal intubation, patients were randomly assigned into 1 of 3 anesthetic groups. Group N (n = 20) received nitrous oxide and oxygen (N_2O:O_2 60:40), Group I (n = 20) received 0.5% isoflurane and oxygen, Group H (n = 20) received 0.5% halothane and oxygen to maintain anesthesia. At the completion of the procedure, inhalation anesthetic was discontinued. Extubation, emergence, recovery times, and adverse events were recorded throughout the duration of the procedure. Results: There was no significant difference in the demographic data among the groups. In the nitrous oxide group 5 children (25%), in the halothane group 2 children (10%), and in the isoflurane group 1 child (5%) moved during MRI and supplemental inhalation anesthesia was required for these patients. Emergence time after nitrous oxide anesthesia was slightly shorter than after isoflurane anesthesia (3.15 ± 2.56 min compared with 4.65 ± 2.64 min, P = 0.162) but significantly shorter than after halothane anesthesia (5.35 ± 2.47 min, P = 0.023). Early recovery time after nitrous oxide and isoflurane anesthesia was significantly more rapid than after halothane anesthesia (4.60 ± 2.58 min and 3.65 ± 1.63 min compared with 7.00 ± 2.15 min, P < 0.05). Conclusion: After induction with propofol, nitrous oxide may provide anesthesia for MRI in pre-medicated children. However, complete immobility was not achieved in all patients with nitrous oxide alone. Nitrous oxide and isoflurane resulted in faster emergence and recovery than halothane, but there was no significant difference between nitrous oxide and isoflurane. Discharge times from the hospital were similar for all 3 groups.