Objective:To reveal the effects of different doses of naloxone on moderate and severe acute head injuries by monitoring of qEEG.Methods:86 patients with moderate and severe acute head injuries (Glasgow Coma Scale 3～12

within 12 hours after injury) were selected for this study.According to the severity of injury

all patients were classified into three groups: GCS3～5

GCS6～8 and GCS9～12.Patients of each group were then randomly assigned to treatment with naloxone or control.In naloxone groups

low doses of naloxone and high doses of naloxone were administered respectively to the patients with acute brain injury of different severity for three days.Relative power of δ frequency and absolute power of 1～25 frequency were monitored with qEEG before and 30 minutes

1

2

24

48

72

120 hours after administration.Results:In GCS 9 to 12 group

relative power of δ frequency and absolute power of 1～25 frequency were significanfly different ( P <0.05) in qEEG between naloxone groups and control group

while there was no significant difference of all parameters between low dose and high dose naloxone groups( P >0.05).In GCS 6 to 8 group

the two parameters were improved significanfly in naloxone groups and were significantly different between low dose and high dose naloxone groups.In GCS 3 to 5 group

all parameters were not significantly different between naloxone group and control group.Conclusion:These results suggest that treatment with naloxone in patients with moderate and severe head injuries is beneficial in terms of improved qEEG and there is no significant difference between low dose and high dose naloxone in GCS 9 to 12 group

but in GCS 6 to 8 group high dose naloxone shows better efficacy than low dose naloxone.