Objective: To summarize the parameter adjustment of mild hypothermia in the treatment of neonatal hypoxic-ischemic encephalopathy

so as to provide reference for clinicians. Methods: PubMed

the Cochrane Library and Web of Science database were retrieved to collect the related literature of mild hypothermia in the treatment of hypoxic-ischemic encephalopathy. Methodological quality of randomized controlled trials (RCT) was assessed by using the Cochrane risk assessment tool

and the quality of observational studies was evaluated by using the Newcastle-Ottawa scale (NOS). Results: Fourteen articles were enrolled in the study

including 6 RCT and 8 observational studies. Mild hypothermia temperature and course of treatment were classified as level I evidence factor

with high credibility that longer and lower temperature did not improve the prognosis

but increased the incidence of adverse events. The onset of mild hypothermia was classified as level II evidence factor

indicating that starting mild hypothermia treatment as early as possible could better improve the prognosis

and it was still partially effective even after 6 h

especially for moderate hypoxic-ischemic encephalopathy. The treatment of mild hypothermia (systemic vs. local mild hypothermia) was classified as level III evidence factor

which might be helpful in predicting the neuroprotective effects of two different mild hypothermia methods. Conclusion: This study preliminarily explores the influence of mild hypothermia parameters on the prognosis of hypoxic-ischemic encephalopathy

and provides reference for the prognosis research. The current study supports the strategy of mild hypothermia from 33.5 to 34.0 °C for 72 h. Regardless of the type of mild hypothermia

it is recommended to start the treatment as soon as possible

even if more than 6 h after birth

therapeutic hypothermia is still partly effective.