Objective To investigate the expression and clinical significance of serum total bilirubin（TBiL）

aspartate aminotransferase（AST）

blood urea nitrogen（BUN）

creatine kinase myocardial band（CKMB） and lactate dehydrogenase（LDH） levels in neonates with different severity of hyperbilirubinemia

with the aim of providing reference for the diagnosis and treatment as well as prognostic assessment of neonates with hyperbilirubinemia in clinical practice.Methods Sixty-five neonates with hyperbilirubinemia attending a hospital in Zhengzhou from April 2020 to April 2021 were selected as the observation group

and 63 healthy neonates with laboratory indexes tested at the same period were selected as the control group.The children in the observation group were divided into 8 cases with severe（TBiL level >342 μmol/L）

21 cases with moderate（257～342 μmol/L）

and 36 cases with mild（TBiL level <257 μmol/L） hyperbilirubinemia according to the severity of the disease.All study subjects underwent laboratory tests

and the indexes included AST

CKMB

LDH

BUN

and TBiL.Serum-related laboratory test indexes were compared between the 2 groups:AST

CKMB

LDH

BUN

and TBiL levels were recorded in the observation and control groups.The levels of AST

CKMB

LDH

BUN and TBiL inchildren with mild

moderate and severe disease were compared before and after 24 h of treatment.The prognosis of children with different conditions was compared

the incidence of complications during the treatment was counted.Results The levels of AST

CKMB

LDH

and TBiL inthe observation group were lower than those in the control group

and the differences were statistically significant（P<0.05）.The differences were not statistically significant（P>0.05） when comparing the BUN levels in the 2 groups.Before treatment

the levels of AST

CKMB

LDH

and TBiL were lower in the moderate and mild groups than in the severe group

and the higher of AST

CKMB

LDH

and TBiL were lower in the mild group than in the moderate group

and the differences were all statistically significant（P<0.05）.After treatment

the levels of AST

CKMB

LDH and TBiL ofchildren in the three groups were lower than those before treatment

and the differences were all statistically significant（P<0.05）.The levels of AST

CKMB

LDH and TBiL ofchildren in the moderate and mild groups were lower than those in the severe group

and the levels of AST

CKMB

LDH and TBiL ofchildren in the mild group were lower than those in the moderate group

and the differences were all statistically significant（P<0.05）.The complication rates of children in the moderate and mild groups were lower than those in the severe group

and the differences were statistically significant（P <0.05）.There was no statistically significant difference between the complication rates of children in the mild and moderate groups（P >0.05）.Conclusion The combined test of AST

CK-MB

LDH and TBiL iseffective in the clinical management of neonates with hyperbilirubinemia

which can effectively identify the severity of the disease

guide clinical treatment and improve the quality of prognosis

and is worthy of clinical promotion.