OBJECTIVE: To probe into the effects of low-dose sufentanil combined with ketamine on hemodynamics and cerebral oxygen saturation during anesthesia induction in children with congenital heart surgery in high altitude areas. METHODS: Totally 120 children with congenital heart disease admitted into Qinghai Red Cross Hospital from Mar. 2016 to May 2020 were extracted to be divided into the control group and the observation group vai the random number table

with 60 cases in each group. The control group was given basic ketamine anesthesia

while the observation group received low-dose sufentanil combined with ketamine. Both groups were given intravenous compound drugs to induce tracheal intubation. Heart rate（ HR）

mean arterial pressure（ MAP）

stroke volume index（ SVI）

cardiac index（ CI）

systemic resistance index（ SVRI） and the maximum pressure gradient（ dp/dtmax） and pulse pressure variation degree（ PPV） and cerebral oxygen saturation（ r Sc O

2

） at different time points [after basic anesthesia（ T

0

）

1 min after anesthesia induction（ T

1

）

2 min（ T

2

） and 5 min（ T

3

）

1 min after endotracheal intubation（ T

4

）

2 min（ T

5

）

5 min（ T

6

） and 10 min（ T

7

） ]of two groups were observed. RESULTS: Compared with the control group

HR

MAP

SVRI

dp/dtmaxand PPV decreased significantly at each time point in the observation group

while SVI

CI and r ScO

2

increased significantly. HR in the observation group was significantly lower than that in the control group from T

0

to T

7

; MAP in the observation group was significantly lower than that in the control group from T

0

to T

2

; SVI in the observation group was significantly higher than that in the control group from T

1

to T

6

; CI in the observation group was significantly higher than that in the control group from T

1

to T

2

; SVRI in the observation group was significantly lower than that in the control group from T

0

to T

2

and from T

4

to T

5

; dp/dtmaxin the observation group was significantly lower than that in the control group from T

0

to T

1

; PPV of the observation group was significantly lower than that of the control group from T

0

to T

5

; r ScO

2

in the observation group was significantly higher than that in the control group from T

0

to T

2

with statistically significant differences（ P

<

0. 05）. CONCLUSIONS: Lowdose sufentanil combined with ketamine is more suitable for maintaining the stability of hemodynamics and regional cerebral oxygen saturation during anesthesia induction in children with congenital heart disease in high altitude areas.