Objective To evaluate the effect of the single-person hyperbaric chamber on hemodynamics of superior mesenteric artery in the personnel rushing to the extremely high altitude area.Methods Sixty healthy young male subjects who traveled by car from the plains(890 m above sea level)to a very high altitude area(5 130 m above sea level)were randomly divided into a control group,a low-flow oxygen therapy group and a hyperbaric oxygen group,with 20 cases in each group.After entering the plateau area,no intervention was made in the control group;in the low-flow oxygen therapy group,low-flow oxygen therapy was performed once a day by means of nasal oxygen cannula(oxygen flow rate of 2 L/min,60 min/times);in the hyperbaric oxygen group,hyperbaric oxygen therapy was carried out once a day in a single-person hyperbaric oxygen chamber(pressuri-zation pressure of 0.25 MPa,60 min/times).The subjects in the three groups had their peak systolic velocity(PSV),resistance index(RI),and pulsation index(PI)of the main trunks of the SMAs and their grade 1 and 2 branches measured and compared using color Doppler ultrasound diagnostic instruments on days 30,60,and 90,respectively,after acute entry to the plateau.SPSS 19.0 software was used for statistical analysis.Results There were no significant differences in PSV,RI and PI of SMA and its 1 st and 2nd grade branches between the 3 groups 30 days after entry(P＞0.05).Sixty days after entry,the control group had the values of PSV statistically higher than those of the other two groups(P＜0.05);there were no significant differences between the low-flow oxygen therapy group and the hyperbaric oxygen group in the values of PSV(P＞0.05);the three groups had no obvious differences in the values of RI and PI(P＞0.05).Ninety days after entry,the control group had the values of PSV,RI and PI all significantly higher than those of the other two groups(P＜0.05);the low-flow oxygen therapy group had the values of PSV statistically higher than those of the hyperbaric oxygen group(P＜0.05),while the values of RI and PI not significantly different from those of the hyperbaric oxygen group(P＞0.05).Conclusion Single-person hyperbaric oxygen chamber significantly improves the SMA blood flow changes due to oxygen partial pressure reduction in the plateau,and thus is of significance for preventing ischemic enteropathy of the personnel rushing to the plateau.[Chinese Medical Equipment Journal,2023,44(10):59-63]