Effects Of Different Doses Of Norepinephrine On Hemodynamics Of Lower Limb Arteries Based On Ultrasound Technology

Objective: Although some studies showed that norepinephrine have effects on lower extremity,there are few literatures focused on the lower extremity hemodynamics of patients with different doses of norepinephrine.Our experiment observed the hemodynamic changes of different doses of norepinephrine on multiple sites of the lower limb artery by bedside ultrasound,to provide theoretical basis for guiding the more rational use of norepinephrine in clinical practice,find the safe dose range during the use of norepinephrine,and reduce the incidence of chronic concealed lower limb artery ischemia and lower limb hypoperfusion caused by the use of norepinephrine.Methods: Collect specimens from August 2022 to December 2022 Yangzhou University Affiliated Hospital for patients who meet the inclusion criteria in the Department of Critical Medicine of the affiliated hospital,the hemodynamic indexes of the common femoral artery,superficial femoral artery,popliteal artery and dorsal pedis artery were measured by color Doppler ultrasound when norepinephrine was not used,at low dose(<0.1 ug/kg/min),medium dose(0.1-0.3 ug/kg/min),and high dose(>0.3 ug/kg/min),and their changes were analyzed.Relative indicators to be collected are: vessel diameter,maximum peak blood flow velocity,pulsation index and blood flow.The effects of different doses of norepinephrine on the above arterial hemodynamic indexes were compared using SPSS26.0 software,ANOVA and repeated measurement analysis of variance.Results: A total of 50 patients were included in the study,including 29 males and 21 females.(1)Maximum peak blood flow velocity and blood flow: the maximum peak blood flow velocity and blood flow can be seen in the common femoral artery,superficial femoral artery,popliteal artery and dorsalis pedis artery,all reaching the highest value when using low dose norepinephrine.And along with the increase of the dose of norepinephrine,the above results gradually decreased after reaching the maximum value.P values were all<0.05,with statistical significance.(2)Vessel diameter: for the common femoral artery and superficial femoral artery,the vessel diameter did not change significantly at low dose,but decreased gradually along with the dose increase,but the change was not statistically significant(P>0.05);For popliteal artery and dorsalis pedis artery,with the increase of norepinephrine dose,the diameter of the artery decreased gradually with the change of dose,with statistical difference(P<0.05).(3)Pulse index: for the common femoral artery and superficial femoral artery,the pulse index did not change significantly when using low-dose norepinephrine,but with the gradual increase of the dose of norepinephrine,the pulse index gradually increased,but the change was not statistically significant(P>0.05);For popliteal artery and dorsalis pedis artery,the pulsation index increased with the increase of dose,with statistical difference(P<0.05).Conclusion:(1)Norepinephrine is safe and effective at low dose;(2)When the middle and high doses of norepinephrine are continuously pumped,the flow rate and blood flow of the lower extremity arteries(especially the peripheral vessels)will decrease,which may affect the blood perfusion of the lower extremity,leading to the performance of persistent chronic ischemia;(3)Doppler ultrasound can be used as an effective method to continuously observe the arterial hemodynamics of lower limbs.