The Effect Of Ketamine On Bispectral Index Of The Electroencephalogram Under Dexmedetomidine For Sedation

Objective To study the effect of different dosages of ketamine on bispectral index(BIS) of the eletroencephalogram under dexmedetominedine for sedation, to study the effect of dexmedetomidine and ketamine on the patient’s sedation and hemodynamics,to give help for anesthesia.Methods Eighty ASA class I or II female patients under epidural ansthesia were randomly assigned to ketamine groups(groupKl-K3) and saline group(group N) with20cases each.After epdural anesthesia achieved the intended plane, all groups had received an infusoin over10mins of0.5ug.kg-1dexmedetomidine,as a bolus,for induction.The patients then received an infusion of0.5-1.0ug.kg-1.hr-1of dexmedetomidine to make the bispectral index≤60.When BIS has been stable for10minite, The patient received an infusion of ketamine(K1-K3group) or sadline (N group)10ml over5mins following,Klgroup:0.2mg.kg-1ketmine,K2group:0.4mg.kg-1,K3group:0.6mg.kg-1.Heart rate (HR)、Mean artery blood press(MAP)、BIS and OAA/S was recorded before and Omin、3min、6min、9min、12min、15min after the infusion of ketamine or sadline.Results.HR、MAP、BIS had no significant change in group K1,but OAA/S lowered significantly(P<0.05)at0-15minite.HR、MAP had no significant change in group K2(P>0.05),BIS increased at3minite (P<0.05), recovered at6minite,OAA/S lowered significantly(P<0.05) at0-15minite.MAP had no significant change in group K3(P>0.05),but HR increased significantly(P<0.05), BIS had increased significantly(P<0.05) during3-9minite after ketamine infusion,then recovered at12minite;OAA/S lowered significantly(P<0.05) at0-15minite. OAA/S、HR、MAP、BIS in group K1has no change (p>0.05) when compared to group N’s.BIS has increased significantly (P<0.05) in group K2at3min after infusion of ketamine when compared to group N’s,OAA/S has lowered significantly (p<0.05) at0-15minite compared to group N’s,but HR、MAP has no sigificantly change (p>0.05)。BIS has increased significantly (P<0.05) in group K3at3-9min compared to group N’s,OAA/S has lowered sigificantly (p<0.05)at0-15minite,but HR、MAP has no change(p>0.05).Conclusion The effect of low-dose ketamine on bispectral index of the electroencephalogram under dexmedetomidine for sedation depends on the dose of ketamine. Ketamine<0.2mg.kg"1given intravenously has no effect on BIS,BIS increased significantly after ketamine was infused during dexmetemidine sedation when ketamine≥0.4mg.kg-1.The use of dexmedetomidine and low dose of ketamine can engender good sedation and stable hemodynamics.