Measurement Of Propofol Consumption For LOC Inpatients Of Different Ages Guided By Narcotrend

Objective To measure the dose of propofol and the changes of Narcotrend index(NTI) at the loss of consciousness(LOC) in different ages. To explore the correlation between age and propofol dose, the relationship between age and NTI.Methods Patients of 3-70 years old scheduled for general surgery were investigated, and divided into seven groups according to age, in group 1(G1, 3~10yr), in group 2(G2, 11~20yr), in group 3(G3, 21~30yr), in group 4(G4, 31~40yr), in group 5(G5, 41~50yr), in group 6(G6, 51~60yr) and in group 7(G7, 61~70yr). 20 patients(10 males and 10 females) with normal BMI were enrolled in each group. Induction of anesthesia with a continuous 20mg·kg-1·h-1 propofol, when the patients became unconsciousness, stopped infusing propofol and recorded the time to LOC, propofol dose, HR, MAP and NTI.Results The correlation coefficient between age and dose was negative(r=-0.566,P<0.001), the propofol requirement of G1(3-10yr) was about 2.2mg/kg, and G7(61-70yr) was about 1.4mg/kg. The time of LOC was shortened with the growth of age. The NTI were different in groups at LOC, there was no correlation between age and NTI. Compared with G1, the NTI were significant lower in G2-G6(P<0.05). Compared G2-G6 with G7, there were no differences(P>0.05), and compared with G1 and G7, there were no differences(P>0.05). MAP and NTI were significant decreased after infusing propofol(P<0.05), there were no differences in HR(P>0.05).Conclusion The changes of the propofol dose were difference in different ages, the propofol dose of LOC was higher in younger patients than others. The changes of the NTI were difference in different ages, the NTI of LOC was higher in younger patients than others.