The Clinical Study On Target Controlled Infusion Of Propofol In Elderly Patients During Anesthetic Induction

ObjectiveIn this study, hemodynamic status of the elderly patients’tracheal intubation during induction of general anesthesia will be investigated through the combination of the continuously monitored hemodynamic parameters from arterial pressure cardiac output. Thus, the target plasma concentration of propofol target-controlled infusion that is suitable for the elderly patients during induction of general anesthesia, will be found and used for clinical reference.MethodsA total of 90 ASA I-III patients, aged 69-82 years, weighed 47-90kg, who are enrolled for elective knee replacement surgery. These patients were randomly divided into three groups that consist of 30 patients of laryngeal mask airway (LMA) insertion. A group:50, B group:45, C group:40.1.5ug/mL TCI propofol target plasma concentration is selected as the initial concentration. After 2 min TCI propofol, 3ng/mL remifentanil TCI is injected.0.6 mg/kg Rocuronium is injected after BIS value is smaller than 70. The target concentration is increased by 0.5ug/mL for each 2 min interval until the goal BIS values of A, B and C groups are achieved. Then laryngeal mask is implanted. The following parameters will be observed for investigation/The BIS values,i.e.,before induction (To), before LMA insertion (T1), after LMA insertion (T2),5 min after LMA insertion(T3); Hemodynamics parameters,e.g., noninvasive blood pressure (SBP, DBP, MAP), heart rate (HR), cardiac output (CO), cardiac index (CI), stroke volume (SV),and stroke volume variation (SW); Propofol target plasma concentration at the the goal BIS values; the induction dosage of propofol; Adverse reactions,e.g., intraoperative awareness,nausea and vomiting.ResultsFor the comparison between groups, no significant difference in hemodynamics parameters was found before induction. After induction, The values of CO and DBP in C group were obviously lower that those in A group, showing statistically significant difference (P<0.05);CI values in C group were obviously smaller than those in A group at the T1, T3 time points, and CI values in B and C groups were obviously lower than those in A group at the T2 time points(P<0.05); SBP values in C group were obviously smaller than those in A group at the T1 time point, and SBP values in B and C groups were obviously lower than those in A group at the T3 time points(P<0.05); MAP values in A group exhibited statistically significant difference from in C group at the T1, T2 time point, and MAP values in A groups were obviously larger than those in B and C group at the T3 time points(P<0.05); MAP values in A group exhibited statistically significant difference from in C group at the T1, T2 time points, and MAP values in A groups were obviously larger than those in B and C groups at the T3 time points(P<0.05); Heart rates in C group were obviously smaller than those in A and B groups at the Tl time point (P<0.05); SW values in C group were obviously larger than those in A and B groups at the Tl, T2 time points.For the comparison within the groups, CO values after induction decreased significantly, relative to those values before induction, as for three groups at three time pionts (P<0.05); As for A group, CI values were obviously decreased after induction at the T1, T3 time points, while CI values at the T2 time point had no obvious change; As for B and C groups, CI values had significant decrease after induction at three time points (P<0.05); As for A and B groups, SBP, DBP and MAP values had significant decrease, and SBP values were decreased much more at the T3 time point (P<0.05); DBP values in A group presented no obvious difference between the time points, DBP values in B and C groups were decreased much more at the T3 point time (P<0.05); Heart rates in A and B groups were obviously decreased at the T3 point tune, heart rates before LMA insertion and instant heart rates in C group were obviously decreased (P<0.05).These are the propofol concentrations at the goal BIS values. A group:(2.3± 0.1)ug/mLL,B group:(2.7±0.2) ug/mL, C group:(3.2±0.2) ug/mL. Three groups had significant differences (P<0.01).Cardiac index<2L/min/m2and last longer than 30 s or more:A group had three cases, B group had five cases, C group had ten cases at the T1 time point; C group had four cases at the T2time point; B group had two cases, C group had five cases at the T3 time point.As for the cases that SBP values that were less than 30% of the baseline value and last longer than 30 s or more:A group had three cases, B group had six cases, C group had ten cases at the T3time point.As for three groups, intraoperative awareness and respiratory depression have not been found in the postoperative random survey, two nausea and vomiting cases have been found in C group.ConclusionPlasma target-controlled propofol infusion can obviously inhibit the stress response after LMA insertion, and slightly affect the hemodynamics and adverse reactions of elderly patients; As for the 50 BIS value, the hemodynamic was the most stable during anesthesia induction of elderly patients, in which target plasma concentration of propofol was (2.3±0.1) ug/mL; Plasma target-controlled propofol infusion can be safely and effectively used in anesthesia induction of elderly patients.