The Effect Of Target-controlled Infusion Of Propofol On Autonomic Nervous System During Pneumoperitoneum

ObjectiveAutonomic nervous system is an important regulation system that maintain cardiovascular function. Heart rate variability (HRV) analysis is a new research method about autonomic nervous system function. Pneumoperitoneum may have significant effects on haemodynamics during laparoscopic cholecystectomy due to hypercapnia and stress reaction and extice sympathetic nerve activation and increase catecholamine release, increase renin-angiotensin system activity. In our study, we want to investigate automonic nervous system changes and the effect of target-controlled infusion of propofol on autonomic nervous system during pneumoperitoneum.MethodsTirty healthy patients who were ASA class I or II, and ranged in age from 18 to 60 yr undergoing elective laparoscopic cholecystectomy were divided into two groups randomly. Group I (isoflurane group, n=15) is contrast group, and group P (propofol group, n=15) is test group. No premedication was administered before arrival of the patient in the operation room. The functions of brain, lungs, liver and kidneys are normal. In the group I anaesthesia was induced with midazolam 0.04mg/kg, fentanyl 4 g/kg,vecuronium 0.1mg/kg and propofol 2mg/kg. In the group P anaesthesia was induced with midazolam 0.04mg/kg, fentanyl 4 g/kg, vecuronium 0.1mg/kg and target-controlled infusion of propofol with target concentration was 4.0ug/ml. Endotracheal intubation was performed and mechanical ventilation began. In group I anesthesia was maintained with 1.75MAC isoflurane, in group P anesthesia was maintained with target-controlled infusion of propofol with target concentration 4.0|ag/ml. HRV values were recorded during awake state, after induction and intubation, and after pneumoperitoneum. The parameters of HRV, included low frequency (LF); high frequency (HF); rato of LF/HF.ResultsLF in group I decreased remarkably compared with baseline (P<0.05) after induction, before pneumoperitoneum, after pneumoperitoneum 15min, 20min, 25min and 30min and no changes after intubation, after pneumoperitoneum 5min and 10min (P>0.05). LF in group P decreased remarkably compared with baseline (P<0.05) after pneumoperitoneum 20min, 25min and 30min and no changes after induction, after intubation, before pneumoperitoneum, after pneumoperitoneum 5min, lOmin, 15min(P>0.05). There was no difference between two groups. FIF in group I decreased remarkably compared with baseline (P<0.05) after induction, before pneumoperitoneum, after pneumoperitoneum 10min, 15min, 20min, 25min, 30min. HF in group P decreased remarkably compared with baseline(P<0.05) after induction, after pneumoperitoneum lOmin, 15min, 20min, 25min, 30min. There was no difference between two groups. LF/HF in two groups inceased remarkably with baseline(P<0.05), after intubation, after pneumoperitoneum 5min, lOmin, 15min, 20min.DiscussionAutonomic nervous system is an important regulation system that maintain cardiovascular function. Spectral heart rate variability included (I) high frequency (HF); (2) middle frequency (MF); (3) low frequency (LF). rato of LF/HF. Pneumoperitoneum may have significant effects on cardiovascular system, autonomic nervous system and endocrine system during laparoscopic cholecystectomy due to hypercapnia and stress reaction. It is necessary to understand the effects laparoscopic cholecyste- ctomy on autonomic nervous system.Earlier showed that propofol decrease significantly sympathetic nerve and vagus nerve activity and autonomic nervous system tone. In our study, LF decreased after induction and increased from pneumoperit- oneum start to 15min compared with before pneumoperitoneum in contrast group. LF/HF was no changes after induction, and increased sig- ificantly within 20min from pneumoperitoneum start. In our study in group P LF showed an intendency to decrease, but no statistically signifi- cant, and increase significantly compared with before pneumoperitoneum within 20min from pneumoperitoneum start. LF/HF was similar to contr- ast group and was no changes after induction, and i...