Microphone Up To Alprazolam With Propofol Target Sedation Of Icu Patients Undergoing Mechanical Ventilation Heart Rate Variability

Objective Heart rate variability(HRV) is regarded as the noninvasive index of evaluating the automomic nervous system so far.Bispectral index scale(BIS) is the great advance in the field of anesthesia and the assessment of sedation depth.In this study,we sedated the mechanically ventilated patients in surgical intensive care unit with midazolam or propofol combined with fentanyl,which is controlled by BIS.Our aims were to investigate the effects of midazolam and propofol on the hemodynamic parameters as well as the heart rate variability under optimal sedation.Meanwhile,the efficacy and safety ofmidazolam and propofol when used in those patients were observed.Methods Forty postoperative and mechanically ventilated ICU patients undergoing general anesthesia were randomly divided into 2 groups:Midazolam+fentanyl and Propofol+fentanyl.When the patient became conscious,sedative drugs were administered intravenously with a bolus,then were continuously infused through by miniinfusion pump and the dosage was adjusted to reach optimal sedation according to the value ofBIS.Hemodynamic parameters before and after sedation were written down,the time for the medicine to take effct and recovery time as well as sedation time were recorded.The minute the sedative drugs were used,the dynamic EEG started to work till the cessation of sedation,which would be analyzed by the HRV software.Results As for the hemodynamic parameters,both group induced a significant decrease in BP (P＜0.05).Howeve,compared with propofol which decreased HR,midazolam resulted in a little increase in HR(P＜0.05).As far as SPO₂ was concerned,the difference was not statistically significant (P＞0.05).When it came to the heart rate variability analysis,as for the time domain analysis of HRV, SDNN of both group decreased significantly(P＜0.05),which showed a lowering trend,while rMSSD was in the normal range.For the frequency analysis,despite the significant decrease in LF/HF for goup MF and the lower decrease in LF/HF for group PF,both group showed decrease in TP,LF,HF, the difference of which was obvious(P＜0.05).Among the two group,the time for the medicine to take effect were individually 30±3s,26±5s and the recovery time were respectively 54±4s,28±3s,the difference was significant(P＜0.05). There was no significance between the sedation time for both group(P＞0.05).Conclusion 1.The effects ofmidazolam and propofol sedation on the patient's autonomic nervous system could be reflected by heart rate variability analysis,which should be considered while sedative drugs were used so as to make more reasonable and safe sedation therapy for postoperative ICU patients.2.Under the monitor of BIS,both midazolam and propofol could achieve ideal sedation effect which is safe.Propofol should be preferred for patients in need of quick sedation and quick recovery,leading to prompt extubation and ventilator withdrawal.In case of patient under unstable circulation,careful observation is necessary when propol is used.