Effect Of Combined General-epidural Anesthesia On Old Patients For Intrapulmonary Shunt And Arterial Oxygenation During One-lung Ventilation

Background and ObjectiveOpen the chest surgery anesthesia often USES single pulmonary ventilation (OLV) make the two lung isolation. But, OLV vulnerable to hypoxemia. Hypoxic pulmonary vasoconstriction (hypoxic pulmonary vasoconstriction, HPV) can minimally reduce the lungs shunt (Qs/Qt) and hypoxemia occurrence, HPV and independent regulation by surgery, anesthesia methods and drugs, etc., many factors. Epidural anesthesia compound anesthesia (GEA) has the advantages of reducing the amount of intraoperative anesthetic drugs, provide satisfactory postoperative analgesia, reduce thoracic surgery complications etc, and GEA can effectively maintain the patient intraoperative circular function stability, reduce the dosage of general anesthetics, speed up the patient’s postoperative revival, but epidural anesthesia in elderly patients during one lung ventilation whether to expand pulmonary vascular, reduce pulmonary vasoconstriction, weaken the HPV mechanism and cause Qs/Qt change is not clear, the artery oxygenation influence also not determined, and epidural anesthesia in the application of different concentrations of lidocaine on HPV influence also need to be further discussed. Therefore this research based on the elderly patients with general anesthesia and general anesthesia were simple compound different concentration lidocaine epidural anesthesia, and to observe different anesthetic scheme of single lung ventilation (OLV) during the lungs FenLiuLv and artery oxygenation influence, this paper discusses the safety of application in elderly patients, in order to better guide clinical anesthesia.Materials and Methods1. Patient ProfileSelect elderly patients with open thoracic surgery in135cases, according to the table of random number method is divided into three groups:general anesthesia (group S), general anesthesia compound1.0%lidocaine epidural anesthesia group (L1.0group), general anesthesia compound1.5%lidocaine epidural anesthesia group (L1.5group), each group45cases each.2. Anesthetic ProcedureL1.0group, L1.5group line T5～6or T4～5clearance epidural puncture, injection of2%lidocaine3ml, wait for plane determine5minutes before the general anesthesia induction. Do right internal jugular vein puncture buy central venous catheter, general anesthesia induction drugs choose propofol1.5～2.0mg/kg, sufentanil0.3u g/kg, vecuronium bromide0.1mg/kg. Vein fast after induction insertion double cavity bronchial catheter (F37～39), connection anesthesia machine to breath control. Anesthesia maintain period through the trace pump pump into the propofol3.6～6.6mg/kg/h to calm. After the start of the operation, L1.0group was given1.0%lidocaine5ml, L1.5group was given1.5%lidocaine5ml, intraoperative continuous micro pump pump into4～6ml/h. S group right internal jugular vein puncture, general anesthesia induction and maintain with the above two groups.3. monitoring indexesIntraoperative continuous monitoring the following indexes, electrocardiogram (ECG), heart rate, blood pressure, MAP, central venous pressure (CVP), PETCO2, SpO2, tidal volume (VT), FIO2, average airway pressure (Paw), continuous cardiac output (CCO), brain electric double frequency index (BIS). Choose before anesthesia (awake on spontaneous breathing air)(T1), double pulmonary ventilation15min (T2), OLV15min (T3), OLV45min (T4) four time point, in the radial artery blood1.5ml, blood gas analysis. The lungs FenLiuLv (Qs/Qt) through the following formula calculated:①Qs/Qt=(Cc’O2-CaO2)/(Cc’O2-CvO2)×100%;②Cc’O2=(Hb×1.31×SaO2)+(149-PaCO2/0.8)×0.003;③CaO2=(Hb×1.34) SaO2+(PaO2x0.0031);④CvO2=(Hb×1.34) SvO2+(PvO2×0.0031)Results1. L1.5group and S group comparison, TLV15min, two groups of PaO2and Qs/Qt value has no significant difference (P>0.05), OLV15min, OLV45min, PaO2decrease (P<0.05), Qs/Qt value increased (P<0.05). L1.0group and comparison group S, each time point PaO2and Qs/Qt value differences were no statistical significance (P>0.05). L1.0group and LI.5group comparison, TLV15min, two groups of no significant difference (P>0.05); OLV15min, OLV45min, PaO2value L1.0group is higher than L1.5group, Qs/Qt value L1.0group is lower than L1.5group (P<0.05).2. during the operation, the L1.0group and L1.5groups of patients MAP and average heart rate (HR) is S low group (P<0.05), and relatively low before anesthesia (P<0.05). Intraoperative each time point L1.5MAP, HR group are lower than those of L1.0group (P<0.05). Intraoperative each each time point PaCO2than preoperative lower (P<0.05); Intraoperative the same time point PaCO2and Paw is compared between groups, there are no significant difference (P>0.05). See table4.3. Three application after mechanical ventilation, three groups SaO2, SvO2, PvO2than preoperative elevated (P<0.05, or P<0.01); OLV15min and OLV45min, L1.5group PvO2, SvO2value is the TLV15min significantly reduced (P<0.05), and significantly lower than S group and L1.0group (P<0.05), and the S group and L1.0group PvO2, SvO2value compare various time points were no significant difference (P>0.05). PvCO2, PH value two indexes before and after anesthesia each time point is compared between groups, were no significant difference (P>0.05).4. L1.5group and L1.0groups were used in anesthesia sufentanil, propofol, vecuronium bromide, propofol,, concentration-dependent dose are below S group (P<0.05). L1.5group and L1.0between group, no significant difference (P>0.05).5. L1.0group and L1.5group in extubation time, revival time and drawing tube restless when incidence were superior to S group (P<0.05), L1.0group and comparison between L1.5group, no significant difference (P>0.05). Three groups of patients were not happen intubation response, chills, muscle stiffness, agitated, dizziness and other adverse reaction.Conclusions1. General anesthesia compound high concentration (1.5%) lidocaine epidural anesthesia in elderly patients with heart surgery during one lung ventilation in lung shunt increases, artery oxygenation reduce.2. General anesthesia compound low concentration (1.0%) lidocaine epidural anesthesia in elderly patients with heart surgery during one lung ventilation in the lungs shunt and artery oxygenation no significant influence.3. General anesthesia compound low concentration (1.0%) lidocaine epidural anesthesia for the elderly patients with heart surgery more safe and reliable, it is worth clinical promotion.