Effects Of Combined Sevoflurane-thoracic Epidural Anesthesia On Hypoxia-induced Lung Injury And The Medical Economics Analysis For Patients Undergoing Thoracic Surgery

Partâ… Effects of combined sevoflurane- thoracic epidural anesthesia on hypoxia-induced lung injuryObjective The acute hypoxic is one of the potential complications during thocacic surgery anesthesia which may lead to acute lung injury.Our objective was to assess the potential modifying effects of thoracic epidural anaesthesia on hypoxia-induced lung injury in the animals.Methods Twenty eight rabbits anaesthetised with pentobarbital(30 mg·kg^-1 iv) were randomly assigned to four groups:control group(Group C),hypoxia group(Group G), sevoflurane group(Group S) and combined sevoflurane-epidural anesthesia group (Group ES)(n=7).in Group ES,the catheter was inserted at T_5-6 interspace and advanced 1 cm into the epidural space cephalad.3 mg·kg^-1 lidocaine 1%was injected after the epidural block was confirmed by epidurography,followed by injecting the same dose every one hour.After tracheotomized and intubated,the animals were mechanically ventilated(FiO₂=21%,VT=10～12 mL/kg,RR=25bpm,I:E=1:2). 30 minutes later,animals in Group H,S and ES inhaled gas mixed with N₂ and O₂(FIO₂=14%).The FiO₂ in Group C remained 21%.1 MAC of sevoflurane was also used in Group S and ES.The acute lung injury(ALI)models were considered to have been induced successfully after PaO₂/FiO₂＜300.3 hours after reaching the ALI standard,all animals recovered spontaneous breathing(FiO₂=21%).Arterial bloodgases were measured during spontaneous breathing(T₀)(baseline),at 15 min,30 rain,1 h,2 h,3 h after ALI induced and recovering spontaneous breathing(T_1-6) in Group H,S and ES and at the corresponding mechanically ventilation time in Group C.HR,MBP,RR and VT were recorded in all groups at T₀ and T₆.Arterial blood 5 mL were get in all groups at T₀ and T₅ in order to measure serum IL-6,IL-8 and IL-10. Bronchoalveolar lavage Fluid(BALF) were harvested for total phosholipid(TPL), saturated phosphatidylcholine(SatPC) and total protein(TP) measurement.The Dry/Wet weight ratio(D/W),light microscope and transmission electron microscope were also examined.The expression of IL-6,IL-8 and IL-10 mRNA in lung were assessed by realtime-PCR.Results1.There was no difference in general data among the four groups.2.There was no significant difference among the four groups during spontaneous breathing.Hypoxia leaded to the decrease of HR,MBP and PaO₂.ALI models were induced at 15 minites after hypoxia.MBP in Group H,S and ES were less than those in Group C at T₆(P＜0.05).PaO₂ at T₁ and MV at T₆ in Group ES were (33.3±6.7) mmHg and(928.2±27.3) mL/min,which were higher than those in Group S(P＜0.05).3.Serum IL-6 and IL-8 at T₅ in Group H were(94.1±15.1) and(59.5±14.9) pg/mL while they in Group S were(90.2±17.3) and(53.9±8.7) pg/mL.They were all significantly higher than those at T₀(P＜0.05).IL-10 in the two groups were(24.9±7.6) and(25.2±4.9) pg/mL at T₅,which were lower than those at T₀(P＜0.05). IL-6 at T₅ in Group ES were(56.2±19.9) pg/mL and they were lower than those in Group H and S(P＜0.05).Besides,IL-6 in Group H and S at T₅ were significantly higher than control group(P＜0.05). 4.Compared with control group,SatPC/TPL and SatPC/TP were decreased in Group H,S and ES(P＜0.05).SatPC/TP in Group S was significantly less than those in Group H and ES(P＜0.05) while SatPC/TPL in Group S was less than in Group ES(P＜0.05).Only in Group H,the Dry/Wet weight ratio was significantly less than in control group(P＜0.05).5.Among the four groups,the expression of IL-6 mRNA in Group H was higher than that in other groups(P＜0.05) and it in Group S was higher than that in control group and Group ES(P＜0.05).The expression of IL-8 mRNA in Group H and S were significantly higher than the other two groups(P＜0.05) while the expression of IL-10 mRNA were lower(P＜0.05).6.Pathologic examination showed that the control group had no swelling or disruption of the alveolar epithelium while the other groups had some denuded basement membranes of it.The alveolar typeâ…¡cells in all groups contained several lamellar bodies(surfactant).In Group H and S,the alveolar was congestion,edema and PMN adhering to epithelium,the alveolar typeâ…¡cells were swelling and the lamellar bodies were less than other groups no matter in numbers or the alveolar surfactant within them.There was less PMN in Group ES and the alveolar structure was better than Group H and S.Conclusions Acute hypoxia can cause lung injury in rabbit model.Combined sevoflurane-thoracic epidural anesthesia can lighten this injury by improving the respiratory function and inhibitting both systemic and local inflammation.Partâ…¡The medical economics analysis of combined thoracic epidural-sevoflurane anesthsia for patients undergoing thoracic surgeryBackground Thoracotomy may induce severe postoperative pain and other serious complications.Combined epidural-general anesthesia and general anesthesia were both commonly used in thoracic surgery nowadays.However,in a pharmacoeconomic approach of anesthesia,the economic evaluation of the two methods were uncertain. Our objective was to analyze the cost and effectiveness for the comparison of combined thoracic epidural-sevoflurane anesthsia and general anesthesia for patients undergoing thoracic surgery.Methods In this prospective observational study,40 patients aged 18-65,ASAâ… -â…¡, scheduled for esophagectomy were randomly divided into 2 groups:combined epidural-sevoflurane group(Group E) and general group(Group G),with 20 patients in each group.Patients in Group G were induced with fentanyl 2-3μg/kg,propofol 1.5-2 mg/kg and succinylcholine 1-2mg/kg.oxygen(5 L/min) was administered via face mask throughout induction.Vecuroniun 0.08-0.1 mg/kg were used for muscle relaxation.Anesthesia was maintained with inhalation of sevoflurane(MAC 0.7-1.1) and intermittent fentanyl and vecuronium(â…³).Patients in Group E underwent epidural blockade before induction.Epidural block was performed at T_7-8 with an epidural catheter inserted cranially for 4cm.A test dose of 2%lidocaine 3mL was given via the catheter.When epidurai blockade was confirmed,the patients were induced with the same agents as those in Group G.Before the operation,0.25% bupivacaine containing epinephrine 10μg/ml 15mL was infused via epidural catheter. The anesthesia was maintained with the same concentration of bupivacaine 5mL/h combined with inhalation of sevoflurane and intermittent fentanyl and vecuronium (â…³).All the patients were mechanically ventilated(IPPV,FiO₂=50%,VT=8mL/kg, RR=10bpm,I:E=1:2).HR,ABP,SpO₂,CVP and BIS were measured.BIS was maintained bewteen 40 and 60.The changes of HR and ABP were kept within 20% compared to the baseline.SpO₂ was retained above 90%during one-lung ventilation (FiO₂=100%,1L/min).Fluid replacement was given according to CVP.Patients in Group E were received postoperative continuous epidural analgesia with 0.125% bupivacaine plus 20μg/ml morphine plus 6 mg tropistron.Patients in Group G received postoperative continuous intravenous analgesia with 0.6-1 mg/h morphine plus 6 mg tropistron.All patients were sent to PACU after surgery and were allowed to wards when their Aldrete scores were above 9.The information recorded included the patients' epidemiologic characteristics,time indicatrix during operation,the use of anesthetics,the volume of blood loss,urinary,fluid replacement and blood transfusion, the information in PACU,the pain distribution,side effects,VAS scores and additional drugs to treat pain at postoperative several time points(4 h,1 d,2 d,3 d, 4 d and 5 d).Locomotor activity,motion blockage of lower limbs,the hospital day (HOD) after operation,all costs and patients' satisfaction scores were also recorded.Results1.There was no difference in general data between the two groups(P＞0.05). 2.There were no differences in induction time,operation time,intraoperative fluid replacement,the volume of blood loss and urinary between the two groups(P＞0.05),but the extubation time and the intraoperative use of fentanly, propofol,vecuronuim and sevoflurane were significantly lower in Group E(P＜0.05).3.Length of stay in PACU and the first time to make VAS scores in Group E were (36.7±18.9) min and(14.9±11.8) min,respectively.They were both lower than those in control group(P＜0.05).In Group E,3 patients occurred drowsiness.The first VAS score was 1.4±1.1.Only 1 patient needed additional pain intervention. They were all less than Group G(P＜0.05).There was no difference in PONV incidence between the two groups(P＞0.05).4.No motion blockage was observed in the patients.A better VAS score was showed in Group E than in Group G when the patients were quiet at 4 h,1 d and 2 d after surgery(P＜0.05).Until 3 d after the operation,the VAS scores were still lower in Group E when the patients were at activity(P＜0.05).There were less patients who had drowsiness or needed pain invention in Group E(P＜0.05).The HOD after surgeries and the time of urethral catheterization were also shorter in Group E(P＜0.05).But itch of skin occurred more frequently in Group E than in Group G(P＜0.01).There were no differences in dizziness and PONV incidence between two groups(P＞0.05).The average bed rest time,evacuation time and eating time were also the same(P＞0.05).Group E was siginificantly better than Group G in postoperative analgesia(P＞0.05).Overall satisfaction scores were significantly higher in Group E(8.7±1.2) than in Group G(7.2±1.3)(P＜0.01).5.Direct costs of anesthesia costs accounted for 11.3%in control group while the ratio in Group E was 12.8%.The cost constituent ratio of the two groups was similar(P＞0.05).Although the intraoperative anesthesia cost in control group was much lower than in Group E(P＜0.01),the costs of postoperative analgesia, antiemetics,hospitalization,treatment and indirect costs were higher in Group G(P＜0.05).There was no difference in costs between two groups(P＞0.05).Conclusions From the social point of view,combined thoracic epidural-sevoflurane anesthsia is an economical and effective method for patients undergoing thoracic surgery.