Objective To evaluate the effect of oxycodone preconditioning on liver injury induced by intestinal ischemia-reperfusion (I/R) in rats and the role of different opioid receptors.Methods Fiftyfour adult male Sprague-Dawley rats, weighing 200-300 g, were randomly divided into 9 groups (n =6 each) using a random number table: sham operation group (group S), group I/R, oxycodone preconditioning group (group OP) , μ receptor antagonist CTOP group (group CTOP) , δ receptor antagonist naltrindole group (group NTD), κ receptor antagonist nor-binaltorphimne group (group BNI), CTOP + oxycodo ne preconditioning group (group CTOP+OP) , naltrindole + oxycodone preconditioning group (group NTD+ OP) , and nor-binaltorphimne + oxycodone preconditioning group (BNI+OP).The model of intestinal I/R was established by occlusion of the superior mesenteric artery for 45 min followed by 2 h reperfusion in anesthetized rats.The superior mesenteric artery was only exposed, but not occluded in group S.In OP,COTP+OP, NTD+OP and BNI+OP groups, oxycodone 0.5 mg/kg was injected intravenously at 10 min prior to ischemia.COTP 1 mg/kg and naltrindole 5 mg/kg were injected intravenously at 20 min prior to ischemia in COTP+OP and NTD+OP groups, respectively.Nor-binaltorphimne 5 mg/kg was injected intravenously at 25 min prior to ischemia in group BNI+OP.In CTOP and NTD groups, the corresponding doses of CTOP and naltrindole were injected intravenously at 10 min prior to ischemia.In group BNI, the corresponding dose of nor-binaltorphimne was injected intravenously at 15 min prior to ischemia.The rats were sacrificed at 2 h of reperfusion, and left hepatic lobes were removed for microscopic examination and for detection of apoptosis in liver cells (using TUNEL).The apoptosis index (AI) was calculated.Results Compared with group S, the AI was significantly increased in the other groups (P＜0.05).Compared with group I/R, the AI was significantly decreased (P＜0.05) , and the pathological changes of livers were reduced in OP, COTP+OP, NTD+OP and BNI+OP groups, and no significant change was found in AI and pathological changes of livers in CTOP, NTD and BNI groups (P＞0.05).Compared with group OP, the AI was significantly increased (P＜0.05), and the pathological changes of livers were aggravated in COTP+ OP, NTD+OP and BNI+OP groups.There was no significant difference in AI and pathological changes of livers among groups COTP+OP, NTD+OP and BNI+OP (P＞0.05).Conclusion Oxycodone preconditioning can mitigate liver injury induced by intestinal I/R in rats, and μ, δ and κ receptors mediate the role with comparable effects.

Objective To evaluate the advantages of sevoflurane inhalation anesthesia combined with lumbosacral plexus block for hip replacement in elderly patients. Methods Sixty patients of both se-xes, aged 65-85 yr, with body mass index of 18-25 kg∕m2, of American Society of Anesthesiologists physical statusⅠ-Ⅲ, scheduled for elective unilateral hip replacement, were divided into 2 groups(n=30 each)using a random number table: total intravenous anesthesia group(TIVA group)and GasMan software-guided sevoflurane inhalation anesthesia combined with lumbosacral plexus block group(SEV-B group). After the laryngeal mask airway was inserted, the patients were mechanically ventilated in both groups. Heart rate and mean arterial pressure(MAP)were recorded before anesthesia(T0), immediate-ly after insertion of laryngeal mask airway(T1), immediately after skin incision(T2), immediately after intramedullary reaming(T3), immediately after prosthesis implanting(T4), at the end of surgery(T5) and at 5 min after removal of the laryngeal mask airway(T6). The end-tidal concentration of sevoflurane at T2-5was also recorded in group SEV-B. The time for removal of the laryngeal mask airway, duration of stay in post-anesthesia care unit and first ambulation time were recorded. The consumption of anesthetics used during patient-controlled intravenous analgesia(PCIA), effective pressing times of PCIA, requirement for rescue analgesic and adverse reactions were also recorded at 24 h after surgery. The patient′s cognitive func-tion was assessed using Mini-Mental State Examination at 1 day before surgery and 1 and 3 days after surger-y, and the occurrence of postoperative cognitive dysfunction was recorded. Results Compared with group TIVA, heart rate at T1-6and MAP at T2-6were significantly decreased, and MAP at T1was increased in group SEV-B, and the time for removal of the laryngeal mask airway, duration of stay in post-anesthesia care unit and first ambulation time were significantly shortened, the consumption of anesthetics used during PCIA, effective pressing times of PCIA, requirement for rescue analgesic and incidence of adverse reac-tions were reduced at 24 h after surgery, the Mini-Mental State Examination scores were increased at 1 day after surgery, and the incidence of postoperative cognitive dysfunction was decreased at 1 day after surgery in group SEV-B(P<005). Conclusion GasMan software-guided sevoflurane inhalation anesthesia com-bined with lumbosacral plexus block can provide more accurate anesthesia management for hip replacement and promote rapid rehabilitation after surgery in elderly patients.