Objective To investigate the effect of dexmedetomidine on minimum alveolar concentration (MAC) of isoflurane required to inhibit the body movement during skin incision. Methods Forty-eight ASA Ⅰ or Ⅱ patients aged 40-60 yr with body mass index of 22-27 kg/m2 undergoing elective upper abdominal surgery under general anesthesia were randomly divided into 3 groups: control group (group C, n = 15);low dose dexmedetomidine group (group D1, n = 17) and high dose dexmedetomidine group (group D2, n = 16). The patients were unpremedicated. Dexmedetomidine 0.4 and 0.8 μg/kg in normal saline (NS) 15 ml was infused over 15 min before induction of anesthesia in D1 and D2 groups respectively. Anesthesia was induced with fentanyl-propofol-succinylcholine. The patients were mechanically ventilated after tracheal intubation. Anesthesia was maintained with isoflurane. MAC of isoflurane was determined by up-and-down technique. The initial end-tidal isofiurane concentration was set at 1.0%, 0.8% and 0.6% in C, D1 and D2 groups respectively. Each time the end-tidal isoflurane concentration was increased/decreased by 0.2%. Skin incision was made after 15 min of equilibration, when the twitch height returned to more than 90% of its control value. Movement of body and limbs including swallowing and coughing were carefully looked for when skin incision was made. MAC of isoflurane was the mean of end-tidal concentration of isoflurane of each crossover pair, and 95 % CI was calculated. Results MAC of isoflurane was significantly decreased in D1 and D2 groups as compared with group C and in group D2 as compared with group D1( P ＜ 0.05 or 0.01 ). Conclusion Dexmedetomidine can significantly decrease MAC of isoflurane required to inhibit the body movement during skin incision in a dose-dependent manner.

Objective To evaluate the effects of autologous blood withdrawal-reinfusion on inflam-matory responses of patients undergoing cardiac surgery with different time courses of cardiopulmonary by-pass(CPB). Methods A total of 120 patients, aged 18-70 yr, of American Society of Anesthesiologists physical status Ⅱ-Ⅳ, were divided into 2 groups(n=60 each)using a random number table: autologous blood withdrawal-reinfusion group(ABWR group)and non-autologous blood withdrawal-reinfusion group (NABWR group). Each group was further divided into 3 subgroups(n=20 each)according to the expected time of CPB: long time course(>120 min)subgroup(L subgroup), medium time course(>60 min-≤120 min)subgroup(M subgroup)and short time course(≤60 min)subgroup(S subgroup). In group ABWR, after the end of CPB and after heparin was reversed with protamine, blood shed from the surgical field and left in the autologous blood recycling machine pipeline after the end of CPB was collected, filtra-ted, washed, concentrated and reinfused. After the end of CPB, blood left in the autologous blood recy-cling machine pipeline was directly kept in the storage bag and partially or totally reinfused in group NAB-WR. Before operation and at 1, 6, 24 and 48 h after the end of CPB, blood samples were collected for de-termination of serum tumor necrosis factor-alpha(TNF-α), interleukin-6(IL-6)and IL-10 concentrations by enzyme-linked immunosorbent assay. Results Compared with ABWR-S subgroup, the serum TNF-α and IL-6 concentrations were significantly increased at each time point after the end of CPB(P<005), and no significant change was found in serum IL-10 concentrations in ABWR-L and ABWR-M subgroups (P>005). There were no significant differences in serum TNF-α, IL-6 and IL-10 concentrations between ABWR-L subgroup and ABWR-M subgroup(P>005). Compared with NABWR subgroup of the same time course, the serum TNF-α concentration was significantly decreased at each time point after the end of CPB, the serum IL-6 concentration was decreased at 6-48 h after the end of CPB(P<005), and no significant change was found in serum IL-10 concentrations in ABWR-L subgroup(P>005); the serum TNF-α con-centration was significantly decreased at 1 h after the end of CPB, and the serum IL-6 concentration was de-creased at 6 and 24 h after the end of CPB in ABWR-M subgroup(P<005); no significant difference was found in the serum concentrations of TNF-α, IL-6 or IL-10 at each time point after the end of CDB in AB-WR-S subgroup(P<005). Conclusion With prolongation of the time courses of CPB, the efficacy of autologous blood withdrawal-reinfusion in inhibiting inflammatory responses of patients undergoing cardiac surgery is more significant.

Objective:To investigate the predictive value of serum proenkephalin A 119-159 (penKid) on incidence and the 28-day mortality in patients with sepsis-associated acute kidney injury (SA-AKI).Methods:This study was a single center, observational cohort study. Sepsis/septic shock patients admitted to Department of Critical Care Medicine of Taizhou People's Hospital Affiliated to Nanjing Medical University from September 2021 to September 2022 were selected and divided into the SA-AKI group and the non-SA-AKI group according to whether acute kidney injury (AKI) occurred within 28 days. Patients in the SA-AKI group were subdivided into the death group and the survival group according to whether death occurred within 28 days. Baseline data and laboratory indicators such as penKid concentration were compared among different groups. COX regression analysis was used to explore the risk factors of death within 28 days in the SA-AKI patients, And Kaplan-Meier curve was used to analyze patient prognosis.Result:A total of 161 patients were included in this study, of whom 66 (41.0%) developed AKI. The baseline penKid concentration in the SA-AKI group was significantly higher than that in the non-SA-AKI group [(2.99 ± 0.68) μg/L vs. (1.86±0.75) μg/L, P<0.05]. Multivariate COX regression analysis showed that the baseline penKid ( HR=5.608, 95% CI: 3.507-8.967, P<0.001) and lactate (LA) ( HR=1.089, 95% CI: 1.003-1.183, P=0.043) were independent risk factors for AKI in sepsis/septic shock patients. Of the 66 SA-AKI patients, 27 (40.9%) died within 28 days, and the baseline penKid concentration in the death group was significantly higher than that in the survival group [ (3.55 ± 0.54) μg/L vs. (2.60±0.47) μg/L, P<0.05]. COX regression analysis showed that penKid ( HR=5.892, 95% CI: 2.457-14.132, P<0.001) was an independent risk factor for mortality in SA-AKI patients. Kaplan-Meier curve showed that the 28-day mortality of patients with baseline penKid ≥ 3.24 μg/L was significantly higher than that of patients with baseline penKid <3.24 μg/L ( P<0.001). Conclusions:In sepsis/septic shock patients, the penKid concentration measured on the first day in the SA-AKI group is significantly higher than that in the non-SA-AKI group. In SA-AKI patients, the penKid concentration measured in patients who survived within 28 days is significantly lower than that in the death group. PenKid is an independent risk factor for the occurrence and death of SA-AKI.