The objective of this study was to compare chlorhexidine digluconate and other antibiotics susceptibility of four species of the Acinetobacter baumannii complex, and further investigate the chlorhexidine digluconate (CHG) tolerance mechanisms and molecular epidemic characteristics. Of 889 A. baumannii complex isolates, A. baumannii, A. nosocomialis, A. pittii, and A. seifertii accounted for 84.2%, 10.9%, 3.4%, and 1.5%. Acinetobacter baumannii was generally resistant to all tested antibiotics, while other three species were commonly more susceptible; 92.1% (313/340) CHG-tolerant A. baumannii, 19.6% (19/97) CHG-tolerant A. nosocomialis, 3.3% (1/30) CHG-tolerant A. pittii, and 15.4% (2/13) CHG-tolerant A. seifertii were identified. Furthermore, compared to A. baumannii ATCC 19606, upregulated expression was found in qacEΔ1, fabI, and efflux pump encoding genes in CHG-tolerant A. baumannii, but the expression level of oprD was reduced. Additionally, only the expression level of fabI was increased in the CHG-tolerant A. nosocomialis, and the expression level of adeG was increased in the CHG-tolerant A. pittii and A. seifertii. Furthermore, CHG-tolerant A. baumannii may have a relatively high clonal correlation, the predominant sequence type of which was ST208 (90%, 36/40). It is rather necessary to identify specific species members among the A. baumannii complex for clinical treatment options and antibiotics resistance monitoring.

目的 分析脑脓肿的临床、微生物学特征及其预后相关因素.方法 回顾性分析2012年1月至2019年12月温州医科大学附属第一医院脑脓肿患者的临床资料,采用MALDI-TOF-MS微生物鉴定系统和VITEK?2?Compact全自动微生物分析系统对脑脓肿患者各类送检标本中培养出的病原菌进行鉴定和药敏试验,并通过分析比较脑脓肿患者的临床结局以发现其预后不良的危险因素.结果 共纳入患者96例,主要见于>50岁的中老年患者,平均年龄为54.47岁,以男性患者居多,临床表现以局灶性症状多见,74.0％的患者为隐源性感染来源,37.5％的患者为多发性脑脓肿,85.4％的患者预后良好.Logistic多因素分析结果显示,GCS评分下降和脓肿临近脑室是脑脓肿患者出院时预后不良的危险因素.共有15株病原菌分离自38例经手术治疗的脑脓肿患者脓液标本,其中大多数分离菌株对临床常用抗菌药物具有较好的敏感性.结论 脑脓肿常见于中老年男性患者,其中隐源性脑脓肿更为常见,临床表现具有不典型性,所分离菌株对临床常用抗菌药物的耐药率较低,GCS评分下降和脓肿临近脑室是脑脓肿患者预后不良的危险因素.

Introduction Globally, Pseudomonas aeruginosa (PA) is emerging as a predominant nosocomial pathogen that often induces aggressive and even deadly infections. Pseudomonas type III repressor A (PtrA) can be activated specifically by copper ions and interacts with type-III transcriptional activator ExsA. This study aims to provide insight into the PtrA-mediated regulation of the pathogenicity and antibiotics resistance of PA. Methods and Results The results of transcriptome sequencing analyses and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) showed that PtrA plays a dual regulatory role in the virulence systems of PA: negatively regulates the type-III secretion system (T3SS) and positively regulates the quorum-sensing system (QS). The ptrA mutant attenuated extracellular virulence related to QS like pyocyanin, elastase, rhamnolipids, proteolytic activity, and biofilm production. According to adhesion and invasion experiments, PtrA can not only contribute to the adhesiveness but also the invasive of PA. Moreover, the PtrA-mediated regulation of PA pathogenicity was determined both in vivo and in vitro through cytotoxicity and Galleria mellonella survival experiments. In addition, apart from virulence, PtrA was found to influence the carbapenems resistance of PA. After deleting ptrA, the minimum inhibitory concentration (MIC) of carbapenems antibiotics was decreased by 2-fold, while a 2–8 fold increase was noted for the complemented strain. Conclusion Our findings establish that PtrA exerts a regulatory role in both pathogenicity and carbapenems resistance of PA. This work may shed light on a novel target for the clinical treatment of PA.

P. aeruginosa is a ubiquitous Gram-negative opportunistic pathogen associated with a wide array of life-threatening acute and chronic infections. However, the improper and excessive use of antibiotics has contributed to the increasing emergence of multidrug-resistant (MDR) P. aeruginosa , even colistin-resistant strains, which presents a major challenge to clinical anti-infection treatment.

Chlorhexidine is used widely to prevent the spread of bacteria in the hospital environment. However, bacteria are increasingly becoming tolerant to chlorhexidine. Here we investigated clinical characteristics, tolerance mechanisms, and molecular epidemiology of chlorhexidine-tolerant Pseudomonas aeruginosa. According to the proposed epidemiological cut-off value to determine chlorhexidine tolerance (50 µg/mL) in P. aeruginosa, 32 chlorhexidine-tolerant isolates were detected from 294 P. aeruginosa isolates, which accounted for 10.9%. Our results indicated MICs of chlorhexidine-tolerant strains were 64 µg/mL. Patient's data showed chlorhexidine tolerance was associated with following factors: hospital length of stay, ICU admission, length of stay in ICU, invasive procedure, duration of mechanical ventilation, chlorhexidine usage, and occurrence of nosocomial pneumonia. Tolerance mechanisms were analyzed by efflux pump inhibition test, qRT-PCR, and serial passage experiment. Increased expression of efflux pump genes mexA, mexC, mexE and mexX, and decreased expression of oprD were observed in chlorhexidine-tolerant and chlorhexidine-induced strains, which suggested that hyperexpression of Mex-Opr efflux pump was the main mechanism. Moreover, serial passage experiment found chlorhexidine-induced strains showed decreased susceptibility to tested antibiotics, which illustrated that long-term exposure of P. aeruginosa to chlorhexidine could result in multidrug-resistant (MDR) or cross-resistance phenotypes. MLST and PFGE analysis demonstrated the homology of 32 chlorhexidine-tolerant strains was low and no obvious clonal transmission was observed. We comprehensively investigated the development and molecular mechanisms of chlorhexidine-tolerant P. aeruginosa, which revealed that the control and surveillance of chlorhexidine tolerance should be more strict. Moreover, it seems to make sense to avoid the continuous or unreasonable application of chlorhexidine in hospital settings.

Klebsiella pneumoniae (K. pneumoniae) is one of the most common causes of bacterial meningitis worldwide. The purpose of this study was to investigate the clinical and microbiological characteristics of K. pneumoniae meningitis, as well as the association of antimicrobial resistance, virulence, and patient prognosis. The clinical data of patients with K. pneumoniae meningitis from 2014 to 2020 in a tertiary teaching hospital were retrospectively evaluated. Antimicrobial susceptibility profiles were performed by the agar dilution method and broth microdilution method. The isolates were detected for virulence-related genes, resistance genes, capsular serotypes, and molecular subtypes. A total of 36 individuals with K. pneumoniae meningitis were included in the study, accounting for 11.3% (36/318) of all cases of bacterial meningitis. Of the 36 available isolates, K1, K47, and K64 were tied for the most frequent serotype (7/36, 19.4%). MLST analysis classified the isolates into 14 distinct STs, with ST11 being the most common (14/36, 38.9%). Carbapenem resistance was found in 44.4% (16/36) of the isolates, while hypervirulent K. pneumoniae (HvKP) was found in 66.7% (24/36) of the isolates. The isolates of hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP) were then confirmed to be 36.1% (13/36). Importantly, individuals with meningitis caused by Hv-CRKP had a statistically significant higher mortality than the other patients (92.3%, 12/13 vs. 56.5%, 13/23; P < 0.05). The high percentage and fatality of K. pneumoniae-caused meningitis, particularly in Hv-CRKP strains, should be of significant concern. More effective surveillance and treatment solutions will be required in future to avoid the spread of these life-threatening infections over the world.

Abstract Background Most studies had used sufentanil and ropivacaine for intrathecal anesthesia in adults or children，but few studies had used sufentanil and ropivacaine for peripheral nerve block, especially in children. Brachial plexus block was one of the most commonly used nerve block methods in children. Therefore, the purpose of this study was to investigate whether 0.1µg/kg sufentanil combined with 0.25% ropivacaine can improve analgesia and prolong analgesia in children compared with ropivacaine alone.Methods 80 children, ASA I, aged 5-10 years old, undergoing upper limb surgery, were randomly divided into two groups: RS group(0.25% ropivacaine combined with 0.1µg/kg sufentanil) and R group (0.25% ropivacaine alone). The dosage of 0.25% ropivacaine administered in each group was 0.5ml/kg. After general anesthesia, all children underwent ultrasound-guided brachial plexus block and were performed by the same experienced anesthetist. The primary outcome measures were the FLACC score at 2, 4, and 6 h after surgery and the duration of analgesia in each group. Secondary outcome measures were the changes in vital signs during surgery in each group, the incidence of postoperative agitation, the postoperative awake time and the duration of stay in PACU. Results The FLACC scores at 2, 4 and 6 hours after surgery and the duration of analgesia showed no statistically significant difference. There were no statistically significant differences in the changes in vital signs during surgery in each group. The incidence of postoperative agitation was significantly lower in RS group than R group(20% vs 45%, P<0.05). Comparison of the postoperative awake time and the duration of stay in PACU showed that there were no significant differences respectively.Conclusion Compared with 0.25% ropivacaine alone, 0.1µg/kg sufentanil combined with 0.25% ropivacaine for pediatric brachial plexus block did not improve analgesia and prolong analgesia, but reduced postoperative agitation in the children.Trial RegistrationRegistration of Chinese Clinical Trial Registry(Date:19/04/2020, Number:ChiCTR2000032071).

Due to the lack of research on the characteristics of different clusters of Enterobacter cloacae complex (ECC), this study aimed to characterize and explore the differences among species of the ECC. An analysis based on hsp60 showed that Enterobacter hormaechei was predominant in ECC. Interestingly, the antibiotic resistance rates of clusters were different, among which E. hormaechei subsp. steigerwaltii (cluster VIII) and Enterobacter cloacae IX (cluster IX) possessed high resistant rates to ciprofloxacin and levofloxacin, but cluster II (Enterobacter kobei) had low resistant rates. Cluster II exhibited a strong biofilm formation ability. Different motility and protease production ability were shown for distinct clusters. A PCR analysis showed that clusters I, III, VI, VIII, and IX carried more virulence genes, while cluster II had fewer. Clusters I, VIII, and IX with high pathogenicity were evaluated using the Galleria mellonella infection model. Thus, the characteristics of resistance, biofilm-forming ability, mobility, and virulence differed among the clusters. The strains were divided into 12 subgroups based on hsp60. The main clusters of ECC clinical strains were I, II, III, VI, VIII, and IX, among which IX, VIII, and I were predominant with high resistance and pathogenicity, and cluster II (E. kobei) was a special taxon with a strong biofilm formation ability under nutrient deficiency, but was associated with low resistance, virulence, and pathogenicity. Hence, clinical classification methods to identify ECC subgroups are an urgent requirement to guide the treatment of clinical infections.

Purpose This study aimed to evaluate the in vitro activity of meropenem-vaborbactam (MVB) against a collection of carbapenem-resistant Escherichia coli (CREC) isolates and to compare the activity with other antibiotics with regard to different separation sites, carbapenem-resistant mechanisms, and sequence types (STs). Methods A total of 58 CREC strains were used as the experimental strains from the First Affiliated Hospital of Wenzhou Medical University in southeastern China. The minimum inhibitory concentrations of MVB, ceftazidime-avibactam, and tigecycline against all the experimental strains were determined by the microdilution broth method. Results MVB exhibited higher antimicrobial activity (83% susceptibility) than that of other antibiotics, except for colistin and tigecycline. The susceptibility of CREC strains towards MVB varied with regard to carbapenem-resistant mechanisms and STs, especially in Klebsiella pneumoniae carbapenemase (KPC)-positive isolates and ST8 isolates. Conclusion MVB exhibited considerably high activity against KPC-producing and ST8 CREC isolates. It has the great potential to be an alternative for the treatment of infections caused by CREC after determining the type of carbapenemase, the susceptibility to MVB and/or STs.

2020年国际疼痛研究协会(international association of the study for pain,IASP)将"疼痛"的定义修订为"疼痛是一种与实际或潜在的组织损伤相关的不愉快的感觉和情绪情感体验,或与此相似的经历"[1].目前国际上对疼痛的关注程度也越来越高.在美国仍有约66％的患者经历了中度以上术后疼痛[2].一项2020西班牙多中心横向调查发现73％的患者经历了术后急性疼痛[3].目前国内仍缺少由麻醉科医师主导的大范围术后疼痛情况数据.本研究调查患者术后急性疼痛的现状,为指导疼痛管理工作提供参考.

Colistin is being considered as “the last ditch” treatment in many infections caused by Gram-negative stains. However, colistin is becoming increasingly invalid in treating patients who are infected with colistin-resistant Escherichia coli ( E. coli ) and Klebsiella Pneumoniae ( K. pneumoniae ). To cope with the continuous emergence of colistin resistance, the development of new drugs and therapies is highly imminent. Herein, in this work, we surprisingly found that the combination of quercetin with colistin could efficiently and synergistically eradicate the colistin-resistant E. coli and K. pneumoniae , as confirmed by the synergy checkboard and time-kill assay. Mechanismly, the treatment of quercetin combined with colistin could significantly downregulate the expression of mcr-1 and mgrB that are responsible for colistin-resistance, synergistically enhancing the bacterial cell membrane damage efficacy of colistin. The colistin/quercetin combination was notably efficient in eradicating the colistin-resistant E. coli and K. pneumoniae both in vitro and in vivo . Therefore, our results may provide an efficient alternative pathway against colistin-resistant E. coli and K. pneumoniae infections.

Purpose The emergence of colistin resistance among Gram-negative bacteria (GNB) poses a serious public health threat. Therefore, it is necessary to enhance the antibacterial activity of colistin through the combination with other drugs. In this study, we demonstrated the synergistic activity and the possible synergy mechanism of colistin with PFK-158 against colistin-resistant GNB, including non-fermenting bacteria and Enterobacteriaceae. Patients and Methods Thirty-one colistin-resistant GNB, including Pseudomonas aeruginosa (n = 9), Acinetobacter baumannii (n = 5), Escherichia coli (n = 8) and Klebsiella pneumoniae (n = 9), were collected as the experimental strains and the minimum inhibitory concentrations (MICs) of colistin, other routine antimicrobial agents and PFK-158 against all strains were determined by the broth microdilution method. The synergistic activity of colistin with PFK-158 was assessed by the checkerboard assay and time-kill assay. The biofilm formation assay and scanning electron microscopy were used to demonstrate the biofilm formation effect of colistin with PFK-158 against colistin-resistant GNB. Results The results of the checkerboard assay showed that when colistin was used in combination with PFK-158, synergistic activity was observed against the 31 colistin-resistant GNB. The time-kill assay presented a significant killing activity of colistin with PFK-158 against the 9 colistin-resistant GNB selected randomly, including Pseudomonas aeruginosa (n = 6), Acinetobacter baumannii (n = 1), Escherichia coli (n = 1), and Klebsiella pneumoniae (n = 1). The biofilm formation assay and scanning electron microscopjihy showed that colistin with PFK-158 can effectively suppress the formation of biofilm and reduce the cell arrangement density of biofilm against most experimental strains. Conclusion The results of the performed experiments suggest that the combination of colistin and PFK-158 may be a potential new choice as a new antibiofilm group for the treatment of infections caused by the colistin-resistant GNB.

Colistin is among the few antibiotics effective against multidrug-resistant Gram-negative bacteria (GNB) clinical isolates. However, colistin-resistant GNB strains have emerged in recent years.

Carbapenem-resistant Klebsiella pneumonia (CRKP) infections has become a concerning threat. However, knowledge regarding the characteristics of intestinal CRKP isolates is limited. This study aimed to investigate and compare the clinical, virulence and molecular epidemiological characteristics of intestinal colonization and extraintestinal infections CRKP strains. The clinical characteristics were investigated retrospectively. Polymerase chain reaction was used to investigate the capsular serotype, virulence genes and carbapenemase genes. Capsular polysaccharide quantification assay, serum resistance assay, biofilm formation assay, and infection model of Galleria mellonella larvae were performed to compare the virulence and pathogenicity. Besides, multilocus-sequence-typing (MLST) and pulsed-field-gel-electrophoresis (PFGE) were conducted to explore the homology of intestinal CRKP isolates. A total of 54 intestinal CRKP isolates were included. The main capsular serotypes were K14, K64, and K19. C-reactive protein and the proportion of ICU isolation of the infection group were significantly higher than that of the colonization group (P < 0.05). The carrier rates of various virulence genes of CRKP in the infection group were mostly higher than those in the colonization group, wherein the carrier rates of peg-344 and rmpA were significantly different (P < 0.05). There was no significant difference in capsular polysaccharides, antiserum ability, biofilm formation ability between the two group (P > 0.05), but the lethality of the infection group to Galleria mellonella was significantly higher than that of the colonization group (P < 0.05). The MLST categorized the 54 isolates into 13 different sequence types. PFGE revealed that homology among the 54 CRKP strains was <80%. This study suggested that the CRKP strains in the infection group had higher virulence than those in the colonization group. The development of CRKP isolates colonizing in the intestine should be addressed in future clinical surveillance.

Abstract Background: The emergence of colistin resistance among Gram-negative bacteria poses a serious public health threat and warrants immediate action. Therefore, it is necessary to enhance the antibacterial activity of colistin through the combination with other drugs. In this study, we demonstrate the synergistic activity of colistin combined with PFK-158 against colistin-susceptible but more importantly against colistin-resistant Gram-negative bacteria, including non-fermenting bacteria (P. aeruginosa, A. baumannii) and Enterobacteriaceae (E. coli and K. pneumoniae).Methods: 18 colistin-resistant and 12 colistin-susceptible Gram-negative bacteria were collected as the experimental strains, and the minimum inhibitory concentrations (MICs) of colistin and PFK-158 against all strains were determined by the broth microdilution method. The MICs of routine antimicrobial agents including aztreonam (ATM), ceftazidime (CAZ), cefepime (FEP), imipenem (IMP), ciprofloxacin (CIP), levofloxacin (LVX), gentamicin (GEN), tobramycin (TOB) for all 30 experimental strains were determined by bioMerieux VITEK-2 (BioMérieux, Marcy-l’Étoile, France). The synergistic activity of colistin combined with PFK-158 in vitro was assessed using the checkerboard assay and the time-kill assays.Results: The results of the checkerboard assay showed that when colistin was used in combination with PFK-158, synergistic activity was observed against the 18 colistin-resistant and the 8 colistin-susceptible Gram-negative bacteria, and the remaining 4 colistin-susceptible strains showed additive activity. No irrelevant activity and antagonistic activity was observed for all strains. The results of the time-killing assays presented that the killing activity against the colistin-resistant Gram-negative bacterium were evident for the combination of colistin and PFK-158, compared with the groups adding colistin or PFK-158 alone. Conclusions: In conclusion, our results strongly exhibited that the combination of colistin and PFK-158 displayed the significant synergistic activity against all tested colistin-resistant and most colistin-susceptible Gram-negative strains. PFK-158 was found to potentiate the antibacterial activity of colistin against a wide panel of colistin-resistant and colistin-susceptible Gram-negative strains no matter what species (including non-fermenting bacteria and Enterobacteriaceae). It may be a potential new choice for the treatment of infections caused by the clinical Gram-negative strains.

目的 研究孕期体重指数、三酰甘油及孕期体重增加对巨大儿出生体重及剖宫产率的影响.方法 选取2018年1～8月在温州医科大学附属第三医院分娩巨大儿的孕妇251例,采用Pearson相关性分析研究孕期体重指数、三酰甘油及孕期体重增加对巨大儿出生体重的影响,再根据各自的中位数进行分组,采用χ2检验比较不同组剖宫产率的差异.结果 孕期体重指数、三酰甘油及孕期体重增加均与巨大儿的出生体重呈正相关(P<0.05);不同组孕期体重指数、三酰甘油及孕期体重增加的升高,组间剖宫产率无明显升高,差异无统计学意义(P>0.05).结论 孕期体重指数、三酰甘油及孕期体重增加均与巨大儿出生体重呈正相关,与剖宫产率不相关.

目的 初步分析围术期导致小儿认知和行为功能改变的麻醉相关因素.方法 大样本观察并有效随访温州医科大学附属第二医院2012～2017年期间接受择期非神外非心外手术行全身麻醉的4～7岁学龄前患儿共17854例,将患儿分别按照麻醉方法(静脉麻醉和吸入麻醉)、术中有无低氧血症、低血压、低体温、输血、阿托品使用和胶体使用输血等分组,统计分析导致围术期小儿认知和行为功能改变的麻醉相关因素.结果 17854例患儿中,术后发生认知和行为功能改变者为1.82％(325例).其中吸入麻醉组发生率显著高于静脉麻醉组(302 vs 23例,1.93％vs 1.00％,P<0.05);术中发生低氧血症组(185例,6.80％)较无低氧血症组发生率显著增高(140例,0.93％,P<0.05);术中发生低血压组(54例,3.30％)较无低血压组显著增高(271例,1.67％,P<0.05);术中发生低体温组(243例,6.27％)较无低体温组显著增高(82例,0.59％,P<0.05);有无使用阿托品、胶体和输血分析比较差异均无统计学意义(P均>0.05).多因素Logistic回归分析发现术中低氧血症、低血压、低体温和使用吸入麻醉均是患儿发生围术期认知功能和行为改变的危险因素(OR=4.66,2.34,10.59,1.72),曲线下面积发现以上因素的ROC值分别为0.91、0.79、0.89、0.76.结论 术中低氧血症、低体温、低血压和使用吸入麻醉是患儿发生围术期认知功能和行为改变的独立危险因素.

Objective:To study the in vitro antibacterial activity of three carbapenems in combination with colistin against Enterobacter cloacae complex resistant to both carbapenems and colistin. Methods:Strains of the Enterobacter cloacae complex were isolated from various clinical specimens in the First Affiliated Hospital of Wenzhou Medical University from 2011 to 2018. Their susceptibility to common antimicrobials was detected by Vitek 2-Compact automatic microbial analyzer. A total of 19 isolates of the Enterobacter cloacae complex that were resistant to carbapenems and colistin were screened out. The minimum inhibitory concentrations of carbapenems and colistin to the 19 isolates were detected with agar dilution method. Checkerboard method was used to evaluate the in vitro antibacterial activity of three combination therapy strategies to the co-resistant Enterobacter cloacae complex. Results:The resistance rates of the 19 strains to the first- and third-generation cephalosporins were higher than 90%. Their resistance rates to ertapenem, meropenem and imipenem were 100%, 26.3% and 31.6%, respectively. The combined effect of colistin with imipenem, meropenem or ertapenem on the Enterobacter cloacae complex was mainly synergistic or additive. Both meropenem and imipenem combined with colistin showed unrelated effect to one strain. Conclusions:The combination of carbapenems with colistin had better antibacterial effects on the Enterobacter cloacae complex resistant to both carbapenems and colistin, suggesting a potential treatment strategy for infections caused by multidrug-resistant Enterobacter cloacae complex.

目的 研究莱菔硫烷对人子宫颈鳞癌细胞系SiHa细胞的作用及相关机制.方法 MTT法检测2.5、5、10、20、40 μmol·L-1莱菔硫烷作用24 h对SiHa细胞增殖的作用,流式细胞术检测细胞凋亡情况.采用RhoA/Rho相关激酶(ROCK)通路抑制剂C3转移酶作为阳性对照,实时定量PCR法检测莱菔硫烷对ROCK mRNA表达的影响,蛋白免疫印迹法检测SiHa细胞中ROCK、细胞周期蛋白依赖性激酶1(CDK1)、细胞周期蛋白(cyclin)B1蛋白表达水平.结果 2.5、5、10、20、40 μmol· L-1莱菔硫烷对SiHa细胞增殖的抑制率分别为(3.87±1.22)％、(16.64±2.47)％、(49.04±2.09)％、(70.00±2.14)％和(86.16±1.97)％,诱导SiHa细胞凋亡率分别为(10.60±1.21)％、(30.67±2.09)％、(55.51±2.54)％、(62.67±3.09)％和(75.31±2.63)％,均呈浓度依赖性(F=12.097、13.208,P＜0.01).与对照组相比,莱菔硫烷组与C3转移酶组ROCK蛋白和mRNA表达均显著减少,CDK1及cyclinB1蛋白表达显著增加(P＜0.05或P＜ 0.01).结论 莱菔硫烷可抑制SiHa细胞增殖,并诱导其凋亡,其机制可能与抑制RhoA/ROCK通路有关.

Objective To determine the risk factors for postoperative hyperactive-type delirium (PHTD) in elderly patients undergoing orthopedic surgery.Methods A total of 7 171 elderly patients of both sexes,aged more than or equal to 65 yr,of American Society of Anesthesiologists physical status Ⅰ-Ⅳ,who underwent orthopedic surgery from January 2008 to December 2012 in Second Affiliated Hospital of Wenzhou Medical University,were retrospectively analyzed.Data such as gender,age,preoperative electrolytes,blood glucose,hemoglobin,albumin,senile dementia and use of benzodiazepines,type of operation,anesthesia methods,operation time,intraoperative use of anticholinergic agents and benzodiazepines and hypotension (decrease more than 20％ of the baseline),and postoperative electrolyte,hemoglobin,albumin and hypotension were collected.The patients were divided into postoperative PHTD group (group PHTD) and postoperative non-PHTD group (group non-PHTD) according to whether PHTD developed within 7 days after operation.The risk factors of which P values were less than 0.05 would enter the multivariate logistic regression to stratify the risk factors for postoperative PHTD.Results Ninety-nine patients developed PHTD,and the incidence was 1.38％.The results of logistic regression analysis showed that age more than or equal to 80 yr,hip surgery and preoperative anemia were independent risk factors for postoperative PHTD (P＜0.05).Conclusion Age more than or equal to 80 yr,hip surgery and preoperative anemia are independent risk factors for postoperative PHTD in elderly patients undergoing orthopedic surgery.