Carbapenem-resistant Enterobacteriaceae（CRE）is one of the common pathogens of hospital-acquired infections and has been widely spread in various countries，becoming one of the important public health problems worldwide.With the increase in the proportion of pediatric patients with CRE infections，studies related to the prevention and the control of CRE nosocomial infections have focused more on this group in recent years.Early prevention is particularly important because of the very limited treatment options for CRE infections and the high morbidity and mortality rates.Active screening，as a core measure to prevent CRE infection，has been implemented in several countries in recent years and has been shown to have a positive effect on the prevention and control of nosocomial infection in CRE.The target population of active screening generally includes people in close contact with CRE patients and people at high risk of CRE infection；screening specimens are mostly used in perianal swabs or rectal swabs；detection methods include bacterial culture and molecular detection techniques，with the former being the main method；the timing of screening is to collect the initial specimen within 24 hours of new admission，and follow up people at high risk of infection with regular testing.

Simulation-based medical education（SBME）is an important model in international medical education.With the development of SBME domestically,various forms such as in-situ simulation,team simulation,interdisciplinary simulation,and hybrid simulation are gradually emerging.While post-graduate education and competency receive more attention,SBME has shown its value in areas including education and training,clinical thinking,assessment,and evaluation,as well as improving medical quality and patients safety,especially in the management of emergency and critical care crisis resources.However,the progress of pediatric SBME has been slow despite attracting significant attention within the field of pediatric critical care.The establishment of pediatric critical care skills simulation,scenario simulation,in-situ simulation and other training methods can not only enable clinicians to achieve“standardized operation” and “team collaboration”,but also promote“system transformation”,greatly improving the medical quality of pediatric critical care while ensuring patients safety.

In situ simulation is gradually becoming an important way to test loopholes in medical systems and train team work.But it has not yet started in the field of pediatric intensive care in China.Through the definition,historical development,comparison with training center simulation,application in the field of pediatric intensive care abroad,application challenges,and future prospects of in situ simulation,a preliminary introduction is provided to provoke awareness and attention to in situ simulation,and promote its promotion in the field of pediatric intensive care in China.

Objective:To analyze clinical characteristics of patients within 48 hours in pediatric intensive care unit（PICU）,and investigate causes and prognosis of extubation failure in reintubation children.Methods:A single-center retrospective study was conducted.Patients who were reintubated within 48 hours after extubation in PICU at Children's Hospital of Fudan University from January 1，2019 to December 31，2022 were retrospectively enrolled.Patients with unplanned extubation for various reasons which include re-intubation due to surgery and replacement of tracheal intubation were excluded.We analyzed the clinical characteristics，causes of extubation failure and prognosis.Main outcome measures included principal diagnosis，pediatric critical illness score（PCIS），the reason of intubation，the glasgow coma scale（GCS），the direct cause of reintubation，aeration time，hospitalization period，outcomes at PICU discharge and whether to extubate successfully.Results:During the study period，a total of 2 652 patients were extubated in PICU,and a total of 87 children were enrolled.Finally，63（72.4%）patients survived at PICU，nine（10.3%）patients died in hospital，and 15（17.2%）patients were discharged automatically.In the survival group，38（60.3%）patients were decannulated and 25（39.7%）patients underwent tracheotomy.The top three principal diagnosis in 87 cases were central nervous system disease[34（39.1%）cases]，lower airway disease[18（20.7%）cases] and sepsis[nine（10.3%）cases].Of the 87 children，28（32.2%）patients were reintubated due to central respiratory failure，21（24.1%）patients were reintubated due to lower airway disease，20（23.0%）patients were reintubated due to upper airway obstruction，14（16.1%）patients were reintubated due to cough weakness and/or swallowing disturbance，and four（4.6%）patients were reintubated for other reasons.In children with mechanical ventilation duration ≥7 days before first extubation，central nervous system diseases were the most common primary diseases，and it accounts for 55.6%.Central respiratory failure was the main direct cause of reintubation，accounting for 40.0%，and more patients(40.0%) had GCS scores＜8 before the first intubation.Compared with the successful decannulation group，the extubation failure group had the higher proportion of children with GCS＜8（32.7% vs.10.5%， P＜0.05），the longer median duration of mechanical ventilation before the first extubation[239（123，349）h vs.68.5（19，206）h， P＜0.05]and the longer median length of ICU stay[38（23，54）d vs.24（12，43）d， P＜0.05].After comparing the three groups including survival group，in-hospital death group and automatic discharge group，the PCIS score of the survival group was the highest，and the in-hospital death group was the lowest( P＜0.05). Conclusion:The rate of reintubation at 48 h after extubation in PICU is 3.3%.The immediate causes of reintubation mainly included central respiratory failure，lower airway disease，upper airway obstruction，cough weakness and/or dysphagia.The mortality rate of reintubation in critically ill children is high and the prognosis is poor.

Objective:To evaluate direct and indirect costs for schizophrenia,major depressive disorder(MDD)and bipolar disorder,and to compare their differences of cost composition,and to explore the drivers of the total costs.Methods:A total of 3 175 inpatients with schizophrenia,MDD,and bipolar disorder were recruited.In-patient's self-report total direct of medical costs outpatient and inpatient,out-of-pocket costs,and direct non-medical costs were regarded as direct costs.Productivity loss and other loss caused by damaging properties were defined as indirect costs.The perspectives of this study included individual and societal levels.Multivariate regression analysis was applied for detecting the factors influencing disease costs.Results:The total cost of schizophrenia was higher than those of MDD and bipolar disorder at individual and societal levels.The indirect costs of three mental disorders were higher than the direct costs,and the indirect cost ratio of bipolar disorder was higher than those of schizophre-nia and MDD.Age,gender,working condition and marital status(P＜0.05)were the important drivers of total costs.Conclusion:The economic burden of the three mental disorders is relatively heavy.Schizophrenia has heaviest disease burden,and the productivity loss due to mental disorders is the driving force of the soaring disease cost

Objective:To explore the clinical characteristics and related socio-demographic factors of schizo-phrenia patients with different ages of onset.Methods:Totally 2 016 patients with schizophrenia aged 15 to 70 were selected according to the diagnostic criteria for schizophrenia in the Diagnostic and Statistical Manual of Mental Disorders,Fifth Edition.All of the patients were interviewed by psychiatrists using the Mini International Neuropsy-chiatric Interview to diagnose schizophrenia,Clinical-Rated Dimensions of Psychosis Symptom Severity(CRDPSS)and the Positive and Negative Syndrome Scale(PANSS)to assess symptoms.The cut-off points were 18 and 25 years old for three age groups,i.e.early onset(EOS),youth onset(YOS)and adult onset(AOS).Statistical analy-ses were performed by analysis of variance Pearson correlation analysis,and multivariate linear regression.Results:The early-onset patients had the highest total PANSS score(73.8±28.0)and CRDPSS score(11.7±5.4).Fe-male gender,high education level,Han ethnicity,early onset age,and slower onset of illness were negatively corre-lated with the total and dimension score of PANSS scale and CRDPSS scale(standardized regression coefficient:0.04-0.47),and income level and smoking were negatively correlated with those score(standardized regression coefficient:-0.04--0.14).Conclusion:Early-onset schizophrenia patients have more severe symptoms,and fe-male,high education level,early-onset disease,and chronic onset are the risk factors of symptom severity in patients with schizophrenia.

Objective:To analyze the clinical situation of critically ill children with Montgomery T-tube，aiming to summarize the characteristics of T-tube application in pediatric and the experience of postoperative airway management in PICU.Methods:The etiology，clinical characteristics，complications and ICU admissions of patients with Montgomery T-tube admitted to the Pediatric Hospital of Fudan University from April 2019 to December 2021 were analyzed，and the application of T-tube in patients with critical conditions requiring long-term mechanical ventilation was described in the light of clinical experience.Results:During the study period,seven children were admitted to the PICU after T-tube insertion,including three males and four females,aged 9~75 months.Five children received mechanical ventilation.Among them,there were five cases with congenital laryngeal malformations,one case with tracheoesophageal fistula,and one case with laryngeal papilloma.The main complications were sputum blockage,infection,and granulation proliferation.One child died of secretion blockage,while the other children were successfully evacuated from the T-tube.The longest retention time of the T-tube was 367 days.Five patients experienced hoarseness after removing the T-tube,and upon re-examination with fiberoptic bronchoscopy,no recurrence of subglottic stenosis was observed.There was no respiratory distress or wheezing,and there were no abnormalities observed during regular outpatient follow-up after discharge.After discharge,the quality of life of the six surviving children improved compared to preoperative,and they all resumed oral feeding.There were no complaints of swallowing difficulties or aspiration during outpatient follow-up.But they were all combined with malnutrition.Conclusion:The Montgomery T-tube is a secure and dependable airway stent utilized for airway remodeling and the maintenance of airway patency following interventional surgery.For critically ill children,early management of airway clearance and infection prevention are imperative.

Liquid chromatography-electrospray ionization tandem mass spectrometry(LC-ESI-MS)is a widely utilized technique for in vivo pharmaceutical analysis.Ionization interference within electrospray ion source,occurring between drugs and metabolites,can lead to signal variations,potentially compromising quantitative accuracy.Currently,method validation often overlooks this type of signal interference,which may result in systematic errors in quantitative results without matrix-matched calibration.In this study,we conducted an investigation using ten different groups of drugs and their corresponding me-tabolites across three LC-ESI-MS systems to assess the prevalence of signal interference.Such in-terferences can potentially cause or enhance nonlinearity in the calibration curves of drugs and metabolites,thereby altering the relationship between analyte response and concentration for quanti-fication.Finally,we established an evaluation scheme through a step-by-step dilution assay and employed three resolution methods:chromatographic separation,dilution,and stable labeled isotope internal standards correction.The above strategies were integrated into the method establishment process to improve quantitative accuracy.

Objective:To analyze the drug-resistant gene loci of Mycoplasma pneumoniae (MP) using metagenomic next-generation sequencing (mNGS). Methods:From November 2022 to October 2023, 697 clinical samples (including sputum, alveolar lavage fluid and blood) of 686 children with Mycoplasma pneumoniae positive detected by mNGS were retrospectively analyzed. Samples were divided into intensive care unit (ICU) group and non-ICU group, Chi-square test was used to compare groups, and Mann-Kendall trend test was used to analyze the change trend of the detection rate of drug resistance gene loci over time. Results:Of the 697 samples, 164 were from the ICU group and 533 were from the non-ICU group. The detection rate of Mycoplasma pneumoniae resistance gene was 44.3% (309/697), and all detected drug-resistant gene loci of MP were A2063G. The detection rate of Mycoplasma pneumoniae in ICU group was 50.0% (82/164), and the detection rates of Mycoplasma pneumoniae resistance gene loci in sputum, alveolus lavage fluid and blood samples were 75.0% (18/24) and 48.4% (62/128), respectively. The detection rate in sputum was higher than alveolus lavage fluid samples ( χ2=5.72, P=0.017). The detection rate of Mycoplasma pneumoniae in non-ICU group was 42.6% (227/533), the detection rate of Mycoplasma pneumoniae resistance gene loci in sputum and alveolar lavage fluid was 40.0% (16/40), 44.3% (201/454), and no detection rate in blood samples (0/12). There was no significant difference in the detection rate of alveolar lavage fluid and sputum ( χ2=0.27, P=0.602). From November 2022 to October 2023, the detection rate of submitted samples showed an increasing trend month by month (overall: Z=3.99, ICU inspection group: Z=2.93, non-ICU group: Z=3.01, all P<0.01). Among the bacteria commonly detected with Mycoplasma pneumoniae, Streptococcus pneumoniae accounted for the highest proportion, the detection rate was 15.5% (108/697), and Epstein-Barr virus accounted for the highest proportion of 17.6% (123/697). Conclusions:From November 2022 to October 2023, the detection rate of Mycoplasma pneumoniae drug resistance gene loci showed an increasing trend. The detection rate of drug resistance gene loci in sputum samples of ICU group was higher than alveolus lavage fluid. No new drug resistance site were detected.

Objective:To explore the factors affecting the prognosis of severe pediatric acute respiratory distress syndrome (ARDS) after receiving extracorporeal membrane oxygenation (ECMO) support.Methods:It was a multicenter prospective observational study. A total of 95 children with severe ARDS who were treated with ECMO salvage therapy from January 2018 to December 2022 in 9 pediatric ECMO centers in China were enrolled in the study. The general data, disease severity, organ function, comprehensive treatment and prognosis were recorded, and they were divided into survival group and death group according to the outcome at discharge. T test, chi-square test, multivariate Logistic regression and mixed linear model were used to analyze the relationship among baseline before ECMO treatment, some important indicators (pediatric critical scores, platelet count, albumin, fibrinogen, etc) during ECMO treatment and prognosis. Results:Among the 95 children with severe ARDS who received ECMO, 55 (58%) were males and 40 (42%) were females, aged 36.9 (0.5, 72.0) months. Twelve children (13%) were immunodeficient. Sixty-eight (72%) children were treated with venous artery (VA) mode and 27 (28%) with venous vein (VV) mode. The discharge survival rates of overall, VA, and VV mode children were 51% (48/95), 47% (32/68), and 59% (16/27), respectively. The number of immunodeficient children in the death group was higher, and there were lower pediatric critical scores, platelet count, albumin, fibrinogen and arterial oxygen partial pressure/fraction of inspired oxygen (PaO 2/FiO 2), higher ventilator driving pressure (ΔP), oxygenaion index (OI), and longer ARDS duration before ECMO (all P<0.05). There were no statistically significant differences in other indicators, including age, gender, weight, and ECMO mode among different prognostic groups (all P>0.05). High ΔP, high OI, low P/F, and low albumin were high-risk factors affecting prognosis(all P<0.05). After further grouping, it was found that ΔP≥25 cmH 2O (1 cmH 2O=0.098 kPa), P/F≤67 mmHg (1 mmHg=0.133 kPa) and OI≥35 were the thresholds for predicting poor prognosis ( P<0.05). From 24 h after ECMO, there were significant differences in ΔP, P/F and OI between the dead group and the survival group (all P<0.05), and the differences gradually increased with the ECMO process. The platelet level was significant from 7 days after ECMO ( P<0.05) and gradually expanded. Blood lactate levels showed a significant difference between the 2 groups on before and after ECMO ( P<0.05) and gradually increased from 24 h after ECMO. Conclusions:The risk factors affecting the prognosis of severe ARDS in ECMO include high ΔP, high OI, low P/F and low albumin purification therapy before ECMO. The gradual decrease of ΔP, OI and increase of P/F from 24 h of ECMO predicted a good prognosis, while the gradual increase of lactate after ECMO application showed a poor prognosis.