Objective To compare the technical indicators and clinical effect of catheter-directed thrombolysis(CDT)via two types of non-popliteal venous access in the treatment of acute mixed-type lower extremity deep vein thrombosis(DVT).Methods The clinical data of 119 patients with acute mixed-type lower extremity DVT,who were admitted to the Affiliated Jiangning Hospital of Nanjing Medical University and the Affiliated Nanjing Hospital of Nanjing Medical University of China to receive CDT treatment from January 2016 to June 2022,were retrospectively analyzed.Of the 119 patients,CDT via deep calf vein access was carries out in 45(calf vein group)and CDT via healthy-side femoral venous access was performed in 74(femoral vein group).The success rate of vascular puncture,success rate of catheterization technique,number of successful CDT venous puncturing,time spent for sheath placement,time spent for catheterization,thrombolysis time,used amount of thrombolytic agent and associated complications(including vein puncturing and anticoagulant thrombolysis-related complications),the thrombolytic effect of different anatomical segments,and the clinical efficacy during the follow-up period for at least 12 months were compared between the two groups.Results Successful catheterization via deep calf vein access and via healthy-side femoral vein access was obtained in 31 and 58 CDT patients respectively,with a technical success rate of 68.89％(31/45)and 78.38％(58/74)respectively,the difference between the two groups was not statistically significant(P=0.248).In 26 patients(67.74％)of the calf vein group,more than two times of puncturing were needed before the sheath placement could be successfully achieved.The time spent for sheath placement in the femoral vein group was(1.84±0.87)min,which was remarkably shorter than(10.52+6.13)min in the calf vein group(P＜0.001),but the time spent for catheterization in the femoral vein group was(41.60±13.31)min,which was obviously longer than(20.06+4.46)min in the calf vein group(P＜0.001).The thrombolysis time in the femoral vein group and the calf vein group was(5.34+1.43)days and(5.06±1.18)days respectively(P=0.354),and the used amount of thrombolytic agent in the femoral vein group was(352.16±71.98)×104 U,which was prominently larger than(284.68±77.64)× 104 U in the calf vein group(P＜0.001).The last follow-up check showed that the patency rate of the popliteal vein in the calf vein group was significantly higher than that in the femoral vein group(P=0.037).No statistically significant differences in the incidence of post-thrombotic syndrome(PTS)and the mean VEINES-QOL/Sym scores existed between the two groups(all P＞0.05).Conclusion Compared with CDT via healthy-side femoral vein access,CDT via deep calf vein access can better remove the thrombus in the popliteal vein and superficial femoral vein,and improve the femoropopliteal vein patency rate,although it has no obvious advantages in reducing the occurrence of PTS and in improving the VEINES-QOL/Sym score,moreover,the deep calf vein puncture and sheath placement require a high-level technique.

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 investigate the level of coagulation factor Ⅺ(FⅪ)in patients with venous thrombosis of lower limbs and its correlation with recurrence risk.Methods A total of 220 pa-tients with deep vein thrombosis(DVT)admitted in our hospital from February 2018 to February 2019 were enrolled as the study group,and another 50 healthy individuals taking physical exami-nation during same period served as the control group.After a 3 years followed,the study group ultimately included 197 cases,according to the results of restricted cubic spline(RCS),the study group was divided into low(FⅪ＜10.3 U/L,94 cases),medium-(10.3-12.1 U/L,52 cases)and high-level groups(＞12.1 U/L,51 cases).The plasma level of FⅪ was detected in the study group 1 month after the end of anticoagulant therapy,and the results were compared with those of the control group during physical examination.Cox model was used to analyze the influence of FⅪ on the recurrence of DVT,and RCS was employed to analyze the relationship between DVT recur-rence and FⅪ level.Kaplan-Meier curve was plotted to analyze the recurrence risk of DVT with different FⅪ levels.The patients from the study group were followed up for 3 years.Results The FⅪ level was significantly higher in the study group than the control group(P＜0.05).During fol-low-up period,33 patients(16.75％)had DVT recurrence.The Cox model analysis after adjust-ment of sex and age showed that FⅪ level was a risk factor for DVT recurrence(P＜0.05).When the FⅪ level was set into tertile and the risk ratio was calculated after adjustment,FⅪ＜10.3 U/L,and the average FⅪ level at this stage was 9.2 U/L,the risk ratio was 0.82(95％CI:0.673-0.984);Patients with FⅪ between 10.3 and 12.1 U/L,and the average FⅪ at this stage was 11.4 U/L,the risk ratio of 1.04(95％CI:0.813-1.432).The those with FⅪ＞12.1 U/L,and the average FⅪ at this stage was 13.8 U/L,hazard ratio of 1.38(95％CI:0.921-1.563).Kaplan-Meier curve analysis showed that the recurrence risk was 28.62％(95％CI:25.633-31.609),30.10％(95％CI:27.594-32.606)and 38.06％(95％CI:34.306-41.371),respectively for the low-,medium-,and high-level groups,with significant correlation among the three groups(x2=6.631,P=0.036).Conclusion Compared with healthy individuals,plasma FⅪ level is at a high level in the DVT patients.With the increment of FⅪ level,the risk of DVT recurrence increases.Two FⅪ levels,10.3 U/L and 12.1 U/L,can be used as reference points for the obvious increase of DVT recur-rence rate.

Purpose To investigate the feasibility of apoptosis small-molecule probe CYS-F for in vivo molecular imaging in acute middle cerebral artery embolization and recalculation models,and to explore its ability to reflect lesions.Materials and Methods Hela cell apoptosis was induced by Adriamycin,and the targeting ability of the probe was verified in vitro.Clinical middle cerebral artery embolization was simulated,acute ischemic stroke model(n=15)and recanalization model(n=15)were constructed,and the vessels were evaluated by magnetic resonance angiography imaging.The distribution of CYS-F was investigated by injecting the probe into the caudal vein.24 hours after modeling,the lesion volume rate was assessed on T2WI,and apoptosis was assessed in vivo by near infrared imaging.Niss and c-fos staining were used to compare the differences between the two groups.Results CYS-F showed a good ability to target apoptosis in vitro.After modeling,Doppler flowmeter and magnetic resonance angiography showed that the middle cerebral artery was successfully embolized in the embolization group,and the artery was recanalized in the recanalization group.Near infrared imaging showed the loss of fluorescence signal in the middle cerebral artery region in the embolized group.24 hours after modeling,T2WI showed that the infarct volume rate in the recanalization group was significantly lower than that in the embolization group(0.055±0.015 vs.0.512±0.220;t=19.761,P<0.001).The fluorescence intensity of the embolization group was significantly stronger than that of the recusing group,the target to background ratio was 1.215±0.162 and 0.731±0.085,respectively(t=10.252,P<0.001).In the embolization group,a large number of activated neurons expressed c-fos protein,and a large number of cells underwent nuclear condensation and lysis by Niss staining.Conclusion The acute embolization model and recalculation model of middle cerebral artery in mice are close to the clinic.CYS-F can be used to image apoptosis in vivo,reflect the lesion degree,and reflect the local tissue blood perfusion at the initial stage of injection.

Objective:To investigate the efficacy and safety of AcoStream peripheral thrombus aspiration system combined with catheter-directed thrombolysis in the treatment of lower extremity deep vein thrombosis.Methods:The clinical data of 16 lower extremity deep vein thrombosis cases treated with AcoStream peripheral thrombus aspiration system combined with catheter-directed thrombolysis, admitted to the authors′ hospital from May 2022 to November 2022, were retrospectively analyzed. The differences in circumferential diameter between the affected limb and the healthy side, venous patency score, thrombus clearance grade and intraoperative blood loss were observed and compared. The Villalta score was used during the follow up. Paired sample t-test and Wilcoxon rank sum test were used to compare the changes in the observed indicators before and after treatment to evaluate the efficacy. Results:Treatment were successfully performed in all patients. Before treatment, the circumference differences between the affected and unaffected thighs and calves were (3.69±0.97) and (3.34±0.75)cm, respectively, the venous patency score of the affected side was 8(7.25,9) points. After treatment, the circumference differences between the affected and unaffected thighs and calves were (0.81±0.68) and (0.84±0.70)cm, respectively. The venous patency score of the affected side was 1(0,1)points, with statistically significant differences ( P<0.001). Grade Ⅲ thrombus clearance was achieved in 7 patients, grade Ⅱ thrombus clearance was achieved in 9 patients. The average blood loss during thrombus aspiration was (133.1±12.0) ml. Following up for 6 months, the Villalta score was 0(0,1.75) points. Conclusion:Acostream peripheral thrombus aspiration system combined with catheter-directed thrombolysis is safe and effective for the treatment of lower extremity deep venous thrombosis, with satisfactory short-term efficacy and high clinical application value.

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.

Medical physicists play an important role in the delivery of radiotherapy. Compared with China′s mainland, Hong Kong has established a more mature training mode and a more complete management system for medical physics talents. In this article, the authors introduced the current state of medical physics talent training, as well as the recruitment, certification and promotion of medical physicist in Hong Kong by querying the official websites of medical physics organizations, reviewing related literature and interviewing senior medical physicists in Hong Kong. The authors also analyzed the shortcomings in the construction of medical physics talent system in China′s mainland and made valuable suggestions.

Virtual reality (VR) is a technology, which can simulate human vision, touch, hearing and other sensory functions, and it synthesizes a computer-generated 3D world to provide immersive experiences.VR technology has the characteristics of interactivity, immersion and imagination, and its application in medical education and simulation training improves the quality and efficiency of learning.At the same time, VR technology also plays a certain role in clinical treatment such as surgery, rehabilitation, psychology, sedation and analgesia.With the development of VR technology, its application in pediatric medicine field is expected to solve some difficulties of pediatric practitioners.For example, the application of virtual standard patient in pediatric training, and VR technology relieving pain and anxiety.

Objective To develop an evidence-based,localized practice protocol for the interhospital transfer of critically ill children.Methods Through a comprehensive evidence summary and semi-structured interviews,a preliminary inter-hospital transfer practice protocol for critically ill children was formulated.A panel of 31 experts from 12 hospitals in China participated in 2 rounds of expert correspondence between May and July 2022,facilitating meticulous revision of the protocol entries.Results The response rate for both rounds of questionnaires was 100%,and the expert authority coefficients ranged from 0.926 to 0.931.In the second round of consultation,the coefficient of variation for the importance score of each entry ranged from 0.036 to 0.226,and the Kendall's W was determined to be 0.201(P＜0.001).Additionally,the coefficient of variation for the feasibility score of each entry fell within the range of 0.070 to 0.314,with Kendall's W of 0.124(P＜0.001).Ultimately,the final interhospital transfer protocol for critically ill children comprised 8 level Ⅰ entries,16 level Ⅱ entries,and 75 level Ⅲ entries.Conclusion The interhospital transfer protocol constructed in this study is grounded in scientific evidence and exhibits practical feasibility.It serves as a valuable reference for organizing and implementing interhospital transfers of critically ill children.