Objective:To investigate the diagnostic value of machine learning model based on 18F-FDG PET/CT for polymyalgia rheumatica (PMR). Methods:From November 2014 to December 2022, 177 patients (119 males, 58 females; age: 67.0 ( 61.0, 72.0) years) admitted to the Department of Rheumatology and Immunology, the First People′s Hospital of Changzhou, with suspected PMR and undergoing 18F-FDG PET/CT examination were retrospectively analyzed. Patients were randomly divided into training set and validation set at the ratio of 7∶3. Three machine learning models, including classification and regression tree (CART), the least absolute shrinkage and selection operator (LASSO) algorithm, and logistic regression, were established based on the PET/CT imaging features to aid in the diagnosis of PMR. The diagnostic efficacy of each model was evaluated by ROC curve analysis and differences among AUCs were analyzed by Delong test. Results:There were 78(44.1%, 78/177) PMR patients and 99(55.9%, 99/177) non-PMR patients, and 124 patients in the training set and 53 patients in the validation set. The logistic regression model (training set: AUC=0.961; validation set: AUC=0.930) was superior to the CART (training set: AUC=0.902, z=2.96, P=0.003; validation set: AUC=0.844, z=2.46, P=0.014) in diagnosing PMR, and was similar to LASSO algorithm (training set: AUC=0.957, z=0.95, P=0.340; validation set: AUC=0.930, z=0.00, P=1.000), but with fewer sites evaluated. The simplified PMR-Logit score had the AUC of 0.951 in the overall population, with the sensitivity of 89.74%(70/78) and the specificity of 90.91%(90/99). Conclusion:Machine learning models based on 18F-FDG PET/CT imaging features are expected to be an effective diagnostic tool for PMR.

Objective:To investigate the relationship between intramuscular adipose tissue index (IATI) calculated from computed tomography images at transverse process of the first lumbar and all-cause mortality in maintenance dialysis patients, and to provide a reference for improving the prognosis in these patients.Methods:It was a multicenter retrospective cohort study. The clinical data of patients who received maintenance hemodialysis or peritoneal dialysis treatment from January 1, 2017 to December 31, 2019 in 4 grade Ⅲ hospitals including Zhongda Hospital Affiliated to Southeast University, Taizhou People's Hospital Affiliated to Nanjing Medical University, Affiliated Hospital of Yangzhou University, and the Third Affiliated Hospital of Soochow University were retrospectively collected. IATI was calculated by low attenuation muscle (LAM) density/skeletal muscle density. The receiver-operating characteristic curve was used to determine the optimal cut-off value of IATI, and the patients were divided into high IATI group and low IATI group according to the optimal cut-off value. The differences of baseline clinical data and measurement parameters of the first lumbar level between the two groups were compared. The follow-up ended on December 23, 2022. The endpoint event was defined as all-cause mortality within 3 years. Kaplan-Meier survival curve and log-rank test were used to analyze the survival rates and the differences between the two groups. Multivariate Cox regression analysis models were used to analyze the association between IATI and the risk of all-cause mortality in maintenance dialysis patients. Multivariate logistic regression analysis model was used to analyze the influencing factors of high IATI.Results:A total of 478 patients were eligibly recruited in this study, with age of (53.55±13.19) years old and 319 (66.7%) males, including 365 (76.4%) hemodialysis patients and 113 (23.6%) peritoneal dialysis patients. There were 376 (78.7%) patients in low IATI (<0.42) group and 102 (21.3%) patients in high IATI (≥0.42) group. The proportion of age ≥ 60 years old ( χ2=24.746, P<0.001), proportion of diabetes mellitus ( χ2=5.570, P=0.018), fasting blood glucose ( t=-2.145, P=0.032), LAM density ( t=-3.735, P<0.001), LAM index ( t=-7.072, P<0.001), and LAM area/skeletal muscle area ratio ( Z=-9.630, P<0.001) in high IATI group were all higher than those in low IATI group, while proportion of males ( χ2=11.116, P<0.001), serum albumin ( Z=2.708, P=0.007) and skeletal muscle density ( t=12.380, P<0.001) were lower than those in low IATI group. Kaplan-Meier survival analysis showed that the 3-years overall survival rate of low IATI group was significantly higher than that in high IATI group (Log-rank χ2=19.188, P<0.001). Multivariate Cox regression analysis showed that IATI<0.42 [<0.42/≥0.42, HR(95% CI): 0.50 (0.31-0.83), P=0.007] was an independent protective factor of all-cause mortality, and age ≥60 years old [ HR (95% CI): 2.61 (1.60-4.23), P<0.001], diabetes mellitus [ HR (95% CI): 1.71 (1.06-2.78), P=0.029] and high blood neutrophil/lymphocyte ratio [ HR (95% CI): 1.04 (1.00-1.07), P=0.049] were the independent risk factors of all-cause mortality in maintenance dialysis patients. Stepwise Cox regression analysis showed that IATI<0.42 was still an independent protective factor of all-cause mortality in maintenance dialysis patients [<0.42/≥0.42, HR (95% CI): 0.45 (0.27-0.76), P=0.003]. Multivariate logistic regression analysis showed that low skeletal muscle density [ OR (95% CI): 0.84 (0.81-0.88), P<0.001] and high serum triglyceride [ OR (95% CI): 1.39 (1.07-1.82), P=0.015] were the independent influencing factors of IATI≥0.42. Conclusion:IATI<0.42 of the first lumbar level is an independent protective factor of all-cause mortality in maintenance dialysis patients. Localized myosteatosis within high-quality skeletal muscle may reduce the risk of all-cause mortality in these patients.

The pursuit of cosmetic effects in post-surgical wounds has led to the development of ultra-minimally invasive techniques in surgery. Minimal invasive surgery has replaced open surgery and has become the new gold-standard for treating diseases. One such technique is the single incision triangulated umbilicus surgery (SITUS), which offers several advantages over traditional laparoscopic and other scarless surgeries, including reduced trauma, faster recovery, and better cosmetic outcomes. SITUS also has a short learning curve, aligns with conventional instrumentation operating habits, and can be used for whole abdominal surgeries. Chinese scholars have made further improvements to the SITUS technology, including expanding its applicability in intra-abdominal surgery and refining its incision closure methods to achieve superior cosmetic results. Currently, SITUS technology is experiencing rapid development in urology applications and has demonstrated satisfactory results in both domestic and international reports. This review aims to discuss the effectiveness and development of the SITUS technique in urology.

Dystrophinopathies caused by variants of DMD gene are a group of muscular diseases including Duchenne muscular dystrophy, Becker muscular dystrophy, and DMD-associated dilated cardiomyopathy. With the advancement of genetic testing techniques and wider implementation of genetic screening, especially the expanded carrier screening, more and more individuals carrying DMD gene variants have been identified, whereas the genetic counseling capacity is relatively insufficient. Currently there is still a lack of professional norms for genetic counseling on dystrophinopathies. In this consensus, the main points to be covered in the pre- and post-test consultation have been discussed, with an aim to provide genetic counseling guidance for the disease diagnosis, treatment, and family reproduction.

Purpose: We aimed to evaluate whether the addition of pemetrexed is effective in improving progression-free survival (PFS) in epidermal growth factor receptor (EGFR)–mutated patients with or without concomitant alterations. Materials and Methods: This multicenter clinical trial was conducted in China from June 15, 2018, to May 31, 2019. A total of 92 non–small cell lung cancer (NSCLC) patients harboring EGFR-sensitive mutations were included and divided into concomitant and non-concomitant groups. Patients in each group were randomly treated with EGFR–tyrosine kinase inhibitor (TKI) monotherapy or EGFR-TKI combined with pemetrexed in a ratio of 1:1. PFS was recorded as the primary endpoint. Results: The overall median PFS of this cohort was 10.1 months. There were no significant differences in PFS between patients with and without concomitant and between patients received TKI monotherapy and TKI combined with pemetrexed (p=0.210 and p=0.085, respectively). Stratification analysis indicated that patients received TKI monotherapy had a significantly longer PFS in non-concomitant group than that in concomitant group (p=0.002). In concomitant group, patients received TKI combined with pemetrexed had a significantly longer PFS than patients received TKI monotherapy (p=0.013). Molecular dynamic analysis showed rapidly emerging EGFR T790M in patients received TKI monotherapy. EGFR mutation abundance decreased in patients received TKI combined chemotherapy, which supports better efficacy for a TKI combined chemotherapy as compared to TKI monotherapy. A good correlation between therapeutic efficacy and a change in circulating tumor DNA (ctDNA) status was found in 66% of patients, supporting the guiding role of ctDNA minimal residual disease (MRD) in NSCLC treatment. Conclusion EGFR-TKI monotherapy is applicable to EGFR-sensitive patients without concomitant alterations, while a TKI combined chemotherapy is applicable to EGFR-sensitive patients with concomitant alterations. CtDNA MRD may be a potential biomarker for predicting therapeutic efficacy.

Objective:To investigate the combination of internal fixation for periprosthetic fractures of the proximal femur (PFFF) after hip arthroplasty.Methods:The data of 58 patients with periprosthetic fractures after hip arthroplasty from May 2008 to March 2022 were retrospectively analyzed, including 31 males and 27 females. The average age was 75.5±18.2 years (range, 35-95 years). There were 39 total hip arthroplasty and 19 hemiarthroplasty; 37 biological prosthesis and 21 cemented prosthesis. Intraoperative periprosthetic fractures occurred in 6 cases and 52 cases postoperatively. Unified classification system (UCS): UCS IV.3A1 type 2 cases, 3A2 type 1 case, 3B1.1 type 19 cases, 3B2.1 type 25 cases, 3B3 type 2 cases, 3C type 9 cases. Fracture site: 3 cases in zone A (greater trochanter), 46 cases in zone B (around the femoral stem), and 9 cases in zone C (distal to the tip of the femoral stem. Internal fixation is composed of primary and secondary fixation, the main fixation method was the cerclage of steel wire or titanium cable, locking compression plate, and locking attachment plate fixation. The secondary fixation method was the cerclage of titanium cable, which was required to cover three zones A, B and C to form an overall balanced fixation. The modified Harris hip scores (mHHS), plate length, working length and screw number of different internal fixation combinations were compared.Results:The follow-up time was 54.2±21.6 months (range, 11-86 months). All patients showed signs of fracture healing at 10.2±1.5 weeks (range, 7-13 weeks) after operation, and bony union was observed at 19.6±1.3 weeks (range, 17-22 weeks) after operation. No delayed union or nonunion was observed. After operation, one case had a stress fracture and was revised with double-plate internal fixation; one case had a failed internal fixation and was revised with double-plate internal fixation and a large allograft bone graft. The mHHS score of UCSIV.3B2.1 group (80.3±4.6) was the lowest at 6 months after operation, and the difference between the groups of different types was statistically significant ( F=256.72, P<0.001). The score of simple internal fixation group (91.6±4.2) was higher than that of revision combined with internal fixation group (81.9±4.1), and the difference was statistically significant ( t=8.32, P<0.001). The plate length and working length were 24.9±2.5 cm and 12.6±1.7 cm for UCS IV.3B1.1, 25.4±2.6 cm and 13.6±1.8 cm for 3B2.1 and 28.1±2.5 cm and 4.9±1.9 cm for 3C, respectively ( F=5.33, P=0.005; F=6.78, P<0.001). The number of screws in zone A was significant difference among different UCS types ( F=52.67, P<0.001); UCS IV.3B1.1 (6.5±2.3) and 3B2.1 (6.7±2.2) were more than 3B3 (3.5±1.5) and 3C (3.7±1.6). The number of screws in zone B was significant difference among different UCS types ( F=42.15, P<0.001); The number of UCS IV.3B1.1 (2.3±1.6) and 3B2.1 (2.8±1.9) were significantly more than that of 3B3 (1.0±0.5) and 3C (1.2±0.6). The number of screws in zone C was significant differences among different UCS types ( F=39.62, P<0.001); The number of UCS IV.3B1.1 (3.8±1.9) and 3B2.1 (3.9±1.7) were more than that of 3B3 (2.0±0.5), the difference was statistically significant ( P<0.05). Conclusion:The function of hip after simple internal fixation of proximal femoral periprosthetic fractures was better than that of those who underwent revision at the same time; the number of screws of UCSIV.B1 and B2 is more than that of B3.

Objective:To investigate the epidemiological characteristics, diagnosis, treat-ment and prognosis of gallbladder cancer in China from 2010 to 2017.Methods:The single disease retrospective registration cohort study was conducted. Based on the concept of the real world study, the clinicopathological data, from multicenter retrospective clinical data database of gallbladder cancer of Chinese Research Group of Gallbladder Cancer (CRGGC), of 6 159 patients with gallbladder cancer who were admitted to 42 hospitals from January 2010 to December 2017 were collected. Observation indicators: (1) case resources; (2) age and sex distribution; (3) diagnosis; (4) surgical treatment and prognosis; (5) multimodality therapy and prognosis. The follow-up data of the 42 hospitals were collected and analyzed by the CRGGC. The main outcome indicator was the overall survival time from date of operation for surgical patients or date of diagnosis for non-surgical patients to the end of outcome event or the last follow-up. Measurement data with normal distribu-tion were represented as Mean±SD, and comparison between groups was conducted using the t test. Measurement data with skewed distribution were represented as M( Q1, Q3) or M(range), and com-parison between groups was conducted using the U test. Count data were described as absolute numbers or percentages, and comparison between groups was conducted using the chi-square test. Univariate analysis was performed using the Logistic forced regression model, and variables with P<0.1 in the univariate analysis were included for multivariate analysis. Multivariate analysis was performed using the Logistic stepwise regression model. The life table method was used to calculate survival rates and the Kaplan-Meier method was used to draw survival curves. Log-rank test was used for survival analysis. Results:(1) Case resources: of the 42 hospitals, there were 35 class A of tertiary hospitals and 7 class B of tertiary hospitals, 16 hospitals with high admission of gallbladder cancer and 26 hospitals with low admission of gallbladder cancer, respectively. Geographical distribution of the 42 hospitals: there were 9 hospitals in central China, 5 hospitals in northeast China, 22 hospitals in eastern China and 6 hospitals in western China. Geographical distribution of the 6 159 patients: there were 2 154 cases(34.973%) from central China, 705 cases(11.447%) from northeast China, 1 969 cases(31.969%) from eastern China and 1 331 cases(21.611%) from western China. The total average number of cases undergoing diagnosis and treatment in hospitals of the 6 159 patients was 18.3±4.5 per year, in which the average number of cases undergoing diagnosis and treatment in hospitals of 4 974 patients(80.760%) from hospitals with high admission of gallbladder cancer was 38.8±8.9 per year and the average number of cases undergoing diagnosis and treatment in hospitals of 1 185 patients(19.240%) from hospitals with low admission of gallbladder cancer was 5.7±1.9 per year. (2) Age and sex distribution: the age of 6 159 patients diagnosed as gallbladder cancer was 64(56,71) years, in which the age of 2 247 male patients(36.483%) diagnosed as gallbladder cancer was 64(58,71)years and the age of 3 912 female patients(63.517%) diagnosed as gallbladder cancer was 63(55,71)years. The sex ratio of female to male was 1.74:1. Of 6 159 patients, 3 886 cases(63.095%) were diagnosed as gallbladder cancer at 56 to 75 years old. There was a significant difference on age at diagnosis between male and female patients ( Z=-3.99, P<0.001). (3) Diagnosis: of 6 159 patients, 2 503 cases(40.640%) were initially diagnosed as gallbladder cancer and 3 656 cases(59.360%) were initially diagnosed as non-gallbladder cancer. There were 2 110 patients(34.259%) not undergoing surgical treatment, of which 200 cases(9.479%) were initially diagnosed as gallbladder cancer and 1 910 cases(90.521%) were initially diagnosed as non-gallbladder cancer. There were 4 049 patients(65.741%) undergoing surgical treatment, of which 2 303 cases(56.878%) were initially diagnosed as gallbladder cancer and 1 746 cases(43.122%) were initial diagnosed as non-gallbladder cancer. Of the 1 746 patients who were initially diagnosed as non-gallbladder cancer, there were 774 cases(19.116%) diagnosed as gallbladder cancer during operation and 972 cases(24.006%) diagnosed as gallbladder cancer after operation. Of 6 159 patients, there were 2 521 cases(40.932%), 2 335 cases(37.912%) and 1 114 cases(18.087%) undergoing ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) examination before initial diagnosis, respec-tively, and there were 3 259 cases(52.914%), 3 172 cases(51.502%) and 4 016 cases(65.205%) undergoing serum carcinoembryonic antigen, CA19-9 or CA125 examination before initially diagnosis, respectively. One patient may underwent multiple examinations. Results of univariate analysis showed that geographical distribution of hospitals (eastern China or western China), age ≥72 years, gallbladder cancer annual admission of hospitals, whether undergoing ultrasound, CT, MRI, serum carcinoembryonic antigen, CA19-9 or CA125 examination before initially diagnosis were related factors influencing initial diagnosis of gallbladder cancer patients ( odds ratio=1.45, 1.98, 0.69, 0.68, 2.43, 0.41, 1.63, 0.41, 0.39, 0.42, 95% confidence interval as 1.21-1.74, 1.64-2.40, 0.59-0.80, 0.60-0.78, 2.19-2.70, 0.37-0.45, 1.43-1.86, 0.37-0.45, 0.35-0.43, 0.38-0.47, P<0.05). Results of multivariate analysis showed that geographical distribution of hospitals (eastern China or western China), sex, age ≥72 years, gallbladder cancer annual admission of hospitals and cases undergoing ultrasound, CT, serum CA19-9 examination before initially diagnosis were indepen-dent influencing factors influencing initial diagnosis of gallbladder cancer patients ( odds ratio=1.36, 1.42, 0.89, 0.67, 1.85, 1.56, 1.57, 0.39, 95% confidence interval as 1.13-1.64, 1.16-1.73, 0.79-0.99, 0.57-0.78, 1.60-2.14, 1.38-1.77, 1.38-1.79, 0.35-0.43, P<0.05). (4) Surgical treatment and prognosis. Of the 4 049 patients undergoing surgical treatment, there were 2 447 cases(60.435%) with complete pathological staging data and follow-up data. Cases with pathological staging as stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲa, stage Ⅲb, stage Ⅳa and stage Ⅳb were 85(3.474%), 201(8.214%), 71(2.902%), 890(36.371%), 382(15.611%), 33(1.348%) and 785(32.080%), respectively. The median follow-up time and median postoperative overall survival time of the 2 447 cases were 55.75 months (95% confidence interval as 52.78-58.35) and 23.46 months (95% confidence interval as 21.23-25.71), respectively. There was a significant difference in the overall survival between cases with pathological staging as stage 0, stage Ⅰ, stage Ⅱ, stage Ⅲa, stage Ⅲb, stage Ⅳa and stage Ⅳb ( χ2=512.47, P<0.001). Of the 4 049 patients undergoing surgical treatment, there were 2 988 cases(73.796%) with resectable tumor, 177 cases(4.371%) with unresectable tumor and 884 cases(21.833%) with tumor unassessable for resectabi-lity. Of the 2 988 cases with resectable tumor, there were 2 036 cases(68.139%) undergoing radical resection, 504 cases(16.867%) undergoing non-radical resection and 448 cases(14.994%) with operation unassessable for curative effect. Of the 2 447 cases with complete pathological staging data and follow-up data who underwent surgical treatment, there were 53 cases(2.166%) with unresectable tumor, 300 cases(12.260%) with resectable tumor and receiving non-radical resection, 1 441 cases(58.888%) with resectable tumor and receiving radical resection, 653 cases(26.686%) with resectable tumor and receiving operation unassessable for curative effect. There were 733 cases not undergoing surgical treatment with complete pathological staging data and follow-up data. There was a significant difference in the overall survival between cases not undergoing surgical treatment, cases undergoing surgical treatment for unresectable tumor, cases undergoing non-radical resection for resectable tumor and cases undergoing radical resection for resectable tumor ( χ2=121.04, P<0.001). (5) Multimodality therapy and prognosis: of 6 159 patients, there were 541 cases(8.784%) under-going postoperative adjuvant chemotherapy and advanced chemotherapy, 76 cases(1.234%) under-going radiotherapy. There were 1 170 advanced gallbladder cancer (pathological staging ≥stage Ⅲa) patients undergoing radical resection, including 126 cases(10.769%) with post-operative adjuvant chemotherapy and 1 044 cases(89.231%) without postoperative adjuvant chemo-therapy. There was no significant difference in the overall survival between cases with post-operative adjuvant chemotherapy and cases without postoperative adjuvant chemotherapy ( χ2=0.23, P=0.629). There were 658 patients with pathological staging as stage Ⅲa who underwent radical resection, including 66 cases(10.030%) with postoperative adjuvant chemotherapy and 592 cases(89.970%) without postoperative adjuvant chemotherapy. There was no significant difference in the overall survival between cases with postoperative adjuvant chemotherapy and cases without postoperative adjuvant chemotherapy ( χ2=0.05, P=0.817). There were 512 patients with pathological staging ≥stage Ⅲb who underwent radical resection, including 60 cases(11.719%) with postoperative adjuvant chemotherapy and 452 cases(88.281%) without postoperative adjuvant chemotherapy. There was no significant difference in the overall survival between cases with postoperative adjuvant chemo-therapy and cases without post-operative adjuvant chemo-therapy ( χ2=1.50, P=0.220). Conclusions:There are more women than men with gallbladder cancer in China and more than half of patients are diagnosed at the age of 56 to 75 years. Cases undergoing ultrasound, CT, serum CA19-9 examination before initial diagnosis are independent influencing factors influencing initial diagnosis of gallbladder cancer patients. Preoperative resectability evaluation can improve the therapy strategy and patient prognosis. Adjuvant chemotherapy for gallbladder cancer is not standardized and in low proportion in China.

Objective:To investigate the correlation between the SUV index (SUV max of the lesion/SUV mean of the liver) in 18F-FDG PET/CT imaging and the invasiveness of early lung adenocarcinoma presenting as ground-glass nodule (GGN). Methods:From January 2012 to March 2020, 167 GGN patients (49 males, 118 females; age: (61.5±9.0) years) with early lung adenocarcinoma who underwent PET/CT imaging in Changzhou First People′s Hospital were retrospectively enrolled. The image parameters including the GGN number, location, type, edge, shape, abnormal bronchus sign, vacuole sign, pleural depression, vessel convergence sign, GGN diameter ( DGGN), solid component diameter ( Dsolid), consolidation to tumor ratio (CTR, Dsolid/ DGGN), CT values (CT value of ground-glass opacity (CT GGO), CT value of lung parenchyma (CT LP), ΔCT GGO-LP (CT GGO-CT LP)) and SUV index were analyzed. Single and multivariate logistic regressions were used to analyze the correlation between SUV index and infiltration. The generalized additive model was used for curve fitting, and the piece-wise regression model was used to further explain the nonlinearity. Results:In 189 GGNs, invasive adenocarcinoma accounted for 85.2% (161/189). Single logistic regression showed that the GGN number, type, shape, edge, abnormal bronchus sign, pleural depression, vessel convergence sign, DGGN, Dsolid, CTR, CT GGO, ΔCT GGO-LP and SUV index were related factors of infiltration (odds ratio ( OR) values: 0.396-224.083, P<0.001 or P<0.05). After fully adjusting for confounding factors, SUV index was significantly correlated with increased risk of invasion ( OR=2.162 (95% CI: 1.191-3.923), P=0.011). Curve fitting showed that the SUV index was non-linearly related to the risk of infiltration, and the risk of infiltration increased significantly only when the SUV index was greater than 0.43 ( OR=3.509 (95% CI: 1.429-8.620), P=0.006). The correlation between SUV index and infiltration had no interaction between age, vacuoles, pleural depression and CTR subgroups (all P>0.05). Conclusions:SUV index is an independent factor related to the invasiveness of early lung adenocarcinoma. The higher the SUV index, the greater the risk of invasion; but the two are not simply linearly correlated.

Objective:To compare the effects of five different types of videolaryngoscopes in patients with a simulated difficult airway.Methods:575 patients who needed endotracheal intubation in Nanjing Hospital Affiliated to Nanjing Medical University from May 2021 to September 2021 were randomly divided into 5 groups [UE videolaryngoscope group (U group), GlideScope videolaryngoscope group (G group), C-MAC videolaryngoscope group (C group), Airtraq videolaryngoscope group (A group) and A. P.advance videolaryngoscope group (AP group)], with 115 patients in each group. They all wore cervical collar to simulate difficult airway. The main observation index was the success rate of first endotracheal intubation. Secondary observation indicators included overall success rate, laryngoscope exposure field, intubation time, operator′s subjective score, cause of failure, adverse events, and complications of intubation.Results:The patients′ mouth opening degree was reduced from (46±6)mm to (24±4)mm ( P<0.05) after wearing the cervical collar; The success rate of the first endotracheal intubation were 96%(UE), 92%(C-MAC), 86%(GlideScope), 85%(Airtraq), and 60%(AP.Advance) respectively, with statistically significant difference ( P<0.05); Compared with AP group and G group, the incidence of soft tissue injury or bleeding in U group and C group were lower ( P<0.05); There were significant difference in the overall success rate of videolaryngoscopes, laryngoscope visual field exposure, intubation time, the subjective score of the operator and adverse events ( P<0.05); There was no significant difference in the complications of intubation among the groups ( P>0.05). Conclusions:Among 575 patients with a simulated difficult airway with limited neck mobility and limited mouth opening, there were significant differences in the use of five videolaryngoscopes. Among them, UE video laryngoscope had the highest first intubation success rate and lowest tissue trauma rate, C-MAC video laryngoscope, GlideScope video laryngoscope and Airtraq video laryngoscope followed in performance, while A. P.Advance video laryngoscope performed the worst.

Objective:To analyze the clinical characteristics of patients infected with 2019-nCoV Omicron variants BA.1 and BA.2 in Zhuhai city.Methods:A retrospective study was conducted to compare clinical characteristics of patients infected with 2019-nCoV Omicron variants BA.1 and BA.2, who were admitted in the Fifth Affiliated Hospital of Sun Yat-sen University during January 13 to March 8 2022. The Mann-Whitney U-test or Kruskal-Wallis H test was used for quantitative data, and the χ2 test or Fisher’s exact test was used for qualitative data. Results:Among 122 patients infected with the Omicron variant, there was 79 adults (BA.1 23 cases, BA.2 56 cases) and 43 children (BA.1 19 cases, BA.2 24 cases). In adults, patients infected with BA.2 sub-variant had a higher baseline viral loads at admission than BA.1 infected patients [7.64(6.92, 8.55) lg copies/mL vs. 6.64(6.04, 7.34) lg copies/mL; Z=-3.022, P=0.003]; compared to BA.1 patients, BA.2 patients had a higher proportion of mild and asymptomatic cases and a lower proportion of common infection cases ( χ2=8.052, P=0.012); the proportion of patients with pneumonia imaging changes in BA.1 patients was higher than that in BA.2 infected patients [(6/23, 26.1%) vs. (2/56, 3.6%); χ2=6.776, P=0.009). In children, the rate of fever in BA.2 group was higher than that in BA.1 group [(16/24, 66.7%) vs. ( 5/19, 26.3%); χ2=6.910, P=0.009); the proportion of patients with reduced lymphocyte counts in BA.2 group was higher than that in BA.1 group [(17/24, 70.8%) vs.(1/19, 5.3%); χ2=18.734, P<0.001). Compared with adult cases, children with BA.2 sub-variant infection had higher fever rate [(16/24, 66.7%) vs. (19/56, 33.9%); χ2=7.317, P=0.007). The viral loads of daily nasal swabs in BA.2 infected patients increased first and then decreased in both adults and children, with a greater decrease than BA.1 during the first two weeks. Conclusions:Compare with 2019-nCoV Omicron variant BA.1, BA.2 has a higher baseline viral loads in adults, which means much more contagious in the early stages. But the viral load drops faster in BA.2 infected patients. In children, BA.2 patients are more likely to have fever and reduced lymphocyte counts, which indicates that the prevention and control of 2019-nCoV Omicron sub-variant BA.2 is more difficult.