Viral sepsis is an often neglected heterogeneous form of sepsis，which can be caused by a variety of viruses.Infants and young children are at high risk of viral sepsis，which is related to their relatively low immunity.Viral sepsis is different from bacterial infection in terms of pathogenesis，clinical phenotype,and treatment strategy.Effective elimination of virus and immune regulation according to different immune types may be beneficial to improve the prognosis.

The heterogeneity of sepsis plays critical roles in determining the response of clinical intervention and the outcome of sepsis.Based on the host-response revealed from multiomics,the new idea of the endotype of sepsis was revealed from multiple perspectives,such as transcriptome,proteome,epigenome,and exosome signature spectrum,etc.In recent years,in the field of sepsis endotype,the research of clinical subtype,metabolic subtype,and immune subtype is booming.This concept has gradually penetrated into multiple aspects,including the diagnosis,severity assessment,patients screening for clinical research,and the reference for individualized clinical treatment.It brings a new perspective for clinical individualized treatment of sepsis.

Sepsis is dysregulated host response caused by infection leading to systemic inflammation and organ dysfunction.Hemophagocytic lymphohistiocytosis（HLH）could be caused by multiple factors，leading to abnormal immune regulation and resulting in inflammatory storm and organ dysfunction.Their pathogenesis is similar that dysregulated strong inflammatory response developing in the body，but different in activation profiles of immunologic cells and cytokines.Sepsis is caused by infection，while the etiology of HLH includes various conditions such as genetic defects，infection，rheumatic disease，malignancies，etc.There are differences in the degree of inflammation between the two diseases，with sepsis being systemic inflammation and HLH being extremely strong hyperinflammation.Anti-infection is the key to the treatment of sepsis，while immunosupressive measures are essential for HLH except for etiological treatment.Besides shock，central nervous system involvement is significant cause of death，and neuromonitoring should be applied aggressively.

As one of the important causes of death in critically ill patients，septic shock has always been the focus of research in the field of critical care medicine.Correct and rational use of vasoactive drug is an important treatment for septic shock.The hemodynamic changes of septic shock in children and adults are different，which lead to the different use of vasoactive drugs.This review summarized the similarities and differences of the application of vasoactive drugs between children and adults with septic shock，thus could provide a reference for clinical practice.

Sepsis-induced thrombocytopenia-associated multiple organ failure（TAMOF）is a severe subtype of sepsis-related organ dysfunctions，which has high mortality and poor prognosis.The main clinical characteristics are thrombocytopenia caused by infection and multiple organ dysfunction.However，the exact molecular mechanism of TAMOF remains unclear.The current studies have shown ADAMTS-13，which is a von Willebrand factor lyase，plays an important role during the disease.Plasma exchange could be a treatment method，but still need more large-scale randomized controlled trials to verify.In the future，von Willebrand factor and ADAMTS-13 could become the therapeutic targets for new drug development.

Objective:To explore the distribution characteristics and antibiotic resistance of pathogen in children with hematological disorders and cancers complicated with sepsis in pediatric intensive care unit (PICU).Methods:The clinical data of children with hematological disorders and cancers complicated with sepsis hospitalized at Shenzhen Children′s Hospital affiliated to China Medical University from January 2016 to August 2023 were retrospectively analyzed. Patients were divided into survival group and death group based on the outcome of sepsis on 28 days after diagnosis.Results:A total of 202 sepsis episodes occurred in 176 children were enrolled in this study. Among all, 144 (71.3%) cases of bloodstream infection, 59 (29.2%) cases of pulmonary infection, 21 (10.4%) cases of abdominal infection, 9 (4.5%) cases of soft tissue infection, 9 (4.5%) cases of nervous system infection, and 3 (1.5%) cases of urinary tract infection. A total of 244 pathogenic strains were identified, in which 74 (30.3%) cases were gram-positive bacteria. The top 3 pathogens isolated were Coagulase negative Staphylococcus (21 strains), Staphylococcus aureus (19 strains) and Streptococcus pneumoniae (13 strains). Gram-negative bacteria accounted for 122 (50.0%) strains, in which top 3 were Klebsiella pneumonia (33 strains), Escherichia coli (25 strains), and Pseudomonas aeruginosa (23 strains). Fungi comprised 48 (19.7%) strains:the top 3 were Candida tropicalis (14 strains), Candida albicans (10 strains), Aspergillus and Pneumocystis jirovecii (7 strains each). The incidence of Acinetobacter baumannii, Stenotrophomonas maltophilia, and Pseudomonas aeruginosa were significantly higher in death group compared to survival group[9.0%（6/67）vs. 2.3%（4/177）, χ2＝3.971 ，P＝0.046; 9.0%（6/67）vs. 1.1%（2/177）, χ2＝7.080 ，P＝0.008;16.4%（11/67）vs. 6.8%（12/177）, χ2＝5.288 ，P＝0.021]. The samples of 57 cases were simultaneously detected by both culture and metagenomic next-generation sequencing (mNGS). Pathogens were detected in 25 cases by both culture and mNGS. In 30 cases, pathogen detection were mNGS positive but culture negative. Two cases showed positive results only with culture. A total of 79 (46.8%) strains were multi-drug resistant bacteria, including 27 (34.2%) strains of gram-positive bacteria and 52 (65.8%) strains of gram-negative bacteria. A total of 174 (86.1%) children with sepsis received empirical anti-infective drugs within 24 hours of fever onset. A total of 124 (61.4%) cases were appropriately covered by the initial empirical antibiotics, while 40 (19.8%) cases were not adequately covered and 10 (5.0%) cases had incomplete coverage. Despite the inclusion of pathogenic in the coverage, resistance to initial antibiotics was observed in 22 (10.9%) cases. Fifty-one patients died. Conclusion:The predominant pathogens responsible for sepsis in PICU with hematological disorders and cancers is gram-negative bacteria, followed by gram-positive bacteria and fungi. In comparison to healthy children with sepsis, there is a higher incidence of fungal infections among hematological disorders and cancers. The proportion of multi-drug resistant bacteria infection is high. Early identification and combination of local etiological distribution and drug resistance, along with the empirical selection of appropriate anti-infection treatment strategies, can greatly enhance survival rate.

Objective:To evaluate the diagnostic value of intestinal regional oxygen saturation（rSO 2）and fecal calprotectin in the occurrence and severity of necrotizing enterocolitis（NEC）in premature infants. Methods:A prospective observational study was conducted among premature infants admitted to Quanzhou Children's Hospital from October 2019 to December 2022. Intestinal rSO 2 was monitored within two hours of diagnosis of NEC，and fecal calprotectin was measured. Results:A total of 60 patients were included, including 30 cases with NEC and 30 cases without NEC, 14 cases of medical NEC, 16 cases of surgical NEC, and eight infants died due to NEC. Infants with NEC had lower intestinal rSO 2 [49（30，60）% vs. 66（60，69）%] and higher calprotectin levels [479（297，886）μg/g vs. 203（113，275）μg/g] than those in infants without NEC ( P<0.01). The levels of intestinal rSO 2 were lower in surgical NEC than those in medical NEC，and were lower in the death group than that in the survival group ( P<0.01)，but no similar difference was found in the levels of calprotectin. ROC curve analysis showed that intestinal rSO 2 combined with calprotectin had a sensitivity of 73%，a specificity of 100%，and the largest area under curve of 0.91 in the diagnosis of NEC. Intestinal rSO 2 had an optimal cut-off value of 31% in predicting death in infants with NEC，with a sensitivity of 100%，a specificity of 95%，and an area under curve of 0.99. Conclusion:Intestinal rSO 2 and fecal calprotectin can effectively identify the presence of NEC，and their combined detection can improve the diagnostic efficiency. Intestinal rSO 2 is a good predictor of the severity of NEC，but not fecal calprotectin.

Objective:To analyze the clinical characteristics of eosinophilic gastroenteritis in children under 6 years old.Methods:The clinical data，laboratory examinations，imaging examinations，gastrointestinal endoscopy，histopathology，treatment，and prognosis of patients under 6 years old with eosinophilic gastroenteritis who were hospitalized in the Department of Gastroenterology，Beijing Children's Hospital from January 1，2016 to December 31，2022 were collected and analyzed.Results:A total of 31 children under 6 years of age with eosinophilic gastroenteritis were enrolled in the study,including 14 cases≤3 years old and 17 cases>3 years old, and 38.71% (12/31) of them had multiple sites involved. The main clinical manifestations were abdominal pain（20/31，64.52%），vomiting（11/31，35.48%），hematochezia（7/31，22.58%），and diarrhea（7/31，22.58%）.The children with eosinophilic duodenitis and eosinophilic colitis were more likely to have abdominal pain, with an incidence of 83.33%(10/12)（ P<0.05）. Eosinophilia increased in 70.97%（22/31）of children，which was more common in children >3 years of age（88.24% vs. 50.00%， P<0.05）.Anemia was seen in 29.03%（9/31）of the patients，and it was more common in children under 3 years of age（50.00% vs. 11.76%， P<0.05）.Hypoalbuminemia was found in 22.58%（7/31）of patients. Specific IgE（sIgE）was positive in 73.33%（22/30）of children. Milk，egg，and wheat were the most common allergens. Gastrointestinal endoscopy showed mucosal edema（29/31，93.55%），erythema（26/31，83.87%），roughness（12/31，38.71%），ulcer（10/31，32.26%），et al.All children were treated with the elimination diet. Besides,10 cases were treated with omeprazole, 16 cases were treated with montelukast, and 17 cases were treated with glucocorticoid. The incidence of relapse or steroid resistance was 32.26%（10/31），and 70.00%（7/10）of them occurred within one year of treatment. Conclusion:Eosinophilic gastroenteritis in children under 6 years of age may involve single or multiple sites.Abdominal pain is the most common clinical manifestation. Children may have elevated peripheral blood eosinophils，anemia，or hypoalbuminemia.Most children have food allergens. Nearly one-third of children experience relapse or steroid resistance.

Objective:To summarize the clinical characteristics and first aid measures of children with drowning，and to provide scientific basis for the treatment and prevention of drowning in children.Methods:The clinical data of drowning children admitted to the Children's Medical Center of the First Affiliated Hospital of Hunan Normal University（Hunan Provincial People's Hospital）from January 2011 to December 2021 were retrospectively summarized. Baseline characteristics，prehospital emergency care and prognosis of the included children were analyzed.According to the time span, drowning children were divided into two stages, the first stage (2011-2016) and the second stage (2017-2021). According to cerebral performance category assessment scale,drowning children with cardiac arrest were divided into two groups: a group with good neurological prognosis and a group with poor neurological prognosis. The baseline characteristics,pre-hospital emergency care, and prognosis of drowning children during different periods and with different prognosis were analyzed.Results:A total of 53 children were enrolled during the study period，with 24 cases in the first phase（2011-2016）and 29 cases in the second phase（2017-2021）.Boys accounted for 73.6%（39/53）of the cases, the age ranged from 1 month and 24 days to 14 years old，with 1-4 years old being the most common，accounting for 58.5%（31/53）, and the season in which drowning occurred was more common in the summer（39.6%, 21/53）.Six cases (11.3%) had significant neurological sequelae, and the mortality rate was 3.8%（2/53）.There was a decrease in the proportion of drowning with water control in the second stage compared to the first stage（37.5% vs. 13.79%, P=0.046）.Thirty-two（60.4%）children experienced on-site cardiopulmonary resuscitation(CPR) after drowning，with 24 cases in the group with good neurological prognosis and 8 cases in the group with poor neurological prognosis.Children in the poor neurological prognosis group required CPR for a long duration [10.00（1.50, 25.00）min]，had lower body temperature，Glasgow Coma Score，pH and higher blood glucose levels on admission（all P < 0.05）. Conclusion:Drowning is most common in preschool children，common in boys，and drowning prevention measures for young children deserve focused attention. Children found to be in cardiac arrest at the time of drowning have a long duration of drowning and CPR，which predicts a poor neurological prognosis，and timely and effective on-site CPR is the key to reducing the drowning rate.

Sepsis is a life-threatening organ dysfunction caused by the host disordered response to infections.As one of the most important innate immune cells in the body，macrophages can maintain the immune homeostasis by recruiting other immune cells，clearing pathogens，presenting antigens，and play important regulatory roles in infectious diseases such as sepsis by releasing inflammatory factors.As a critical neurotransmitter，dopamine not only participates in the neurological processes such as learning and cognition，but also regulates the immune processes，including regulating the activation，proliferation and functional changes of immune cells such as neutrophils，lymphocytes，monocytes and macrophages.Current studies demonstrate that during the infection and inflammation process of sepsis，the phagocytosis，polarization，and release of inflammatory factors of macrophages are regulated by dopamine.This review summarized the recent research progress on the regulatory functions and the underlying mechanisms of dopamine on macrophages in sepsis.