Objective:To investigate the effects of Vibrio vulnificus ( Vv) quorum-sensing protein LuxS on the homeostasis of pulmonary innate immune cells in sepsis-induced acute lung injury. Methods:This study constructed luxS knockout and complemented Vv strains. The time required for wild type, luxS knockout, and complemented Vv strains to grow to an absorbance of 600 nm in liquid medium was measured using a spectrophotometer. Iron-overloaded mice were intraperitoneally infected with 1×10 5 CFU of the above three kinds of Vv strains, respectively. Clinical scoring for sepsis-induced dyspnea was used to evaluate the respiratory quality in mice. At 7 h after infection, the pathological changes in lung tissues were observed by HE staining; the bacterial loads in lung tissues were measured; the single-cell suspension of lung tissues was analyzed by flow cytometry. Uniform manifold approximation and projection (UMAP) was used to reduce the dimension of the distribution of CD45 + immune cells in lung tissues of mice in the PBS control group and infection groups with different strains. The frequency and absolute number of innate immune cells in lung tissues were analyzed by multicolor flow cytometry. One-way analysis of variance and t test were used for statistical analysis. Results:There was no significant difference in the growth rate of wild type, luxS knockout, and complemented Vv strains in liquid medium. Compared with the mice infected with the wild type or complemented strain, the mice infected with the luxS knockout strain exhibited overall alleviated respiratory difficulty, decreased inflammatory cell infiltration in lung tissues, and reduced bacterial load in lung tissues ( P<0.05). Besides, there was no significant difference in clinical respiratory scores, inflammatory cell infiltration, or bacterial loads between the mice infected with the complemented strain and wild type strain. UMAP analysis showed that compared with the mice infected with the luxS knockout strain, the mice infected with the wild type or complemented strain showed increased proportions of neutrophils and eosinophils in lung tissues. Results of multicolor flow cytometry analysis further verified that the proportions of neutrophils and eosinophils were significantly lower in the mice infected with the luxS knockout strain than in the mice infected with wild type or complemented strain ( P<0.01, P<0.000 1), while the proportion of alveolar macrophages was significantly higher as compared with that in the mice infected with wild type or complemented strain ( P<0.01). Conclusion:During Vv infection, LuxS may promote acute lung injury by affecting the homeostasis of neutrophils, eosinophils and resident macrophages in lung tissues.

Objective:To investigate the role of autophagy in the regulatory of phagocytosis in Vibrio vulnificus ( V. vulnificus)-infected murine macrophages. Methods:The expression of cellular autophagy-related proteins in PBS-treated and V. vulnificus-infected RAW264.7 and BMMφ cells was detected by Western blot. The co-localization of V. vulnificus-GFP and LC3Ⅱ protein in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells were detected using confocal microscopy. The phagocytosis of V. vulnificus in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells with or without autophagy inhibition using Bafilomycin A1 was detected by flow cytometry. Results:The up-regulated levels of Atg7, Atg12 and Atg16L1 proteins, increased LC3Ⅱ/actin ratio, as well as down-regulated p62 protein levels were significantly detected in V. vulnificus-infected RAW264.7 and BMMφ cells. The co-localization of V. vulnificus-GFP and LC3Ⅱ protein was clearly observed in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells. Enhanced phagocytosis of V. vulnificus and increased autophagy were exhibited in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells, while weakened phagocytosis, accumulation of Atg7, Atg12, Atg16L1, LC3Ⅱ and p62 protein levels, as well as blocking autophagy flux were detected in those cells within autophagy inhibition using Bafilomycin A1. Conclusion:Autophagy induced by V. vulnificus infection could promote phagocytosis of V. vulnificus in macrophages.

Objective:To investigate the effects of Vibrio vulnificus ( Vv) quorum-sensing protein LuxS on the homeostasis of pulmonary innate immune cells in sepsis-induced acute lung injury. Methods:This study constructed luxS knockout and complemented Vv strains. The time required for wild type, luxS knockout, and complemented Vv strains to grow to an absorbance of 600 nm in liquid medium was measured using a spectrophotometer. Iron-overloaded mice were intraperitoneally infected with 1×10 5 CFU of the above three kinds of Vv strains, respectively. Clinical scoring for sepsis-induced dyspnea was used to evaluate the respiratory quality in mice. At 7 h after infection, the pathological changes in lung tissues were observed by HE staining; the bacterial loads in lung tissues were measured; the single-cell suspension of lung tissues was analyzed by flow cytometry. Uniform manifold approximation and projection (UMAP) was used to reduce the dimension of the distribution of CD45 + immune cells in lung tissues of mice in the PBS control group and infection groups with different strains. The frequency and absolute number of innate immune cells in lung tissues were analyzed by multicolor flow cytometry. One-way analysis of variance and t test were used for statistical analysis. Results:There was no significant difference in the growth rate of wild type, luxS knockout, and complemented Vv strains in liquid medium. Compared with the mice infected with the wild type or complemented strain, the mice infected with the luxS knockout strain exhibited overall alleviated respiratory difficulty, decreased inflammatory cell infiltration in lung tissues, and reduced bacterial load in lung tissues ( P<0.05). Besides, there was no significant difference in clinical respiratory scores, inflammatory cell infiltration, or bacterial loads between the mice infected with the complemented strain and wild type strain. UMAP analysis showed that compared with the mice infected with the luxS knockout strain, the mice infected with the wild type or complemented strain showed increased proportions of neutrophils and eosinophils in lung tissues. Results of multicolor flow cytometry analysis further verified that the proportions of neutrophils and eosinophils were significantly lower in the mice infected with the luxS knockout strain than in the mice infected with wild type or complemented strain ( P<0.01, P<0.000 1), while the proportion of alveolar macrophages was significantly higher as compared with that in the mice infected with wild type or complemented strain ( P<0.01). Conclusion:During Vv infection, LuxS may promote acute lung injury by affecting the homeostasis of neutrophils, eosinophils and resident macrophages in lung tissues.

Objective:To investigate the role of autophagy in the regulatory of phagocytosis in Vibrio vulnificus ( V. vulnificus)-infected murine macrophages. Methods:The expression of cellular autophagy-related proteins in PBS-treated and V. vulnificus-infected RAW264.7 and BMMφ cells was detected by Western blot. The co-localization of V. vulnificus-GFP and LC3Ⅱ protein in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells were detected using confocal microscopy. The phagocytosis of V. vulnificus in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells with or without autophagy inhibition using Bafilomycin A1 was detected by flow cytometry. Results:The up-regulated levels of Atg7, Atg12 and Atg16L1 proteins, increased LC3Ⅱ/actin ratio, as well as down-regulated p62 protein levels were significantly detected in V. vulnificus-infected RAW264.7 and BMMφ cells. The co-localization of V. vulnificus-GFP and LC3Ⅱ protein was clearly observed in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells. Enhanced phagocytosis of V. vulnificus and increased autophagy were exhibited in V. vulnificus-GFP-infected RAW264.7 and BMMφ cells, while weakened phagocytosis, accumulation of Atg7, Atg12, Atg16L1, LC3Ⅱ and p62 protein levels, as well as blocking autophagy flux were detected in those cells within autophagy inhibition using Bafilomycin A1. Conclusion:Autophagy induced by V. vulnificus infection could promote phagocytosis of V. vulnificus in macrophages.

Objective:To investigate the role of an inflammatory microenvironment induced by Porphyromonasgingivalis ( P. gingivalis) in the occurrence of esophageal squamous cell carcinoma (ESCC) in mice. Methods:A total of 180 C57BL/6 mice were randomly divided into 6 groups, i.e. control group, P. gingivalis group, 4NQO group, 4NQO + P. gingivalis group, 4NQO + P. gingivalis + celecoxib group, and 4NQO + P. gingivalis + antibiotic cocktail (ABC, including metronidazole, neomycin, ampicillin, and vancomycin) group, with 30 mice in each group, using the random number table. All mice were normalized by treatment with ABC in drinking water for 2 weeks. In the following 2 weeks, the mice in the control group and the P. gingivalis group were given drinking water, while the other 4 groups were treated with 30 μg/ml 4NQO in the drinking water. In weeks 11-12, the mice in the P. gingivalis group, the 4NQO + P. gingivalis group, the 4NQO + P. gingivalis + celecoxib group, and the 4NQO + P. gingivalis + ABC group were subjected to ligation of the second molar in oral cavity followed by oral P. gingivalis infection thrice weekly for 24 weeks in weeks 11-34. In weeks 13-34, the mice in 4NQO + P. gingivalis+celecoxib group and 4NQO + P. gingivalis + ABC group were administered with celecoxib and ABC for 22 weeks, respectively. At the end of 34 weeks, gross and microscopic alterations were examined followed by RT-qPCR and immunohistochemistry to examine the expression profiles of inflammatory- and tumor-molecules in esophagi of mice. Results:At 34 weeks, 4NQO treatment alone did not affect the foci of papillary hyperproliferation, diseased area, and the thickness of the esophageal wall, but significantly enhanced the foci of hyperproliferation (median 1.00, P＜0.05) and mild/moderate dysplasia (median 2.00, P＜0.01). In addition, the expression levels of IL-6 [8.35(3.45,8.99)], IL-1β [6.90(2.01,9.72)], TNF-α [12.04(3.31,14.08)], c-myc [2.21(1.80,3.04)], pSTAT3, Ki-67, and pH2AX were higher than those in the control group. The pathological changes of the esophageal mucosa were significantly more overt in the 4NQO + P. gingivalis group in terms of the foci of papillary hyperproliferation (median 2.00), diseased area (median 2.51 mm 2), the thickness of the esophageal wall (median 172.52 μm), the foci of hyperproliferation (median 1.00, P＜0.05), and mild/moderate dysplasia (median 1.00, P＜0.01). In mice of the 4NQO + P. gingivalis group, the expression levels of IL-6 [12.27(5.35,22.08)], IL-1β [13.89(10.04,15.96)], TNF-α [19.56(6.07,20.36)], IFN-γ [11.37(8.23,20.07)], c-myc [2.62(1.51,4.25)], cyclin D1 [4.52(2.68,7.83)], nuclear pSTAT3, COX-2, Ki-67, and pH2AX were significantly increased compared with the mice in the control group. In mice of the 4NQO + P. gingivalis group, the diseased area, invasive malignant foci as well as pSTAT3 and pH2AX expression were significantly blunted by celecoxib. Treatment with ABC markedly reduced the papillary hyperproliferative foci, invasive malignant foci, and pSTAT3 expression but not pH2AX. Conclusions:P. gingivalis promotes the occurrence of esophageal squamous cell carcinoma in mice by inducing an inflammatory microenvironment primed with 4NQO induced DNA damage. Clearance of P. gingivalis with ABC or anti-inflammatory intervention holds promise for prevention of esophageal squamous cell malignant pathogenesis via blockage of IL-6/STAT3 signaling and amelioration of inflammation.

Objective:To investigate the role of an inflammatory microenvironment induced by Porphyromonasgingivalis ( P. gingivalis) in the occurrence of esophageal squamous cell carcinoma (ESCC) in mice. Methods:A total of 180 C57BL/6 mice were randomly divided into 6 groups, i.e. control group, P. gingivalis group, 4NQO group, 4NQO + P. gingivalis group, 4NQO + P. gingivalis + celecoxib group, and 4NQO + P. gingivalis + antibiotic cocktail (ABC, including metronidazole, neomycin, ampicillin, and vancomycin) group, with 30 mice in each group, using the random number table. All mice were normalized by treatment with ABC in drinking water for 2 weeks. In the following 2 weeks, the mice in the control group and the P. gingivalis group were given drinking water, while the other 4 groups were treated with 30 μg/ml 4NQO in the drinking water. In weeks 11-12, the mice in the P. gingivalis group, the 4NQO + P. gingivalis group, the 4NQO + P. gingivalis + celecoxib group, and the 4NQO + P. gingivalis + ABC group were subjected to ligation of the second molar in oral cavity followed by oral P. gingivalis infection thrice weekly for 24 weeks in weeks 11-34. In weeks 13-34, the mice in 4NQO + P. gingivalis+celecoxib group and 4NQO + P. gingivalis + ABC group were administered with celecoxib and ABC for 22 weeks, respectively. At the end of 34 weeks, gross and microscopic alterations were examined followed by RT-qPCR and immunohistochemistry to examine the expression profiles of inflammatory- and tumor-molecules in esophagi of mice. Results:At 34 weeks, 4NQO treatment alone did not affect the foci of papillary hyperproliferation, diseased area, and the thickness of the esophageal wall, but significantly enhanced the foci of hyperproliferation (median 1.00, P＜0.05) and mild/moderate dysplasia (median 2.00, P＜0.01). In addition, the expression levels of IL-6 [8.35(3.45,8.99)], IL-1β [6.90(2.01,9.72)], TNF-α [12.04(3.31,14.08)], c-myc [2.21(1.80,3.04)], pSTAT3, Ki-67, and pH2AX were higher than those in the control group. The pathological changes of the esophageal mucosa were significantly more overt in the 4NQO + P. gingivalis group in terms of the foci of papillary hyperproliferation (median 2.00), diseased area (median 2.51 mm 2), the thickness of the esophageal wall (median 172.52 μm), the foci of hyperproliferation (median 1.00, P＜0.05), and mild/moderate dysplasia (median 1.00, P＜0.01). In mice of the 4NQO + P. gingivalis group, the expression levels of IL-6 [12.27(5.35,22.08)], IL-1β [13.89(10.04,15.96)], TNF-α [19.56(6.07,20.36)], IFN-γ [11.37(8.23,20.07)], c-myc [2.62(1.51,4.25)], cyclin D1 [4.52(2.68,7.83)], nuclear pSTAT3, COX-2, Ki-67, and pH2AX were significantly increased compared with the mice in the control group. In mice of the 4NQO + P. gingivalis group, the diseased area, invasive malignant foci as well as pSTAT3 and pH2AX expression were significantly blunted by celecoxib. Treatment with ABC markedly reduced the papillary hyperproliferative foci, invasive malignant foci, and pSTAT3 expression but not pH2AX. Conclusions:P. gingivalis promotes the occurrence of esophageal squamous cell carcinoma in mice by inducing an inflammatory microenvironment primed with 4NQO induced DNA damage. Clearance of P. gingivalis with ABC or anti-inflammatory intervention holds promise for prevention of esophageal squamous cell malignant pathogenesis via blockage of IL-6/STAT3 signaling and amelioration of inflammation.

Objective To summarize the successful experience of extracorporeal membrane oxygenation (ECMO) combined with inhaled nitric oxide (iNO) in the treatment of severe acute respiratory distress syndrome (ARDS) after empyema surgery in a morbid obesity patient,and to explore the nursing points. Methods On July 3,2023,a patient was admitted to the department of intensive care unit (ICU) of Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences),Southern Medical University following the failure of closed thoracic drainage and catheterization at another hospital. Using the rapid integration of the WeChat group,a multidisciplinary team (MDT) model was built. This approach enabled the professional and standardized integration of clinical data and the implementation of targeted treatments,significantly reducing response times and optimizing the overall nursing process. Results A 27-year-old male patient with morbid obesity was admitted to the hospital due to dyspnea and chest pain for more than 7 days. ① Treatment process:on July 4,the patient underwent video-assisted thoracic surgery (VATS),including right chest exploration,pleural adhesion release,and empyema,performed under general anesthesia. Two thoracic drainage tubes were retained and water-sealed bottles were connected. The drainage fluid was purulent. After the operation,the patient was short of breath and the condition was aggravated and transferred to ICU. On admission,the patient's bedside chest X-ray showed that more moist rales were heard in both lungs,especially on the right side. At 18:30 on July 10,the pluse oxygen saturation (SpO2) was 0.75-0.80,and fiberoptic bronchoscopy was performed immediately. The ventilator parameters were up-regulated,the position was changed,and 20 mg of furosemide injection was injected intravenously,the effect was not good. Attempted to perform prone position ventilation,SpO2 did not improve. At 21:30,the SpO2 gradually decreased to 0.60,and the extracorporeal circulation was immediately decided. After veno-venous ECMO (VV-ECMO) at 2:30 on July 11,the SpO2 was 0.90,and the blood gas was stable after multiple reexaminations. During July 12,there was still shortness of breath and poor oxygenation index. According to the MDT consultation opinion,during the emergency treatment combined with iNO treatment,oxygenation improved rapidly to 172 mmHg (1 mmHg≈0.133 kPa) and 190 mmHg after 1 hour and 2 hours,respectively. After 6 days,the oxygenation index stabilized between 222-285 mmHg. On July 17,the iNO support was gradually reduced and successfully removed. On July 21,a chest X-ray showed that the patient's lung lesions were significantly improved,and ECMO support parameters were gradually reduced until ECMO treatment was successfully discontinued. On August 3,the patient's consciousness returned to normal,and the indicators returned to normal. The ventilator-assisted breathing was stopped,and the high-flow oxygen therapy was observed after extubation. He was transferred from the ICU on August 8 and was discharged on August 15. ② Nursing points:we focus on personalized analgesia and sedation,and adjust the types and doses of sedative drugs in stages to reduce oxygen consumption and reduce complications. For the treatment of ARDS with ECMO combined with iNO to improve oxygenation,close monitoring and supportive care were carried out. Special attention was paid to the fixation of ECMO pipeline and tracheal intubation in patients with morbid obesity and individualized fine skin care was implemented. Actively prevent the potential complications of ICU acquired myasthenia,and carry out phased psychological nursing to establish rehabilitation confidence. Conclusion ECMO combined with iNO treatment requires professional teamwork,close observation,effective nursing and perfect monitoring technology to ensure the safety of patients with severe ARDS morbid obesity,reduce complications and improve prognosis,which has important reference significance for relevant medical practice.

Objective To summarize the successful experience of extracorporeal membrane oxygenation (ECMO) combined with inhaled nitric oxide (iNO) in the treatment of severe acute respiratory distress syndrome (ARDS) after empyema surgery in a morbid obesity patient,and to explore the nursing points. Methods On July 3,2023,a patient was admitted to the department of intensive care unit (ICU) of Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences),Southern Medical University following the failure of closed thoracic drainage and catheterization at another hospital. Using the rapid integration of the WeChat group,a multidisciplinary team (MDT) model was built. This approach enabled the professional and standardized integration of clinical data and the implementation of targeted treatments,significantly reducing response times and optimizing the overall nursing process. Results A 27-year-old male patient with morbid obesity was admitted to the hospital due to dyspnea and chest pain for more than 7 days. ① Treatment process:on July 4,the patient underwent video-assisted thoracic surgery (VATS),including right chest exploration,pleural adhesion release,and empyema,performed under general anesthesia. Two thoracic drainage tubes were retained and water-sealed bottles were connected. The drainage fluid was purulent. After the operation,the patient was short of breath and the condition was aggravated and transferred to ICU. On admission,the patient's bedside chest X-ray showed that more moist rales were heard in both lungs,especially on the right side. At 18:30 on July 10,the pluse oxygen saturation (SpO2) was 0.75-0.80,and fiberoptic bronchoscopy was performed immediately. The ventilator parameters were up-regulated,the position was changed,and 20 mg of furosemide injection was injected intravenously,the effect was not good. Attempted to perform prone position ventilation,SpO2 did not improve. At 21:30,the SpO2 gradually decreased to 0.60,and the extracorporeal circulation was immediately decided. After veno-venous ECMO (VV-ECMO) at 2:30 on July 11,the SpO2 was 0.90,and the blood gas was stable after multiple reexaminations. During July 12,there was still shortness of breath and poor oxygenation index. According to the MDT consultation opinion,during the emergency treatment combined with iNO treatment,oxygenation improved rapidly to 172 mmHg (1 mmHg≈0.133 kPa) and 190 mmHg after 1 hour and 2 hours,respectively. After 6 days,the oxygenation index stabilized between 222-285 mmHg. On July 17,the iNO support was gradually reduced and successfully removed. On July 21,a chest X-ray showed that the patient's lung lesions were significantly improved,and ECMO support parameters were gradually reduced until ECMO treatment was successfully discontinued. On August 3,the patient's consciousness returned to normal,and the indicators returned to normal. The ventilator-assisted breathing was stopped,and the high-flow oxygen therapy was observed after extubation. He was transferred from the ICU on August 8 and was discharged on August 15. ② Nursing points:we focus on personalized analgesia and sedation,and adjust the types and doses of sedative drugs in stages to reduce oxygen consumption and reduce complications. For the treatment of ARDS with ECMO combined with iNO to improve oxygenation,close monitoring and supportive care were carried out. Special attention was paid to the fixation of ECMO pipeline and tracheal intubation in patients with morbid obesity and individualized fine skin care was implemented. Actively prevent the potential complications of ICU acquired myasthenia,and carry out phased psychological nursing to establish rehabilitation confidence. Conclusion ECMO combined with iNO treatment requires professional teamwork,close observation,effective nursing and perfect monitoring technology to ensure the safety of patients with severe ARDS morbid obesity,reduce complications and improve prognosis,which has important reference significance for relevant medical practice.

Objective:To investigate the effects of Porphyromonas gingivalis ( P. gingivalis) fimbrillin (FimA) on the progression of esophageal squamous cell carcinoma (ESCC). Methods:Wild-type P. gingivalis and fimA gene-deleted P. gingivalis ( fimA-/-P. gingivalis) were used to infect ESCC cells after morphology and PCR identification. Immunofluorescence, CCK-8 and Transwell chamber were used to detect the effects of FimA on the infectivity of P. gingivalis and it influences on cell invasion, proliferation and migration. Western blot was used to detect pSmad2/3 changes. The growth of tumor was detected in a nude mouse model bearing subcutaneous tumor. Results:Deletion of FimA might reduce the interbacterial adhesion of P. gingivalis. Compared with wild-type P. gingivalis, less fimA-/-P. gingivalis could infect NE6-T cells. Moreover, the proliferation, migration and invasion of NE6-T and KYSE30 cells as well as the activation of pSmad2/3 induced by P. gingivalis were inhibited after deletion of FimA. The growth of KYSE30 infected by fimA-/-P. gingivalis in nude mice was significantly slower than that of the wild-type P. gingivalis group. Conclusions:FimA mediated the effects of P. gingivalis on promoting the evolution of ESCC and was a potential target molecule to block the tumor-promoting effect of P. gingivalis.

Objective:To explore the effects of external diaphragm electrical stimulation on the diaphragm thickness and function in mechanically ventilated children.Methods:A randomized controlled trial was conducted in children who were admitted to PICU at Children′s Hospital of Fudan University and received mechanical ventilation between June 2021 and April 2022.The control group was given the routine treatment of mechanical ventilation, and the intervention group was given external diaphragm electrical stimulation in the early stage of mechanical ventilation in addition to routine treatment.Diaphragm thickness was continuously measured by bedside ultrasound every day for one week after mechanical ventilation, and the changing trend of diaphragm thickness was observed, and the diaphragmatic thickening fraction (DTf) and the incidence of ventilator-induced diaphragmtic dysfunction(VIDD) were calculated at the same time.Results:A total of 32 valid samples were included, including 15 cases in intervention group (10 males) and 17 cases in control group (11 males). The median age of the patients was 33 (10, 77) months, and the median duration of mechanical ventilation was 12 (8, 21) days.The reasons for mechanical ventilation in children included respiratory insufficiency in ten cases, brain dysfunction in ten cases, heart failure in eight cases, and postoperative surgery in four cases.The diaphragm end-expiratory thickness (DTe) in intervention group and the control group showed a gradually decreasing trend from the 1st day to the 7th day.The left thickness was reduced by 11% on the 7th day compared to 1st day in intervention group, which was reduced by 18% in control group; the average daily DTe was reduced by 2% per day in intervention group and by 3% per day in control group.The trends on the right and left were similar.The DTe thickness in the intervention group was greater than that in control group, among which, the mean DTe thickness in the left side of the intervention group on the 7th day was (0.110 7±0.023 7)cm, which was greater than that in control group (0.093 5±0.016 9)cm, and the difference was statistically significant ( t=-2.372, P<0.05); On the second day, the mean DTe thickness on the right side in the intervention group was (0.1267±0.0277) cm, which was greater than that in control group (0.104 7±0.018 1)cm, and the difference was statistically significant ( t=-2.688, P<0.05). DTf in the intervention group was lower than that in control group at 7th day, but the difference was not statistically significant(left DTf: adjusted mean difference was -0.117, P=0.088; right DTf: adjusted mean difference was -0.065, P=0.277). The incidence of VIDD in the intervention group was lower than that in control group(33.3% vs.41.2%), but the difference was not statistically significant ( χ2=0.005, P=0.946). Conclusion:External diaphragmatic electrical stimulation may be helpful for alleviating diaphragmatic atrophy in mechanically ventilated children.However, whether the improvement of diaphragm atrophy is beneficial to clinical outcome still needs further study.