Objective To investigate the effects of hydrogen on post - cardiac arrest brain injury in rabbits.Method Sixty New Zealand rabbits were randomly divided into two groups,namely experiment group ( group A,n =30 ) and control group ( group B,n =30 ).Inhalation of 2％ hydrogen gas was conferred to rabbits immediately at the end of cardiac arrest modeling for 72 hours in the group A. Air instead was given to rabbits in the group B.Blood samples were collected before cardiac arrest (CA),and 4,12,24 and 72 hours after restoration of spontaneous circulation (ROSC) in all rabbits for determining the levels of hydrogen,tumor necrosis factor - α ( TNF - α),neuron - specific enolase (NSE) and protein S100β.At the same time,rectal temperature,mean arterial pressure,heart rate and respiration rate were recorded,and the neurologic deficit scoring (NDS) was carried out.The rate of systemic inflammatory response syndrome ( SIRS ) and the rate of survival of rabbits were analyzed. Results There was no significant difference in level of TNF - α activation between group A and group B within12 h of cardiopulmonary resuscitation (CPR).In group A,TNF - α level and the rate of SIRS peaked at 24 hours after CPR,which were higher than those in group B,and then decreased gradually,and the rate of survival was higher than that in group B in 72 hours after ROSC,the NSE was lower than that in group B at 24 hours after ROSC.In group B,S100β level began to increase significantly 4 hours after CPR,which was higher than that in group A,the level of NDS in group B was higher than that in group A 72 hours after ROSC.Conclusions Inhalation of hydrogen gas lessened inflammation and alleviated the brain injury after CPR.

OBJECTIVE: To study the mechanism of osteopontin (OPN) in viral myocarditis by observing the expression of OPN and collagen I (Col I) in mice myocardium. METHODS: The viral myocarditis models were achieved by infection with myocarditic coxsackievirus B3 (CVB3). The myocardium of mice was stained by HE and Masson staining, and the pathological scores and the collagen volume fraction (CVF )of myocardium were tabulated. The expression of Col I mRNA was measured by RT-PCR. The expression of OPN was detected by RT-PCR and ELISA. RESULTS: The histopathological examination revealed a prevalence of myocardial cell necrosis and obvious inflammation changes at the 7th day post-infection. Subsequently the inflammatory lesions were gradually absorbed. At the 28th day, the inflammatory cells had almost disappeared and obvious fibrosis occurred. The pathological scores and the expression of OPN mRNA were higher than those of the control group (P<0.05), and reached the highest level at the 7th day (P<0.05). From the 14th day, these parameters decreased,reflected also in the ELISA results. At the 7th day and the 14th day, the Col I expression was similar to that of control. Col I expression at the 21th and 28th days was higher than those of the control (P<0.05), and correlated positively to the CVF results. CONCLUSION The OPN mRNA expression increased in acute stage of VMC, and higher than that of the control group when in recovery stage, suggesting that OPN might be related to the inflammatory response in acute stage of, and promote the collagen synthesis of recovery stage.
Animals ; Collagen Type I ; genetics ; metabolism ; Coxsackievirus Infections ; metabolism ; Enterovirus B, Human ; isolation & purification ; Male ; Mice ; Mice, Inbred BALB C ; Myocarditis ; metabolism ; virology ; Osteopontin ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism

Objective:To investigate the effect of the timing of continuous renal replacement therapy (CRRT) administration on the prognosis of acute kidney injury (AKI) in children.Methods:The medical records of children with AKI who were admitted to the Intensive Care Unit of Hunan Children′s Hospital from March 2015 to February 2020 and underwent CRRT were prospectively analyzed.The children who met the criteria were divided into early group (defined as AKI 1 and 2) and delayed group (defined as AKI 3) according to AKI stage.The general conditions, indicators when CRRT was initiated, and prognosis of the children in two groups were recorded.Results:(1) A total of 39 children were included in the study, including 23 in the early group and 16 in the delayed group.There were no significant differences in age, gender, body weight and proportion of mechanical ventilation between two groups ( P>0.05). The score of critical cases in the early group was higher than that in the delayed group ( P=0.008). (2) There were no significant differences in serum potassium and bicarbonate when CRRT was initiated between two groups ( P>0.05). The urine output in the early group was higher than that in the delayed group ( P>0.001). The serum creatinine and urea nitrogen in the early group were lower than those in the delayed group ( P>0.05). (3) The 28-day survival rate and proportion of renal function recovery at 28 days in the early group were significantly higher than those in the delayed group ( P>0.05). The duration of CRRT, ICU stay and duration of mechanical ventilation in the early group were shorter than those in the delayed group ( P>0.05). Conclusion:Early initiation of CRRT at AKI stage 1 and 2 can improve the 28-day survival rate and renal function recovery of survivors when critically ill children are complicated with AKI.

Objective To explore the role and effectiveness of flexible fiberoptic brochoscopy ( FFB) in critically ill children with continuous invasive respiratory support. Methods From July 2014 to June 2017,135 critically ill children with severe pneumonia had received continuous invasive respiratory sup-port and undergone FFB in the pediatric intensive care unit( PICU) of our hospital. These patients were en-rolled into the therapy group. Another 104 severe pneumonia patients who had not received FFB were enrolled into the control group. Clinical characteristics of both groups were collected and compared. Results No sig-nificant differences were detected in patients′gender, age, PCIS, usage of antibiotics, and the levels of CRP and PCT assayed at the time of admission to PICU between the therapy group and control group(P>0. 05). The positive rate of bacteria culture of the bronchoscopic lavage was 78. 52％( 106 cases ) in the therapy group,and it was significantly higher than that in the control group(60. 58％,63 cases) (χ2 =5. 681,P <0. 005). For 106 cases in the therapy group,117 bacteria strains were identified,while there were 72 bacteria strains found in 63 cases with positive bacteria culture in the control group. Gram negative bacteria were the most common type,followed by Gram positive bacteria. The third most common pathogenic microbes were fungi,with a significantly higher frequency in the therapy group. No significant differences were found in PaO2 and oxygenation index between both groups before FFB. However,in a half hour after FFB,the PaO2 and oxygenation index significantly increased in the therapy group,and higher than those in the control group (P<0. 005). The levels of CRP and PCT assayed before and the first day after FFB were not significantly changed(P>0. 05). But the levels of CRP and PCT in the therapy group significantly decreased in the third day after FFB,and more than those in the control group. Furthermore,duration of invasive respiratory sup-port,and the stay of PICU were significantly shorter in the therapy group(P<0. 005). Conclusion FFB can play an important role in the collection of pathogenic microbes. It also achieves better results in the treatment of severe pneumonia for children in PICU. Therefore,it is worthwhile to be recommended as a safe and feasi-ble intervention in PICU.

Objectives To determine the risk factors of ventilator-associated pneumonia (VAP) in the pediatric intensive care unit and to explore effective strategies to reduce the morbidity of VAP. Methods A retrospective analysis was conducted on 455 children admitted into the PICU of Hunan Children's Hospital from June 2014 to June 2017. The 455 children were divided into VAP group (n=43) and non-VAP group (n=412). The incidence of VAP was identified and risk factors were compared using the logistic regression analysis via SPSS 19.0 software.Results There were 311 males and 144 females with a median age of 11 months old (29 days to 9 years and 4 months). The incidence of VAP was 9.45% (43/455). Congenital laryngeal and trachea malformation with pulmonary infection was the first reason for the occurrence of VAP (23.3%), followed by congenital heart diseases with pulmonary infection (18.6%). Via univariate analysis, types of endotracheal intubation (χ2=45.33, P<0.001), duration of mechanical ventilation (Z=1.21, P=0.034), re-intubation (χ2=20.22, P=0.004), early usage of antibiotics (χ2=4.98, P=0.026),and methods of nutritional support(χ2=10.15,P=0.006)were identified as risk factors of VAP in the pediatric intensive care unit patients (P<0.05). Based on the multivariate logistic regression analysis, the followings were all independent predictor for VAP:types of endotracheal intubation(OR=1.87,95%CI:1.48~9.75),duration of mechanical ventilation(OR=1.14, 95%CI:1.08~2.35), re-intubation (OR=3.42, 95%CI:1.26~5.57), early usage of antibiotics (OR=4.55, 95%CI:2.21~8.77). Conclusions Many risk factors were found related with the occurrence of VAP. A comprehensive analysis of the host factors and iatrogenic factors should be conducted. Rational use of antibiotics and daily assessment of extubation might help reduce the incidence of VAP.

Objective To investigate the prevalence of pulmonary fungal infection and drug resist-ance of the pathogenic fungi among children with severe diseases in pediatric intensive care unit(PICU). Methods From July 2013 to June 2017,the complete clinical data,results of fungal culture and drug sensi-tivity of bronchoalveolar lavage fluid in 112 critically ill children with pulmonary fungus infection of PICU hospitalization in our hospital were collected. Samples of peripheral venous blood were collected meantime, including blood routine examination,C reactive protein,G test and GM test. Results One hundred and twen-ty-six fungi were isolated from sputum samples in 112 critically ill children. Severe pulmonary infection (30. 36%,34/112) was the most common form of the primary diseases, the next were severe sepsis (16. 07%,18/112)and severe malnutrition(15. 18%,17/112). Classified based on age difference,the first one was ＜1 year old (43. 75%,49/112),the second one was 1 to 3 years old(29. 46%,33/112). The fun-gal strains were predominantly Candida albicans (61. 90%) and Candida tropicalis (16. 67%),among the infectious cases 14 were diagnosed as mixed infection. Two cases of 3 cryptococcal infectious children were HIV infection,another one was malignant tumor,Cryptococcus was cultured in both sputum,pleural effusion and cerebrospinal fluid. The drug resistance rate of fluconazol in 126 strains of fungi was 12. 70%,the rate of itraconazole was 7. 14%. Generally,the fungi cultured were with very low resistance to 5-fluorocytosine,vori-conazole and amphotericin B. However,the strains of Aspergillus fumigates,Candida kruse,Candida parapsi-losis and Cryptococcus were highly resistant to fluconazol and itraconazole,but with very low resistance to 5-fluorocytosine and amphotericin B. Conclusion Candida albicans is the main pathogenic fungus of pulmo-nary fungal infection among children in PICU,and we could choose voriconazole and amphotericin B as treat-ment of critically ill children with pulmonaty fungal infection.

Objective:To investigate the efficacy and safety of dexmedetomidine in noninvasive continuous positive airway pressure(NCPAP)for acute respiratory failure in children.Methods:Clinical data of children with acute respiratory failure who underwent NCPAP from January 2018 to March 2020 in PICU of Hunan Children′s Hospital were prospectively collected.They were randomly divided into dexmedetomidine group(group D)and midazolam group(group M), with a total of 100 children.We compared the sedation depth of the two groups at 7 time points after sedation at 0.5 h(t1), 1 h(t2), 2 h(t3), 6 h(t4), 12 h(t5), 24 h(t6), and 48 h(t7), time to reach proper sedation, NCPAP time, NCPAP failure rate, oxygenation index(P/F value)before sedation(T0)and 1h(T1), 24h(T2), and 48h(T3)after sedation, and the main vital signs and adverse reactions before sedation(T0)and 1h(T1), 24h(T2), 48h(T3)after sedation.Results:(1)The proportion of proper sedation at T4, T5, T6 and T7 after sedation in group D was higher than that in group M[98%(49/50)vs.84%(42/50), 94%(47/50)vs.90%(45/50), 96%(48/50)vs.88%(44/50), 90%(45/50)vs.88%(44/50), χ2=6.538, 8.043, 8.174, 7.678, all P<0.05]. Time to reach proper sedation in group D was shorter[(58.6±7.9)s vs.(66.7±9.3)s, t=4.682, P<0.01]. (2)The treatment time and failure rate of NCPAP in group D were lower than those in group M[(134.9±25.5)h vs.(147.8±24.3)h, 10%(5/50)vs.28%(14/50), all P<0.05]. P/F after NCPAP treatment in the two groups was improved as compared with that before treatment(all P<0.01), and the improvement was more significant in group D than in group M at T2 and T3 after sedation[(199.3±26.1)vs.(188.5±24.2)mmHg, (212.2±25.4)mmHg vs.(200.8±24.8)mmHg, t=2.132, 2.278, all P<0.05]. (3)There were no significant differences in heart rate(HR), mean arterial pressure(MAP), and respiratory rate(RR)before sedation between the two groups(all P>0.05). HR and RR after sedation in both groups decreased as compared with those before sedation( P<0.01). HR at T1, T2, and T3 after sedation in group D decreased more significantly than that in group M[(116.3±17.6)bpm vs.(124.8±14.1)bpm, (110.2±18.4)bpm vs.(121.9±15.2)bpm, (108.5±18.7)bpm vs.(117.6±12.8)bpm, t=0.479, -3.474, -2.840, all P<0.05]. There was no significant difference in RR after sedation between the two groups( t=1.872, 1.632, 1.675, all P>0.05). MAP at T1 in group D decreased as compared with T0( P<0.01). MAP at T1 in group D was lower than that in group M[(65.5±5.1)mmHg vs.(68.0±5.7)mmHg, t=-2.297, P=0.024]. (4)There was no significant difference in the incidence of total adverse reactions between the two groups[20%(10/50)vs.14%(7/50), P=0.595]. The incidence of bradycardia was higher in group D than in group M[16%(8/50)vs.2%(1/50), P=0.031]. Conclusion:The incidence of adverse reactions of dexmedetomidine and midazolam in the sedation of NCPAP in children with acute respiratory failure is similar, but the sedative effect of dexmedetomidine is better than that of midazolam in the improvement of pulmonary oxygenation.

Objective:To investigate the efficacy and safety of bronchoscopic lavage in children with severe adenoviral pneumonia.Methods:Patients with severe adenovirus pneumonia who were admitted to ICU department of Hunan Children′s Hospital for bronchoscopy were collected from February to June 2019 and divided into lavage group( n=36) and non-lavage group( n=15) in line with whether lavage was performed.Their results, namely, bronchoscopic diagnosis, blood gas analysis before and 2 hours, 24 hours and 48 hours after bronchoscopy, improvement time of clinical symptoms(fever and pulmonary moist rales), the positive rate of pathogen detection and mortality rate, main vital signs such as heart rate, respiratory rate, mean arterial pressure and bronchoscopy-related complications were recorded before and 1 hour, 2 hours and 24 hours after bronchoscopy. Results:A total of 51 children were collected, all of whom suffered from endobronchitis.More secretions were observed in the airways of 36 patients in the lavage group, and only a little or no secretions were observed in 15 patients in the non-lavage group.P/F value and PCO 2 at 2 hours, 24 hours and 48 hours after treatment in the lavage group were improved comparing to those before treatment and were superior to those in the non-lavage group( P<0.05). P/F values at 24 hours and 48 hours after treatment in the non-lavage group increased and PCO 2 decreased at 48 hours after treatment( P<0.05). The thermal duration, time to resolution of moist rales in the lungs in the lavage group were shorter than those in the non-lavage group( P<0.05). The mortality rate in the lavage group was lower than that in the non-lavage group[2.8%(1/36) vs.26.7%(4/15), P<0.05]. The positive rate of pathogen detection in lavage group was higher than that in non-lavage group[55.6%(20/36) vs. 20.0%(3/15), P<0.05]. There was no significant difference in heart rate, respiratory rate, and mean arterial pressure at each time point before and after bronchoscopic treatment( P>0.05). Associated complications were 11 cases of intraoperative transient hypoxemia, four cases of bronchial mucosal bleeding, and one case each of postoperative hypoxemia, intraoperative hypertension and hypotension.There was no significant difference in the incidence of complications between the two groups( P>0.05). Conclusion:Bronchoscopic lavage, in treating children with severe adenovirus pneumonia, may improve clinical symptoms, respiratory function, and rate of pathogen detection, reduce mortality, and is effective and safe.

Objective:To analyze and discuss the application value and teaching effect of simulate patients (SP)-assisted problem-based learning (PBL) combined with team-based learning (TBL) mode in pediatric first aid teaching, in order to provide a new reference for the reform of standardized residency training and teaching mode of pediatrics in the new era in China.Methods:A total of 103 residents who participated in the standardized training in the Department of Pediatrics of Hunan Children's Hospital from January 2018 to December 2020 were selected as the research objects, and they were divided into the control group (50 cases) and the experimental group (53 cases). The control group adopted the previous teaching mode of residents, while the experimental group adopted the SP-assisted PBL combined with TBL mode. In this study, SPSS 22.0 software was used for t test and chi-square test. Results:The examination scores of the experimental group in the theoretical knowledge of pediatric first aid, clinical thinking and skills, and application of pediatric first aid skills were higher than those in the control group [(86.98±3.42), (85.69±5.13), (89.62±4.75)] vs. [(77.23±4.16), (81.16±3.96), (76.54±5.78)], with statistically significant differences between the two groups ( P<0.05). The questionnaire survey showed that the clinical thinking and pediatric emergency skills, doctor-patient communication ability, teamwork ability and other aspects of the experimental group were significantly better than those of the control group ( P<0.05). Conclusion:The SP-assisted PBL combined with TBL mode can produce positive effects in the standardized residency training of pediatrics, which will help residents better master pediatric first aid skills, improve their clinical comprehensive capabilities, and be more conducive to improving the quality of pediatric residency training, which is worth promoting in the new era.

Objective To assess the effect of platycodin D(PD)for alleviating pulmonary fibrosis in mice and explore the underlying mechanism.Methods C57BL/6J mouse models of pulmonary fibrosis induced by bleomycin injection into the airway were treated with daily intragastric administration of 10 mg/kg PD for 28 days.The changes of pulmonary fibrosis and the expression and distribution of transient receptor potential cation channel subfamily C member 6(TRPC6)were evaluated with immunohistochemistry,HE staining and Sirius Red staining.Western blotting was used to detect α-SMA expression in the lung tissues of the mice.Primary cultures of mouse lung fibroblasts were pretreated with PD(2.5,5.0,and 10 μmol/L)or larixyl acetate(LA;10 μmol/L)before exposure to 10 ng/mL transforming growth factor-β1(TGF-β1),and the changes in cell survival rate,expressions of collagen I,α-SMA and TRPC6,reactive oxygen species(ROS)production,mitochondrial membrane potential,and cell proliferation capacity were assessed.Network pharmacology analysis was performed to explore the mechanism by which PD alleviated pulmonary fibrosis.Results PD treatment significantly alleviated pulmonary fibrosis and reduced α-SMA expression in BLM-induced mouse models(P<0.05).In TGF-β1-induced primary mouse lung fibroblasts,PD effectively inhibited the cell proliferation,reduced ROS production(P<0.0001),rescued the reduction of mitochondrial membrane potential(P<0.001),and inhibited the expressions of α-SMA and collagenⅠ(P<0.05).Network pharmacology analysis suggested that TRPC6 mediated the effect of PD for alleviating pulmonary fibrosis.Immunohistochemistry showed that PD significantly reduced TRPC6 expression in the lung tissues of BLM-induced mice.In primary mouse lung fibroblasts,PD significantly inhibited TGF-β1-induced TRPC6 expression(P<0.05),and LA treatment obviously lowered the expression levels of TRPC6,α-SMA and collagenⅠ(P<0.05).Conclusion PD alleviated pulmonary fibrosis in mice possibly by down-regulating TRPC6 and reducing ROS production.