Bilirubin is an important metabolite in the human body，which mainly includes conjugated bilirubin and unconjugated bilirubin.Unconjugated bilirubin plays an important role in the pathogenesis of neonatal bilirubin encephalopathy，and unconjugated bilirubin includes bilirubin bound to albumin and free bilirubin not bound to albumin.Free bilirubin has lipophilic property and can freely infiltrate brain cells through the blood-brain barrier，causing irreversible damage to neonatal brain cells.This review mainly summarized the mechanism of nerve damage caused by free bilirubin，so as to provide clinical ideas for the prevention and treatment of neonatal bilirubin encephalopathy.

The birth weight of newborns in plateau areas was lower than that in plain areas，and showed a downward trend with the increase of altitude.The average birth weight of newborns would decrease by about 100 grams for every 1 000 meters increase in altitude.The mechanism is mainly related to maternal physiological changes caused by hypoxia at high altitude，such as reduced uterine arterial blood flow，changes in placental structure and decreased nutrient transport capacity.Studies have shown that gestational age，altitude，ethnicity，maternal age and the number of prenatal visits are the main factors affecting the birth weight of newborns.The genetic adaptation mechanism of native plateau nationalities（such as Tibetans）can partially alleviate the restriction of fetal growth caused by hypoxia，but its role in ultra-high altitude（>4 500 m）needs further study.Young or advanced maternal age（≥35 years old）and inadequate prenatal care would increase the risk of low birth weight.It is suggested to strengthen health education in plateau area，promote regular prenatal examination，and explore the genetic mechanism of plateau adaptation in order to improve pregnancy outcomes.

Acute respiratory distress syndrome（ARDS）is a common life-threatening disease with high mortality caused by inflammatory disorder and oxidative stress in intensive care unit.Respiratory support is the most important clinical treatment.Transpulmonary pressure can accurately reflect the retraction force of the surface of the pleural cavity against the lung tissue，and is the actual stress acting on the lung.Although there are studies suggesting that the measurement of transpulmonary pressure can guide positve expiratory end pressure titration in ARDS patients,so as to achieve individualized treatment and improve patient oxygenation，its clinical application value is still controversial.This review analyzed the advantages and disadvantages of transpulmonary pressure monitoring，guided the treatment of ARDS，and provided individualized and accurate help for setting ventilator parameters for ARDS patients in clinic.

Objective:To observe the efficacy and safety of combined lienal polypeptide injection therapy in the treatment of Mycoplasma pneumoniae pneumonia（MPP）in children aged 3 to 14 years old in multiple clinical centers.Methods:A randomized，controlled，multi-center clinical study design was adopted.A total of 240 hospitalized children aged 3 to 14 years old with MPP from 7 hospitals from September 1，2023 to January 31，2024 were included.According to the severity of pneumonia，they were divided into the mild MPP group with 80 cases and the severe MPP/refractory MPP（SMPP/RMPP）group with 160 cases，and then randomly divided into the control group and the experimental group at a ratio of 1 ∶1，using the random number table method.After screening，subjects entered a treatment period of 5 to 7 days.The control group was treated with azithromycin，while the experimental group was treated with azithromycin plus lienal polypeptide injection .The recovery of lung CT，length of hospital stay，duration of fever，cough score，whether mild cases developed into severe or refractory cases，duration of hormone use，use of intravenous immunoglobulin（IVIG），bronchoscopy treatment，and immune function were observed between the two groups to evaluate the efficacy of lienal polypeptide injection.Adverse events after medication，vital signs，blood routine，urine routine，liver function，myocardial enzymes，renal function，and electrocardiogram were observed to evaluate the safety. Results:A total of 231 subjects have completed the trial in the 7 hospitals，including 118 cases in the experimental group and 113 cases in the control group.Main observation index：the rate of lung CT aggravation in the experimental group was lower than that in the control group（2.6% vs 15.3%， P<0.01），and the difference was statistically significant.Secondary indexes：there were no statistically significant differences in the length of hospital stay，duration of fever，cough score，duration of hormone use，whether IVIG treatment was used，the number of bronchoscopy treatment cases，and immunoglobulin between the two groups（all P>0.05）.However，the rate of cases of plastic bronchitis（PB）found under bronchoscopy in the experimental group was lower than that in the control group（0 vs 18.8%， P=0.03），and the difference was statistically significant.Among the mild MPP（72 cases），there were no statistically significant differences in the length of hospital stay，duration of fever，cough score，duration of hormone use，whether IVIG treatment was used，the number of bronchoscopy treatment cases，and the improvement rate of lung CT between the two groups（all P>0.05）.However，compared with the control group，the rate of cases developing into SMPP/RMPP in the experimental group was less（24.3% vs 48.6%， P=0.03），and the difference in IgG before and after treatment was small［0.53（-0.04，1.18）g/L vs 1.33（0.48，2.25）g/L， P=0.01］.Among the SMPP/RMPP cases（159 cases），the rate of cases of PB found under bronchoscopy in the experimental group was less than that in the control group（0 vs 20%， P=0.04），and the rate of cases with aggravated lung CT in the experimental group was less than that in the control group（1.3% vs 19.5%， P<0.01），and the improvement rate of lung CT in the experimental group was higher than that in the control group（88.8% vs 75.3%， P=0.03），with statistically significant differences.There were no statistically significant differences in the length of hospital stay，duration of fever，cough score，duration of hormone use，whether IVIG treatment was used，the number of bronchoscopy treatment cases，and immunoglobulin between the two groups（all P>0.05）.Two cases in the experimental group developed rashes，which improved after the drug was discontinued.There were no serious adverse reactions such as abnormal vital signs like dyspnea and cyanosis due to the use of lienal polypeptide injection.There were no obvious changes in blood routine，liver function，myocardial enzymes，renal function，electrocardiogram，and urine routine values before and after medication compared with the baseline. Conclusion:The combined use of lienal polypeptide injection in the treatment of MPP in children can reduce the probability of the transformation from mild cases to SMPP/RMPP，reduce the rate of aggravation of the image findings，promote the absorption of lung inflammation，reduce the rate of PB found under bronchoscopy，and has good safety.

Bilirubin is an important metabolite in the human body，which mainly includes conjugated bilirubin and unconjugated bilirubin.Unconjugated bilirubin plays an important role in the pathogenesis of neonatal bilirubin encephalopathy，and unconjugated bilirubin includes bilirubin bound to albumin and free bilirubin not bound to albumin.Free bilirubin has lipophilic property and can freely infiltrate brain cells through the blood-brain barrier，causing irreversible damage to neonatal brain cells.This review mainly summarized the mechanism of nerve damage caused by free bilirubin，so as to provide clinical ideas for the prevention and treatment of neonatal bilirubin encephalopathy.

The birth weight of newborns in plateau areas was lower than that in plain areas，and showed a downward trend with the increase of altitude.The average birth weight of newborns would decrease by about 100 grams for every 1 000 meters increase in altitude.The mechanism is mainly related to maternal physiological changes caused by hypoxia at high altitude，such as reduced uterine arterial blood flow，changes in placental structure and decreased nutrient transport capacity.Studies have shown that gestational age，altitude，ethnicity，maternal age and the number of prenatal visits are the main factors affecting the birth weight of newborns.The genetic adaptation mechanism of native plateau nationalities（such as Tibetans）can partially alleviate the restriction of fetal growth caused by hypoxia，but its role in ultra-high altitude（>4 500 m）needs further study.Young or advanced maternal age（≥35 years old）and inadequate prenatal care would increase the risk of low birth weight.It is suggested to strengthen health education in plateau area，promote regular prenatal examination，and explore the genetic mechanism of plateau adaptation in order to improve pregnancy outcomes.

Acute respiratory distress syndrome（ARDS）is a common life-threatening disease with high mortality caused by inflammatory disorder and oxidative stress in intensive care unit.Respiratory support is the most important clinical treatment.Transpulmonary pressure can accurately reflect the retraction force of the surface of the pleural cavity against the lung tissue，and is the actual stress acting on the lung.Although there are studies suggesting that the measurement of transpulmonary pressure can guide positve expiratory end pressure titration in ARDS patients,so as to achieve individualized treatment and improve patient oxygenation，its clinical application value is still controversial.This review analyzed the advantages and disadvantages of transpulmonary pressure monitoring，guided the treatment of ARDS，and provided individualized and accurate help for setting ventilator parameters for ARDS patients in clinic.

Respiratory syncytial virus（RSV）is the leading cause of severe lower respiratory tract infections in young children，with a high rate of hospitalization and mortality.Specific anti-RSV therapies have not been reported.The structure of RSV is such that it is mainly F and G proteins in the surface that act as adhesion and invade the host cells.Therefore，monoclonal antibodies against F and G proteins with neutralization sites are currently being developed. This review summarized the mechanism, prevention and treatment of RSV based on neutralizing antibody.

Pediatric acute lung injury(ALI)is a common disease in pediatric intensive care unit with a high fatality rate.Because the etiology of ALI is complex, the exact pathogenesis of ALI is not clear.At present, it is known that the important factors leading to the incidence of ALI in children are oxidative stress and dysregulation of inflammatory response.Progressive hypoxemia and respiratory distress are the main clinical manifestations of ALI.Respiratory support and drug control are the common treatment measures.In recent years, stem cell and molecular targeted therapy as new treatment pathways of ALI, have achieved certain achievements in the research, and are expected to become new treatment methods of ALI in chidren.

The patients with trauma have a high mortality and disability rate, and the incidence of trauma is increasing year by year.Rapid and accurate diagnosis is the key to improve the prognosis of patients with trauma.The traditional diagnostic imaging techniques are X-ray and CT examination.Although X-ray examination can be completed at the bedside, its sensitivity is not high.The diagnostic sensitivity of CT examination is high, but it can not be completed by bedside.Moreover, the process of repeated transportation of patients will delay the best treatment time, even cause secondary injury.Bedside ultrasound has the advantages of fast, real-time, noninvasive and repeatable operation.With the continuous development of bedside ultrasound technology, it has been widely used in the diagnosis of trauma.This review summarized the clinical applications of bedside ultrasound in trauma patients.