Sepsis has the characteristics of high morbidity and high mortality, which is the main cause of death in critically ill patients. Peripheral 5-hydroxytryptamine (5-HT) is mainly synthesized and secreted by enterochromaffin cells and plays a role in the development and progression of inflammation. This article focuses on 5-HT, 5-HT transporter (SERT) and selective serotonin reuptake inhibitors (SSRIs) in immune response, inflammatory factor release, oxidative stress, intestinal bacterial translocation and microcirculation of sepsis. The role of the review is to find new ideas for the clinical treatment of sepsis.

Objective To investigate the clinical application value of pediatric electronic bronchoscopy on the diagnosis of respiratory disease in the pediatric intensive care unit(PICU)by morphological diagnosis.Methods The clinical data of 124 patients with PICU respiratory critically ill patients who underwent bedside electronic bronchoscopy from July 2017 to December 2022 in Lanzhou University Second Hospital were retrospectively analyzed.Pathogen examination of 96 cases of bronchoalveolar lavage fluid(BALF),bronchoscopy guided nasal endotracheal intubation in 3 cases was conducted.The accuracy of diagnosis of lung lesions was compared between electronic bronchoscopy and chest CT,and the morphological changes of lung lesions under electronic bronchoscopy were observed.Results The accuracy of electronic bronchoscopy in the diagnosis of tracheoesophageal fistula,tracheoesophageal rupture and bronchial foreign body is significantly higher than that of chest CT(tracheoesophageal fistula:4 cases vs.0 case,tracheoesophageal rupture:4 cases vs.0 case,bronchial foreign body:4 cases vs.6 cases,all P<0.05),and there was no significant difference in the accuracy of diagnosis of lung contusion and bronchiectasis between electronic bronchoscopy and chest CT.Typical cases confirmed under endoscopic:4 cases(3.23%)had tracheoesophageal fistula.Bronchial rupture 4 cases(3.23%).Endobronchial tuberculosis was diagnosed in 1 case(0.81%)with bronchial neoplasms and white caseous material attached to the mucosa.Positive bacteria were detected in 23 cases(23.96%).Guided nasotracheal intubation was performed in 3 children with jaw or cervical fracture.Endotracheal catheterization under mechanical ventilation was performed in 13 cases.There were no serious complications and death during and after the operation.Conclusion Pediatric bendable bronchoscopy with PICU is safe and reliable.It can improve the diagnosis rate of respiratory diseases in PICU,and has high clinical application value.