| Objective1.To explore and analyze the clinical characteristics,etiological distribution and drug resistance of sepsis in premature infants of different gestational ages.2.To investigate the effect of histological chorioamnionitis(HCA)on premature sepsis.Methods1.The clinical data of 117 premature infants with sepsis were born in neonatal ward of affiliated Hospital of Qingdao University from January 2014 to January 2022 were analyzed retrospectively.According to gestational age,they were divided into two groups:gestational age<32 weeks group and gestational age≥32 weeks group.The clinical characteristics,etiological distribution and drug sensitivity of the two groups were analyzed.2.A total of 406 preterm infants in neonatal ward,delivered in the obstetrics department of the Affiliated Hospital of Qingdao University from November 2016 to May 2021,were analyzed retrospectively.According to the histopathological examination of placenta,the patients were divided into two groups:HCA positive group and HCA negative group.We analyzed the clinical data and outcomes of mothers and premature infants,and analyzed the relationship between influencing factors of HCA and sepsis and other complications of premature infants.The HCA was predicted by drawing receiver operating characteristic curve(ROC).Results1.1 There were 117 cases of sepsis in premature infants with positive blood culture,including 67 cases in gestational age<32 weeks group and 50 cases in gestational age≥32 weeks group.The proportion of central venous catheterization,intravenous nutrition,mechanical ventilation and dyspnea in the<32 weeks group was higher than that in the≥32 weeks group,and the incidence of fever in the≥32 weeks group was significantly higher than that in the<32 weeks group(P<0.05).1.2 A total of 117 strains of pathogens were isolated from 117 cases of blood culture,including 67 strains(57.3%)in<32 weeks group and 50 strains(42.7%)in≥32 weeks group.The main pathogens were Gram-positive bacteria(73.5%),of which Coagulase negative staphylococci(Co NS)were the most common(72.1%).Staphylococcus epidermidis was the main pathogen in Co NS.1.3 The results of drug sensitivity analysis of the main pathogens showed that the resistance rate of 48 strains of Staphylococcus epidermidis to penicillin was 97.9%,and the resistance rate of that to oxacillin and erythromycin was more than 80%.No strains of Gram-positive bacteria were found to be resistant to vancomycin,linezolid,tegacycline,quinupridine/dafoptin.Among gram-negative bacteria,7 strains of Escherichia coli were analyzed and the resistance rate of ampicillin was high.11 strains of Klebsiella were analyzed and 8 strains were detected for drug sensitivity to ampicillin,all of which were resistant to ampicillin.No strains of gram-negative bacteria resistant to piperacillin/tazobactam and carbapenem were found.One strain of Candida albicans was found to be resistant to itraconazole,but no resistant strain was found in other fungal strains.2.1 A total of 406 premature infants were examined by histopathological examination of placenta and met the criteria,including 89 HCA positive infants and 317 HCA negative infants.The proportion of uterine tenderness,tachycardia and fever in HCA positive group was significantly higher than that in HCA negative group(P<0.05).2.2 Univariate analysis showed that Group B streptococcus(GBS)infection,gestational diabetes mellitus,amniotic fluid contamination and premature rupture of membranes were the influencing factors of HCA.Further binary Logistic regression analysis showed that GBS infection(OR=16.396)and amniotic fluid contamination(OR=9.840)were independent risk factors for HCA(P<0.05).2.3 We draw the ROC curve.Within 24 hours in antepartum,the area under the whiteblood cell count curve is 0.715,and the optimal threshold of the white blood cell count is11.325×10~9/L.The white blood cell count≥11.325×10~9/L as a predictor of HCA,the sensitivity is 72.9%and the specificity is 63.7%.The area under the neutrophil count curve is 0.728,and the optimal threshold is 9.580×10~9/L.the neutrophil count≥9.580×10~9/L as a predictor of HCA,the sensitivity is 67.8%and the specificity is 70.7%.The area under the C-reactive protein(CRP)curve is 0.758,and the optimal threshold is 10.505mg/L.CRP≥10.505mg/L as a predictor of HCA,the sensitivity is 66.1%and the specificity is 79.0%.The area under the curve of combined detection of the white blood cell count,the neutrophil count and CRP was 0.758,the sensitivity was 76.3%,and the specificity was 63.1%.2.4 The proportion of the mothers with HCA of early-onset sepsis(EOS)premature infants was significantly higher than the mothers with HCA of non-EOS premature infants(P<0.05).There were significant differences in the incidence of EOS between different stages of HCA positive group and negative groups,and between different grades of HCA positive group and HCA negative groups(P<0.05).The incidence of neonatal respiratory distress syndrome(NRDS),bronchopulmonary dysplasia(BPD)and periventricular leukomalacia(PVL)/intraventricular hemorrhage(IVH)in HCA positive group was significantly higher than that in HCA negative group(P<0.05).Conclusions1.Premature infants with younger gestational age,lower birth weight,and longerhospital stay are more likely to be exposed to invasive procedures such as central venous catheters,intravenous nutrition,and mechanical ventilation,resulting in bloodstream infections.2.The main bacteria detected in sepsis of premature infants ware coagulase-negative staphylococci.The main gram-positive bacteria and gram-negative bacteria were highly resistant toβ-lactam penicillins and cephalosporins.3.The area under the ROC curve and sensitivity of the combined detection of the white blood cell count,the neutrophil count and CRP were higher than the values of three indexes alone.Mothers with three indexes above the threshold and their infants need to be paid more attention and intervened in time.4.Mothers with HCA whose infants are more likely to develop EOS,NRDS,BPD and PVL/IVH.Clinical attention should be paid to the prevention and treatment of HCA so as to reduce the incidence of complications in premature infants. |
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