The Clinical Study On The High Risk Factors For The Death Of The 128 Cases Of Neonatal Sepsis

Since the fetus is usually in the bioclean environment that lacking of microbial antigenic to stimulate the immune system which is keep in inhibitory state, the neonatal is highly susceptible to infectious microorganisms, particularly bacteria. The smaller the gestational age is,more vulnerable to sepsis. The incidence rate of viable birth was 0.1%~1%. The lighter birth weight, the higher the incidence rate is that to the very low birth weight infant it can reach as high as 16.4%, while to the long-term hospitalization it may be as high as 30%, and morbidity is about 13%~50%. Sepsis has been the major cause of the death for neonatal, especially for premature infant. Therefore studying the high risk factors of the neonatal death, taking preventive measures and also assessing the prognosis are very important.This paper includes 128 cases of neonates who were diagnosed and treated as neonatal sepsis in our department from February,2007 to March ,2008. And 98 cases were healed well while 30 cases died, which means the mortality was 23.43%. Descriptive statistics were calculated on a total of 18 variable factors: gender, gestational age, birth weight, delivering in urban or areas, mode of delivery, whether have premature rupture of membranes, the number of the birth, whether have asphyxia, the onset age, whether application of mechanical ventilation, whether complicating with MODS, electrolyte imbalance, metabolic acidosis, surface infection or jaundice, and also white blood cell and platelet count,C-reactive protein et al. Through single-factor and multiple-factors analysis we discuss the high risk factors for death of neonatal sepsis. All the collected clinical data is compared and analyzed statistically with SPSS 12.0 software, admitted P<0.05 is significant.Results: 1. The mortality in each groups which divided basing on different risk factors are quite different from each other: GA less than 32W group: 60.0%(9/15), GA between 32 to 37 weeks(including 32 weeks) group: 27.9%(12/43), GA more than or equal to 37weeks group: 12.85%(9/70). EONS group: 46.67%(14/30),LONS group: 16.32% (16/98). Application of mechanical ventilation group: 56%(14/25), Application of CPAP group: 27.27%(9/33), non- application of mechanical ventilation group: 11.42%(8/70). Complicating with MODS group: 58.82%(20/34), without MODS group: 10.63% (10/94). Complicating with surface infection group: 21.87% (7/32), without surface infection group: 23.95%(23/96). Electrolyte imbalance group: 38.29%(18/47), without electrolyte imbalance group: 14.81%(12/81). Metabolic acidosis group: 37.5% (18/48), without metabolic acidosis group: 15.0%(8/12). Platelet count greater than or equal to 100×109/L group: 13.1%(8/61), platelet count between 50×109 /L to 100×109 /L group: 17.1%(6/35), platelet less than or equal to 50×109 /L group:50%(16/32). In logistic regression analysis GA,the onset age,mechanical ventilation,MODS,surface infection,electrolyte imbalance,metabolic acidosis and platelet count are all significant predictors for prognosis.The above eight kinds of factors are statistically independent high risk factors for the death of neonatal spsis. 2. Further research shows the mortality in different groups to us: BW lighter than or equal to 1500g group: 33.33%(6/18), BW among 1500-2500g group:33.33%(16/48), and BW heavier than or equal to 2500g group: 12.9%(8/62). Single-birth group: 19.81% (22/111), and superfoetation group: 47.05%(8/17). WBC less than 5.0×10~9/L group: 59.09% (14/23), WBC more than normality group: 9.6%(3/31) ,WBC count normally group:17.5% (13/74). In univariate analysis the above three factors have significant independent influence to the mortality (P<0.05) but in multivariate analysis the difference has no statistical significance (P>0.05). So BW,superfoetation and WBC count may be the possible high risk factors for the death of neonatal sepsis.3.More potential factors:male infant group: 25.88% (22/85), female infant group: 18.60% (8/43). Spontaneous delivery group: 17.02%(8/74), elective caesarean section group: 29.72%(22/74). Premature rupture of membrane group:31.8%(7/22), non-premature rupture of membranes group: 21.69%(23/106). Asphyxia group: 27.27%(6/22) and non-asphyxia group: 22.64%(24/106). Born in urban area group:20.93%(9/43) and rural area group: 24.70%(21/85). Acomplicating with jaundice group: 20.00%(9/45) and non-jaundice group: 25.3%(21/83). CRP normal group: 15.15%(5/33), CRP increase to abnormal level group: 26.31%(25/95).In neither univariate or multivariate statistical analysis the above seven factors were significant predictors for the death of neonatal sepsis.That means these factors do not increase the mortality rate of neonatal sepsis.But clinical reports do not match,so further reacher are being needed.4. Laboratory examination results: Only 43 cases of hemoculture are positive among which 14 strains are CNS,9 strains are Klebsiella pneumonia, 7 strains are E. coli,3 strains are staphylococcus aureus,3 strains are Acinetobacter baumannii,2 strains are Pseudomonas aeruginosa and 5 strains are others(including 2 strains of Streptococcus, 1 strain of Enterococci cloacae,1 strain of Pseudomonas alcaligenes and 1 strain of the bacteria Burkholderia). Basing this results we can see that CNS and Klebsiella pneumonia increase significantly to be major pathogenic bacterium, consistenting with the clinical report from Yufen Guo. Drug susceptibility test results: CNS is resistant to penicilin,cephalosporins but sensitive to rifampin,teicoplanin and vancomycin.Klebsiella pneumoniae is resistant to cephalosporins et al but sensitive to imipenem,L-ofloxacin and Meropenem. E. coli has moderate susceptibility to cephalosporins and has high susceptibility to imipenem and Meropenem but highly resistant to cefuroxime, Ticarcillin/clavulanic acid. More and more resistant strains bring more difficulties to clinical treatment.Conclusions:We should pay close attention to GA,the onset age,mechanical ventilation,complication such as MODS,surface infection,electrolyte imbalance,metabolic acidosis and also platelet count. They are independent high risk factors for neonatal spsis. Besides that BW,superfoetation and decrease of WBC may be the potential high risk factors.Other seven factors which reported relevant to the prognosis of neonatal sepsis are not statistically significant factors in this clinical analysis. CNS and Klebsiella pneumoniae are the major pathogenic bacterium while the detection rate of staphylococcus is lower than the two major bacteria. Opportunistic pathogen becomes the major pathogenic bacteria and resistant strains may be the high risk factors for neonatal spsis.