Evaluation of sepsis screen for diagnosis of neonatal septicemia

Fifty clinically suspected cases of neonatal septicemia were studied for evaluating the role of sepsis screen. Sensitivity and specificity of C-reactive protein test, micro-ESR, gastric aspirate cytology for polymorphs and toxic granules in neutrophils were studied singly and in combinations of two and three tests. Positive blood culture was obtained in only 20% cases, thereby underlying the need for a sepsis screen in the diagnosis of neonatal septicemia, especially in areas where adequate micro-biological facilities are lacking.     

Evaluation of micro erythrocyte sedimentation rate in the diagnosis of neonatal sepsis

A simple, inexpensive method using standard hematocrit capillary tubes and blood obtained from heel prick to determine E.S.R. (micro E.S.R.) in newborns is described. Normal values for 75 neonates were obtained, and the usefulness of micro ESR as an indicator of neonatal septicemia was evaluated.     

Evaluation of procalcitonin for diagnosis of neonatal sepsis of vertical transmission

Background  

The results of recent studies suggest the usefulness of PCT for early diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to determine the behavior of serum PCT concentrations in both uninfected and infected neonates, and to assess the value of this marker for diagnosis of neonatal sepsis of vertical transmission.     

脐血IL-6水平与新生儿败血症的早期诊断

为研究IL-6水平与新生儿宫内或产时感染所致败血症之间的关系.应用ELISA双夹心法检测了72例脐血清,其中正常52例,败血症20例.结果显示脐血组IL-6中位数0.024ng/ml(范围≤0.0221～0.0531ng/m1);败血症组中位数0.1730ng/ml(范围0.02660～1.2589ng/ml).经秩和检验,P＜0.0005(单侧).结论提示脐血IL-6水平与新生儿败血症的发生有一定关系,IL-6可作为新生儿败血症的早期诊断指标.     

新生儿败血症诊断指标的研究进展

新生几尤其是早产儿,免疫功能不成熟,败血症的发病率很高,目前败血症仍是导致新生儿死亡或远期不良预后的重要原因.新生儿败血症感染途径较多,起病隐匿,症状缺乏特异性,但进展迅速,数小时内即可出现休克、多器官功能损伤甚至死亡,因此早期诊断和及时治疗是改善预后的关键.血培养是诊断败血症的金标准,但阳性率低,需要时间较长,目前,败血症实验室诊断指标主要包括急性时相反应蛋白、细胞因子、细胞表面抗原及细菌DNA检测等.该文比较和分析新生儿败血症诊断指标的研究现状及优缺点.     

Evaluation of C reactive protein and others immunologic markers in the diagnosis of neonatal sepsis

Neonatal sepsis occurs from 1 to 21 newborns out of 1 000 live births with mortality rates as high as 30% up to 69%. The most important risk factors are prematurity, low birth weight, invasive medical procedure and prolonged hospitalization in neonatal intensive care units. An aimed and restrictive antibiotic therapy has an outstanding importance to reduce both morbidity-mortality rates and multiple drug-resistance. Generally, preterm newborns present nonspecific clinical signs of infection. The use of high sensitivity infection markers and a negative predictive value (near 100%) are important to distinguish infected and noninfected patients before the culture results and to verify adequacy and duration of antibiotic therapy. This article reviews the immunologic function and practical use of C reactive protein (CRP) and other markers in the diagnosis of neonatal sepsis. While CRP is a specific late infection marker, cytokines, cell surface markers and procalcitonin (PCT) are early infection markers. The use of multiple markers as CRP, PCT, IL-6, IL-8, CD64, CD11b is useful both to early (24-48 h) diagnose of neonatal sepsis, and to monitorate the antibiotic treatment while waiting for the results of cultural examinations.     

新生儿早发型败血症诊断进展

新生儿早发型败血症是引起新生儿,尤其在低出生体质量儿死亡的主要原因之一。其临床症状不典型,疾病进展隐匿、迅速,目前的诊断方法不够理想,易误诊、漏诊从而导致高病死率。故早期准确诊断新生儿早发型败血症极为重要。文章就新生儿早发型败血症的相关检查研究进展,包括病原菌培养、外周血细胞计数、降钙素原、C-反应蛋白、细胞因子、分子生物学技术以及新的研究尝试作一综述,为早期诊断新生儿早发型败血症提供帮助。     

新生儿败血症临床检测指标的研究进展

新生儿败血症起病隐匿,进展迅速,临床症状缺乏特异性,极易发生休克、多器官功能损伤等严重并发症,因此,早期诊断是降低败血症新生儿病死率及改善预后的关键.目前,有关新生儿败血症临床检测指标包括细菌培养、急性时相反应蛋白、细胞因子、细胞表面抗原及细菌基因检测等.该文将对上述指标在新生儿败血症的早期诊断、病情评估、治疗监测中的临床意义进行综述.     

Early diagnosis and treatment of neonatal sepsis

Perinatally acquired bacterial neonatal sepsis is a low incidence, high risk disease with a relatively benign treatment. Accurate diagnosis is difficult because there is no definitive diagnostic test; even blood cultures have an unacceptably low sensitivity. Therefore, the clinician must accept that a number of neonates who do not have the disease will have treatment initiated for sepsis. In order to treat rapidly all infants with sepsis and to minimize therapy for those without infection, historical, clinical, and laboratory data can be used together in a management approach to achieve optimal results. A systemized approach using history, examination, sepsis screen laboratory tests, and cultures is presented to guide clinical management.     

Early diagnosis of neonatal sepsis using a hematologic scoring system

Hematologic findings and published complete blood cell count criteria were evaluated as screening tests for neonatal sepsis. From the data obtained, a hematologic scoring system was formulated that assigns a score of 1 for each of seven findings: abnormal total leukocyte count, abnormal total neutrophil (PMN) count, elevated immature PMN count, elevated immature to total PMN ratio, immature to mature PMN ratio greater than or equal to 0.3, platelet count less than or equal to 150,000/mm3, and pronounced degenerative changes in PMNs. There were 298 evaluations for sepsis (243 in the first 24 hours of life and 55 between days 2 and 30). Twenty-six of 27 (96%) infants with sepsis and all 23 infants with probable infection had scores greater than or equal to 3, compared with 35 of 248 (14%) noninfected infants. The likelihood of sepsis with score greater than or equal to 3 was 31%, and this value differed with both gestational and postnatal ages (34% vs 8% in preterm and term infants less than 24 hours of age, and 65% thereafter). The higher the score the greater was the likelihood of sepsis. With score less than or equal to 2 the likelihood that sepsis was absent was 99%. The hematologic scoring system should improve the diagnostic accuracy of the complete blood cell count as a screening test for sepsis and could simplify and standardize the interpretation of this global test.     

Failure of the urinary group B streptococcal antigen test as a screen for neonatal sepsis.

The accuracy of the urinary group B streptococcal antigen latex agglutination (LA) test for screening infants at risk of group B streptococcal (GBS) sepsis in the first 24 hours of life was prospectively studied in 236 infants for six months. Infection with GBS was defined by a positive blood culture while colonisation was defined by GBS cultured from any other site. The combination of infection and colonisation was used as the gold standard for the LA test. Although the LA test had a sensitivity of 90%, the specificity was only 70%, the positive predictive value 12% and the false positive rate 30%. The overall accuracy was only 71%. The LA test was unable to predict GBS sepsis in infants at risk of the disease. The false positive rate was unacceptably high and could not be potentially accounted for in 11 infants. However, a negative test was useful in excluding GBS disease.     

Polymerase chain reaction in rapid diagnosis of neonatal sepsis

In a prospective study a total of hundred neonates who fulfilled the American College of Obstetrics and Gynecology's (ACOG) criteria for probable sepsis admitted to NICU of tertiary care armed forces hospital were investigated for evidence of sepsis. The investigation protocol included sepsis screen, blood culture and 1 mL of venous blood for molecular analysis by polymerase chain reaction (PCR) for bacterial DNA component encoding 16 s RNA in all cases. 100 newborns with probable sepsis were studied to evaluate the molecular diagnosis of sepsis using PCR amplification of 16 S RNA in newborns with risk factors for sepsis or those who have clinical evidence of sepsis. We compared the results of PCR with blood culture and other markers of sepsis screen (total leucocyte count (TLC), absolute neutrophil count (ANC), immature/total neutrophil count ratio (I/T ratio), peripheral blood smear, micro ESR and C reactive protein (CRP). Controls consisted of 30 normal healthy newborns with no overt evidence of sepsis. Sepsis screen was positive in 24 (24%) of cases in study group with sensitivity and specificity of 100% and 83.5% respectively. Blood culture was positive in 09(9%t) with sensitivity of 69.2% and specificity of 100%. PCR was positive in 13(13%) of cases (9% are both blood culture and sepsis screen positive and 4% are positive by sepsis screen); the sensitivity of PCR was 100% and specificity was 95.6%. Blood culture is the most reliable method for diagnosis of neonatal sepsis. Polymerase chain reaction is useful and superior to blood culture for early diagnosis of sepsis in neonates.     

Serial interleukin 6 measurements in the early diagnosis of neonatal sepsis

The objective of the present study was to evaluate serial interleukin 6 (IL6) levels in the early diagnosis of neonatal sepsis. Subjects included 255 neonates from the Neonatal Unit of Johannesburg Hospital evaluated for suspected sepsis between February and May 1998. All infants had IL6, full blood count (FBC), C reactive protein (CRP) and blood cultures done at presentation. CRP and IL6 were repeated after 24 h. Infants were categorized into groups according to the likelihood of infection on the basis of clinical presentation, CRP, FBC and culture results, i.e., group 1 (no infection) to group 4 (definite infection). IL6 was compared between the groups by the U-test of Mann-Whitney; stepwise logistic regression was done to establish the best predictors of infection, sensitivity, specificity, positive and negative predictive values were determined. The initial IL6 level was significantly raised in those infants with possible infection [880.67 pg/ml (2966.04), p value 0.0104], probable infection [422.62pg/ml (4077.7), p value 0.0021] and definite infection [11164.39pg/ml (24139.77), p value 0.0000] as compared to those infants without infection [58.65 (182.4)]. The best predictors of infection were the combination of the initial IL6 value and CRP value after 24 h (goodness of fit 97.7 per cent). An initial IL6 value below 20 pg/ml gave a negative predictive value of 90.18 per cent. It is concluded that an IL6 value done at the time of presentation of signs and symptoms suggestive of infection is useful in the early diagnosis of neonatal sepsis. In particular, an initial IL6 value below 20 pg/ml may allow antibiotics to be withheld in a number of infants evaluated for sepsis. There is no benefit in serial determination of IL6 in the diagnosis of neonatal sepsis.     

Simple hematological tests for diagnosis of neonatal sepsis

Simple hematological tests, TLC, DLC, mESR, platelet count, were performed in 128 neonates of which 50 were controls and 78 were cases of suspected septicemia. Thirty three had positive blood cultures and were taken as 'proved' and remaining as 'probable' sepsis. A band cell neutrophil (B/N) ratio of greater than 0.2 was most sensitive index (92%) followed by raised mESR of greater than 8 mm for 1st hour, whereas leukopenia of greater than 5 x 10(3)/mm3 was most specific index (88%) for the diagnosis of sepsis. Thrombocytopenia of less than 1.5 x 10(5)/cu mm was also taken as positive test for sepsis. A combination of three positive tests had highest positive predictive accuracy (94%) for early diagnosis of sepsis, when compared to single test or two positive test combinations. The best combination of tests was B/N ratio, leukopenia and mESR which can be easily done in a side laboratory.     

Blood leucocyte changes for the early diagnosis of neonatal sepsis

Total leucocyte count, percentage of total neutrophils and band neutrophils were obtained in 20 neonates with proven septicemia and 12 neonates with suspected sepsis. Seventy six blood samples from healthy newborns were also examined to obtain normal hematological values for above parameters. Leucocytosis was present in 25 per cent of cases of both the groups, and total percentage of neutrophils did not vary significantly (30% and 33.3%) in either group. Fifty per cent of neonates with proven sepsis and 25 per cent of neonates with suspected sepsis had elevated band count respectively. The predictive value of elevated band count and simplicity of the test justifies its routine use in early diagnosis of neonatal sepsis.