Alterations in antioxidant status during neonatal sepsis

Septicaemia is a major threat to survival during the early stages of life. There are several reports that suggest that reactive oxygen species (ROs) play a role in a wide variety of diseases. We estimated the activity of xanthine oxidase (XO), malondialdehyde (MDA) content, creatine phosphokinase (CPK) activity, activities of key enzymatic antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and peroxidase (PO), and non-enzymatic antioxidants, viz. uric acid (UA) and albumin (ALB), in 30 neonates with sepsis and 20 age-matched controls. The babies were categorized as preterm/term, early onset/late onset, and shock/without shock, as per clinical and laboratory investigations. The study was carried out to evaluate the status of antioxidant enzymes and non-enzymatic antioxidants with a view to suggesting the introduction of antioxidant therapy in neonatal sepsis. The activities of serum XO, CPK, SOD and GPx, and the content of MDA were found to be significantly elevated in the neonates with sepsis when compared with controls. Conversely, the activity of PO and the levels of UA and ALB were decreased. The septic, full-term neonates registered significantly higher CPK activity (70%) than the preterm septic neonates. However, infants with late-onset and shock sepsis had a significant decrease in CPK activity (p < 0.05) compared with their corresponding sub-groups. Likewise, UA levels were found to be 28% depressed (p < 0.05) in the babies with late-onset sepsis and 51% increased (p < 0.001) in babies with shock compared with their respective sub-groups. Neonates with septic shock also registered a significant elevation in GPx activity (28%) compared with those without shock. This study suggests increased production of ROs in neonates with sepsis, as evidenced by the positive regulation of XO, SOD and GPx activity. The elevation of antioxidant enzymes, however, was not so effective as to protect from cellular damage and thereby result in higher MDA production. It is evident that antioxidant therapy might be useful in the management of neonates with sepsis but further detailed clinico-biochemical investigations are required to define effective antioxidant therapy.     

Dichloroacetate treatment for severe refractory metabolic acidosis during neonatal sepsis

We describe a preterm neonate with documented group B Streptococcus sepsis and associated metabolic acidosis whose lactic acidemia was refractory to conventional sodium bicarbonate therapy but responded well to dichloroacetate treatment.     

Neonatal endocarditis due to staphylococcus aureus as a complication of neonatal sepsis

We present the case of a newborn with bacterial endocarditis with mitral valve involvement as a complication of late-onset sepsis due to Staphylococcus aureus with associated pyelonephritis and meningitis. The diagnosis was confirmed by echocardiogram and blood culture with growth of S. aureus. Treatment was medical and surgical. Neonatal bacterial endocarditis is extremely difficult to diagnose. The signs and symptoms are usually nonspecific and cannot be distinguished from those of sepsis or congenital heart disease. Consequently, a high degree of suspicion is needed for the early diagnosis of this condition. Echocardiography should be performed in children who present sepsis and heart murmur and even in those with staphylococcemia (sepsis due to S. aureus) without associated heart murmur. This investigation enables an early diagnosis of endocarditis to be made and appropriate treatment to be given without having to wait for the development of signs and symptoms that frequently go undetected.     

中性粒细胞粘附分子CD11b表达对新生儿败血症早期诊断价值的研究

目的　观察新生儿败血症中性粒细胞粘附分子CD11b表达的规律 ,并评价其在新生儿败血症早期诊断中的价值。方法　将 5 1例临床疑似败血症的新生儿根据其临床表现及WBC、PLT、血浆CRP和未成熟中性粒细胞数与中性粒细胞总数比值 (I/T)四项指标 ,分为败血症和可疑败血症两组。采用全血流式细胞术检测患儿和 15例正常对照组新生儿中性粒细胞CD11b的平均荧光强度 (MFI)。结果　败血症组 2 3例 ,可疑败血症组 2 8例。两组中性粒细胞CD11b分别为 (32 0± 189)、(4 5 6± 2 13)MFI,均显著低于正常对照组的 (10 90± 338)MFI(t分别为 - 9 0 1、- 7 5 6 ,P均 <0 0 0 1) ,败血症组又低于可疑败血症组 ,差异有显著性 (t=- 2 39,P <0 0 5 )。高CRP组患儿CD11b为 (2 11± 16 4 )MFI,低于低CRP组的 (5 0 5± 2 6 5 )MFI,差异有显著性 (t=2 6 4 ,P <0 0 5 )。中性粒细胞CD11b≤ 6 0 0MFI对疑似败血症新生儿诊断的敏感性、特异性、阳性和阴性预测值分别为 86 3%、10 0 %、10 0 %、6 8 2 % ,CD11b检测阳性率为 86 3% ,高于血培养的阳性率 (17 6 % ) ,差异有显著性 (χ2 m=31 2 ,P <0 0 5 )。结论　新生儿败血症中性粒细胞粘附分子CD11b表达下调 ,其下调与感染严重程度有一定关系。中性粒细胞CD11b的动态检测对早期     

Diagnostic markers for neonatal sepsis

PURPOSE OF REVIEW: To review the current evidence on the use of infection markers for diagnostic evaluation of sepsis in neonates. RECENT FINDINGS: Recent research in immunology has led to the discovery of cell surface antigens, chemokines, cytokines and acute phase proteins that can potentially be used to 'rule in' or 'rule out' sepsis. The diagnostic utilities of key inflammatory mediators, including CD11b, CD64, interleukin-6 and interleukin-8, are promising and likely to become increasingly used as markers of infection for both diagnostic and prognostic purposes. SUMMARY: Serial measurements and use of combinations of markers have been reported to improve sensitivity and negative predictive value of these tests. Current markers are not infallible, however, and do not permit neonatologists to withhold antibiotics in sick infants with suspected infection. Thus, many have emerged as useful indicators for early discontinuation of unnecessary antimicrobial therapy. Some infection markers are also useful for identifying infants with severe infection and adverse prognosis. Advances in flow cytometry have allowed simultaneous measurement of key markers using only minimal blood volume. Judicious selection of a panel of markers with complementary properties could greatly increase the ability of neonatologists to diagnose infection and discern valuable prognostic information.     

Complement components in neonatal sepsis.

Complement components C3, C1q, factor B and breakdown products of C3, i.e. C3c and C3d, were evaluated in the diagnosis and prognosis of sepsis in 24 neonates with proven sepsis. The complement components were measured by electroimmunodiffusion and breakdown products by counterimmunoelectrophoresis (CIEP). The babies with sepsis were found to have decreased levels of C1q and factor B as compared with suitably matched healthy controls. No statistically significant depression was observed in C3 levels of infected babies. However, breakdown products of C3, i.e. C3c and C3d, were detected in 58.3% of these babies. The breakdown products of C3 were not present in any of the healthy controls. The degree of depression of complement components was of no prognostic significance in neonatal sepsis.     

Early-onset neonatal pneumococcal sepsis syndrome.

OBJECTIVE: To report two cases of severe early-onset neonatal sepsis due to Streptococcus pneumoniae, including, to our knowledge, the first reported case of sepsis due to penicillin-resistant S. pneumoniae presenting as early-onset neonatal sepsis. DESIGN: Case reports. SETTING: A level III military and civilian neonatal intensive care unit. PATIENTS: Two infants (gestational ages of 38 and 35 wks), both of whom presented shortly after birth with severe septic shock presumed to be due to group B streptococcus. INTERVENTIONS: Both infants were treated with high-frequency oscillatory ventilation and inhaled nitric oxide, with one infant requiring venoarterial extracorporeal membrane oxygenation. RESULTS: Cultures of blood specimens from both infants yielded S. pneumoniae. For one infant, antibiotic sensitivity testing demonstrated resistance to penicillin, erythromycin, and trimethoprim/sulfamethoxazole. After treatment, both infants recovered well with normal results of examinations and neural imaging studies at the time of hospital discharge. CONCLUSIONS: Clinicians should consider S. pneumoniae as a possible cause of fulminant nonresponsive sepsis in neonates. In areas where antimicrobial-resistant S. pneumoniae is prevalent, when culture results are known, or with a clinical course unresponsive to ampicillin, septic infants may require the addition of a penicillinase-resistant antibiotic to their therapeutic regimen until results of antibiotic sensitivity testing are known. Early transfer to a center with extracorporeal membrane oxygenation should be considered for symptomatic neonates.     

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.     

Salivary C-reactive protein,mean platelet volume and neutrophil lymphocyte ratio as diagnostic markers for neonatal sepsis

Objective

To assess the applicability of salivary C-reactive protein, mean platelet volume, neutrophil-lymphocyte ratio, and platelet lymphocyte ratio in the diagnosis of neonatal sepsis.

Neonatal bacterial sepsis in a neonatal intensive care unit: A 5 year analysis

Objective : To study the pattern of neonatal sepsis in a neonatal intensive care unit (NICU) during a 5 year period and assess the relationship between maternal risk factors and early onset sepsis (EOS).
Methodology : The study reported here was a retrospective analysis of 209 episodes of septicaemia and 5 episodes of bacterial meningitis in 198 newborn infants, 22 of whom died. Eighty-one infants had EOS (≤72h) and 117 infants had late onset sepsis (LOS >72 h). All infants had clinical evidence of sepsis, a computerized haematological score for sepsis of 4 or greater, and either treatment with antibiotics for 7 days or more or had earlier death due to sepsis. The organisms causing neonatal sepsis were analyzed according to the day of onset, gestational age, birthweight and year of infection.
Results : Sepsis occurred in 5.6 per 1000 live births and 3.8% of NICU admissions. There were 81 episodes of EOS and 128 of LOS. Coagulase negative staphylococci (CONS) 38.8%, group B Streptococcus (GBS) 20.1% and Gram-negative bacilli (GNB) 20.1% were the common causes of sepsis; and GBS (50.6%) and CONS (60.9%) were the most common organisms in EOS and LOS, respectively. The mean gestational age and birthweight were heigher in babies with EOS than compared with LOS. The higher likelihood of probable rather than definite infection in infants with EOS was related to more mothers in the EOS group receiving intrapartum antibiotics. GNB infection was more common in their babies.
Conclusions : GBS and CONS were the most common causes of EOS and LOS, respectively. The use of maternal intrapartum antibiotics interferes with neonatal blood culture results. Because blood cultures are not always positive in neonatal septicaemia, a combination of clinical, haematological and other microbiological evidence should be used when diagnosing neonatal septicaemia.