Hospital admissions in the first year of life in very preterm infants

OBJECTIVE: To analyse hospital readmissions to 1 year in infants < 33 weeks' gestation. STUDY DESIGN: Cohort of very preterm infants born in Western Australia. METHODS: Parental social class, history of asthma, race, gestational age, birthweight, sex, severity of respiratory disease and oxygen requirement at 28 days chronic lung disease (CLD), 36 weeks and term, maternal smoking, cohabitation with siblings, breast-feeding duration and hospital readmissions were recorded prospectively. RESULTS: Data were available for 538 of 560 (96%) infants discharged. Eight died in the first year. Two hundred and twenty-five infants (42%) had 443 readmissions, of which 370 were medical and 73 surgical. Risk factors for medical readmission were Aboriginal race, male sex and CLD. Breast-feeding was protective. Risk factors for surgical admission were male sex, lower gestation, severe hyaline membrane disease, severe CLD and birthweight < 10th centile. CONCLUSIONS: Readmission is common after very preterm birth. Risk factors for medical and surgical admission differ with CLD being the only perinatal factor associated with both medical and surgical admission.     

Behaviour at 2 years of age in very preterm infants (gestational age < 32 weeks)

AIM: The objective of this study was to determine behavioural outcome and risk factors for abnormal behaviour at 2 y corrected age in very premature infants in a regionally defined, prospective cohort study. METHODS: The Leiden Follow-Up Project on Prematurity includes all liveborn infants of < 32 wk gestational age, born in 1996/1997 (n = 266). Behaviour was assessed with the Child Behaviour Checklist 2-3. RESULTS: An analysis of 158 questionnaires of 206 survivors (77%) was carried out. Fourteen children (9%) had a total problem score > p90 ("clinical range"). This percentage is comparable with the 10% found in a sample of 2- to 3-y-olds from the Dutch general population. Univariate analysis showed higher syndrome scale scores in one or more of the Child Behaviour Checklist scales in children of lower gestational age, small for gestational age (birthweight < p10), with neurological abnormalities at term or at 2 y and of non-Dutch origin. Lower socioeconomic status and postnatal treatment with dexamethasone were associated with higher scores in the somatic problems scale and lower maternal age at birth with a higher total problem score. After correction for confounding variables, the associations between small for gestational age, neurological abnormalities at 2 y and the anxious/depressed and/or withdrawn scales remained significant. CONCLUSION: The prevalence of behavioural problems at 2 y corrected age in this cohort of very premature infants (gestational age < 32 wk) was comparable with that in a general population sample. Children born small for gestational age or with neurological abnormalities at 2 y of age had higher syndrome scale scores, mainly for anxious/depressed and/or withdrawn behaviour.     

Epidemiology of necrotizing enterocolitis--Part I: Changing regional trends in extremely preterm infants over 14 years

OBJECTIVES: Advances in perinatal care include exogenous surfactant, unequivocal acceptance of antenatal steroids and in utero and ex utero transfers to tertiary centres. Increased survival of extremely premature infants may change the incidence and outcome of necrotizing enterocolitis (NEC). Our aim was to examine the trends in the incidence of NEC, surgery and mortality in infants of 24-28 weeks gestation in a retrospective regional review of three epochs over a span of 14 years. METHODS: Radiologically or surgically proven NEC cases were determined from the New South Wales Neonatal Intensive Care Unit Study database. Three epochs were examined. A total of 360 infants were admitted in 1986-87 (Epoch 1), 622 in 1992-93 (Epoch 2) and 673 in 1998-99 (Epoch 3). RESULTS: There was an increase in neonatal intensive care unit admissions and a decrease in early and overall mortality of these very premature infants across the epochs. None of the early deaths was due to NEC. The incidence of NEC decreased in post day 5 survivors: 33 cases in Epoch 1 (12%), 60 cases in Epoch 2 (12%) and 34 cases in Epoch 3 (6%, P < 0.001). There was no change in surgical intervention (45%, 57% and 41%, respectively) or mortality due to NEC (37%, 27% and 32%). The reduced incidence of NEC was not singularly influenced by antenatal steroids, exogenous surfactant or outborn delivery. In a multivariate analysis, only later epoch of birth was independently associated with reduced NEC risk. CONCLUSIONS: With improved care and survival of extremely premature infants, the incidence of NEC has decreased, but it remains a disease of high mortality and morbidity.     

氢化可的松防治早产儿支气管肺发育不良的研究进展

正支气管肺发育不良(bronchopulmonary dyspla-sia,BPD)是导致早产儿不良预后的重要原因,具有很高的发病率~([1])。目前BPD防治手段十分有限,由于炎症在BPD发病机制中起非常重要的作用~([2]),激素具有良好的抗炎作用,在20世纪90年代曾被广泛应用于BPD的防治~([3])。大量临床研究表明地塞米松能够降低BPD的发生率、加快撤机等,具有     

Recent advances in the management and prophylaxis of respiratory syncytial virus infection

Respiratory syncytial virus (RSV) infection is an important cause of morbidity, particularly in prematurely born infants who have had chronic lung disease. Current therapy is essentially supportive. Overall, the results of randomized trials do not support the use of bronchodilators, corticosteroids or Ribavirin. Nitric oxide and exogenous surfactant may improve the respiratory status of those infants who require ventilatory support. Nosocomial infection can be reduced by appropriate handwashing. There is no safe and effective vaccine for use in infants. Immunoprophylaxis reduces hospitalization and requirement for intensive care. Palivizumab, a humanized monoclonal antibody, is preferred to RSV immune globulin as the immunoprophylactic agent. Immunoprophylaxis should be reserved for infants at highest risk of severe respiratory syncytial virus infection, if this strategy is to be used most cost-effectively.     

Wheezing illness and re-hospitalization in the first two years of life after neonatal respiratory distress syndrome

OBJECTIVES: To determine the impact of respiratory distress syndrome (RDS) on wheezing illnesses and re-hospitalizations in children as old as 2 years of age. STUDY DESIGN: We observed 2 geographically defined cohorts of children with RDS born after 26 weeks of gestation during 1990 to 1995 and 1996 to 1999 and gestationally paired control subjects. Recurrent wheezing illness and the re-hospitalizations caused by a respiratory condition were recorded. RESULTS: In the first year of life, 47 of 224 infants with RDS and 18 of 224 control subjects born in 1990 to 1995 had recurrent wheezing illness (P <.005) compared with 21 of 109 infants with RDS and 14 of 109 control subjects in the latter cohort (P=.27). A higher number of infants with RDS were readmitted to the hospital (25% versus 13%, P=.002) in the former period, and they spent more days in hospital during both periods. The frequencies of wheezing remained constant in the second year of life, but hospital admissions decreased. Siblings at home, male sex, and bronchopulmonary dysplasia were additional risk factors of wheezing illnesses. CONCLUSION: RDS increases the incidence of wheezing illnesses during the first 2 years of life. Changes in the management of RDS during the 1990s was associated with a decreased incidence of subsequent RDS-associated respiratory morbidity.     

Clinical characteristics of chronic lung disease without preceding respiratory distress syndrome in preterm infants

BACKGROUND: Recently, the incidence of atypical presentation of chronic lung disease (CLD) that develops in infants without a history of preceding respiratory distress syndrome (RDS) is increasing. Therefore, the clinical characteristics of CLD without RDS in comparison with CLD with RDS were assessed. METHODS: Prospective cohort analysis was done from 117 very low-birthweight infants who were born in Seoul National University Hospital and survived more than 36 weeks postmenstrual age (PMA). RESULTS: Of the 117 infants analyzed, CLD developed in 44 infants (38%). Among these 44 infants, CLD with RDS developed in 27 infants (23%) and CLD without RDS developed in 17 infants (15%). Each type of CLD was subgrouped according to the presence of chorioamnionitis (CA): RDS(+)CA(+) CLD (n = 8) and RDS(+)CA(-) CLD (n = 19); and RDS(-)CA(+) CLD (n = 12) and RDS(-)CA(-) CLD (n = 5). There were no significant differences in the demographic characteristics between CLD with RDS and CLD without RDS. Chorioamnionitis was significantly more common in CLD without RDS, while patent ductus arteriosus was more common in CLD with RDS. Although the severity of initial respiratory failure was not greater than that of CLD with RDS, CLD without RDS showed a gradually increasing chronic oxygen requirement pattern. Chronic oxygen requirement pattern showed that infants with RDS(+)CA(+)CLD required the highest concentrations of oxygen not only initially but also thereafter until the 28th day of life and 36 weeks PMA. CONCLUSIONS: Although CLD without RDS was still less common than CLD with RDS, it comprised over a third of all cases of CLD in our study. Clinical characteristics and chronic oxygen requirement pattern of CLD without RDS seems to be less severe than those of CLD with RDS. Our data suggest that CLD without RDS may be developed by causes other than initial acute lung injury. Chorioamnionitis may be one of antecedents of CLD without RDS.     

Rehospitalization in the first 2 years of life in children born preterm

Aim: Aim of the study is to investigate the frequency of and predictors for rehospitalization within the first 2 years of life among preterm infants. Methods: All children born before 32 weeks of gestation in Northern Tyrol between January 2003 and July 2008 were prospectively enrolled. Data on rehospitalizations were obtained from hospital admission records. The association between candidate risk factors and readmission was analysed by means of logistic regression analysis. Results: In the first and second years of life, 151 and 93 of 377 children (40.1% and 24.7%), respectively, were readmitted to one of the hospitals in Northern Tyrol. The most common causes of rehospitalization were respiratory disorders, accounting for 42.1% and 47.4% of total readmissions in the first and second years of life. Chronic lung disease (CLD), male sex and smoking in pregnancy were risk conditions relevant to readmission in the first year of life, but only CLD in the second year. Conclusion: Infants born before 32 weeks of gestation have a high risk of rehospitalization with respiratory illness significantly contributing to postdischarge morbidity. Neonatal intensive care should aim to further improve respiratory health in preterm infants, and adequate follow‐up services must be offered.     

Cost-effectiveness analysis of palivizumab as respiratory syncytial virus prophylaxis in preterm infants in Sweden

Aim: To investigate the cost‐effectiveness of palivizumab vs. no prophylaxis for respiratory syncytial virus (RSV) infection in preterm infants in Sweden. Methods: A probabilistic Markov model was populated using a nationwide register linkage and data from the literature. Cost‐effectiveness was investigated from a societal perspective over a lifetime for infants born at <29 weeks of gestation. Palivizumab was modelled using assumptions for its direct effect on RSV hospitalization risk and an indirect effect (via decreased RSV hospitalization) on subsequent asthma and mortality during the epidemic. Costs and effects were discounted by 3%. Results: In the base case, prophylaxis resulted in an additional 0.102 quality‐adjusted life‐year (QALY) at a cost of 20 000 SEK relative to no prophylaxis (incremental cost‐effectiveness ratio [ICER] 195 000 SEK/QALY). The probability of prophylaxis being cost–effective was 99% at a willingness‐to‐pay of 500 000 SEK/QALY. Assumptions about a causal association between RSV infection and subsequent asthma had a moderate impact, while exclusion of the indirect prophylaxis effect on mortality increased the ICER to 492 000 SEK/QALY. When excluding both of these, prophylaxis was not cost–effective. Conclusion: Based on a willingness‐to‐pay of 500 000 SEK/QALY, palivizumab was found to be cost–effective compared with no prophylaxis for infants born at <29 weeks if severe RSV infection was assumed to increase subsequent asthma or mortality risk.     

Lipoproteins in preterm and small-for-gestational-age infants during the first week of life

Plasma lipoprotein levels and composition have been determined in preterm and small-for-gestational-age (SGA) infants, and compared to full-term infants, during the first week of life. Significantly lower levels of HDL and higher levels of VLDL were found in both preterm and SGA infants in comparison to full-term healthy infants. These results suggest a low capacity to metabolize VLDL. Preterm infants showed a behaviour similar to full-term infants with regard to the changes in lipoprotein composition. Small-for-gestational-age infants showed a higher lipoprotein lipid content than preterm infants. A low ratio of cholesteryl ester to free cholesterol (CE/FC) was found in both preterm and SGA infants suggesting a reduced lecithin: cholesterol acyl transferase (LCAT) activity. In preterm infants we observed no changes in the CE/FC ratio during the first week of life, whereas in SGA infants this ratio increased after birth.     

胎龄<32周早产儿支气管肺发育不良临床特点

目的 分析支气管肺发育不良（BPD）患儿6年的流行病学特点及不同时期BPD临床特点的变化。方法 回顾性收集2015年1月至2020年12月确诊BPD患儿的出生后及母亲孕期的临床资料,根据胎龄和出生体质量分组,比较各组BPD发生率变化趋势;并根据确诊时间分为2015—2017年与2018—2020年两组,比较两组临床特点。结果 2015—2020年共收治1 237例<32周胎龄的早产儿,其中BPD患儿155例（12.5%）。不同胎龄组间BPD发生率的差异有统计学意义（P<0.001）,≤26周早产儿BPD发生率最高,BPD发生率随着胎龄的增大而降低。2015—2020年各年份之间BPD患儿的胎龄分布差异有统计学意义（P=0.001）。2015和2016年以28～32周胎龄的比例较高,2017—2020年以26～29⁺⁶周胎龄的比例较高。不同出生体质量组间BPD发生率的差异有统计学意义（P<0.001）,≤750g 早产儿BPD发生率最高,BPD发生率随着出生体质量的增大而降低。2015—2020年各年份之间BPD患儿的出生体质量分布差异有统计学意义...     

Respiratory syncytial virus infection: its role in aeroallergen sensitization during the first two years of life

Our aim was to study the influence of infection with the respiratory syncytial virus (RSV) in non-hospitalized infants on sensitization to aeroallergens and the early manifestation of atopy. Six hundert and nine infants from the prospective German Multicenter Cohort Study on Atopy were included, 38% of whom had an elevated atopic risk. RSV IgG and IgM antibodies were tested by ELISA with gradient purified RSV antigen. Specific IgE against mites, cat dandruff, birch and grass pollens and relevant nutritional antigens were tested with CAP-RAST-FEIA (Pharmacia, Sweden). Of the cord sera 99% were positive for RSV-IgG, 44. 7% at one year and 64. 2% (n=265) at two years of age. The positivity rate after 12 months varied with the season of birth, the number of siblings and the degree of exposure to tobacco smoke; and correlated closely with attacks of wheezing during infancy. Twenty (2. 8%) children were found to be sensitized against at least one aeroallergen at one year, and 28 (10. 5%) at two years. By the first birthday, mite sensitization (n=3) could only be seen in the RSV-infected children; grass pollen sensitization (n=9) was associated with RSV seropositivity (logistic regression model including the confounders mentioned above: with RSV IgG p=0.04 > and IgM p=0.0006), as was birch sensitization (n=5) with RSV IgM (p=0.009). No such differences could be detected at two years. No correlation of RSV seropositivity to any allergic manifestation could be found. We conclude, that it is only in the first year of life, that RSV infection plays a significant role in promoting sensitization against aeroallergens, which do not at this time produce allergic symptoms.     

Expression of chemokine receptor CX3CR1 in infants with respiratory syncytial virus bronchiolitis

Respiratory syncytial virus (RSV) glycoprotein G mimics fractalkine, a CX₃C chemokine, which mediates chemotaxis of leukocytes expressing its receptor, CX₃CR1. The aim of this study was to examine the relationship between RSV infection and expression of perforin and IFN- γ in CX₃CR1-expressing peripheral blood CD8⁺ T cells. Samples were collected from infants with RSV bronchiolitis, both in the acute and convalescence phase (n = 12), and from their age- and sex-matched healthy controls (n = 15). Perforin expression and IFN- γ secretion in CX₃CR1⁺ CD8⁺ T cells were assessed by four-color flow cytometry. The NF- κ B p50 and p65 subunit levels were also determined as markers of RSV-induced inflammation. Study results showed perforin and CX₃CR1 expression to be significantly lower in the convalescent phase of infected infants than in healthy controls. There was no significant difference in IFN- γ secretion and NF- κ B binding activity between two time-points in RSV-infected infants, or when compared with healthy controls. Infants with prolonged wheezing had lower acute-phase CX₃CR1 levels in peripheral blood. These data indicate existence of an event persisting after acute RSV infection that is able to modulate effector functions of cytotoxic T cells, and also link disease severity with CX₃CR1 expression.     

Urinary β2‐microglobulin and bronchopulmonary dysplasia: Trends in preterm infants

Background

The developmental process of bronchopulmonary dysplasia (BPD) is not identical between very preterm infants born small for gestational age (SGA) and those born appropriate for gestational age (AGA). In this study, we compared the pattern of the inflammatory response in infants of each group, by measuring urinary β2‐microglobulin (Uβ2M) as an alternative, concise, and less‐invasive biomarker.

Methods

Uβ2M and clinical details were examined at birth and at 4 weeks of age in 146 very preterm infants.

Results

Of the 57 infants diagnosed with BPD, 18 were SGA, and 39 were AGA. Uβ2M at birth was significantly lower in SGA BPD infants than in AGA BPD infants, but it increased with time. The prevalence of chorioamnionitis (CAM) was significantly lower in SGA BPD infants than in AGA BPD infants, while that of pregnancy‐induced hypertension was the opposite.

Conclusions

Exposure to prenatal factors other than CAM may sensitize fetal lungs to become vulnerable to postnatal inflammation in very preterm SGA infants with BPD.     

2004～2005年冬春季急性下呼吸道感染患儿RSV亚型的检测及分析

目的分析2004～2005年冬春季呼吸道合胞病毒(RSV)流行季节的亚型分布情况。方法采用直接免疫荧光法检测2004年10月～2005年4月间因急性下呼吸道感染住院儿童1040例鼻咽部分泌物中的常见病毒病原,随机选择RSV阳性标本174例,采用间接免疫荧光检测RSVA、B亚型,分析检测结果。结果1040例中,RSV阳性497例(47.8%),其中174例标本中,检测出RSVA亚型23例(13.2%),B亚型105型(60.4%),A、B亚型混合感染36例(20.7%),无法确定亚型的10例(5.7%)。检测期间各月份间、不同的年龄组间和临床诊断间的RSV亚型分布差异均无显著性意义(P>0.05),都以B亚型为主。结论2004～2005年冬春季RSV仍是儿童急性下呼吸道感染的主要病原,以B亚型为主;并有两种亚型同时感染的情况。