Parainfluenza virus type 3 outbreak in a neonatal intensive care unit

Parainfluenza virus (PIV) is a respiratory pathogen in young children and is second only to the respiratory syncytial virus (RSV) as a cause of lower respiratory tract infection. PIV type 3 (PIV3) is the most severe. Herein we describe an outbreak of PIV3 in three infants in a neonatal intensive care unit. They were diagnosed on virus culture from pharyngeal swabs. We prevented the spread of the virus using standard infection control procedures and isolation of the symptomatic infants. One infant had severe chronic lung disease and was complicated with recurrent wheezing for a long time. Because RSV and PIV have many structural, pathogenic, epidemiologic, and clinical similarities, we speculate that PIV infection causes recurrent wheezing, as observed with RSV infection. Therefore, physicians must consider recurrent wheezing at the time of treatment of PIV infection early in life.     

Improved outcomes following the introduction of surfactant to an Australian neonatal unit

Objective : To study the impact of the introduction of artificial surfactant therapy for hyaline membrane disease (HMD) in an Australian neonatal intensive care unit.
Methodology : Infants <32 weeks gestation admitted between June 1991 and Dec 1993 who received treatment with artificial surfactant were compared with infants admitted during the preceding 30 months who would have been candidates for such treatment.
Results : For treated infants with gestations in the range 24-27 weeks, there was a significant reduction in neonatal death (adjusted odds ratio 0.28) and a significant increase in the incidence of chronic lung disease (CLD) (adjusted odds ratio 3.4). With gestations in the range 28-31 weeks, there was no significant change in neonatal death or CLD, but there was a significant reduction in incidence of pneumothorax (adjusted odds ratio 0.32).
Conclusions : A reduced incidence of pneumothorax and neonatal death following the introduction of artificial surfactant. therapy was readily demonstrable in the Australian setting.     

Ureaplasma urealyticum in a neonatal intensive care population

The incidence of Ureaplasma colonization at birth and its effect on the development of chronic lung disease (CLD) and on mortality was studied in a neonatal intensive care population. Ureaplasma colonization was associated with a birthweight < 1000 g (odds ratio [OR] 3.45 confidence intervals [CI] 2.13-5.60) and a gestational age < 30 weeks (OR 2.54 CI 1.71–3.79). In a case-controlled study of 112 infants, significant associations with Ureaplasma colonization were maternal pyrexia in labour ( n = 38 vs 21; P = 0.015), the requirement for antibiotics in labour ( n = 39 vs 16; P = 0.0005) and vaginal delivery ( n = 78 vs 58; P = 0.009). Risk factors associated with the development of CLD were birthweight < 1000 g (OR 3.77 CI 2.53–5.62) and delivery by Caesarean section (OR 1.65 CI 1.11–2.43). Within the group delivered by Caesarean section. Ureaplasma colonization was also associated with an increased risk of CLD (OR 1.97 CI 1.08–3.62). Ureaplasma colonization of infants at birth is associated with factors suggestive of maternal chorioamnionitis as well as preterm birth and low birthweight. In infants delivered by Caesarean section, Ureaplasma colonization is associated with an increased risk of chronic lung disease.     

Death following elective tracheostomy decannulation in chronic neonatal lung disease

Widespread air leak as a fatal complication of elective tracheostomy decannulation in a child aged 20 months with chronic neonatal lung disease (CNLD) is reported. We discuss likely mechanisms for the development of air leak following tracheostomy tube removal in young children with obstructive airways disease and suggest that this procedure be performed in an intensive care or high dependency unit.     

Subependymal caudothalamic groove hyperechogenicity and neonatal chronic lung disease

Chronic lung disease is associated with several poorly defined risk factors for impaired cerebral development. Late neonatal onset of subependymal hyperechogenic areas in the caudothalamic groove has been reported in association with dexamethasone treatment and postnatal cytomegalovirus infection. We reviewed charts of 18 patients who developed subependymal hyperechogenicity beyond the first week of life, as well as charts of 79 patients belonging to a prospective surfactant study group. Thirteen of the 18 patients with subependymal hyperdensities had been treated with surfactant and were all found in the subgroup with chronic lung disease. In the surfactant-treated patients who did not develop chronic lung disease, we could not find any patient with subependymal hyperdensities. From the remaining five patients with ultrasound lesions, but who were not treated with surfactant, three had developed chronic lung disease. There was no evident association with dexamethasone treatment or cytomegalovirus infection. Our results support the idea of an association between chronic lung disease and the described echographic lesions in the caudothalamic groove, but the nature of the link between them is still unclear.     

Comparison of neonatal outcome for inborn and outborn very low-birthweight preterm infants

Background:  The aim of the present study was to compare the neonatal outcome of very low-birthweight (VLBW) preterm infants with regard to inborn and outborn status in a medical center of Southern Taiwan, where short-distance neonatal transport is the rule and maternal transport was not well established.
Methods:  This retrospective study included outborn VLBW preterm infants admitted to the neonatal intensive care unit of Chang Gung Memorial Hospital at Kaohsiung after neonatal transport during the period from 1999 through 2003. An equal number of inborn preterm infants matched for gender and birthweight were included as controls. Infants with lethal congenital anomalies or who died in the delivery room were excluded. Data were collected from reviewing medical charts.
Results:  A total of 34 inborn VLBW infants and 34 outborn VLBW infants with neonatal transport were included. Chronic lung disease (CLD) was significantly more frequent in the outborn group according to McNemar test ( P  = 0.0124) and logistic regression. Logistic regression also showed that outborn status ( P  = 0.0173) and birthweight ( P  = 0.0024) were the two most important risk factors for development of CLD.
Conclusion:  Well-trained short distance neonatal transport is useful and valuable for VLBW infants with gestation age of 27–34 weeks in Southern Taiwan. The respiratory outcome, however, was poor in the outborn group in terms of incidence of CLD. To improve the respiratory outcome, further modification of respiratory care during transportation or antenatal maternal transport is crucial.     

Chest radiograph abnormalities in very low birthweight survivors of chronic neonatal lung disease

Objective : To determine whether the neonatal chest radiograph (CXR) at 28 days in very low birthweight (VLBW) infants who develop chronic neonatal lung disease (CNLD) predicts oxygen therapy duration or CXR abnormalities in early childhood. Also, to assess the inter-observer reliability of the radiologists scoring the CXR.
Methodology : Clinically well survivors of CNLD ( n = 46) had neonatal CXR scored (mean age 28.5 days) and compared with current CXR (mean age 40 months). The CXR were scored independently and 'blindly' by two paediatric radiologists using a standardized scoring system (range 0-10).
Results : There was no correlation between neonatal CXR scores and current CXR scores for either radiologist. There was no association between CXR severity scores and duration of oxygen therapy for either neonatal or current CXR. Radiologist A scored the current CXR significantly more abnormal than radiologist B [medians (range): 3 (1-6) vs 1 (0-5), P <0.001] with reasonable correlation ( r = 0.593, P <0.005) but worse than chance agreement (kappa = - 0.034). The median scores for the neonatal CXR were similar [1.5 (0-8) vs 2 (0-8), P = 0.789] and again there was good correlation ( r = 0.760, P <0.0005) although poor individual agreement (kappa = 0.243) between radiologists.
Conclusions : Follow-up CXR abnormalities in VLBW infants with CNLD are usually minor and are not predictive of the duration of oxygen therapy that will be required nor of the CXR appearance in early childhood. Considerable inter-observer variation exists in the interpretation of the CXR in CNLD.     

Association of development of chronic lung disease of newborns with neonatal colonization of Ureaplasma and cord blood interleukin‐8 level

Background: The aim of the present study was to investigate the association of chronic lung disease (CLD), neonatal Ureaplasma colonization, and interleukin‐8 (IL‐8) level of cord blood in preterm infants. Methods: In 77 infants of <32 weeks gestation, the relationship between IL‐8 level of cord blood, neonatal colonization of Ureaplasma, histological chorioamnionitis (CAM), and development of CLD was studied. Results: Five infants died and 29 infants developed CLD. The CLD group had significantly lower gestation (mean ± SD: 26.6 ± 1.8 weeks) compared with the infants without CLD (28.9 ± 1.9 weeks, P < 0.0001). Logistic analysis showed that the development of CLD was associated with gestational age (odds ratio [OR], 0.5; 95% confidence interval (CI): 0.4–0.8) and Ureaplasma colonization (OR, 4.1; 95%CI: 1.2–14.4). Ureaplasma colonization was also associated with CAM (OR, 6.5; 95%CI: 1.8–23.5), absence of respiratory distress syndrome (OR, 6.2; 95%CI: 1.3–30.5), and development of CLD (OR, 4.0; 95%CI: 1.1–15.3). Elevated cord blood IL‐8 ≥100 pg/mL was associated with female sex and the isolation of microorganisms (OR, 49.4; 95%CI: 4.6–525). Conclusion: The development of CLD defined by oxygen requirement at 36 weeks was associated with neonatal Ureaplasma colonization but not with IL‐8 level of cord blood. Elevated cord blood IL‐8 was associated with neonatal microorganisms isolation.     

Effects of body position on blood gases and lung mechanics of infants with chronic lung disease during tube feeding

BACKGROUND: The effects of body position and feeding on lung mechanics and blood gases in very low birthweight infants with chronic lung disease (CLD) is not fully elucidated. METHODS: Seven very low birthweight infants who were being mechanically ventilated because of CLD were examined. They were enrolled in this study when their feeding volume exceeded 100 mL/kg per day. Each patient was kept on the same position (either prone or supine) during feeding. Feeding was given by a nasogastric tube for over 1 h every 3 h. Blood gases and lung mechanics were evaluated before, 20 min and 40 min after the initiation of the feeding and at the end of the feeding. RESULTS: The prone position resulted in a significant increase in arterial oxygen saturation during feeding. The tidal volume in the prone position was significantly larger than in the supine position only before feeding. There were no significant differences in minute ventilation between these positions during the study. Pulmonary resistance was not different in either position, but the static compliance and the work of breathing of spontaneous breaths were improved significantly when the infants were in the prone position. In the supine position, work of breathing increased and static compliance decreased significantly with time, while in the prone position, those values did not change significantly. CONCLUSION: The improvement in lung mechanics may partly explain better oxygenation obtained in the prone position. The prone position could decrease energy expenditure for spontaneous breathing and may shorten the period of ventilatory support for very low birthweight infants with CLD.     

Risk factors of neonatal respiratory distress following vaginal delivery and caesarean section in the German population

Background: The incidence of caesarean section (CS) is steadily rising world-wide. In particular, CS on maternal demand is performed more frequently. In parts, this might be due to insufficient information of pregnant women about neonatal risks of CS. We sought to specify neonatal outcomes following different modes of delivery, i.e. vaginal delivery, primary CS and secondary CS and to define risk factors for respiratory morbidity and hospitalization.
Methods: We analysed 2073 births (gestational age > 35 weeks) during a two-year period at a tertiary obstetric and neonatal centre in Germany. Statistical analyses were performed for single parameters by SPSS as well as by logistic regression to account for possible confounders. Furthermore, extensive model calculation was done.
Results: Respiratory morbidity was increased following primary and secondary CS (p = 0.001). By multiple logistic regression, the strongest effect on respiratory symptoms was seen with gestational age, each week more in utero reducing the risk by an odds ratio (OR) of 0.69 (95% CI: [0.61; 0.79]; p = 1.9 × 10⁻⁸). Furthermore, a significant interaction between mode of delivery and gestational age was found for the risk of respiratory symptoms (p = 0.0035).
Conclusion: For every eight newborns delivered by primary CS one more than expected with vaginal delivery is hospitalized. It is highly relevant to recognize that each week of gestational age reduces the risk of respiratory symptoms, especially if primary CS is performed. The higher rate of respiratory morbidity and neonatal admission following CS should be clearly recognized in counselling of pregnant women.     

激素对新生鼠高氧肺损伤及血清前列腺素E2、白三烯B4的影响

目的研究产前与产后激素应用对新生鼠高氧肺损伤及血清前列腺素E2、白三烯B4的影响。方法将新生鼠分为产前激素+高氧组、生后激素+高氧组、高氧对照组与空气对照组,每组14只,分别置高氧或空气中14 d。观察指标包括新生鼠病死率、体质量、肺系数、辐射状肺泡计数(RAC)、组织病理变化。原位末端标记法(TUNEL)检测肺泡细胞凋亡指数(AI),酶联免疫吸附法(ELISA)测定血清中PGE2、LTB4值。结果三组置高氧中新生鼠存活率与体质量均明显低于空气对照组(P均<0.05),肺系数则明显高于空气对照组(P<0.05),但三组间比较差异无统计学意义(P>0.05)。置高氧中三组新生鼠肺组织病理变化明显。空气对照组的RAC最高,两组激素组RAC高于高氧对照组(P<0.05),而使用激素的两组间差异无统计学意义(P>0.05)。空气对照组肺组织中可见少数凋亡细胞,AI低于其余各组(P<0.05)。高氧对照组AI高于激素组(P<0.05),激素组间两组比较差异无统计学意义(P>0.05)。四组中空气对照组的PGE2最低(P<0.05),高氧三组间比较差异无统计学意义(P>0.05)。空气对照组LTB4也最低(P<0.05)...     

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.     

Prediction of chronic neonatal lung disease on day 4 of life

Clinical parameters, available on day 4, were collected for 204 ventilated neonates <32 weeks gestation. Logistic regression was used to identify factors significantly and independently associated with chronic neonatal lung disease (CNLD) at 36 weeks postconception, which developed in 29% of neonates. At 36 weeks birth weight, peak inspiratory ventilator pressure and requirement for assisted ventilation on day 4 were such factors. The logistic regression equation for this association was applied to each infant resulting in a value between 0 and 1. By knowing which neonates developed CNLD, the discriminatory ability of this value was assessed. A receiver-operator characteristic curve for this value had an area under the curve of 0.97 (SE 0.03) in an unrelated population. A logistic equation value >0.4 had a sensitivity of 90% and a specificity of 88% in predicting CNLD at 36 weeks.     

Risk factors for the different types of chronic lung diseases of prematurity according to the preceding respiratory distress syndrome

BACKGROUND: Recently, atypical chronic lung disease (CLD) of prematurity that develops in the absence of preceding respiratory distress syndrome (RDS) have been observed frequently. The specific risk factors for atypical CLD that are presumed to be different from those for classical CLD that develops following RDS were assessed. METHODS: Prospective cohort analysis was done from 115 very low-birthweight infants who were born in Seoul National University Hospital, Seoul, Korea, and survived more than 36 weeks postmenstrual age or 28 days of life. All subjects were classified into either a preceding RDS group (n = 35) or a non-RDS group (n = 80). Logistic regression analysis was done for the multivariate assessment of specific risk factors for CLD in both groups. RESULTS: The analysis showed that short gestational age (GA; relative risk [RR], 3.1 per 1 week decrement; 95% confidence intervals [CI], 2.7-3.4), of the male gender (RR, 9.8; CI, 0.9-112), and poor response to surfactant (RR, 14; CI, 1.2-156) were significant risk factors for CLD in the preceding RDS group. In the non-RDS group, chorioamnionitis was one of the significant risk factors for CLD (RR, 4.8; CI, 1.1-21) along with short GA and high mean airway pressure (MAP) during the first 3 days of life. CONCLUSION: Chorioamnionitis was a risk factor for atypical CLD in addition to short GA and high MAP during the early postnatal period, and poor response to surfactant was a risk factor for classical CLD in addition to short GA and being male. Therefore, CLD is considered to have type-specific risk factors.     

Point-of-care glucose monitoring on the neonatal unit

Aim: This study aims to compare the accuracy and precision of the Nova StatStrip glucometer against the Radiometer ABL gas analyser. Based on the results, to establish if the Nova StatStrip glucometer could be adopted as a reliable alternative for near‐patient glucose monitoring on the neonatal unit. Methods: Seven hundred twenty‐eight paired samples were collected prospectively from babies on a neonatal intensive care unit. Analytical performance of the Nova StatStrip glucometer was assessed based on the ISO 15197 criteria and the American Diabetic Association standards. Its performance compared with the Radiometer ABL gas analyser was assessed statistically using Bland–Altman analysis and clinically by use of an error grid. Results: A percentage of 98.8 of StatStrip values less than 4.2 mmol/L and 97.9% of values greater than 4.2 mmol/L met the ISO criteria. Bland–Altman analysis showed good correlation between the readings. An error grid showed that most infants would be appropriately managed for hypoglycaemic episodes as per local guidelines. Conclusions: The Nova StatStrip performed well on statistical analysis compared with the Radiometer. Very few hypoglycaemic patients would be missed using the Nova StatStrip glucometer. We would recommend its use on our unit.     

Predictors of chronic lung disease in the 'CPAP era'

OBJECTIVE: To assess predictors of chronic lung disease (CLD), in infants requiring nasal continuous positive airway pressure (CPAP) support in the first 4 weeks of life. METHODS: A retrospective case note audit of infants of birthweight 1250 g or less was undertaken. RESULTS: Of 290 infants identified, 50% were initially treated with ventilation, 41% with CPAP, 4% required no support, and 5% had care withdrawn. Of infants initially treated with CPAP, 23% subsequently required ventilation. Overall mortality was 19%, with a further 21% of infants developing CLD. For infants requiring CPAP support, requirement for supplementary oxygen at between 10 and 21 days predicted increased risk of CLD, and receiver operating characteristic curves suggest requirement for supplementary oxygen at 14 days to be the most reliable cut-off (area under curve = 0.72). Positive predictive values for future CLD or death for FiO2 .25, .30 and .40 while on CPAP at 14 days were 0.56, 0.61 and 0.76, respectively. CONCLUSIONS: CLD remains prevalent in very low birthweight infants in the CPAP era. Oxygen requirement at 14 days is the strongest predictor of CLD. Infants requiring 30% oxygen or more while on CPAP at 14 days have a 60% risk of subsequent CLD or death.     

Chronic lung disease in very low birthweight infants: A prospective population-based study

A prospective population-based study of chronic lung disease among all very low birthweight infants (birthweight 500-1499 g) born in New Zealand in 1986 is reported. Of 413 of these infants admitted to neonatal units, 355 (86%) survived to 28 days. An additional 50 infants were recorded as liveborn but died in the labour ward or other place of birth. Both observed survival and survival adjusted for birthweight, gestation and gender were significantly (P less than 0.05) better in larger centres. Oxygen requirement was assessed at 28 days of age, 36 weeks equivalent gestation and 84 days of age, when 38.6, 23.1 and 13.8% of infants, respectively, were being treated with oxygen. To examine the joint effects of predictor variables on oxygen requirement at each age, the data were analysed using multiple logistic regression methods. At 28 days, lower birthweight, shorter gestation, respiratory distress syndrome (all P less than 0.0001), and gender and hospital principally caring for the infant (both P less than 0.05) were significantly associated with treatment with oxygen. In comparison with other studies, New Zealand appears to have a relatively high rate of chronic lung disease. We speculate that a contributing factor may be the small size of some regional neonatal units.     

The role of matrix metalloproteinases -9 and -2 in development of neonatal chronic lung disease

AIM: Matrix metalloproteinases (MMPs) -9 and -2 degrade type-IV collagen, a major constituent of lung basement membrane, and may have a role in the pathogenesis of neonatal chronic lung disease (CLD). We determined factors influencing MMP levels in neonatal bronchoalveolar lavage (BAL) fluid to establish whether an imbalance between MMP and its inhibitor could be implicated in CLD. METHODS: We measured MMP-9 and -2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in 316 BAL fluid samples from 121 babies of gestational ages 23 to 42 wk over the first 14 d of life to determine effects of gestation and postnatal age. Median MMP-9, -2, TIMP-1 and MMP-9/TIMP-1 ratio in BAL were further studied in a subgroup of 85 babies <33 wk gestation to determine their ability to predict CLD and to establish effects of antenatal corticosteroid therapy (ANCS). RESULTS: MMP-9, -2 and TIMP levels did not vary with postnatal age over the first week. Median MMP-9 levels and MMP-9/TIMP-1 ratio increased with decreasing gestation in preterm babies. The MMP-9/TIMP-1 ratio was higher in babies who developed CLD, implying a proteinase/antiproteinase imbalance, but this association disappeared when controlled for gestational age. ANCS had no effect on BAL fluid MMP or TIMP levels. CONCLUSION: MMPs may have a role in the development of lung injury and fibrosis, but estimating their levels in the first week of life does not help with prediction of CLD.     

Evaluation of echocardiography on the neonatal unit

BACKGROUND: Echocardiography is an investigation that is being used increasingly on the neonatal unit. There is some controversy as to whether this service can be provided safely and effectively by neonatologists or whether it should only be performed by paediatric cardiologists. AIMS: To describe (a) the indications for an echocardiogram, (b) the yield and range of positive findings, (c) the resulting changes in clinical management, and (d) the reliability of echocardiography in the hands of neonatologists when it is performed on the neonatal unit. METHODS: Information about all echocardiograms performed on the neonatal unit was collected prospectively. Indications for performing echocardiography, echocardiographic findings, and any resulting changes in clinical management were determined. The concordance of findings in infants who underwent echocardiograms performed by both a neonatologist and a paediatric cardiologist was described. RESULTS: A total of 157 echocardiograms were performed in 82 infants. Echocardiography identified 44 infants with a structural cardiac abnormality and a further 17 infants with a trivial abnormality. In addition, 13 babies were found to have an important functional abnormality. Echocardiography prompted a specific change in clinical management in 64 (78%) babies. In 31 of the 38 infants who had paired scans performed, there was complete concordance between the two examinations. No infants had scans that were completely different. Some discrepancy was identified in seven infants, but this did not prevent appropriate immediate clinical management. CONCLUSIONS: Echocardiography on the neonatal unit has a high yield for the diagnosis of structural and functional cardiac abnormalities, often results in a change in clinical management, and can be a reliable tool in the hands of neonatologists.