The effect of selenium supplementation on outcome in very low birth weight infants: a randomized controlled trial. The New Zealand Neonatal Study Group

BACKGROUND: Low selenium (SE) status has been documented in preterm infants and has been suggested to be a risk factor for chronic lung disease. METHODS: A total of 534 infants with birth weight <1500 g were enrolled in 8 New Zealand centers in a double-blind placebo-controlled randomized trial of SE supplementation from week 1 of life until 36 weeks' postmenstrual age or discharge home. Supplemented infants received 7 microg/kg/d of SE when fed parenterally and 5 microg/kg/d when fed orally. Plasma SE and glutathione peroxidase concentrations were measured in mothers after delivery and in infants before randomization and at 28 days and 36 weeks' postmenstrual age. Primary outcome measures were oxygen dependency at 28 days and total days oxygen dependency. RESULTS: No significant differences were seen between the groups with respect to primary or secondary outcome measures, with the exception that fewer supplemented infants had an episode of sepsis after the first week of life (P <.038). Mean plasma SE concentrations were 0.33 micromol/L before randomization in both groups and at 28 days had risen in the supplemented group (0.56 micromol/L) but fallen in the control group (0.29 micromol/L) (P <.0001). There was no association between outcome measures and SE concentrations at 28 days or 36 weeks' postmenstrual age. However, lower maternal and infant prerandomization SE concentrations were associated with increased respiratory morbidity. CONCLUSIONS: Postnatal SE supplementation in very low birth weight infants did not improve neonatal outcome. Further investigation of SE supplementation of mothers from the second half of pregnancy is warranted.     

Plasma lipid metabolites are associated with gestational age but not bronchopulmonary dysplasia

Aim: To test the hypothesis that plasma lipid metabolite levels in premature infants are associated with the development of bronchopulmonary dysplasia (BPD). The studies also tested a secondary hypothesis that plasma lipid metabolite levels were correlated with gestational age. Methods: Infants born <32 weeks’ gestation were enrolled during the first 72 h of life. Plasma samples were obtained and lipid levels were measured by LC‐MS/MS. Clinical data were collected to determine infant outcomes and BPD diagnosis. Results: Following adjustment for confounders, lipid levels were not associated with BPD; however, levels of specific lipid metabolites were correlated with gestational age. Conclusion: Immature lipid metabolism pathways in premature infants may contribute to the pathogenesis of BPD and other diseases.     

外周血内皮祖细胞与极低出生体重早产儿并发症发生相关性

目的 分析内皮祖细胞（EPCs）与极低出生体重早产儿发生支气管肺发育不良（BPD）、早产儿视网膜病（ROP）和脑室内出血（IVH）并发症的相关性。方法 选取于复旦大学附属儿科医院NICU住院的胎龄<32周、出生体重<1 500 g的早产儿,分别于出生时、生后7、14、21和28 d及纠正胎龄36周时收集外周血,流式细胞仪检测EPCs水平,酶联免疫法检测血管内皮生长因子（VEGF）、基质细胞衍生因子等水平。结果 68例极低出生体重早产儿纳入分析,其中对照组30例,BPD 组20例, ROP组 10例,IVH组 8例。BPD组与对照组出生时EPCs水平差异无统计学意义,生后7 d时点EPCs水平较对照组明显降低,CD34+KDR+: (0.019 ±0.009) % vs (0.026±0.012)%, P<0.05; KDR+CD133+: (0.004±0.002)% vs (0.008±0.004)%, P<0.01; CD34+KDR+CD133+: (0.005±0.002)% vs (0.008±0.004)%, P<0.05。从出生时至生后21 d,BPD组血浆VEGF水平均明显低于对照组。ROP组出生时至生后28 d的EPCs水平与对照组差异无统计学意义,纠正胎龄36周时KDR+CD133+和CD34+KDR+CD133+ EPCs与对照组相比略有升高趋势。与对照组相比, IVH组生后不同时点的EPCs水平差异均无统计学意义。结论 生后早期的EPCs和VEGF水平降低可能参与了早产儿BPD的发生,但其具体机制仍需进一步研究。     

Changes in vasopressin, atrial natriuretic factor, and water homeostasis in the early stage of bronchopulmonary dysplasia

Arginine vasopressin (AVP), atrial natriuretic factor, and water balance were examined in the infants with or without bronchopulmonary dysplasia (BPD) during the first 4 wk of life. Fourteen premature infants, nine in the early stage of BPD secondary to respiratory distress syndrome (BPD infants) and five healty low birth wt infants (LBW infants), were the subjects of this study. The water and sodium balance, renal function, and plasma AVP and atrial natriuretic factor concentrations were determined during the first 4 wk of life. Plasma AVP and atrial natriuretic factor levels of BPD infants at the 4th wk of life were higher than those of LBW infants at the corresponding age. Urine osmolality was higher and free water clearance was lower in BPD infants at the 4th wk of life when compared with each parameter in LBW infants, respectively. Paco2 of BPD infants at the 4th wk of life was more elevated than that of LBW infants. These results suggest that elevated plasma AVP level may be related with pulmonary abnormalities and that atrial natriuretic factor may hence compensate the water retention resulted from the functionally activated AVP in the early stage of BPD.     

Lung volumes in infants who had mild to moderate bronchopulmonary dysplasia

New bronchopulmonary dysplasia (BPD) has been suggested to be a maldevelopment sequence with reduced alveolarisation of the lungs; affected infants then would be predicted to have low lung volumes. The aim of this study was to test that hypothesis by comparing the lung volumes of infants who had had mild-moderate BPD with those without BPD of similar postmenstrual age. Lung volumes of 17 infants who had mild-moderate BPD (oxygen dependent beyond 28 days, but not past term) (BPD infants) were compared to those of 17 infants without BPD (non-BPD infants). All were born at less than 33 weeks of gestation and studied at postmenstrual ages of 33 to 39 weeks. Lung volume was assessed by measurement of functional residual capacity (FRC). The BPD infants had lower lung volumes (median 19.1 ml/kg) than the non-BPD infants (median 26.5 ml/kg) (p=0.0001). The BPD compared to the non-BPD infants were of greater postnatal age (p=0.0003), born at a lower gestational age (p=0.0001) and of lighter birthweight (p=0.0001). Regression analysis, however, demonstrated that lung volume was significantly related to BPD status (p=0.005), independently of postnatal age, birthweight and gestational age. It is concluded that the lower lung volumes of the infants who had had mild-moderate BPD support the hypothesis that new BPD is associated with poor alveolarisation.     

Management of infants with chronic lung disease of prematurity in Australasia

Chronic lung disease is common in extremely preterm infants born in Australasia. In 2002, 53% of surviving infants born before 28 weeks' gestation remained either oxygen-dependent or on other respiratory support at 36 weeks' postmenstrual age. In the first weeks of life oxygenation should be kept generally "lower", although what is the most appropriate level remains uncertain. During the mid-phase of the neonatal course, functional oxygen saturation levels around 90-95% probably confer the best benefit/risk balance. The most appropriate target saturation range for infants on home oxygen also remains uncertain. Definitive data to guide clinical practice is lacking regarding the use of postnatal corticosteroids, bronchodilators, and diuretics for either the treatment or prevention of chronic lung disease. Home oxygen programmes are effective in avoiding prolonged hospitalisation for infants with chronic lung disease, but require the coordination of a large, multidisciplinary team.     

Plasma endothelin-1 like immunoreactivity levels in neonates

We attempted to determine the plasma endothelin-1-like immunoreactivity (ET-1) levels and to evaluate its physiological significance in 29 neonates: 5 with respiratory distress syndrome (RDS), 3 with transient tachypnoea of the newborn (TTN), 4 with neonatal asphyxia, 5 with bronchopulmonary dysplasia (BPD) following RDS, 7 healthy preterm infants and 5 healthy full-term infants. Plasma ET-1 levels in infants with RDS were significantly higher than those in healthy full-term infants through the 1st week of life. Plasma ET-1 levels in infants with neonatal asphyxia were high on the first 2 days of life and then gradually decreased to those of healthy full-term infants. Plasma levels in infants with TTN were the same as those in healthy full-term infants. Plasma ET-1 levels in infants with BPD were high when compared with those in healthy preterm infants during the first 2 months of life. This study showed that plasma levels were markedly elevated for a long time in the infants with respiratory distress. We speculate that plasma ET-1 may be a specific marker for pulmonary endothelium injury in infants with respiratory distress.     

Relation between serum insulinlike growth factor-1, insulinlike growth factor binding protein-2, and insulinlike growth factor binding protein-3 and nutritional intake in premature infants with bronchopulmonary dysplasia.

BACKGROUND: The usefulness of serum insulinlike growth factor (IGF)-system-peptide measurement to assess the adequacy of nutritional intake in premature infants with chronic lung disease bronchopulmonary dysplasia (BPD) was assessed. METHODS: Twenty-nine premature infants had serial measurements taken of their serum IGF-1, insulinlike growth factor binding protein (IGFBP)-2, and IGFBP-3 concentrations between 2 and 6 weeks of age. Regression analyses were used to examine the relation between nutritional parameters and IGF-1, IGFBP-2, and IGFBP-3 concentrations in premature infants with and without BPD. RESULTS: The group of infants with BPD (n = 12) did not differ from infants without BPD (n = 17) in gestational age or weight at entry, but gained less weight during the study period. In infants without BPD, IGF-1 correlated positively with protein intake (r = 0.50) and caloric intake (r = 0.41) over the 3 days before sample collection and with weight change over the previous week (r = 0.46). In contrast, infants with BPD showed a significant correlation between IGF-1 and weight change (r = 0.54) only. There was a significant negative correlation between IGFBP-2 and protein intake in infants without BPD (r = -0.50) and in infants with BPD (r = -0.41). Negative correlations between IGFBP-2 and both weight change (r = -0.64) and caloric intake (r = -0.43) over the previous week were found only in the group of infants without BPD. IGFBP-3 correlated positively with weight changes and protein intake in both groups but correlated with caloric intake only in the group without BPD. Multiple regression analyses were used to determine significant independent variables associated with IGF-1, IGFBP-2, and IGFBP-3. In infants without BPD, significant independent predictors of IGFBP-2 were 7-day weight change and 2-day protein intake; 3-day caloric intake was the only significant independent predictor for IGFBP-3. For infants with BPD, 3-day weight gain was the only independent variable associated with serum IGF-1. Protein intake in the week before sample collection was an independent predictor of IGFBP-2 and 3-day weight change and 2-day protein intake were independent predictors of IGFBP-3. CONCLUSIONS: These results confirm that changes in serum IGF-1, IGFBP-2, and IGFBP-3 reflect the nutritional status of premature infants and demonstrate that the relation between these proteins and nutritional intake differs in premature infants with and without BPD. Refinement of these observations by future studies may permit a more accurate determination of the protein and caloric intake sufficient for growth and repair after injury in premature infants with lung disease.     

Early detection of delayed myelination in preterm infants

Myelination of the central nervous system can be demonstrated with magnetic resonance imaging. The influence of periventricular-intraventricular hemorrhage and periventricular leukomalacia on cerebral myelination was studied using magnetic resonance imaging. The subjects were 33 preterm infants of less than 30 weeks' gestation studied at 44 weeks' postmenstrual age: 11 infants with periventricular-intraventricular hemorrhage, 7 with periventricular leukomalacia, and 15 without periventricular-intraventricular hemorrhage or periventricular leukomalacia. There were no differences in mean gestational age and birth weight between the three groups. However, infants without periventricular-intraventricular hemorrhage or periventricular leukomalacia had significantly less respiratory distress syndrome. At 44 weeks postmenstrual age, infants with periventricular leukomalacia had a significantly delayed myelination pattern (stage M2) in comparison with infants without periventricular-intraventricular hemorrhage or periventricular leukomalacia and infants with periventricular-intraventricular hemorrhage (stages M3 and M4). The latter two groups had myelination stages that were similar to those of healthy term infants at 44 weeks' postmenstrual age. The results demonstrate that periventricular leukomalacia causes delayed myelination of the cerebrum, whereas periventricular-intraventricular hemorrhage does not.     

Cerebral tissue oxygenation index in very premature infants

AIM: To describe normal values of the cerebral tissue oxygenation index (TOI) in premature infants. METHODS: TOI was measured by spatially resolved spectroscopy in preterm infants on the first 3 days of life. Infants with an abnormal cranial ultrasound were excluded. Other simultaneously measured variables were PaO(2), PaCO(2), pH, mean arterial blood pressure, heart rate, haemoglobin, glycaemia, and peripheral oxygen saturation. RESULTS: Fifteen patients with a median postmenstrual age of 28 weeks were measured. There was a significant increase in median TOI over the first 3 days of life: 57% on day 1, 66.1% on day 2, and 76.1% on day 3. Multiple regression analysis showed no correlation between TOI and postmenstrual age, peripheral oxygen saturation, mean arterial blood pressure, PaO(2), PaCO(2), and haemoglobin concentration. CONCLUSION: Cerebral TOI increases significantly in the first 3 days of life in premature babies. This increase probably reflects the increase in cerebral blood flow at this time.     

Eosinophilia in premature infants: correlation with chronic lung disease

We attempted to clarify the possible pathophysiological significance of eosinophilia in bronchopulmonary dysplasia (BPD). The subjects studied were 17 premature infants, i.e. seven with respiratory distress syndrome (RDS) followed by bronchopulmonary dysplasia (the BPD group: four with stage IV and three with stage III BPD) and 10 infants without BPD (the non-BPD group), who comprised seven with RDS, two with meconium aspiration syndrome and one with transient tachypnea of the newborn. Peripheral eosinophil counts, the number of nuclei of eosinophils and serum eosinophilic cationic protein (ECP) levels, and ECP and polymorphonuclear leukocyte (PMN) elastase levels of intratracheal aspirates (TA) were determined once a week during the first 4 weeks of life. Peripheral eosinophil counts were higher in infants with BPD than those in the non-BPD group. Hypersegmented nuclei of peripheral eosinophils with more than four nuclei were more frequently present in the infants with BPD. A good correlation was observed between peripheral eosinophil counts and serum ECP levels. ECP levels of the TA in the infants with BPD were significantly elevated. There was a good correlation between ECP and PMN elastase levels of the TA. Lung tissue specimens of two infants of the BPD group, both of whom had patent ductus arteriosus (PDA), were obtained from the lower portion of the left lung when they underwent an operative procedure for PDA at 24 and 25 days of life, respectively. Immunohistochemical staining of eosinophil-derived granular major basic protein (MBP) was performed on the lung tissue specimens. Infiltration of a few MBP-staining eosinophils was observed on the specimens from both infants. Our results suggest that peripheral eosinophils in sick premature infants may be activated and appear to be correlated with the severity of BPD. Further studies will be needed to more clarify the physiological role of eosinophils in premature infants.     

Plasma arginine and urinary nitrate and nitrite excretion in bronchopulmonary dysplasia

The aim of this prospective study was to determine whether preterm infants with bronchopulmonary dysplasia (BPD) and signs of increased pulmonary artery pressure have a deficiency of plasma arginine (ARG) and systemic nitric oxide (NO) synthesis. Plasma amino acid concentrations, Doppler pulmonary systolic time intervals (ratio of acceleration time and ejection time corrected for heart rate: AT/ET(C)) and urinary nitrate and nitrite concentrations were determined at the 28th day postnatal age and at 36 weeks postmenstrual age in 73 preterm infants less than 30 weeks gestational age. The AT/ET(C) ratios were significantly lower in infants with BPD (n = 32) compared to controls. However, total amino acid concentrations, ARG intake as well as plasma ARG concentrations were not different between groups (median (interquartile-range) micromol/l): control: 58 (42.5-75.5) and 54.5 (42-71) at day 28 and 36 weeks; BPD: 54.5 (31.5-70.5) and 43 (35-62), respectively. Urinary nitrate and nitrite concentrations, were not different between groups at day 28, but significantly higher in infants with BPD at 36 weeks (p = 0.014). In conclusion, plasma ARG concentrations and systemic NO synthesis were not deficient in preterm infants with BPD and signs of elevated pulmonary artery pressure.     

Evaluating "old" definitions for the "new" bronchopulmonary dysplasia

OBJECTIVES: To examine the accuracy of different criteria for the diagnosis of bronchopulmonary dysplasia (BPD), based on the final age at which oxygen therapy was stopped, in predicting pulmonary and neurologic outcomes at 18-month corrected age. STUDY DESIGN: Data were collected prospectively on infants with birth weights between 500 and 999 g enrolled in the Trial of Indomethacin Prophylaxis in Preterms (TIPP) who survived to discharge home. Differing postnatal ages and postmenstrual ages at which supplemental oxygen therapy was no longer required formed the criteria for defining BPD. Diagnostic accuracy of each criterion for defining BPD was calculated for both poor pulmonary and poor neurosensory outcomes. RESULTS: The prevalence of poor pulmonary outcome was 54% and of poor neurosensory outcome was 34% in the 956 infants who were eligible for this analysis. Accuracy of different definitions of BPD was limited but greatest when using supplemental oxygen requirement at 36 weeks' postmenstrual age to predict long-term pulmonary outcome (63%) and 40 weeks to predict long-term neurosensory outcome (68%). CONCLUSIONS: Poor pulmonary outcome and poor neurosensory outcome are common late adverse outcomes in this population. BPD as defined by duration of oxygen therapy is a less accurate surrogate currently than in previous eras.     

肺脏超声对早产儿长期氧依赖肺部原因的鉴别价值

目的 肺脏超声已经广泛应用于肺脏疾病的诊断与鉴别诊断,本文旨在研究肺脏超声对明确早产儿长期氧依赖肺部原因的可行性与必要性.方法 对临床上诊断为支气管肺发育不良（bronchopulmonary dysplasia,BPD）的50例患儿进行肺脏超声筛查,并记录相关所见结果.结果 50例临床诊断为BPD的患儿中,肺脏超声检查发现肺不张9例、肺炎4例、严重肺水肿2例、肺水肿伴局灶性肺实变3例.对其进行相应处理后,患儿对氧的依赖消肖失或程度明显减轻,即超过1/3（36％,18/50）患儿的氧依赖并非BPD或非单纯BPD引起.结论 肺脏超声对协助诊断与鉴别患儿长期氧依赖的肺部病因有重要价值,有助于避免诊断扩大化及指导治疗,提示有必要对目前使用的BPD诊断标准予以修订.     

Incidence and prediction of bronchopulmonary dysplasia in a cohort of premature infants

Farstad T, Bratlid D. Incidence and prediction of bronchopulmonary dysplasia in a cohort of premature infants. Acta Pzdiatr 1994;83:19–24. Stockholm. ISSN 0803–5253
A prospective study on the incidence of bronchopulmonary dysplasia (BPD) in premature infants is reported. A cohort of premature infants with gestational ages 32 weeks, treated during 1989, was followed for one year. Of a total study population of 117 infants, 23 (19.6%) developed BPD, defined as oxygen dependence at 28 postnatal days. However, only 15 infants (12.8%) needed supplementary oxygen at the age of 36 gestational weeks and 5 infants (4.2%) needed supplementary oxygen periodically at one year of age. BPD was found to account for a significant part of both the total and late mortality in the cohort. Measurements of pulmonary mechanics were performed at 3 ± 1 and 12(13) ± 1 days of life in a subgroup of 26 infants with RDS who required assisted ventilation for 4 days or longer. No significant difference in lung compliance or resistance could be found during the first examination between infants who later devleoped BPD and infants with RDS only. At the second examination, infants who later developed BPD had significantly lower lung compliance (0.48 ± 0.23 ml/cmH₂O) than infants in the RDS group (1.50 ± 0.72 ml/cmH₂O) (p<0.001). Measurements of pulmonary mechanics could be of importance for early prediction of infants at risk of BPD.     

Cerebrospinal fluid values in very low birth weight infants with suspected sepsis at different ages.

OBJECTIVES: Lumbar puncture can be an essential part of the septic work-up in premature infants who are at risk for sepsis and meningitis. Cerebrospinal fluid (CSF) values for cell counts, protein concentrations, and glucose concentrations in children and full-term infants are well established. CSF values in premature infants, however, have not been well studied. We sought to determine CSF values in very low birth weight premature infants at different ages (birth, postmenstrual age, and postnatal age). DESIGN: Medical records of all very low birth weight premature infants with suspected sepsis who were admitted to our neonatal intensive care unit between 1991 and 2005 were reviewed. Infants were excluded if they had evidence of intraventricular hemorrhage, sepsis/meningitis, or major congenital abnormalities or had a traumatic lumbar puncture. SETTING: Neonatal intensive care unit. PATIENTS: Patients were 455 infants who underwent lumbar puncture. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Medical records of 455 infants who underwent 648 lumbar punctures were reviewed. Of these, 243 infants met our inclusion criteria, and 88 patients underwent lumbar puncture only at birth. Patients' mean gestational age and birth weight were 28.8 +/- 2.6 wks and 1080 +/- 279 g, respectively. There were no correlations between gestational age and CSF white blood cell (WBC) count or between gestational age and CSF protein concentrations at birth. CSF WBC count remained unchanged at different postmenstrual ages. However, CSF protein concentration decreased with advancing postmenstrual age (Spearman's rho correlation coefficient, r = -.29; p < .01), and both CSF WBC count and CSF protein concentration decreased with advancing postnatal age (Spearman's rho correlation coefficient, r = -.319 and r = -.376, respectively; p < .01). A subgroup analysis revealed differences in CSF WBC count and CSF protein concentrations between infants who had a lumbar puncture at birth, at 2 wks, and at 3 wks of life at the same postmenstrual age. CONCLUSIONS: In very low birth weight premature infants, CSF WBC count and CSF protein concentrations vary with advancing postnatal and postmenstrual ages.     

支气管肺发育不良早产儿1岁和2岁时体积描记肺功能的随访研究

目的 探讨支气管肺发育不良 (BPD)早产儿的远期肺功能。 方法 以2012年1月至2013年12月在复旦大学附属儿科医院新生儿病房住院的胎龄≤ 32周、出生体重≤ 1 500 g的BPD早产儿为BPD组,以同期住院非BPD早产儿按1∶1匹配为对照组,于纠正年龄1岁和2岁时召回随访,行体积描记（体描）肺功能检测,分析早产儿BPD及不同严重度BPD在纠正年龄1岁和2岁时肺功能状况。 结果 149例BPD早产儿和与之匹配的149例非BPD早产儿进入文本分析,1岁和2岁时召回随访,BPD组37例（轻中度22例,重度15例）和25例（轻中度15例,重度10例）,非BPD组33例和10例。在纠正年龄1岁及2岁时,BPD组公斤体重残气量（FRCp/kg）、达峰时间比（TPTEF/TE）、达峰容积比（VPTEF/VE）、肺内剩余25%潮气量时潮气呼气流速（TEF25）显著低于非BPD组,公斤体重有效气道阻力（Reff/kg）显著高于非BPD组。在纠正年龄1岁时,重度BPD亚组FRCp/kg 、TPTEF/TE显著低于轻中度BPD亚组, Reff/kg显著高于轻中度BPD亚组;在纠正年龄2岁时,重度BPD亚组VPTEF/VE显著低于轻中度BPD亚组,Reff/kg显著高于轻中度BPD亚组。 结论 BPD早产儿存在功能残气量降低及小气道阻塞,以重度BPD患儿更为明显。     

Interleukin-1 balance in the lungs of preterm infants who develop bronchopulmonary dysplasia

BACKGROUND: The local pulmonary balance between the agonist and antagonist of interleukin-1 (IL-1) may influence the development of inflammatory disease and resultant structural damage in a variety of human diseases including adult respiratory distress syndrome and asthma. OBJECTIVES: We tested the hypothesis that IL-1 cytokines are early markers for bronchopulmonary dysplasia (BPD), when measured in tracheal aspirates (TAs) obtained from premature infants being ventilated for respiratory distress syndrome during the first week of life. METHODS: Serial TAs were collected on days 1, 3, 5 and 7 from 35 preterm infants (16 BPD, 19 non-BPD) in the absence of chorioamnionitis, and were assayed for IL-1 cytokines and leukocytes. RESULTS: In spite of comparable maternal demographic and clinical characteristics, premature infants who developed BPD had higher levels of IL-1 receptor antagonist (Ra) in their airways on the first day of life. This antagonist IL-1Ra was an early and persistent marker for BPD during the first week of life. The agonist IL-1beta also increased significantly for BPD patients early, both compared to non-BPD patients, and also within the BPD group. While the early (day 1) IL-1 antagonist/agonist molar balance offered protection, by days 5 and 7, a threshold for IL-1Ra in the presence of increasing IL-1beta expression-favored pro-inflammation in the BPD group. CONCLUSIONS: We conclude that a strong and early expression of airway antagonist (IL-1Ra) proves ultimately to be sub-optimal and non-protective due to the robust expression of airway agonist (IL-1beta) seen by day 5 in premature infants who develop BPD.     

Abnormal circulatory stress responses of preterm graduates

Preterm birth and chronic lung disease may increase the risk of hypertension and cardiovascular disease in infancy and adolescence. Here we looked for evidence of early circulatory dysfunction associated with these perinatal complications. We compared infants born at term (n = 12) with those born preterm with an uncomplicated neonatal course (n = 12) or diagnosed with bronchopulmonary dysplasia (BPD) (n = 10). We measured blood pressure (BP) (Finometer), and heart rate (HR) responses to 4 min of breathing 4% CO2 during quiet sleep. Hypercapnia accelerated HR and increased BP of term infants. Preterm infants either (i) had an exaggerated pressor but little or no HR response to CO2 (healthy or mild-moderate BPD) or (ii) had a diminished pressor response and accompanying decrease in HR (severe BPD). Short-term reflex cardiovascular control was consequently altered by premature birth, with potentially more serious aberrations associated with severe BPD. Most anomalies had not resolved by the time infants born preterm reached term age; some may be early signs of emerging long-term cardiovascular dysfunction.     

Management of bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD), also known as chronic lung disease of prematurity, and typically defined as the need for supplemental oxygen at 36 weeks' postmenstrual age, affects approximately 10% and 40% of very low birth weight and extremely low birth weight infants, respectively. Contributing factors include infection, oxygen exposure and ventilator induced lung injury, which can lead to impaired lung function. Several preventative and therapeutic strategies have been used in BPD, including lung protective ventilator strategies, and pharmacologic interventions. While many infants with BPD are treated with a wide variety of medications, little evidence for the efficacy of these treatments exist. This article will review current practice in the prevention and management of this complication of prematurity.