Biomedical subjects

Neil Marlow

Publications and source records attributed to Neil Marlow.

24 records · Page 2Linked to original sources

PubMed2003

Pulmonary function at follow-up of very preterm infants from the United Kingdom oscillation study.

Prematurely born infants supported by conventional ventilation (CV) frequently have abnormal pulmonary function when assessed in childhood. The aim of this study was to test the hypothesis that infants who were randomly assigned to high-frequency oscillatory ventilation would have superior pulmonary function at follow-up compared with those who received CV (UK Oscillation Study). Infants from 12 trial centers were recruited for pulmonary function testing at a single center. Seventy-six infants, of a mean gestational age 26.4 weeks, were studied after sedation with chloral hydrate at between 11 and 14 months of age, corrected for prematurity. Infants assigned to CV had similar pulmonary function compared with those assigned to high-frequency oscillatory ventilation, with mean (SD) results as follows: functional residual capacity measured by whole-body plethysmography, 26.9 (6.3) versus 26.5 (6.4) ml/kg; functional residual capacity measured by helium dilution, 24.1 (5.4) versus 23.5 (5.7) ml/kg; inspiratory airway resistance, 3.3 (1.3) versus 3.4 (1.6) kPa. second. L; expiratory airway resistance, 4.4 (2.8) versus 4.1 (2.5) kPa. second. L; respiratory rate, 31.2 (6.0) versus 33.9 (8.0) breaths/minute. We conclude that early use of high-frequency oscillatory ventilation in very preterm infants appears to offer no advantage over CV in terms of pulmonary function at follow-up.

Bronchopulmonary Dysplasia↗

PubMed2003

Prediction of outcome from the chest radiograph appearance on day 7 of very prematurely born infants.

UNLABELLED: Our aim was to determine whether the chest radiograph appearance at 7 days predicted chronic lung disease development (oxygen dependency at 36 weeks post-menstrual age) or death before discharge and if it was a better predictor than readily available clinical data. Two consecutive studies were performed. In both, chest radiographs taken at 7 days for clinical purposes were assessed using a scoring system for the presence of fibrosis/interstitial shadows, cystic elements and hyperinflation and data were collected regarding gestational age, birth weight, use of antenatal steroids and post-natal surfactant and requirement for ventilation at 7 days. Oxygenation indices were calculated in the first study (study A) at 120 h and in the second (study B) at 168 h. In study A, there were 59 infants with a median gestational age of 26 weeks (range 24 to 28 weeks) and in study B, 40 infants with a median gestational age of 27 weeks (range 25-31 weeks). In both studies, infants who developed chronic lung disease had a significantly higher total chest radiograph score, with a higher score for fibrosis/interstitial shadowing than the rest of the cohort. Infants who died before discharge differed significantly from the rest with regard to significantly higher scores for cysts. In both studies, the areas under the receiver operator characteristic curves with regard to prediction of chronic lung disease were higher for the total chest radiograph score compared to those for readily available clinical data. CONCLUSION: In infants who require a chest radiograph for clinical purposes at 7 days, the chest radiograph appearance can facilitate prediction of outcome of infants born very prematurely.

Chronic Disease↗

PubMed2003

Angiotensin-converting enzyme DD genotype is associated with worse perinatal cardiorespiratory adaptation in preterm infants.

OBJECTIVES: The angiotensin-converting enzyme (ACE) deletion (D) variant is associated with greater ACE activity and perhaps with deleterious cardiorespiratory pathophysiological responses. We determined whether the early health status of the preterm infant was adversely influenced by homozygosity for the D allele (DD genotype) compared with ID or II genotype. Study design Angiotensin-converting enzyme genotype was determined in a cohort of 148 preterm infants born in Bristol, United Kingdom (median gestational age, 31 weeks; range, 28-32). Intensive care data were prospectively obtained. Primary analysis was by Mann-Whitney U and chi(2) tests. RESULTS: Higher oxygen, circulatory support requirements, and base deficit in the first 12 hours after birth were found in infants with DD genotype (minimum inspired oxygen concentration in first 12 hours, median [interquartile range], DD 0.26 [0.21-0.40], ID/II 0.21 [0.21-0.30], P=.028; blood pressure support in first 12 hours, DD 12 [30%], ID/II 15 [14%], P=.039; worse base deficit in first 12 hours, DD 4.8 [7.7 to 0], ID/II 0 [5.3 to 0], P=.020). CONCLUSIONS: Angiotensin-converting enzyme polymorphism has a role in the development of preterm cardiorespiratory disease. The DD genotype, encoding higher angiotensin-converting enzyme activity, may adversely influence the early health status of preterm infants.

Cardiovascular Diseases↗

PubMed2003

Is interleukin-6 -174 genotype associated with the development of septicemia in preterm infants?

OBJECTIVE: Systemic infection affects one quarter of preterm infants. Defense from infection is in part mediated by the cytokine interleukin-6 (IL-6). We tested the hypothesis that the IL-6 -174 GG genotype, associated with lower IL-6 response to inflammation, is also associated with the development of septicemia in preterm infants. METHODS: The study group comprised 157 infants who were born at < or =32 weeks. Genotype distribution (34% [54] GG, 46% [72] GC, 20% [31] CC) and C allele frequency (0.43; 95% confidence interval [CI]: 0.37-0.48) were similar to the UK adult population. Among the patients who developed bacterially confirmed septicemia (n = 51 [33%]), there was a significantly higher prevalence of the IL-6 -174 GG genotype than that observed in those who did not develop infection (47% vs 28% for GG: odds ratio [OR]: 2.3; 95% CI: 1.1-4.5). This association remained statistically significant (OR: 2.7; 95% CI: 1.2-6.3) after multiple binary logistic regression adjustment for other significant predictors of the development of septicemia. Late infection alone was similarly associated with GG genotype (septicemia 47% vs no septicemia 29% for GG: OR: 2.2; 95% CI: 1.1-4.3). CONCLUSIONS: Variation in the IL-6 gene seems to influence the defense against bacterial pathogens in the very preterm infant.

Alleles↗

PubMed2002

High-frequency oscillatory ventilation for the prevention of chronic lung disease of prematurity.

BACKGROUND: There remains uncertainty concerning the safety and efficacy of high-frequency oscillatory ventilation as compared with those of conventional ventilation for the respiratory support of very preterm infants. We conducted a multicenter trial to determine whether early intervention with high-frequency oscillatory ventilation reduced mortality and the incidence of chronic lung disease among newborns with a gestational age of 28 weeks or less. METHODS: We randomly assigned preterm infants with a gestational age of 23 to 28 weeks to either conventional ventilation or high-frequency oscillatory ventilation within one hour after birth. Randomization was stratified according to center and gestational age (23 to 25 weeks or 26 to 28 weeks). RESULTS: A total of 400 infants were assigned to high-frequency oscillatory ventilation, and 397 were assigned to conventional ventilation. The composite primary outcome (death or chronic lung disease, diagnosed at 36 weeks of postmenstrual age) occurred in 66 percent of the infants assigned to receive high-frequency oscillatory ventilation and 68 percent of those in the conventional-ventilation group (relative risk in the group assigned to high-frequency oscillatory ventilation, 0.98; 95 percent confidence interval, 0.89 to 1.08). Similar proportions of infants died or had chronic lung disease in each gestational-age group. In both treatment groups treatment failure occurred in 10 percent of infants (relative risk in the group assigned to high-frequency oscillatory ventilation, 0.99; 95 percent confidence interval, 0.66 to 1.50). There were no significant differences between the groups in a range of other secondary outcome measures, including serious brain injury and air leak. CONCLUSIONS: The results obtained with high-frequency oscillatory ventilation and conventional ventilation do not differ significantly in the early treatment of respiratory disease in very preterm infants. Assessment of long-term effects will require additional follow-up.

Bronchopulmonary Dysplasia↗

PubMed2002

Patterns of motor disability in very preterm children.

Motor development in very preterm children differs in several important ways from that of children born at full term. Variability is common, although the anatomic and physiologic bases for that variability are often poorly understood. Motor patterns over the first postnatal year may depend on behaviours learned during often long periods of neonatal intensive care. The normal pattern of development may be modified by disturbances of brain function caused both by the interruption of normal brain maturation ex-utero and the superimposition of focal brain injuries following very preterm birth. Abnormal patterns of development over the first year may evolve into clear neuromotor patterns of cerebral palsy or resolve, as "transient dystonias." Cerebral palsy is associated with identified patterns of brain injury secondary to ischaemic or haemorrhagic lesions, perhaps modified by activation of inflammatory cytokines. Cerebral palsy rates have not fallen as might be expected over the past 10 years as survival has improved, perhaps because of increasing survival at low gestations, which is associated with the highest prevalence of cerebral palsy. Children who escape cerebral palsy are also at risk of motor impairments during the school years. The relationship of these impairments to perinatal factors or to neurological progress over the first postnatal year is debated. Neuromotor abnormalities are the most frequent of the "hidden disabilities" among ex-preterm children and are thus frequently associated with poorer cognitive ability and attention deficit disorders. Interventions to prevent cerebral palsy or to reduce these late disabilities in very preterm children are needed.

Age Factors↗