Diaphragmatic hypoplasia in association with hypoplastic lungs.
Explore the source record for details and available documents.
Abnormalities, Multiple↗
Biomedical subjects
A Greenough
Publications and source records attributed to A Greenough.
Lung function in 6-20 month old infants born very preterm but without respiratory troubles.
Lung function results of 21 healthy infants born very prematurely are reported. The median gestational age was 29 weeks, but none had developed respiratory distress or required any form of respiratory support in the neonatal period. Lung function was assessed by measurements of thoracic gas volume (TGV) and airway resistance (Raw) plethysmographically, and of functional residual capacity (FRC) using a helium gas dilution technique. Two separate measurements were made between 6 and 20 months of age; all infants were measured once in the first and once in the second year of life. Regression equations were calculated for TGV, Raw, and FRC related to weight, height, and postnatal age. These data provide a new set of values for very preterm infants, in part small for gestational age, without neonatal respiratory trouble.
Age Factors↗
Neonatal complications of extreme prematurity in mechanically ventilated infants.
Previous data have suggested that neonatal complications amongst preterm ventilated infants increase with decreasing gestational age and thus are likely to be greatest among ventilated infants of less than 28 weeks gestational age. The aim of this study was to test that hypothesis, thus we report the neonatal complications of 175 extremely preterm mechanically ventilated infants (gestational age less than or equal to 28 weeks). Of the infants 152 were ventilated because of respiratory distress syndrome (RDS) or respiratory distress of severe prematurity, 41% of these infants died. Amongst infants with RDS or respiratory distress of extreme prematurity, mortality was significantly increased in infants of gestational age less than or equal to 24 weeks and birth weight less than or equal to 1000 g. In this group 20% developed a pneumothorax, and mortality was inversely related to gestational age. In infants with RDS, 43% developed a periventricular haemorrhage and 37% were still oxygen-dependent at 28 days of age; neither of these complications was significantly related to birth weight or gestational age. Of infants with RDS 38% developed a patent ductus arteriosus and 16% developed retinopathy of prematurity. These data suggest that even amongst very immature infants there has been an impressive reduction in the neonatal complications of mechanical ventilation.
Gestational Age↗
Acute deteriorations in neonatal chronic lung disease.
Preterm infants with chronic lung disease (CLD) have frequent respiratory relapses. The aim of this study was to assess the aetiology of such deteriorations and in particular the proportion due to viral infections. During the study period 118 preterm infants with birth weight less than 1500 g were consecutively admitted to the neonatal intensive care unit; 22 (18.6%) developed CLD. At the onset of all respiratory deteriorations, infants were examined for the presence of patent ductus arteriosus, apnoea or aspiration; they were also carefully screened for both viral and bacterial infection. The 22 infants had a total of 74 episodes of respiratory deterioration; median 3 per baby (range 1-8). Two episodes were associated with patent ductus arteriosus, 18 with apnoea and 5 with aspiration. Infection was suspected or proven in association with all other episodes. On ten occasions the infants had positive blood cultures and on a further eight, bacteria were isolated only from the endotracheal or nasopharyngeal secretions. On the remaining 31 occasions, 27 associated with chest X-ray film abnormalities, infection was suspected, but no bacteria isolated. Viral infections were identified in association with 8 (11%) of these episodes. We conclude viral infection should be considered as a cause of otherwise unexplained respiratory deteriorations in infants with neonatal CLD.
Acute Disease↗
Ventilatory requirements for respiratory distress syndrome in small-for-gestational-age infants.
Neonatal ventilatory requirements and outcome were examined in 135 very preterm, small-for-gestational age (SGA) infants to determine whether fetal growth retardation protects against severe respiratory distress syndrome (RDS) in very immature infants. Their results were compared to those from gestational age- and gender-matched controls. Although there was no significant difference in the median duration of mechanical ventilation between the two groups, more SGA infants required ventilation and were ventilated because of RDS. In a subgroup also matched for mode of delivery, there was no significant difference between the proportion of SGA infants requiring mechanical ventilation for RDS compared to their matched controls. The mortality was greater in the SGA group. We conclude that fetal growth retardation does not protect against severe RDS.
Birth Weight↗
Evaluation of triggering systems for patient triggered ventilation for neonates ventilator-dependent beyond 10 days of age.
The performance of two triggering systems was compared during patient triggered ventilation (PTV) of infants ventilator-dependent beyond 10 days of age. Ten infants were studied who had a median gestational age of 26.5 weeks and a postnatal age of 15.5 days. PTV was administered via the SLE ventilator and the two triggering systems, an airway pressure monitor and the MR10 respiration monitor, were used in random order each for 30 min. The airway pressure trigger had a superior performance in that, although it did not differ significantly in delivered inflation volume or sensitivity to the MR10 respiration monitor, it had a shorter trigger delay (P < 0.01). Oxygenation improved in eight of the ten infants on the airway pressure trigger, but only in three on the MR10 respiration monitor. The reduction in PaCO2 was greater during PTV with the airway pressure trigger compared with the MR10 respiration monitor (P < 0.01). We conclude that the airway pressure trigger has a superior performance compared to the MR10 respiration monitor trigger in infants who are ventilator-dependent beyond 10 days of age.
Chronic Disease↗
Dexamethasone and hypertension in preterm infants.
The magnitude and duration of the effect of dexamethasone on systolic blood pressure has been examined in 13 very preterm infants (median gestational age 25 weeks). All had chronic lung disease (CLD). To exclude any effect of CLD on blood pressure each infant acted as his or her own control. Systolic blood pressure increased in all infants (P less than 0.01) and remained elevated for at least 48h following cessation of therapy. The median maximum increase in blood pressure was 24 mmHg (range 13-49 mmHg) and occurred on day 4 (median, range 2-10) of treatment. One infant developed hypertensive encephalopathy. These results demonstrate the need to monitor infants with CLD throughout steroid therapy and preferably for some days after it has ceased.
Chronic Disease↗
Non-invasive blood pressure monitoring in preterm infants receiving intensive care.
It is essential to have regular, accurate blood pressure (BP) monitoring of sick preterm infants. Invasive direct arterial BP measurements are often recommended, but it was our clinical experience that such measurements may not be possible in all infants. We therefore assessed the proportion of infants receiving neonatal intensive care in whom reliable arterial BP measurements could be made, the accuracy of a non-invasive method (Doppler technique) and established a reference range of BP results related to postnatal age using this non-invasive technique. Arterial catheters were established in 44 infants (study population) of the 45 in whom access was attempted. Median gestational age was 27 weeks and birth weight 949 g. Over the 1st week, however, arterial catheters had to be removed because of complications or improving respiratory status. From those catheters that remained in situ, accurate measurements were not always possible because of damping; by day 7 only 22 catheters remained in situ and 14% of the arterial waveforms were damped. Doppler systolic BP measurements correlated well with the accurate (non-damped) arterial results (r = 0.96, P less than 0.01). Systolic blood pressure was measured on all 44 infants daily for the 1st week using the Doppler technique and increased linearly with increasing postnatal age (r = 0.92, P less than 0.01) from a mean of 41.7 mmHg on day 1 to 49.3 on day 7. We conclude that Doppler non-invasive BP monitoring is a useful method for regular monitoring of sick preterm neonates as it can be applied accurately, unlike direct arterial monitoring, to all patients.
Age Factors↗
Nosocomial bacterial infections in very low birth weight infants.
The occurrence of congenital and nosocomial bacterial septicaemia has been documented by identifying the number of positive blood cultures by reviewing the laboratory and clinical records of 394 very low birth weight infants who were consecutively admitted to a neonatal intensive care unit over a 40-month period. The incidence of congenital septicaemia was 6% and of nosocomial septicaemia 17%. The commonest causes of congenital infection were Streptococcus agalactiae Staphylococcus epidermidis and Enterococcus faecalis (each in 18% of cases). The commonest cause of nosocomial infection was S. epidermidis (51% of cases), except in infants of birth weight less than 750 g. Risk factors for nosocomial infection were extremely low birth weight, very preterm birth and prolonged ventilation. Nosocomial infection was associated with significantly lengthened hospital admission.
Cross Infection↗
Longitudinal assessment of infant lung function following pregnancies complicated by prolonged and preterm rupture of the membranes.
Serial measurements of functional residual capacity (FRC) were made in 22 infants (median gestational age at delivery 32 weeks, range 25-40) during the first 2 years of life. All infants had been delivered from pregnancies complicated by prolonged and preterm rupture of the membranes (PPROM) of at least 1 week in duration. The onset of membrane rupture was at a median of 26 weeks (range 15-32) with a median duration of 5.5 weeks (range 1-21). The mean FRC at all postnatal ages studied: 25 ml/kg at 6 and 12 months and 24 ml/kg at 18 and 24 months did not differ significantly from the control population (mean 24 ml/kg). There was, however, a wider scatter of results in the study population: four infants born very preterm consistently had FRC results above the 95% confidence limits of the controls but only two infants had FRCs consistently below this range. These results suggest PPROM may not be an invariable association of abnormal antenatal lung growth.
Child, Preschool↗
Effect of dexamethasone on blood pressure--relationship to postnatal age.
The relationship of the change in blood pressure levels of very preterm infants treated with dexamethasone to postnatal age was investigated. Sixteen infants, median gestational age 26 weeks (range 23-33) (early treatment group), and 15 infants, median gestational age 26 weeks (range 24-32) (late treatment group) were recruited. Dexamethasone was administered at a median postnatal age of 17 days (range 3-26) and 50 days (range 29-112), respectively. The systolic blood pressure at the start of treatment and the maximum systolic blood pressure achieved during therapy were both significantly lower (P less than 0.01) in the early rather than the late treatment group. The change in blood pressure, however, that is, from the pre-treatment level to the maximum systolic blood pressure achieved during therapy, was similar in the two groups (median 38 mmHg, range 23-59 early treatment group and median 34 mmHg, range 16-66 late treatment group). We conclude that, even in the first 4 weeks of life, dexamethasone can cause a marked elevation of systolic blood pressure. As a consequence, regardless of the postnatal age at which dexamethasone is administered, blood pressure levels must be measured regularly.
Age Factors↗
Neonatal blood pressure levels of preterm infants who did and did not develop chronic lung disease.
The aim of this study was to assess if, in the neonatal period, there were differences in the blood pressure (BP) level of infants who did and did not develop chronic lung disease. If such differences were demonstrated to exist, we also hoped to determine influencing factors. Forty infants, consecutively admitted to our unit and who remained there throughout the neonatal period were studied. Twenty infants, median gestational age 29 weeks (range 27-32), did not develop CLD (non-CLD group) and 20 infants, median gestational age 26 weeks (range 24-32), developed CLD. Systolic BP was assessed using a non-invasive Doppler technique on day one and subsequently at weekly intervals. After day one and throughout the neonatal period BP levels, corrected for birthweight, were higher in the CLD group compared to the non-CLD group, by a mean of 5 mmHg. There was no significant difference between the numbers of infants in each group receiving theophylline or pancuronium. Significantly more infants in the CLD group had an umbilical catheter inserted and their catheters remained in situ significantly longer, a median of 8 days compared to a median of one day in the non-CLD group. We conclude that even in the neonatal period infants who develop CLD may have a modest elevation of BP, this is associated with prolonged umbilical arterial catheterisation. Our results, however, suggest that significant hypertension in infants who develop CLD, occurs after the neonatal period.
Blood Pressure↗
Lung function and the Hering Breuer reflex in the neonatal period.
Lung function and the occurrence of the Hering Breuer reflex during the neonatal period has been investigated. To assess the effect of extrauterine and intrauterine maturation on the strength of the reflex both preterm and term infants were recruited. Ten preterm infants, born at a median gestational age of 29.5 weeks (range 27-34) were studied serially over the first four weeks of life and 10 term infants were studied at a median postnatal age of 1.5 days (1-4). All of the infants were recruited from the neonatal unit and initially had had some form of respiratory distress. Respiratory rate, tidal volume and compliance were measured and end inspiratory occlusion performed in an attempt to provoke the Hering Breuer reflex. The Hering Breuer reflex was provoked in all infants on all occasions. There was no difference in the strength of the reflex between the preterm and term infants or preterm infants studied at different postnatal ages. All infants studied regardless of maturity or postnatal age had non-compliant lungs and a rapid respiratory rate. These data suggest a lack of intrauterine and extrauterine maturation of the Hering Breuer reflex in the neonatal period amongst infants with non-compliant lungs.
Aging↗
Neonatal respiratory support and lung function abnormalities at follow-up.
We have investigated if respiratory distress syndrome (RDS) treated by an increased inspired oxygen concentration, rather than mechanical ventilation, was associated with impaired lung function at follow-up and/or an increase in respiratory symptoms. Thoracic gas volume (TGV) and airways resistance (RAW) were measured in eight pre-term infants (median gestational age 29 weeks) at 6 and 12 months of age. The infants had suffered from RDS but had not required mechanical ventilation. Their results were compared to 16 other infants, matched for gestational age; eight who had required ventilation in the neonatal period and eight who had had no RDS. In all three groups the occurrence of respiratory symptoms was recorded. The lung function of the infants requiring oxygen in the neonatal period was similar to those who had not suffered from RDS, but their airways resistance was significantly lower at 6 but not 12 months than that of infants ventilated in the neonatal period (P less than 0.05). There was no significant difference in recurrent respiratory symptoms between the three groups although a greater proportion of the infants ventilated in the neonatal period were symptomatic in the first 6 months of life. These results suggest that oxygen therapy alone does not result in an impairment of lung function which is independent of the effect of prematurity.
Airway Resistance↗
Inhaled sodium cromoglycate for pre-term children with respiratory symptoms at follow-up.
Children born prematurely frequently have recurrent respiratory symptoms at follow-up and benefit from bronchodilator therapy. We have assessed if regular inhaled sodium cromoglycate would reduce this respiratory morbidity and need for bronchodilator therapy. Sixteen symptomatic children (median gestational age 29 weeks, post-natal age 15 months) were entered into a randomized double-blind, placebo-controlled trial. In two 3-week periods, the patients received either placebo or sodium cromoglycate (5 mg) as one puff q.d.s. from an inhaler via a coffee cup. Parents recorded their child's symptoms and need for bronchodilator therapy throughout and lung function was assessed by measurement of functional residual capacity (FRC) at the beginning and end of each 3-week period. The symptom score was reduced by 49% in the active compared to the placebo period (P less than 0.01) and bronchodilator was taken on a mean of 2.9 days per infant in the active period compared to 7.9 days in the placebo period (P less than 0.01). There was a significant improvement in FRC in ten of 16 patients over the active period but only in two infants over the placebo period (P less than 0.01). We conclude regular inhaled sodium cromoglycate is useful prophylaxis for symptomatic pre-term children.
Administration, Inhalation↗
Congenital bacterial sepsis in very preterm infants.
The results of body fluid and surface cultures from 148 preterm infants less than 33 weeks gestational age obtained routinely on admission to a neonatal intensive care unit were reviewed. The aim was to determine the occurrence of congenital bacterial sepsis in this population and to examine whether surface cultures yielded information helpful in management. Gastric aspirate and umbilical, nasal and ear swabs were cultured and the results were compared to those of blood cultures. Nine infants (5.4%) had congenital bacterial sepsis diagnosed by positive blood cultures. Only the results of microscopy of gastric aspirate were available within hours of birth and before the results of blood culture. Microscopy of gastric aspirate, demonstrating pus cells, alone had a sensitivity of 0.86 in predicting congenital sepsis but a specificity of 0.49; the specificity, however, rose to 0.80 if both organisms and pus cells were observed on microscopy. Thus, only this combination was a useful pre-indicator of congenital sepsis. In infants who did not develop septicaemia, treatment was modified only if Streptococcus agalactiae was cultured from surface sites; in all such cases, the organism was grown from the ear swab. Our results demonstrate that congenital bacterial sepsis is common amongst very preterm infants admitted for neonatal intensive care but routine screening of surface cultures should be restricted to an ear swab only.
Bacterial Infections↗
Lung volume measured by functional residual capacity in infants following first trimester amniocentesis or chorion villus sampling.
OBJECTIVE: To determine the incidence of respiratory problems and lung volume abnormalities in babies born after first trimester amniocentesis or chorion villus sampling. DESIGN: A prospective randomized study. SETTING: Harris Birthright Research Centre for Fetal Medicine, Paediatric Respiratory Laboratory, King's College Hospital. SUBJECTS: Babies of mothers who had undergone first trimester amniocentesis (n = 74) or chorion villus sampling (CVS) (n = 86) for fetal karyotyping because of advanced maternal age, parental anxiety or family history of chromosomal abnormality in the absence of parental chromosome re-arrangement. MAIN OUTCOMES: Respiratory distress in the neonatal period and lung volume as assessed by measurement of functional residual capacity (FRC). RESULTS: CVS was associated with a significantly higher incidence of neonatal respiratory distress, six infants in the CVS group but none in the amniocentesis group required admission to the special care baby unit because of respiratory distress (P less than 0.05). Although there was no significant difference in the mean FRC between the two groups (amniocentesis 29.7 ml/kg vs CVS 29.6 ml/kg) the overall incidence of FRC values less than 2.5th centile of the normal range was 9%. CONCLUSION: Both amniocentesis and CVS performed in the first trimester of pregnancy may impair antenatal lung growth.
Amniocentesis↗
Persistence of respiratory symptoms into the second year of life: predictive factors in infants born preterm.
Preterm infants frequently suffer from recurrent respiratory symptoms in the first year of life. Our aims were to assess if such respiratory morbidity persisted beyond the first year and to define the predictive factors. One hundred and seventeen infants (median gestational age 29 weeks) were followed prospectively for two years. Thirty-eight infants had symptoms only in the first year (group A) and in a further 20 infants, symptoms were present in both years (group B). Comparison of these two groups revealed no significant difference in birth weight or gestational age, but the duration of ventilation and increased inspired oxygen concentration were significantly longer in group B. Significantly more infants in group B had had an air leak in the neonatal period, and airways resistance at six months of age was also significantly higher in group B. We conclude that infants with severe neonatal respiratory distress are likely to have persisting respiratory morbidity and that respiratory function measurements at six months of age provide the most accurate predictor of chronic respiratory symptoms.
Airway Resistance↗