PubMed Health⌕ Search

Biomedical subjects

U M MacFadyen

Publications and source records attributed to U M MacFadyen.

At least 19 recordsLinked to original sources
PubMed2001

Catch-up growth in small-for-gestational-age term infants: a randomized trial.

BACKGROUND: Small-for-gestational-age (SGA) term infants are at risk of long-term growth deficits. OBJECTIVE: The objectives were to test the hypothesis that postnatal growth in SGA term infants can be altered by dietary intervention and to examine whether there is a critical window for nutritional programming of the growth trajectory during the first 9 mo postnatally. DESIGN: Healthy term (gestation > or =37 wk) infants with birth weights below the 10th centile were randomly assigned to receive standard term formula (TF; n = 147) or nutrient-enriched formula (EF; n = 152) for the first 9 mo; 175 breast-fed SGA term infants formed a reference group. The main outcome measures were weight, length, and occipitofrontal head circumference (OFC) at 9 and 18 mo. RESULTS: The infants fed the EF showed greater gains in length by 9 (1.1 cm; 95% CI: 0.38, 1.79) and 18 (1.0 cm; 0.25, 1.83) mo and in OFC by 9 (0.5 cm; 0.1, 0.9) and 18 (0.6 cm; 0.2, 1.1) mo than did infants fed the TF; the differences were larger in females. The dietary effects were independent of the pattern of growth retardation. Breast-fed infants showed greater gains in weight and OFC by 18 mo than did infants fed the TF; however, these differences disappeared after adjustment for age, parental size, and birth order. CONCLUSIONS: Linear growth and OFC gains in SGA term infants improve after nutritional intervention during the first 9 mo of life and the effects persist for > or =9 mo beyond the intervention period. Further information on whether catch-up growth is beneficial or detrimental to long-term outcomes is required before public health interventions can be recommended.

Analysis of Variance↗
PubMed2001

Randomized trial of nutrient-enriched formula versus standard formula for postdischarge preterm infants.

OBJECTIVES: Preterm infants are frequently discharged from the hospital growth retarded and show reduced growth throughout childhood. In a large efficacy and safety trial, we tested the hypothesis that nutritional intervention in the first 9 months postterm would reverse postdischarge growth deficits and improve neurodevelopment without adverse safety outcomes. PARTICIPANTS AND INTERVENTION: Two hundred eighty-four infants (mean gestation: 30.9 weeks) were studied; 229 were randomly assigned a protein, energy, mineral, and micronutrient-enriched postdischarge formula (PDF; N = 113) or standard term formula (TF; N = 116) from discharge (mean 36.5 weeks' postmenstrual age). A reference group (N = 65) was breastfed until at least 6 weeks' postterm. Outcome measures. Anthropometry was performed at 6 weeks and 3, 6, 9, and 18 months. Development was measured at 9 months (Knobloch, Passamanick, and Sherrard's developmental screening inventory) and 18 months (Bayley Scales of Infant Development II; primary outcome) postterm. RESULTS: At 9 months, compared with the TF group, those fed PDF were heavier (difference 370 g; 95% confidence interval [CI]: 84-660) and longer (difference 1.1 cm; 95% CI: 0.3-1.9); the difference in length persisted at 18 months (difference 0.82 cm; 95% CI: -0.04-1.7). There was no effect on head circumference. The effect of diet was greatest in males; at 9 months length deficit with TF was 1.5cm (95% CI: 0.3-2.7), and this remained at 18 months (1.5cm [95% CI: 0.3-2.7]). There was no significant difference in developmental scores at 9 or 18 months, although PDF infants had a 2.8 (-1.3-6.8) point advantage in Bayley motor score scales. At 6 weeks' postterm, exclusively breastfed infants were already 513 g (95% CI: 310-715) lighter and 1.6cm (95% CI: 0.8-2.3) shorter than the PDF group, and they remained smaller up to 9 months' postterm. CONCLUSIONS: 1) Improving postdischarge nutrition in the first 9 months may "reset" subsequent growth-at least until 18 months for body length. We intend to follow-up the children at older ages. The observed efficacy of PDF was not associated with adverse safety outcomes. 2) We cannot reject the hypothesis that postdischarge nutrition benefits motor development and this requires additional study. 3) Our data raise the possibility that breastfed postdischarge preterm infants may require nutritional supplementation, currently under investigation.

Anthropometry↗
PubMed1999

Respiratory function in childhood following repair of oesophageal atresia and tracheoesophageal fistula.

AIM: To determine the relation between respiratory function in infancy and at school age in children who have undergone oesophageal atresia and tracheoesophageal fistula repair, and assess the value of infant respiratory function testing; and to examine the effect of bronchodilators. METHOD: Fourteen children (6 girls, and 8 boys) who had undergone respiratory function testing in infancy were retested at school age (7-12 years). Measurements included lung volume, airways resistance, peak flow, and spirometry. Clinical problems were investigated by questionnaire. Twelve children had repeat measurements after taking salbutamol. RESULTS: Predominant complaints were non-productive cough and dysphagia, but even those children with major problems in infancy reported few restrictions at school or in sport or social activities. Respiratory function and clinical findings at school age appeared unrelated to status in infancy, such that even the patients with severe tracheomalacia requiring aortopexy did not have lung function testing suggestive of malacia at school age. Most patients showed a restrictive pattern of lung volume which would appear to result from reduced lung growth after surgery rather than being a concomitant feature of the primary congenital abnormality. Although six children reported wheeze and four had a diagnosis of asthma, only one responded to salbutamol. This suggests that a tendency to attribute all lower respiratory symptoms to asthma may have led to an overdiagnosis of this condition in this patient group. CONCLUSION: Respiratory function testing in infancy is of limited value in medium term prognosis, but may aid management of contemporary clinical signs. In children respiratory function testing is valuable in assessing suspected asthma and effects of bronchodilators.

Albuterol↗
PubMed1994

Clinical findings and respiratory function in infants following repair of oesophageal atresia and tracheo-oesophageal fistula.

Survival rates for infants undergoing surgical repair of oesophageal atresia with tracheo-oesophageal fistula (OA-TOF) have improved dramatically, but this condition remains associated with substantial morbidity. Most studies of patients following OA-TOF repair have concentrated on school-age and older people; whereas, the most hazardous period is infancy. We aimed to assess respiratory function in a group of infants following primary operative repair, and to relate the results to clinical findings during the first year of life. We studied 16 infants within 3 months of primary repair of OA-TOF. Measurements were made of maximum expiratory flow at functional residual capacity (VmaxFRC), thoracic gas volume (TGV) and airways resistance (Raw). Ten infants had tests repeated, usually to assess progress alongside continuing symptoms, or to ascertain improvement following additional surgery. Seven infants had essentially normal initial respiratory function tests, and six remained either symptom-free or developed only minor clinical problems. One infant subsequently developed stridor, with spontaneous improvement towards the end of the first year. The remaining nine infants had abnormal initial respiratory function tests: one was symptom-free at that time. The remainder developed respiratory and/or gastro-oesophageal symptoms. The functional abnormalities appeared to reflect the severity of the clinical problems encountered. We conclude that respiratory function testing in infants following OA-TOF repair may augment the value of clinical appraisal, help define postoperative respiratory status, and provide a general guide to likely clinical progress.

Airway Resistance↗
PubMed1993

Comparison of peripheral chemoreceptor responses in monozygotic and dizygotic twin infants.

The peripheral chemoresponses of infant twin pairs were determined using a single-breath hyperoxic stimulus. A total of 43 twin pairs of comparable gestation and birth weight were studied during sleep at a mean (SD) age of 8 wk (1.4) while alternately breathing either air or 16% oxygen in nitrogen. Infants responded to a single breath of 100% oxygen by a reduction in ventilation; the mean (SEM) reduction in air was 273 ml/min (10.6) and in 16% oxygen 560 ml/min (18.4). Within-pair variances were compared in 14 monozygotic and 28 dizygotic pairs utilizing combined responses (air + 16% oxygen) computed for measurements made in behavioral quiet sleep and in 9 monozygotic and 20 dizygotic pairs for whom data were complete in polygraphically confirmed quiet sleep. The variance of responses within dizygotic twin pairs was greater than in monozygotic pairs when expressed in ml/min: F ratio 4.11 (p = 0.005) for all data and F ratio 7.67 (p = 0.003) in quiet sleep. Expressed in ml/min/kg the difference was less significant: F ratio 1.83 (p = 0.126) for all data and F ratio 3.46 (p = 0.039) in quiet sleep. Gender, birth weight, and birth order had no effect on these findings. This closer similarity of response in monozygotic twin pairs is explained by proposing a high degree of heritability for the response.

Chemoreceptor Cells↗
PubMed1992

Variations in results of simultaneous ambulatory esophageal pH monitoring.

Twenty-four-hour esophageal pH monitoring is regarded as the gold standard investigation for gastroesophageal reflux (GER) (1) and the possibility of an "incorrect" answer, false positive or false negative, is only rarely considered (2). However, when a group of infants in this hospital had such pH studies performed on two consecutive days, considerable differences in the results were found (3). This also had been reported from other centers (4-6). It seems likely that most of the differences were due to true "biological" variability in the amount of GER from day to day, but it remains possible that variation in the accuracy of the equipment in detecting acid reflux was also involved.

Ambulatory Care↗
PubMed1992

Gaviscon and Carobel compared with cisapride in gastro-oesophageal reflux.

We compared the efficacy of the prokinetic agent cisapride with that of Gaviscon (an alginate/alkaline compound) plus Carobel (carob seed flour) in the treatment of gastrooesophageal reflux (GOR). Fifty infants with confirmed GOR received either oral cisapride (0.8 mg/kg/day) or Gaviscon plus Carobel for one month in a randomised, parallel group study. Parental evaluations, diary scores, and 24 hour lower oesophageal pH recordings before and at the end of each treatment were compared. In the cisapride group 14/26 (53%) were considered better by their parents compared with 19/24 (79%) of those who received Gaviscon plus Carobel. Diary scores, range (0.00-1.00), improved in both groups with the median change being greater in the Gaviscon plus Carobel group (-0.21) than the cisapride group (-0.15). Five of 17 pH variables had significantly improved from baseline in infants who had received cisapride compared with 11/17 in those receiving Gaviscon plus Carobel. However, unpaired analysis of diary and pH data showed no significant differences between the two groups. We conclude that first line treatment of GOR with cisapride is no more effective than conventional treatment with Gaviscon plus Carobel.

Alginates↗
PubMed1991

Gastro-oesophageal reflux and respiratory function in infants with respiratory symptoms.

This study aimed to define the incidence and severity of gastro-oesophageal reflux (GOR), as measured using 24 hour oesophageal pH monitoring, in 38 infants with recurrent respiratory symptoms and to relate these findings to measures of respiratory function. Twenty one infants had a pH under 4 for more than 5% of the time (one definition of abnormal GOR) and nine had GOR exceeding age related normal values. Maximum expiratory flow at functional residual capacity was reduced in 37 infants, airways resistance was raised in 19 infants, and thoracic gas volume was abnormal in 11 infants. There was no association between indices of GOR and measures of lung function whether assessed by correlation or by chi 2 analysis for normal versus abnormal values. However, individual infants appeared to have respiratory symptoms produced by GOR. This suggests that host responsiveness to GOR may be of greater relevance than the amount of GOR.

Female↗
PubMed1991

The effect of a single breath of 100% oxygen on breathing in infants at 1, 2, and 3 months of age.

Sequential measurements of the ventilatory response to a single breath of oxygen delivered during quiet sleep were made in 16 healthy infants between 1 and 3 months of age, alternately breathing air and 16% oxygen in nitrogen. At 1 month the response to a single breath of oxygen during normoxia was a decrease in minute ventilation of 264 +/- 34.2 (SEM) ml.min-1 during the 10-s period following the stimulus (p less than 0.001). During mild hypoxia the decrease in ventilation averaged 471 +/- 49.1 (SEM) ml.min-1 (p less than 0.001). The difference in response between measurements in air and mild hypoxia was significant (p less than 0.001). By the age of 3 months, the absolute ventilatory response to a single breath of oxygen increased significantly in normoxia by 118 +/- 35.2 ml.min-1 (p less than 0.01); the test response to breathing 16% oxygen paralleled the response to normoxia and was on average 254 +/- 26.6 ml.min-1 larger than the response when breathing air (p less than 0.001). When the three age groups were compared, calculating the response per killigram body weight showed that the response was similar at all three ages tested. These data provide a reference baseline for normal infants.

Chemoreceptor Cells↗
PubMed1990

Reproducibility of 24 hour oesophageal pH studies in infants.

Thirteen infants who had undergone 24 hour oesophageal pH monitoring to diagnose gastro-oesophageal reflux had a second study carried out to see if the results were reproducible. The studies were done without restricting the babies' activities. Appreciable differences were found, the percentage of the total time during which the pH was less than 4 varying by up to 3.7-fold between the two tests. The differences were largely the result of biological rather than technical variability. From these results estimates were made of the reliability of a single diagnostic study and the size of changes that would be necessary to show the effect of treatment. These findings have a considerable impact on the diagnosis of abnormal gastro-oesophageal reflux and its response to treatment whether using 24 hour pH monitoring or any other method of measurement.

Eating↗
PubMed1989

Measurement of lung volumes during active and quiet sleep in infants.

The question of whether functional residual capacity (FRC) falls in infants during active sleep has been clouded by studies using different subject groups and techniques for measurements of lung volume and determination of sleep state. Twenty healthy full-term infants within the first week of life participated in the present study. Neurophysiological and behavioral criteria were used to define sleep state, and measurements of FRC were made using a specially constructed closed-circuit helium dilution system. Regularity of respiration was recorded using magnetometers on the chest and a modified respirator monitor. Results showed that no significant changes in FRC occurred, related either to sleep state or to regularity of respiration. In addition, we failed to detect any differences in FRC between the sexes.

Body Weight↗