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Biomedical subjects

L W Doyle

Publications and source records attributed to L W Doyle.

At least 91 records · Page 5Linked to original sources
PubMed1991

Changing two-year outcome of infants weighing 500 to 999 grams at birth: a hospital study.

Survival and neurodevelopmental outcome to 2 years were determined for two cohorts of infants weighing 500 to 999 gm at birth, born in a tertiary maternity hospital. Live births increased over time from an annual average of 48.7 in the first era (January 1977 to March 1982) to 64.6 in the second era (January 1985 to December 1987), largely from referrals of additional mothers with pregnancy complications. In the first era, 33.6% (86/256) of infants survived to 2 years; the survival rate improved significantly to 45.9% (89/194) in era 2. After adjustment for birth weight, the odds ratio for survival in era 2 versus era 1 was 1.39 (95% confidence interval = 1.12, 1.73; p less than 0.01). One known survivor in each era was not seen at 2 years of age. In the first era, 59.3% (51/86) of 2-year-old children were free of disability compared with 68.5% (61/89) in era 2 (NS), but the Mental Development Index of the Bayley Scales improved significantly, from 90.0 in era 1 to 98.0 in era 2. For infants weighing less than 800 gm at birth, not only did the 2-year survival rate improve, adjusted for birth weight (odds ratio = 1.53; 95% confidence interval = 1.06, 2.20; p less than 0.05), but there was also a significant reduction in neurologic disabilities in survivors (p = 0.03). For infants weighing 800 to 999 gm at birth, there was a significant improvement in the survival rate, adjusted for birth weight (odds ratio = 1.37; 95% confidence interval = 1.04, 1.79; p less than 0.05), but the rate of neurologic disabilities was unchanged. Increased survival in our tertiary maternity center was achieved without increasing the annual number of severely disabled 2-year-old survivors.

Child, Preschool↗
PubMed1991

Outcome to 8 years of infants less than 1000 g birthweight: relationship with neonatal ventilator and oxygen therapy.

The study involved a cohort of 59 consecutive survivors with birthweights less than 1000 g, born between 1977 and 1980, to 8 years of age. The aim of the report was to determine if those survivors who had received more oxygen and ventilator therapy differed in their outcome compared with those who had received less oxygen and ventilation. Children were graded into four groups, characterized by decreasing durations of oxygen and ventilation. Children who had received less oxygen and ventilation were more likely to be below the third percentile for weight at 2, 5 and 8 years but the trends were significant only at 2 and 5 years (P = 0.006, P = 0.013 and P = 0.19 respectively). The rate of cerebral palsy was 8% at 8 years; the only children with severe or moderate disabilities from their cerebral palsy were in the lowest oxygen and ventilation group (n = 4, P less than 0.02). The frequency of hospital re-admission and the duration of re-hospitalization did not vary significantly between the four groups at any age. The rates of recurrent wheezing episodes or asthma did not vary significantly between the groups. Although the cohort as a whole had some impairment of lung function compared with healthy full-term controls, there was no significant difference between the four groups. Contrary to expectations, our findings suggest lower rates of poor growth and adverse neurological outcomes with increasing durations of oxygen and ventilation in the newborn period.

Birth Weight↗
PubMed1991

Inguinal hernia in very low birthweight children: a continuing risk to age 8 years.

The prevalence of inguinal hernia repair up to 8 years of age was determined in 205 inborn children of birthweight less than 1500 g who had survived to the age of 8 years; 37 (18.0%) of the children required surgery for inguinal hernia, significantly more frequently for boys than girls (32.0% and 3.9% respectively). The cumulative percentage of inguinal hernia operations in boys was 8.7% during primary hospitalization, 20.4% by 2 years, 30.1% by 5 years and 32.0% by 8 years; 36.4% (12 of 33) hernias in boys occurred beyond 2 years of age. The risk of hernia in boys was only marginally higher in those who required assisted ventilation and in those of birthweight less than 1000 g. Very low birthweight infants, particularly boys, are at risk of developing an inguinal hernia not only in infancy but also to at least 8 years of age.

Child↗
PubMed1991

Survivors of extreme prematurity--outcome at 8 years of age.

Of 149 infants liveborn in a large maternity hospital in 1980 to 1982 and delivered between 24 and 29 completed weeks of gestation inclusive, 91 (61%) survived; 88 (97%) survivors were assessed at 8 years' corrected age; 77% of children were not disabled; disability was mild in 13%, moderate in 2% and severe in 4% of children. Although survival decreased with decreasing gestation, disability in survivors did not increase. An earlier assessment of the same children at approximately 2 years of age had been unduly pessimistic particularly for those born less than or equal to 26 weeks' gestation. The only other reports in the literature on outcome by gestation have all assessed the children in early childhood, and estimates of severe disability rates from these studies will probably also be too pessimistic. Since the rate of severe disabilities in infants of borderline viability is not much higher than in more mature infants the obstetrician should mainly consider survival chances for the fetus, and not be overly concerned with long-term neurological outcome, when making clinical decisions.

Australia↗
PubMed1990

Health and hospital readmissions of very-low-birth-weight and normal-birth-weight children.

Rehospitalizations and ongoing health problems at 5 years of age were contrasted between 197 very-low-birth-weight (VLBW) children and 47 normal-birth-weight children. At 5 years of age, the VLBW children had a mean of 1.7 hospital admissions and 8.5 days in a hospital; these means were significantly more than the 0.5 admissions and 1.7 days, respectively, for the normal-birth-weight children. Overall, respiratory tract problems and ear, nose, and throat surgery were the most common reasons for readmissions. Malformations and intensive care sequelae infrequently caused readmissions. No combination of sociodemographic or perinatal variables identified the VLBW children who were destined for hospital readmissions. At 5 years of age, the VLBW children, compared with the normal-birth-weight children, had significantly more ongoing sensorineural problems (29.9% and 10.6%, respectively), ongoing respiratory problems (39.6% and 19.1%, respectively), and other morbidities (31.0% and 17.0%, respectively). The VLBW children, compared with the normal-birth-weight children, had more hospital admissions during the first 5 years of life and more ongoing problems at 5 years of age.

Child, Preschool↗
PubMed1990

Five-year outcome of infants of birthweight 500 to 1500 grams: relationship with neonatal ultrasound data.

Of 154 consecutive survivors of birthweight 500 to 1500 gm, 139 (90.3%) were seen at 5 years of age, corrected for prematurity, and 137 (89%) were able to be fully assessed by both the psychologist and pediatrician. All but two children had had serial cranial ultrasonography with a linear array real-time scanner in the neonatal period. At 5 years, of 39 children with cerebral ultrasound abnormalities detected during their primary hospitalization, seven (17.9%) had cerebral palsy, but 32 (82.1%) did not. A further three children with cerebral palsy at 5 years had had no cerebral abnormalities on ultrasound. Of the cerebral abnormalities diagnosed by ultrasound, ventricular dilation, with or without cerebroventricular hemorrhage, had the highest positive predictive value (40%) for cerebral palsy at 5 years. In the 127 children free from cerebral palsy at 5 years, two (1.6%) had severe intellectual impairment, both of whom had had normal cerebral ultrasonography. Although neonatal cranial ultrasonography with a linear array was somewhat predictive of cerebral palsy at 5 years, the majority of infants with abnormal scans had no severe sensorineural impairments at 5 years.

Cerebral Hemorrhage↗
PubMed1990

Changing diagnosis of cerebral palsy in very low birthweight children.

The stability of the diagnosis of cerebral palsy from 2 to 5 years of age was examined in 83 children of birthweight under 1000 gm, and 112 of birthweight 1000 to 1500 gm. In 20 2-year-old children with cerebral palsy, the diagnosis persisted in 11 (55%, 95% confidence intervals 35.1 to 76.9%); 2 of 175 children (1.1%) free of cerebral palsy at 2 years of age subsequently developed the condition. Severe or moderate cerebral palsy at 2 years persisted in all eight children (100%). In 9 of 12 children in whom cerebral palsy at 2 years had disappeared by 5 years, minor neurologic abnormalities and left-hand preference occurred frequently but mean psychologic tests scores were similar to children always free of cerebral palsy. In this cohort, cerebral palsy at 2 years was not a static condition, but overestimated later prevalence.

Cerebral Palsy↗
PubMed1990

Extracorporeal membrane oxygenation (ECMO) for non-ECMO intensive care nurseries.

An extracorporeal membrane oxygenation (ECMO) centre has been established in the sole outborn-only level 3 nursery in Melbourne. In the absence of other guidelines, an infant may qualify for ECMO if the expected mortality, based on assessment of the severity of hypoxia, exceeds 80%. However, for a non-ECMO centre, this involves the additional hazard of transport for an already critically-ill infant. The aim of this study was to determine the predictors of at least 80% mortality in babies who might have qualified for ECMO but who were cared for in a non-ECMO level 3 nursery. Regardless of the severity or duration of hypoxia, we were unable to identify a group of infants whose mortality exceeded 80%. Since outborn infants were disproportionately over-represented amongst those who might qualify for ECMO, it would be advisable to admit preferentially those born outside the level 3 perinatal centres who might qualify for ECMO directly to the ECMO centre. For infants born within our level 3 perinatal centre, it is recommended not to transfer those who might qualify based on data from other centres until the exact role of ECMO is determined. Alternatively, a randomized controlled trial of transfer versus non-transfer to the ECMO centre for severely hypoxic infants cared for in non-ECMO level 3 nurseries could be considered.

Australia↗
PubMed1990

Immunoglobulin and anti-Escherichia coli antibody in lower respiratory tract secretions from infants weighing less than 1500 g at birth.

Concentrations of immunoglobulins and anti-Escherichia coli antibody were studied longitudinally in tracheobronchial aspirates from 33 premature intubated neonates, median gestational age 27 weeks. Aspirates collected at birth contained IgG, IgA, and IgM in 100%, 93%, and 79% of samples, respectively. The median IgA concentration at birth was 0.7 micrograms/mg total protein and increased to 5.8 micrograms/mg protein by the sixth week. IgG and IgM antibodies to E coli were present in 90% and 30%, respectively, of tracheobronchial aspirates collected at birth. Samples from three of 28 neonates (11%) contained IgA anti-E coli antibody at birth, and the proportion with IgA antibody rose to 50% during the sixth week. Secretory component associated IgA and IgM were detectable in samples tested at birth and at 4 weeks of age, and secretory component associated anti-E coli antibody was present in aspirates from three of nine neonates studied at 4 weeks of age, but had not been detectable at birth.

Antibodies, Bacterial↗
PubMed1989

Increasing the survival of extremely-immature (24- to 28-weeks' gestation) infants--at what cost?

In one tertiary perinatal centre, the advent of positive-pressure assisted ventilation in the 1970s improved the survival of neonates of 24 to 28 completed weeks of gestation. However, the rate of increase in the resources for assisted ventilation and the improvements in survival rates were stepwise and not smooth. Consequently, it has been possible to calculate the cost-effectiveness of neonatal intensive care up to the time of hospital discharge over two separate eras of stable consumption of resources for assisted ventilation. During 1977-1983, to produce one survivor at 24-weeks' gestation compared with one at 28-weeks' gestation consumed 14.4-times the number of patient-days of assisted ventilation, and 4.9-times more of the total nursery resources; the cost-effectiveness of intensive care during this period decreased with decreasing maturity. The over-all cost-effectiveness up to the time of hospital discharge for infants of 24- to 28-weeks' gestation during 1977-1983, compared with 1971-1974, when assisted ventilation was rare, was $62,268 per additional survivor. After 1983, the consumption of resources for assisted ventilation more than doubled in infants of 24- to 28-weeks' gestation. However, there was a diminishing return with respect to the gains in survival during 1984-1986 and the costs per additional survivor averaged $99,574, which was 60% more than were those for 1977-1983. We speculate that to improve survival further in the most-immature infants by increasing resources for assisted ventilation only can be more difficult and more expensive, and even less cost-effective.

Australia↗
PubMed1989

Retinopathy of prematurity in infants of 24-30 weeks' gestational age.

Over the 10-year period from January 1, 1977 to December 31, 1986, 1114 infants with gestational ages of 24 to 30 completed weeks were cared for on a long-term basis in our nursery; 757 (68%) infants survived. As expected, both the mortality rate and the prevalence of stage-3 or stage-4 retinopathy of prematurity among survivors fell with increasing maturity at birth (P less than 0.0001). Adjusting for gestational age, and excluding infants with lethal malformations, the mortality rate decreased significantly (P = 0.018) over time by an estimated 11.5%; also the survival rate of infants with at least stage-3 retinopathy of prematurity increased significantly (P = 0.005) by an estimated 6.8%. In other words, for every 10 additional survivors over the decade, six survivors would have been expected to show at least stage-3 retinopathy of prematurity in either eye. Although the prevalence of advanced stages of retinopathy of prematurity increased in immature survivors, it was not in epidemic proportions; however, it was more likely to be related to the survival of the increasing numbers of at-risk immature infants who, in earlier times, would have died.

Australia↗
PubMed1989

Mortality with increasing assisted ventilation of very-low-birth-weight infants.

From Jan 1, 1977, to Jan 1, 1987, very-low-birth-weight (VLBW) infants consumed almost 90% of total patient-days of assisted ventilation of all infants born in one tertiary perinatal center. In the latter five years compared with the first five years, increasing resources allowed proportionately more VLBW infants to be offered assisted ventilation, and the patient-days of assisted ventilation consumed per live birth rose by almost 60%. All VLBW infants did not benefit equally from the increased assisted ventilation. Mortality in infants with birth weights below 1200 g decreased; unexpectedly, mortality in larger VLBW infants (birth weights, 1200 g to 1499 g) rose (relative odds, 3.11; 95% confidence intervals, 1.21 to 7.99). Despite the increased consumption of ventilator resources, there was no substantial impact on overall mortality in VLBW infants.

Apgar Score↗
PubMed1989

Correction of developmental and intelligence test scores for premature birth.

When using tests of infant development and intelligence in children born prematurely, the subject's age is commonly corrected for the degree of prematurity. However, there is disagreement: first, on whether this correction should ever be applied, and second, at what age to discontinue the adjustment. In a theoretical model, the difference between corrected and uncorrected scores in early infancy was massive and the difference remained clinically important until the age of 8.5 years in children who were born extremely prematurely. The clinical implications of using corrected or uncorrected scores were then evaluated in 174 very low birthweight children without severe sensorineural disabilities and with paired Bayley Mental Development Index (MDI) and Wechsler Preschool and Primary Scales of Intelligence (WPPSI) full scale scores. Failure to correct for prematurity reduced the mean MDI by 12.1 points but reduced the mean WPPSI by only 4.1 points. The disparity between individual MDI and WPPSI scores increased significantly with decreasing gestational age if uncorrected scores were used (P = 0.015) but not if scores were corrected. Using corrected scores, the MDI correctly predicted the WPPSI category in 86.1% of children (P less than 0.001) but in only 54.6% using uncorrected scores (the difference was not significant). It is suggested that a practical solution to the dilemma is to correct test scores for prematurity in the age range 2-8.5 years recognizing that only in extremely immature infants will uncorrected scores be substantially lower than corrected ones at a later age.

Child↗
PubMed1989

Selective improvement in cognitive test scores of extremely low birthweight infants aged between 2 and 5 years.

The cognitive development at 2 and 5 years of a cohort of extremely low birthweight (ELBW) children (birthweight 500-999 g) was compared with that of cohorts of larger very low birthweight (VLBW) children (birthweight 1000-1500 g) and normal birthweight (NBW) children (birthweight greater than 2500 g) to determine whether the improvements in cognitive function of ELBW infants between 2 and 5 years are apparent or real. At 2 years of age, ELBW children had a mean Mental Developmental Index (MDI) on the Bayley Scales of 90.4, significantly lower than the means of 100.3 for the larger VLBW children (P = 0.006), and 107.8 for the NBW children (P = 0.0002). However by 5 years the mean scores on the Wechsler Preschool and Primary Scales of Intelligence (WPPSI) full-scale for the ELBW and larger VLBW children were virtually identical (105.9 and 106.0 respectively)--but still lower than the mean WPPSI full-scale of 114.6 for the NBW children. After standardizing the MDI and WPPSI scores relative to the NBW children, the ELBW children improved between 2 and 5 years (paired t-test, t = 3.2, P = 0.004) whereas the larger VLBW infants did not. We postulate that ELBW children require more time than larger VLBW children after birth to compensate for perinatal and other stresses, and that developmental delay at 2 years may not always persist to 5 years.

Birth Weight↗
PubMed1989

Growth and very low birth weight.

Information on the likelihood of catch up growth in poorly grown very low birthweight children is sparse. The centiles for weight, height, and head circumference were recorded at both 2 and 5 years of age for 135 very low birthweight children and 42 normal birthweight children. At both ages significantly more children of very low birth weight were under the 10th centile for weight and height. Children of birth weight under 1000 g were more often under the 10th centile for weight at 5 years compared with those of birth weight 1000-1500 g. Mean incremental weight gain between 2 and 5 years was significantly less for very low birthweight children. Mean increment in weight from 2 to 5 years was less for very low birthweight children who had been under the 10th centile for weight at 2 years; children who had been under the 10th centile for height also had lower mean height increments. The growth centiles achieved by 2 years of age were useful predictors of poor growth at 5 years, with perinatal data of marginal importance. Only six of 43 (14%) children with a weight at 5 years of age under the 10th centile were small for gestational age at birth. Very low birthweight children who had a weight or height under the 10th centile at 2 years of age usually remained in this category at 5 years with no evidence of catch up growth.

Aging↗
PubMed1989

Antenatal steroid therapy and 5-year outcome of extremely low birth weight infants.

Over a 63-month period beginning January 1, 1977, 258 infants with birth weights of 500-999 g were born alive at one tertiary perinatal center; 170 were offered full intensive care. The mothers of 67 (39.4%) of these 170 infants had been given betamethasone antenatally to accelerate fetal lung maturation. Of the 67 infants exposed to steroids antenatally, 46 (68.7%) survived their primary hospitalization, compared with 43 (41.7%) of the 103 infants who had not been exposed to steroids. This difference is highly significant (chi 2 = 10.7; P less than .005) but is biased because infants in the steroid group had a better prognosis. After adjustment for discrepancies in birth weight and gestational age and other confounding obstetric variables, survival in the steroid group remained substantially higher (relative odds of survival 1.85, 95% confidence intervals 1.16-2.86; P = .006). The improvements in survival were not at the expense of increased rates of chronic ill health or impairments of growth neurodevelopment up to at least 5 years of age. For extremely immature and extremely low birth weight infants, steroids are rarely contraindicated on fetal grounds.

Betamethasone↗