Hilary Whyte

Doppler echocardiographic measurement of pulmonary artery pressure from ductal Doppler velocities in the newborn

The ductal flow velocities in 37 newborns (group 1: persistent pulmonary hypertension [n = 16], transient tachypnea [n = 3], other [n = 2]; group 2: respiratory distress syndrome [n = 16]) were prospectively evaluated by Doppler ultrasound for the purpose of deriving systolic pulmonary artery pressures. Maximal tricuspid regurgitant Doppler velocity in 21 of these patients was used to validate the pulmonary artery pressures derived from ductal flow velocities. There was a significant linear correlation between tricuspid regurgitant Doppler velocity and pulmonary artery systolic pressure derived from ductal Doppler velocities in patients with unidirectional (pure left to right or pure right to left) ductal shunting (p less than 0.001, r = 0.95, SEE 8) and in those with bidirectional shunting (p less than 0.001, r = 0.95, SEE 4.5). Systolic pulmonary artery pressure in group 1 (67 +/- 13 mm Hg) was significantly higher than that in group 2 (39 +/- 10 mm Hg) (p less than 0.001). In those with bidirectional shunting, duration of right to left shunting less than 60% of systole was found when pulmonary artery pressure was systemic or less, whereas duration greater than or equal to 60% was associated with suprasystemic pulmonary artery pressures. Serial changes in pulmonary artery systolic pressure, reflected by changes in ductal Doppler velocities, correlated with clinical status in persistent pulmonary hypertension of the newborn. Persistently suprasystemic pulmonary artery pressure was associated with death in five group 1 patients. It is concluded that ductal Doppler velocities can be reliably utilized to monitor the course of pulmonary artery systolic pressures in newborns.

VEP's in normal full-term and premature neonates: longitudinal versus cross-sectional data

Abstract VEPs have been shown to change with CNS maturation in children, yet few studies had documented maturational changes in the premature infant. Using LED goggles, VEPs were studied in 75 neurologically normal infants of 22–42 weeks gestational age (GA) within the first 3 days of life. Twenty of these (22–32 weeks GA) were also followed longitudinally. The 22–23 week GA neonates had no identifiable waves. In all infants >24 weeks a large negative wave is seen with a latency around 300 msec (N300). After 27 weeks GA a late positive wave was present (P400), but with more variable latency and morphology. Between 30 and 35 weeks GA a small positive wave (P200) was seen in over one-third of the neonates; this component was present in all infants > 36 weeks GA. The consistency of the N300 across the ages studied suggests that it might arise from the basilar dendrites in the visual cortex, which are well developed by 24 weeks GA and undergo relatively little further development between 24 weeks and term. The P200 is suggested to arise from the apical dendrites which develop in the last trimester, explaining the emergence of P200 after 30 weeks GA. The infants followed longitudinally showed the same components, emerging in the same order, but with more rapid development (particularly of P200) compared to the cross-sectional studies. These data suggest that there are differences in the maturation of the visual system in the extrauterine versus intrauterine environment.

Growth and Nutrient Intakes of Human Milk–Fed Preterm Infants Provided With Extra Energy and Nutrients After Hospital Discharge

OBJECTIVES. The purpose of this pilot study was to determine whether mixing a multinutrient fortifier to approximately one half of the human milk fed each day for a finite period after discharge improves the nutrient intake and growth of predominantly human milk–fed low birth weight infants. We also assessed the impact of this intervention on the exclusivity of human milk feeding. METHODS. Human milk–fed (≥80% feeding per day) low birth weight (750–1800 g) infants (n = 39) were randomly assigned at hospital discharge to either a control or an intervention group. Infants in the control group were discharged from the hospital on unfortified human milk. Nutrient enrichment of human milk in the intervention group was achieved by mixing approximately one half of the human milk provided each day with a powdered multinutrient human milk fortifier for 12 weeks after discharge. Milk with added nutrients was estimated to contain ∼80 kcal (336 kJ) and 2.2 g protein/100 mL plus other nutrients. Intensive lactation support was provided to both groups. RESULTS. Infants in the intervention group were longer during the study period, and those born ≤1250 g had larger head circumferences than infants in the control group. There was a trend toward infants in the intervention group to be heavier at the end of the intervention compared with those in the control group. Mean protein, zinc, calcium, phosphorus, and vitamins A and D intakes were higher in the intervention group. CONCLUSIONS. Results from this study suggest that adding a multinutrient fortifier to approximately one half of the milk provided to predominantly human milk–fed infants for 12 weeks after hospital discharge may be an effective strategy in addressing early discharge nutrient deficits and poor growth without unduly influencing human milk feeding when intensive lactation support is provided.

The long‐term consequences of periventricular brain damage on language and verbal memory

Sixty‐eight extremely low birthweight children, of whom 41 sustained damage to the periventricular region of the brain in the perinatal period, completed language and memory tasks at 6 years of age. Their performance was compared to that of 20 children, born at term, who were matched to the preterm children in terms of age and socioeconomic status as measured by annual household income. Category fluency, rate of learning, and the retention of a simple prose passage were not impaired after early periventricular damage. Deficits in sentence comprehension and working memory were associated with germinal layer hemorrhage or mild intraventricular hemorrhage plus or minus mild hypoxic‐ischemic damage. In addition to these impairments, a reduced receptive vocabulary and naming difficulties were observed in patients in whom the intraventricular hemorrhage included ventricular dilatation or invaded the parenchyma or in whom there was associated widespread periventricular leukomalacia.

Outcome of infants 23-26 weeks' gestation pre and post surfactant

To describe mortality and neurodevelopmental outcome before and after the introduction of rescue therapy with natural surfactant in two neonatal units in Toronto, Canada, a retrospective cohort study of 891 liveborn 23–26 wk gestational age infants, 421 presurfactant (1982–1987) and 470 postsurfactant (1990–1994) was performed. Overall mortality was stable over time (41% vs 35%, p = 0.077), but declined for inborn 24 (71% vs 43%, p = 0.03) and 26 wk (26% vs 13%, p = 0.01) gestational age infants and was higher in surfactant‐treated infants (p > 0.0001). Chronic lung disease (61% vs 34%, p > 0.0001) and bilateral blindness (8% vs 4%, p = 0.004) declined over time, with stable rates of cerebral palsy (12% vs 15%), cognitive deficit (27% vs 26%) and aided sensorineural hearing loss (5% vs 4%). Sixty‐five percent of surviving infants in both eras were free from neurodevelopmental impairment, and severe impairment declined over time (p = 0.035).

Intravenous paraldehyde for seizure control in newborn infants

We studied 14 newborn infants with seizures after birth asphyxia or other causes. Paraldehyde was given as a 200 mg/kg IV bolus followed by an infusion of 16 mg/kg/h (10 cases), or as a 400 mg/kg bolus (4 cases). Serum concentrations of paraldehyde were higher in periods of adequate seizure control than in periods of little or no response. Paraldehyde serum concentrations above 10 mg/dl were associated with anticonvulsant effects and were achieved in most neonates with a 2-hour infusion of 200 mg/kg/h. If there is no effect, serum concentrations are probably below 10 mg/dl and an additional 200 mg/kg can be given safely over 1 hour.

Serial visual evoked potentials and outcome in term birth asphyxia

Birth asphyxia is a major cause of neonatal mortality and morbidity. It remains difficult to predict accurately neurologic outcome among survivors, particularly infants with moderate hypoxic-ischemic encephalopathy. Visual evoked potential (VEP) is a reproducible measure of cortical function and reflects acute changes in central nervous system status secondary to asphyxial insult. We performed serial VEPs on 36 term infants with documented birth asphyxia to investigate the relationship between VEPs and neurodevelopmental outcome at 18 months of age. Fourteen infants were neurologically intact at subsequent examination; all had normal VEPs during the first week of life. Twenty-two infants had died or were significantly handicapped at 18 months of age; 20 had abnormal VEPs persisting beyond day 7 of life. Abnormal VEPs accurately predicted abnormal outcome (100%) and were both sensitive (91%) and specific (100%). In 20 infants who were classified as moderately asphyxiated according to the criteria of Sarnat and Sarnat, even greater accuracy, sensitivity, and specificity (all 100%) were observed. VEPs demonstrate good correlation with neurodevelopmental outcome in term infants with birth asphyxia and provide accurate prognostic information useful in the clinical management of these infants.

Growth and body composition of human milk-fed premature infants provided with extra energy and nutrients early after hospital discharge: 1-year follow-up.

Objectives: Human milk (HM) is the optimal source of nutrition for premature infants; however, it is unclear whether HM alone is sufficient to meet their elevated nutritional requirements early after hospital discharge. We previously reported that premature infants (750–1800 g birth weight) fed HM containing extra nutrients for 12 weeks after discharge had dietary intakes closer to recommended levels and grew more rapidly than those fed HM alone. The objectives of the present article are to examine the impact of this intervention on bone mineralization, body composition, and HM use up to 1 year. Data are also presented on general developmental level at 18-month corrected age (CA). Patients and Methods: At discharge, predominantly HM-fed infants were randomized to receive for 12 weeks either approximately half of their feedings containing a multinutrient fortifier (intervention, n = 19) or all of their feedings as HM alone (control, n = 20). Results: Intervention infants remained longer (P < 0.001) and had greater whole-body bone mineral content (P = 0.02) until 12-month CA compared with controls. Intervention infants born less than or equal to 1250 g continued to have a larger mean head circumference throughout the first year of life (P < 0.0001). Human milk feeding (mL · kg−1 · day−1) differed between groups at 6- (P = 0.035), but not 12-month CA. No statistically significant differences were found between groups in the mental, motor, or behavior rating scale scores of the Bayley II at 18-month CA. Conclusions: Adding a multinutrient fortifier to HM provided to predominantly HM-fed premature infants early after discharge results in sustained differences in weight, length, and whole-body bone mineral content, and in smaller babies, head circumference for the first year of life.

Independent walking after neonatal arterial ischemic stroke and sinovenous thrombosis

Few studies have examined walking after neonatal arterial ischemic stroke and sinovenous thrombosis. We looked at the development of walking in a retrospective and consecutive cohort study of 88 term and near-term neonates. We used Kaplan-Meier survival curves and Cox proportional hazards models to assess (1) sex, (2) stroke type (arterial ischemic stroke or sinovenous thrombosis), (3) number of cerebral hemispheres with infarction, and (4) presence of neonatal comorbidity as predictors of the probability over time of starting to walk independently. These variables were assessed as predictors of parent-reported gait normality using the chi-square test on 2 × 2 contingency tables. Seventy-five of 83 survivors (90.4%, 95% confidence interval = 81.9—95.7) walked with a median time of first steps at 13 months of age (95% confidence interval = 12—14). Only bilateral strokes were associated with a lower probability over time of initiating independent walking (hazard ratio = 0.41, P = .04). Parents reported normal gait for 58 of 75 walkers (77.3%, 95% confidence interval = 67.8—86.8). No variables predicted parent-reported gait normality. Our findings suggest that most survivors of neonatal arterial ischemic stroke and sinovenous thrombosis walk with a gait that appears normal to parents, but bilateral infarctions decrease the probability over time of starting to walk independently. (J Child Neurol 2003;18:530—536).

The costs of planned cesarean versus planned vaginal birth in the Term Breech Trial

Background: The Term Breech Trial compared the safety of planned cesarean and planned vaginal birth for breech presentations at term. The combined outcome of perinatal or neonatal death and serious neonatal morbidity was found to be significantly lower among babies delivered by planned cesarean section. In this study we conducted a cost analysis of the 2 approaches to breech presentations at delivery. Methods: We used a third-party–payer (i.e., Ministry of Health) perspective. We included all costs for physician services and all hospital-related costs incurred by both the mother and the infant. We collected health care utilization and outcomes for all study participants during the trial. We used only the utilization data from countries with low national rates of perinatal death (≤ 20/1000). Seven hospitals across Canada (4 teaching and 3 community centres) were selected for unit cost calculations. Results: The estimated mean cost of a planned cesarean was significantly lower than that of a planned vaginal birth (