Identification and evaluation of mental retardation.

Mental retardation in young children is often missed by clinicians. The condition is present in 2 to 3 percent of the population, either as an isolated finding or as part of a syndrome or broader disorder. Causes of mental retardation are numerous and include genetic and environmental factors. In at least 30 to 50 percent of cases, physicians are unable to determine etiology despite thorough evaluation. Diagnosis is highly dependent on a comprehensive personal and family medical history, a complete physical examination and a careful developmental assessment of the child. These will guide appropriate evaluations and referrals to provide genetic counseling, resources for the family and early intervention programs for the child. The family physician is encouraged to continue regular follow-up visits with the child to facilitate a smooth transition to adolescence and young adulthood.

Survival and subsequent outcome to five years of age for infants with birth weights less than 801 grams born from 1983 to 1989.

OBJECTIVE: To determine the neurodevelopmental status for 5-year-old survivors with birth weights (BW) <801 gm born in the 1980s and to assess differences in outcome for those born from 1986 to 1989 compared with those born from 1983 to 1985. STUDY DESIGN: This investigation was a longitudinal follow-up of all infants with BW from 450 to 800 gm born at one of two hospitals in Kansas City, Mo., between January 1983 and December 1989. Medical records were reviewed at discharge to determine obstetric and neonatal interventions and complications. Neurodevelopmental outcome was assessed by a multidisciplinary evaluation at 60 +/- 3 months old. Multiple logistic regression analyses were used to determine factors statistically associated with survival and long-term outcome. RESULTS: The percentage of infants surviving to hospital discharge was not different between periods. From 1986 to 1989, there were more infants with BW <601 gm and <26 weeks' gestational age. Survival was greater for gestational age categories > or = 24 weeks. BW, gestational age, female gender (p < 0.0001), and birth era (p < 0.01) were each independently significantly associated with improved survival. At 5 years of age, there were no significant outcome differences between birth era cohorts. Overall, approximately 21% of infants had severe disabilities. Long-term outcome was significantly influenced by the occurrence of intracranial hemorrhage and socioeconomic status. CONCLUSION: For infants with BW <801 gm, survival of infants > or = 24 weeks' gestational age was greater in 1986 to 1989 compared with 1983 to 1985, although the 5-year neurodevelopmental outcome was not different between groups. The significant impact of social risk status on outcome suggests that factors outside the intensive care nursery must be addressed to improve long-term outcome.

High-dose phenobarbital therapy in term newborn infants with severe perinatal asphyxia: a randomized, prospective study with three-year follow-up.

OBJECTIVE: To determine whether 40 mg/kg phenobarbital given to term infants with severe asphyxia would result in a lower incidence of seizures in the newborn period and an improved neurologic outcome. METHODS: We conducted a randomized, controlled, prospective study. Entry criteria included (1) an initial arterial pH less than or equal to 7.0 with a base deficit 15 mEq/L or more, (2) Apgar score less than or equal to 3 at 5 minutes of age, or (3) failure to initiate spontaneous respiration by 10 minutes of age. Sample size was calculated to detect a 50% reduction in the incidence of neonatal seizures. RESULTS: No differences were present between treatment and control groups with respect to severity of asphyxia assessed by initial arterial pH, base excess, cerebrospinal fluid lactate dehydrogenase concentration or detection of CSF creatine kinase of its BB isoenzyme. Seizures occurred in 9 of 15 infants in the treatment group and 14 of 16 infants in the control group (p = 0.11). No adverse effects were observed from phenobarbital on heart rate, respiratory rate, blood pressure, or arterial blood gas values. Three-year follow-up revealed normal outcome in 11 of 15 infants in the treatment group and 3 of 16 in the control group (p = 0.003). CONCLUSION: Phenobarbital, when administered in a dose of 40 mg/kg intravenously over 1 hour in term, severely asphyxiated newborn infants appeared to be safe and was associated with a 27% reduction in the incidence of seizures and a significant improvement in neurologic outcome at 3 years of age.

Seasonal respiratory viral infections. Impact on infants with chronic lung disease following discharge from the neonatal intensive care unit.

OBJECTIVE: To determine the frequency and severity of acute respiratory infections in infants with bronchopulmonary dysplasia following discharge from the neonatal intensive care unit. DESIGN: A prospective cohort study of 30 oxygen-dependent children who were younger than 2 years (mean age, 9.8 months; range, 3 to 24 months) were studied from September 1990 through April 1991. MEASUREMENTS/RESULTS: During the study, 101 (90.2%) of 112 visits for illness were prompted by new or worsening respiratory symptoms. Diagnoses included upper respiratory tract infection (30.4%), otitis media (26.0%), pneumonia (11.1%), acute exacerbation of bronchopulmonary dysplasia (10.4%), reactive airway disease (9.6%), and bronchiolitis (5.9%). Among these children, an increase in the fraction of inspired oxygen was necessary during 43% of visits. Ten children were hospitalized on 25 occasions for a mean of 37.6 hospital days per child (range, 1 to 107 days), and mean length of stay for each hospitalization was 15 days (median, 6 days). Five children were admitted to the pediatric intensive care unit. Respiratory viruses isolated included respiratory syncytial virus (n = 7), parainfluenza 3 virus (n = 3), and adenovirus (n = 2). No isolates of influenza A or B were detected. Anthropometrics at study entry and study end were converted to z scores as descriptors of weight for age, height for age, and weight for height. Growth improved during the 8 months of the study; however, overall, the children were leaner at study end than at study entry. CONCLUSIONS: In children with bronchopulmonary dysplasia, respiratory viral infections led to significant morbidity, which included long and frequent hospitalizations during the peak of the respiratory viral season. Although weight and linear growth increased throughout the study, patients were leaner at study conclusion than at study entry.

Growth patterns for infants weighing less than 801 grams at birth to 3 years of age.

Anthropometric measurements of infants weighing < 801 gm were monitored to evaluate growth patterns from birth to 36 months chronologic age, using both standard growth percentiles and Z score descriptors. Mean gestational age was 25.8 weeks, and birth weight was 708.4 gm. The infants had growth delay at hospital discharge with some catch-up growth occurring in the first year. Discrete changes in body growth using the Z score as a descriptor showed movement from a negative SD at 12 months toward the reference mean of zero at 36 months. However, mean length remained < 5th percentile, and mean weight was at approximately the 10th percentile for chronologic age. At 36 months 45% of infants had a head circumference smaller than the 5th percentile for chronologic age. Birth weight < 701 gm was a significant predictor of smaller occipital-frontal circumference at 3 years (p = 0.03). Interruption of intrauterine growth after extremely premature birth appears to have long-term effects on growth outcome much like prenatal growth retardation.

Systemic hypertension in infants with severe bronchopulmonary dysplasia: associated clinical factors.

The clinical course of 87 infants with bronchopulmonary dysplasia (BPD) on home oxygen therapy was reviewed to determine the occurrence of systemic hypertension (HTN) and to evaluate associated clinical features. Eleven of 87 (13%) infants developed systemic HTN either in the neonatal intensive care unit or following discharge. Clinical features that distinguished the hypertensive from the normotensive group were as follows: greater use of bronchodilators, 91% vs 37% (p < 0.001), and diuretics, 91% vs 55% (p < 0.05), longer duration of home oxygen therapy 21.6 +/- 9.9 vs 9.2 +/- 5.8 months (p < 0.05), and greater mortality, 36% vs 1% (p < 0.001). The course of systemic HTN in the surviving patients (7 of 11) was benign and resolved in all patients prior to weaning from home oxygen therapy. Systemic HTN is frequently present in infants with severe BPD and appears to be related to the clinical severity of lung disease.

Kidney function in very low birth weight infants with furosemide-related renal calcifications at ages 1 to 2 years.

To determine whether long-term renal sequelae follow the use of furosemide in preterm infants, we evaluated renal function in 27 former very low birth weight infants (less than 1500 gm) at 1 to 2 years of age. Patients were classified into three groups on the basis of status at the time of discharge from the hospital: group 1 (n = 7) had no furosemide treatment or renal calcifications, group 2 (n = 10) had furosemide therapy but no calcifications, and group 3 (n = 10) had furosemide therapy with renal calcifications. Renal ultrasonography at the time of the study demonstrated resolution of the calcifications in six patients in group 3. No differences in renal function were observed between groups 1 and 2. Creatinine clearance (mean +/- SEM) in group 3 (83.6 +/- 7.8 ml/min per 1.73 m2) was significantly lower than clearance in groups 1 and 2 (103.2 +/- 6.5 and 109.1 +/- 5.1, respectively; p less than 0.05). Children in group 3 had significantly higher urinary calcium/creatinine ratios and fractional excretion of sodium and lower tubular reabsorption of phosphate than children in the two other groups had. Urine-blood difference in carbon dioxide tension after oral acetazolamide load, which indicates the ability of the distal tubule to secrete hydrogen ions, was 8.4 +/- 3.4 mm Hg in group 3, significantly lower than values in groups 1 and 2 (22.6 +/- 3.1 and 28.0 +/- 4.3 mm Hg, respectively, p less than 0.05). Within group 3 the four children with persistent renal calcifications had significantly lower urine-blood carbon dioxide tension differences than did those with resolution of calcifications (p = 0.02). We conclude that furosemide-related renal calcifications in very low birth weight infants may lead to glomerular and tubular dysfunction; further long-term follow-up of this population is recommended.

Furosemide-related renal calcifications in the premature infant. A longitudinal ultrasonographic study.

Low birthweight infants treated with chronic furosemide therapy are at risk for the development of intrarenal calcifications. A prospective longitudinal renal ultrasound investigation was conducted to study the correlation of diuretic therapy, clinical course and ultrasonographic findings. Of 117 premature infants studied ultrasonographically upon discharge from the hospital, 20 had intrarenal calcifications. Eight patients at age 16.3 +/- 2.6 months had sonographic resolution of renal calcifications, 6.6 +/- 1.1 months after furosemide therapy had been discontinued. Of the 12 patients with persistent calcifications, 4 died from severe pulmonary disease and autopsy in 3 of them confirmed the ultrasonographic diagnosis. All 12 children but 2 continued to receive furosemide for their chronic lung disease demonstrating significant association between chronic use of loop diuretics and persistence fo the renal calcifications (p less than 0.001). Two patients required nephrolithotomy and 4 suffered from recurrent urinary tract infections. In 4 patients, 5 kidneys were of small size and in 2 bilateral collecting system dilation was noted. We conclude that discontinuation of furosemide therapy is associated with resolution of the renal calcifications. On the other hand, continued treatment with furosemide is associated with high renal morbidity which indicates ongoing clinical and ultrasonographic follow-up.

Improved survival and neurodevelopmental outcome for infants less than 801 grams birthweight.

We reviewed the perinatal management and subsequent outcome of infants 401 to 800 gm birthweight delivered in 1983 to 1985 compared with those born in 1980 to 1982. Intrapartum fetal heart rate monitoring, cesarean section delivery, attempted delivery room resuscitation, and 5-minute Apgar scores greater than 5 were more frequent in 1983 to 1985. Significantly greater neonatal survival was evident for infants 500 to 700 gm birthweight (31%) and 24 to 27 weeks' gestation (45%) in 1983 to 1985, p less than 0.005. Infant birthweight, gestational age, gender, and 5-minute Apgar score, in addition to intrapartum tocolysis use, were predictors of higher survival by stepwise discriminant analysis. At a mean follow-up of 27 months, 13% (6 of 46) born in 1983 to 1985 had major disability compared with 67% (6 of 9) of infants born in 1980 to 1982. There has been a significant increase in survival and improvement in neurodevelopmental follow-up status for infants less than 801 gm birthweight. These improved outcome data should be considered by caregivers providing perinatal management and counseling parents regarding extremely low birthweight infants.

Neurodevelopmental follow-up of infants with birthweight less than 801 grams with intracranial hemorrhage.

The incidence and severity of intracranial hemorrhage (ICH) were determined in a group of surviving infants with birthweights less than 801 g born during the period of 1983 through 1985. Neurodevelopmental status was assessed at 2 and 3 years of age to determine the relationship between neonatal ICH and later outcome in these infants. Forty-four of 77 neonatal survivors (57%) had ICH. Infants with ICH were less mature than those without (25.7 weeks' vs 26.5 weeks' gestation, P less than .05). There were no other perinatal factors that significantly differed between groups. At both 2 and 3 years of age, there were no significant differences between groups of infants with no or mild ICH and those with severe ICH regarding frequency of developmental delay, cerebral palsy, or visual impairment. Persistent ventriculomegaly in infants with ICH was associated with the highest incidence of neurodevelopmental disabilities. For extremely low birthweight infants, the presence and severity of neonatal ICH, in itself, did not adequately predict neurodevelopmental outcome at 2 or 3 years of age. Among infants with ICH, ventriculomegaly persisting to hospital discharge may indicate the greatest risk for neurologic and visual disabilities.