Neurological sequelae in children surviving mechanical ventilation in the neonatal period

Antenatal and perinatal causes of handicap: definitions and size of the problem

The conditions of childhood that follow prenatal or perinatal problems are defined. These conditions are mental retardation in varying degree, the cerebral palsies, the syndrome of minimal cerebral dysfunction, language disorders and defects of hearing and vision. The difficulties in accurately measuring disability and handicap are discussed and an estimate of the size of the problem is offered. The contribution made by the low birthweight group is also considered and it is pointed out that, although within this group there is a much higher incidence of problems, the majority of children with handicapping conditions were of normal birthweight.

Cerebral palsy in low-birthweight infants. I. Spastic hemiplegia: associations with intrapartum stress

Children with and without spastic hemiplegia were identified among a representative sample of 1048 low-birthweight survivors by clinical assessment after three years of age. The hypothesis that hemiplegia was predetermined at birth was tested by estimating the probability of hemiplegia for each infant by logistic regression analysis, using data from hospital records on conditions known at the time of birth. 16 of 42 children with cerebral palsy had spastic hemiplegia. Allowing for the lower birthweights of hemiplegic children, increased prevalence was associated with previous reproductive loss, breech vaginal delivery, later birth-order, prolonged second stage of delivery, emergency caesarean section, and low Apgar scores. These variables identified correctly most children as having a higher or lower estimated probability of hemiplegia. Hemiplegia was also associated with prolonged respiratory disease and intraventricular haemorrhage. In this population it is likely that intrapartum events were closely related to the pathogenesis of hemiplegia; their effects may have been mediated by postnatal events.

An analysis of potential biases in the loss of indigent infants to follow-up

Loss to follow-up is a major problem in indigent inner-city populations. We evaluated a large, well-described, inborn indigent population of high-risk infants (HRI) and control infants (CI) to assess possible selection biases in loss to follow-up at one year adjusted age. Serial clinic visits, phone calls, and letters and payment of $20.00 for attending at 1 year was used to minimize patient loss. Yet, the 1 year loss rate was high, and among HRI, greater for ventilator-treated infants greater than 1500 g birthweight (71/114; 62%) than for ventilator-treated very-low-birthweight (VLBW; less than 1500 g) infants (39/108; 36%) or non-ventilated VLBW infants (62/145; 43%) (P less than 0.05). Multivariate analyses indicated that those lost to follow-up were at no greater risk of a poor outcome on the basis of prenatal and perinatal medical and socioeconomic findings than were those in the same risk group (HRI or CI) or subgroup of HRI who were examined at 1 year. In a review of hospital records, similar rates of hospitalization and neurologic problems during infancy were identified for HRI examined and HRI lost to follow-up. The identification of such morbidity during infancy may be less complete for HRI lost to follow-up than for those examined. Thus, the high frequency of deficits observed in follow-up evaluation of indigent HRI is unlikely to result from loss of unaffected infants.

Apgar score, meconium and acidaemia at birth in small-for-gestational age infants born at term, and their relation to neonatal neurological morbidity

Neonatal neurological morbidity was studied in relation to Apgar score, meconium stained amniotic fluid and acidaemia at birth in 247 small-for-gestational age (SGA) maturely born infants. SGA infants, and especially the severely SGA infants and those born abdominally, showed higher rates of neurological morbidity, acidaemia and meconium stained amniotic fluid than appropriate-for-gestational age (AGA) controls. The examined indicators of asphyxia at birth showed slightly higher correlation coefficients with the 'neonatal neurological optimality score' (NNOS) in SGA, than in AGA term infants, but the percentage of explained variance was low, except in the 23 infants born abdominally. In this group poor neurological outcome was restricted to the 14 infants who showed signs of fetal hypoxaemia diagnosed by decelerative fetal heart rate (FHR) patterns. In 11 of them, FHR decelerations occurred antepartum. These FHR abnormalities appear to be better predictors for the neonatal neurological outcome than indicators of asphyxia at birth.

The contribution of fetal-newborn complications to motor and cognitive deficits

A total of 364 selected high-risk premature and mature infants were studied prospectively to assess the relationship between fetal-newborn complications and motor and cognitive deficits identified during the first year of life. Deficits occurred in 24 per cent of the children: 14 per cent had one or more major deficit and the other 10 per cent had one or more minor deficit. Prematurity was one of the fetal-newborn complications not associated with deficits at one year. Complications that were associated with deficits included fetal hypoxia, respiratory difficulties, infection and newborn encephalopathy. There was also a significant association between fetal hypoxia, newborn respiratory complications, infection and newborn encephalopathy, which is in keeping with the concept that the first three may be mechanisms in CNS injury and subsequent deficits, while newborn encephalopathy reflects the injury and is an important predictor of such deficits.

A case for long-term treatment with anticonvulsants

Seizures occurring in the neonatal period are one of the most significant discriminating factors in predicting childhood neurologic mortality and morbidity (epilepsy, cerebral palsy and mental retardation). Data derived from retrospective and prospective studies indicate that different variables, such as cause and severity of seizure activity, birth weight, neurologic examination and electroencephalogram, help predict which of these children will be severely affected. Most physicians treat such children with an anticonvulsant (phenobarbital) for the first year of life on the supposition that this therapy will minimize mortality and long-term morbidity. There are no controlled studies to indicate whether anticonvulsant therapy affects the outcome in children with neonatal seizures. It may now be possible to select those who are at significantly higher risk for neurologic morbidity, and these infants may benefit from anticonvulsant prophylaxis with phenobarbital.

Visual defects in children after cerebral hypoxia

Visual functions were examined in 18 survivors of perinatal hypoxia/ischemia with mild to severe neurological sequelae, aged between 3 months and 17 years, and in two patients, aged 8 and 13 years, who had suffered postnatal hypoxic events. All but two patients showed clear visual deficits ranging from mild defects in visual acuity, visual field size, and/or optokinetic nystagmus to blindness. In 5 patients, the visual field was restricted to tunnel vision, a finding which appeared to be specifically related to the hypoxic/ischemic nature of the brain damage. The severity of the visual defects after perinatal hypoxia was related to the occurrence of neonatal seizures, later neurological outcome, and gestational age at birth. This is discussed in relation to previous studies of the effects of perinatal hypoxia/ischemia.

Outcome at school-age after neonatal mechanical ventilation

103 school-age children (5 to 12 years) who survived mechanical ventilation for neonatal respiratory failure were evaluated for growth, neurological, intellectual, psychological and school function in order to determine those children most at risk for handicap. A major handicap occurred in seven children, preventing attendance at normal school or normal classes. Neurological sequelae were significantly associated with perinatal asphyxia and with birthweights of 1500g or less, and neurological sequelae and socio-economic factors were the major determinants of ability. The effects of the Neonatal Intensive Care Unit (NICU) experience on parents and subsequent parent-child relationships were also investigated: 67 per cent of the mothers were very upset by the experience and many continue to worry excessively about the health of their child. Parents who visited their child in the NICU frequently were significantly more anxious and overprotective, restricting many activities even when the child was of school age.

A follow-up of the survivors of mechanical ventilation in a paediatric intensive care unit

Fifty-eight long-term survivors of mechanical ventilation have been traced and examined for evidence of auditory, visual, behavioural, developmental and central nervous system abnormalities. There were four children with serious neurological or intellectual handicaps, the causes of which did not seem to be related to deficiencies of their ventilator treatment but rather to events preceding ventilation or to the disease which had necessitated ventilation. There were an additional eight children who may have some intellectual damage. The occurrence of convulsions or hypoxic episodes during or preceding the period of treatment was significantly more common among the 12 children with a poor outcome, than those with a good outcome.

A critical evaluation of the obstetric use of alcohol in preterm labor

The clinical use of alcohol to delay premature labor is critically reviewed. The evidence indicates that this procedure is no more effective in arresting preterm labor than placebo, i.e., bed rest. The rational for the clinical use of alcohol in obstetrics is also questionable. Furthermore, increasing evidence indicates that the blood alcohol levels associated with this method often causes nausea, vomiting, and headaches in mothers and can cause deleterious effects in the fetus, including death.

Growth and development in children recovering from bronchopulmonary dysplasia

Of 26 patients with bronchopulmonary dysplasia, 20 (77%) survived and were followed prospectively for two years post-term. Lower respiratory tract infections occurred in 17 of the 20 children (85%), and required hospitalization in ten (50%) during the first and in four (20%) during the second year. At two years post-term only two patients had significant respiratory symptoms at rest, but 78% had residual radiographic changes. The average weight and height at term were at or below the third percentile. Growth occurred at an accelerated rate with improvement of respiratory symptoms, with average weight reaching the third to tenth percentile for both sexes, and tenth to twenty-fifth percentile for height in the boys and the twenty-fifth percentile for the girls by two years post-term. Growth retardation was associated with severe and prolonged respiratory dysfunction. Fifteen (75%) were free of major developmental defects. Five had mean Bayley scores less than 85 at 18 months post-term; one also had hydrocephalus. Developmental outcome seems related to perinatal and neonatal events rather than to the presence or absence of BPD.

Oral ritodrine maintenance in the treatment of preterm labor

Seventy patients with preterm labor and intact membranes were initially treated with ritodrine hydrochloride to delay preterm delivery. Tocolysis beyond 24 hours was achieved in 59 patients. Fifty-five of the 59 patients were then placed on either oral ritodrine or placebo as maintenance therapy in a randomized double-blind manner. If preterm labor recurred, the sequence of intramuscular and then oral treatment was repeated. The number of days gained after initiation of intramuscular treatment was similar in both groups (oral ritodrine = 34 days, oral placebo = 36 days). In those 55 patients receiving oral treatment, there was a smaller number of relapses requiring repeat intramuscular treatment in the oral ritodrine group (1.11 in the ritodrine patient vs. 2.71 in the placebo patient, p less than 0.05), and the mean interval between beginning oral treatment and the first relapse/delivery was 5.8 days in the oral placebo group and 25.9 in those receiving oral ritodrine (p less than 0.05). Cardiovascular side effects, notably maternal tachycardia and palpitations were frequent but well tolerated. The results suggest that oral ritodrine maintenance will decrease the incidence of recurrent preterm labor in patients who have had initial successful tocolysis.

Evaluation of mechanical ventilation in newborn infants. II. Pulmonary and neuro-developmental sequelae in relation to original diagnosis

The incidence of bronchopulmonary dysplasia (BPD) and neuro-developmental sequelae in 135 infants surviving intermittent positive pressure ventilation (IPPV) in the newborn period were studied in relation to primary disorders requiring IPPV. The rate of BPD increased over the 6-year study period in hyaline membrane disease survivors from 14% to 28%, but decreased in infants with apnoea repetens from 38% to 13%. Immaturity seemed to be one important factor for development of BPD. The incidence of neuro-developmental sequelae in IPPV treated infants fell from 22% to 13% over the years. In infants with birth weight below 1501 g the rate of neurological handicaps was 11%.

The need for improved perinatal care in prevention of cerebral palsy

Of 314 children assessed at the Ontario Crippled Children's Centre during 1975-77, 84% had cerebral palsy resulting from potentially preventable perinatal factors. The importance of risk scoring in pregnancy is stressed, as is the necessity for referral to a well equipped perinatal centre when problems are anticipated. The majority of children in this study were born in centres where these facilities were not available.

Pharmacologic inhibition of preterm labor

Preterm labor is responsible for a majority of cases of perinatal morbidity and deaths. Prevention of preterm labor is not usually possible; thus pharmacologic treatment is the only recourse available. Numerous agents have been used to treat preterm labor, but none has proved to be superior. This report reviews the current information available about the pharmacology of labor-inhibiting drugs and discusses the clinical approach to the management of preterm labor.

Long-term prognosis of infants with idiopathic respiratory distress syndrome. Follow-up studies in infants surviving after the introduction of continuous positive airway pressure

Fifty-one children surviving IRDS with CPAP alone or CPAP and IPPV were studied at the age of 2.5 to 4.0 years. One child had developed tetraplegia and mental retardation and 6 children were speech-retarded. Correlation with perinatal events showed that this group of children had a significantly lower gestational age and birth weight, a lower Apgar score and a higher PCO2 prior to ventilatory treatment than the remainder. Re-examination by age 4.0 to 5.0 years showed persistent handicaps in only four of the seven children.

Infants of very low birthweight. II: Perinatal factors in and conditions associated with respiratory distress syndrome

The incidence and case fatality of certain neonatal conditions reported in 692 liveborn infants of birthweights 2000g or less born in South East London in 1970, 1971 and 1973 are presented. 210 (30.3 per cent) died in the neonatal period: respiratory disease and cerebral haemorrhage were the leading causes of death. 482 (69.7 per cent) survived. In these infants, jaundice, respiratory disease and biochemical disorders were the most frequently reported conditions. Because of the numerical importance of the respiratory distress syndrome, both as a single and as an associated diagnosis, a special study was made of predisposing factors. Gestational age, sex, condition of the infant assessed after birth, temperature of the infant on admission for care, and caesarean section were all shown to be independently associated with the incidence of respiratory distress. This confirms the views that the incidence could be reduced if particular attention were paid to the maintenance of body temperature, especially in those infants at risk by reason of the other factors identified.