[Recommendations are not changed--let infants sleep in supine position. Surgical specialists' contribution to population studies would be of value].
Explore the source record for details and available documents.
Craniosynostoses↗
Biomedical subjects
G Sedin
Publications and source records attributed to G Sedin.
[An extensive study indicates good prognosis for children with extremely low birth weight].
Explore the source record for details and available documents.
Cause of Death↗
Speech and language skills in children who required neonatal intensive care: evaluation at 6.5 y of age based on interviews with parents.
Speech and language skills at 6.5 y of age were studied in a follow-up of a cohort of children who had required neonatal intensive care (NIC) at Uppsala University Children's Hospital. An interview with the parents indicated that preterm and full-term NIC children were older than control children when they reached certain stages in language development (short sentences, intelligible speech). Absence of babbling was more common in NIC children born at 23-27 wk than in other preterm NIC children, and occurrence of stuttering was more commonly noticed in preterm NIC children born at 23-27 wk than in those born at >32 wk and controls.
Apgar Score↗
Assisted mechanical ventilation using combined elastic and resistive unloading in cats with severe respiratory failure: effects on gas exchange and phrenic nerve activity.
This study tests the efficacy of respiratory mechanical unloading as a mode of assisted mechanical ventilation in cats with an intact breathing-control system but severe pulmonary parenchymal injury. Twelve anaesthetized, intubated cats received multiple saline lung lavages so that their total respiratory system compliance decreased from 56.1+/-10.4 to 26.8+/-6.8 ml/kPa (p < 0.001) and their PaO2 fell to 12.38+/-4.71 kPa when 100% O2 was used as inspired gas. They were then exposed to three consecutive 15-min periods of CPAP of 0.5 kPa, respiratory unloading and again CPAP of 0.5 kPa. Unloading was applied with end-expiratory pressure of 0.5 kPa, elastic assistance of 0.03 kPa/ml and resistance compensation of 2.0 kPa/l/s. Arterial blood gases for the CPAP baselines did not differ significantly before and after unloading: pH 7.14+/-0.04 vs. 7.16+/-0.06; PaCO2 8.99+/-2.07 vs. 8.33+/-2.01 kPa; PaO2 12.4+/-4.7 vs. 13.3+/-7.6 kPa. Nor did the baselines differ in terms of tidal volume, respiratory rate and phrenic nerve activity. Unloading increased tidal volume substantially by about 50% and increased respiratory rate slightly, while inspiratory time remained unchanged. PaCO2 fell to 6.63+/-1.57 kPa and pH rose to 7.25+/-0.06. Phrenic nerve activity was significantly down-regulated in terms of total number of impulses and mean impulse frequency in the phrenic nerve burst. These results suggest that combined elastic and resistive unloading may be an effective means of assisted mechanical ventilation in severe respiratory failure of pulmonary parenchymal origin.
Airway Resistance↗
Speech and language skills in children who required neonatal intensive care. II. Linguistic skills at 6 1/2 years of age.
Linguistic skills at 6 1/2 y of age were examined in a cohort of 284 children requiring neonatal intensive care (NIC) and in 40 controls. Ten linguistic areas were assessed. The results are presented for gestational age groups. The 10th percentile score of the controls was identified in each linguistic area. Seventy percent of the controls and <27% of the NIC children had no score lower than the 10th percentile score. Scores lower than the 10th percentile score were more common in NIC children born at term or at 23-31 wk, and within the latter group in those born at 28-31 wk, than in those born at 32-36 wk gestational age. The linguistic areas of auditory discrimination, imitation of articulatory positions and imitation of sentences were most frequently affected. NIC children born at 32-36 wk performed better in the last two areas than those born at <32 wk. To be a twin and born at 28-31 wk was associated with an increased risk of having more than five scores lower than the 10th percentile score of the controls.
Age Factors↗
Short-term outcome of perinatal care in a Swedish county. Mortality, neonatal intensive care and overall evaluation of neuromotor function at 0-10 months of corrected age in preterm and term infants.
Improvements in obstetrical and neonatal care during the last decades have led to a marked increase in survival rate of preterm and term infants. In order to study the short- and long-term outcome in infants who survived neonatal intensive care (NIC) and were born in the county of Uppsala between January 1st 1986 and April 30th 1989, a prospective long-term follow-up study was conducted. Epidemiological data on all infants born in the county during the study period and the short-term outcome, measured as overall neuromotor function at term and at 2, 4, 6 and 10 months of corrected age in 245 infants surviving NIC and 72 healthy control infants are presented. The infants' neuromotor function was evaluated with different clinical neurological methods. In the study population of NIC infants 85.9% survived the neonatal period. The early infant mortality was high in this group 11.6% compared to that of all infants born in the county of Uppsala (0.30%). Only a minority of the infants showed abnormal neuromotor function. A comparison of the results of the overall evaluation of neuromotor function at 10 months of age with those of the examinations made at an earlier age showed poor correspondence in individual infants, especially in preterm and very preterm infants.
Bronchopulmonary Dysplasia↗
Speech and language skills in children who required neonatal intensive care. I. Spontaneous speech at 6.5 years of age.
Spontaneous speech at age 6.5 years was studied separately in a follow-up of speech and language skills in a regional cohort of 284 children requiring neonatal intensive care and in 40 controls. Eight aspects of spontaneous speech were evaluated in a conversation: A1, information; A2, speech motor function; A3, sound pattern; A4, word finding; A5, word selection; A6, grammar; A7, interaction; and A8, motivation. The children were grouped by gestational age. Most children had well developed spontaneous speech. The different groups showed very few differences in types of deviations in spontaneous speech. All groups differed from the controls in speech motor function and formal language (A2-A6), but only one child, born at <32 weeks, had a pronounced deviation in one of these aspects. Obvious deviations in one or more aspects of spontaneous speech were more common among children born at 28-31 weeks and in those born fullterm (> or =37 weeks) than among extremely preterm children born at 23-27 weeks.
Age Factors↗
Transepidermal water loss in infants born at 24 and 25 weeks of gestation.
The rate of evaporation of water from the skin of 13 infants born at 24 (n=3) and 25 (n=10) weeks of gestation was measured on the first day after birth and at postnatal ages of 1, 3, 7 and 28 d, using the gradient method. Transepidermal water loss was estimated from this rate and corrected to an ambient relative humidity (RH) of 50%. Transepidermal water loss, corrected to 50% RH, was high on the first day after birth (58.4+/-14.8 g m(-2) h(-1)) and remained at the same level during the second day (59.3+/-17.6 g m(-2)h(-1)). It then decreased significantly to 43.8+/-9.5 at a postnatal age of 3 d, 36.1+/-12.6 at 7 d and 24.2+/-7.7 g m(-2) h(-1) at 28 d (p < 0.001). Within the group investigated, there was no significant correlation between transepidermal water loss and body or skin temperature, birth weight, gender, mode of delivery or gestational age. Transepidermal water loss on the first day after birth was somewhat lower than the highest losses previously found in infants born at 25 weeks of gestation, and of the same magnitude as previously reported for infants born at 25-27 weeks. Transepidermal water loss at postnatal ages of 1, 3, 7 and 28 d in the present study was higher than that previously found in the group of infants born at 25-27 weeks. In conclusion, in infants born at 24-25 completed weeks of gestation transepidermal water loss was high immediately after birth and decreased with increasing postnatal age, but at a slower rate than previously reported for slightly more mature infants.
Body Temperature↗
Neurosensory outcome and growth at three years in extremely low birthweight infants: follow-up results from the Swedish national prospective study.
A prospective national investigation comprising 633 extremely low birthweight (ELBW) infants born alive in the 2-y period 1990-1992 with a birthweight of < or = 1000 g and gestational age of > or = 23 completed weeks was conducted regarding neurosensory outcome and growth. Three-hundred and sixty-two (98%) surviving ELBW infants were assessed at a median age of 36 months, using a specially designed protocol. At follow-up, mean height, weight and head circumference in both boys and girls were significantly lower than the reference values. The incidence of cerebral palsy was 7% among all children and 14%, 10% and 3% in children born at 23-24, 25-26 and > or = 27 gestational weeks, respectively. At least one obvious handicap was present in 14%, 9% and 3% of these three groups of children, respectively. After adjustment for gestational age, a significantly increased risk of handicap was found in children with intraventricular haemorrhage grade > or = 3 and/or periventricular leucomalacia and in children with retinopathy of prematurity stage > or = 3. The results show that more than 90% of ELBW children born at > or = 25 completed gestational weeks were without neurosensory handicap at 36 months of corrected age. In infants born at 23-24 weeks of gestation, both survival and long-term outcome were less favourable.
Birth Weight↗
Lung hyaluronan and water content in preterm and term rabbit pups exposed to oxygen or air.
Rabbit pups were delivered by cesarean section 1 or 2 d before term, or vaginally around term, and then reared in room air or exposed to intermittent or continuous hyperoxia (> 85%) for up to 9 d. Pups were killed at different ages, and lung hyaluronan (HA; microgram/g of dry lung weight) and lung water content, measured as wet/dry lung weight, were determined. Compared with the day of birth, the lung HA concentration did not change significantly on succeeding days in pups kept in air delivered 2 d (-2 d) or 1 d (-1 d) before term, whereas the water content decreased significantly. Continuous exposure to hyperoxia resulted in a significantly raised lung HA concentration 6 d postterm in both -2 d and -1 d pups, and intermittent exposure to hyperoxia resulted in a significantly raised HA concentration 6 d postterm in -1 d pups, compared with the groups exposed to room air. These increases were accompanied by significantly elevated wet/dry lung weight ratios. Microscopic examination revealed significantly increased HA staining scores in alveoli, arterioles, and bronchioli in both hyperoxia-exposed groups of -2 d pups 6 d postterm, and nonsignificantly higher scores in -1 d and vaginally delivered pups of comparable age, compared with the scores at birth. The results indicate that oxygen exposure neonatally may result in an increase in lung HA accompanied by an increase in lung water content. The increase in lung HA concentration in our study may be an effect of oxygen free radicals or of oxygen-induced stimulation of inflammatory mediators.
Air↗
Interaction between mothers and infants born at risk during the first six months of corrected age.
The effects of preterm birth and the perinatal infant health condition on mother-infant interactions were analysed in 278 mother-infant pairs, divided into four groups according to infants' gestational age at birth: group 1, 23-31 weeks; group 2, 32-36 weeks; group 3, 37-42 weeks; and group 4, a control group of healthy full-term infants. The methodological approach was based on observation of the pairs at 2, 4 and 6 months of infants' corrected age (+/- 1 week) during undressing of the infant and face-to-face interaction. It was found that mother-infant pairs with preterm infants (groups 1 and 2) did not differ in interactional variables from those of the control group. On the other hand, the birth of a full-term infant in need of neonatal intensive care (group 3) affected maternal and infant interactive behaviour. Additionally, infants from group 3 did not show stability in their interactive behaviour between any ages of measurement. This result suggests that interactive behaviour of full-term infants in need of neonatal intensive care are rather unpredictable during their first 6 months of life, which might have contributed to the less optimal interactive pattern observed for their mothers compared with mothers of the control group.
Female↗
The Swedish national prospective study on extremely low birthweight (ELBW) infants. Incidence, mortality, morbidity and survival in relation to level of care.
In a 2-year (1990-92) prospective national investigation, comprising all stillborn and live-born ELBW infants with a birthweight of < or = 1000 g born at 23 completed weeks of gestation or more, we examined the incidence, neonatal mortality, major morbidity and infant survival in relation to level of care and place of residence. A total of 633 ELBW infants were live-born, i.e. 0.26% of all live-born infants, and 298 were stillborn. The average neonatal mortality was 37% and 91% at 23 weeks, 70% at 24 weeks, and 40% at 25 weeks of gestation. Of neonatal survivors, 8% had intraventricular haemorrhage grade 3, 10% retinopathy of prematurity of stage > or = 3, 2% necrotizing enterocolitis, and 28% were oxygen-dependent at a time corresponding to 36 weeks of gestation. In all, 77% were treated with mechanical ventilation, whereas 19% survived without, almost all of them being CPAP treated. Infant mortality among infants born at level III (tertiary centres) was 30%, at level IIa (with full perinatal service) 46% and at level IIb (with basic neonatal service) 55%. Only 1% was born at hospital level I. Regarding the relation to place of residence, the mortality rates among infants residing in the areas served by levels III, IIa and IIb hospitals were 36%, 45% and 41%, respectively. The referral system thus functioned well, but can be improved, and increased perinatal referral, at borderline perinatal viability, might provide a better quality of care and a better chance of survival.
Cause of Death↗
Thermal balance in term and preterm newborn infants nursed in an incubator equipped with a radiant heat source.
A radiant hood warmer, a device that heats the incubator roof independently of the incubator's main heat source, was used to study the thermal balance of 11 full term and 13 preterm (gestational age 25-34 weeks) infants exposed to an isolated elevation of incubator roof temperature at stable ambient air temperature and humidity. After initial measurements without active heating of the incubator roof, the hood warmer was set to 33 degrees C, 36 degrees C and finally (preterm infants only) to 39 degrees C. At least 18 min of measurements with the infant asleep were made at each hood warmer setting. In the term infants an increase in roof temperature from 30.5 degrees C to 35.6 degrees C resulted in an increase in skin temperature from 35.4 to 35.9 degrees C, and a decrease in radiative heat loss from 32.8 to 20.7 W/m2 exposed skin. In the preterm infants an increase in roof temperature from 31.0 to 38.4 degrees C led to an increase in skin temperature from 35.7 to 36.3 degrees C and a decrease in radiative heat loss from 34.1 to 13.0 W/m2 exposed skin. The increased inner roof surface temperature did not affect evaporative or convective heat loss, skin blood flow, respiratory water loss, oxygen consumption or transepidermal water loss in either group. Thus, at stable ambient air temperature and humidity, the increase in incubator roof temperature resulted in an increase in skin temperature and a decrease in radiative heat loss in both term and preterm infants.
Analysis of Variance↗
Evaporation rate and skin blood flow in full term infants nursed in a warm environment before and after feeding cold water.
Earlier results have shown that some infants born by elective Caesarean section start to sweat in a warm environment while others do not, and that sweating can be inhibited by feeding cold glucose. To determine whether these earlier observations, indicating a difference in postnatal temperature adaptation, could be reproduced in vaginally born infants, we measured the rate of evaporation from the skin surface, body and skin temperatures from several sites, skin blood flow and respiratory rate in newborn infants nursed in a warm environment, before and after feeding cold water. In all infants the body and skin temperatures increased in the warm environment (p < 0.01), with a decreasing difference between oesophageal and leg skin temperature (p < 0.01). Visible sweating occurred in 9/14 infants at a rectal temperature of 37.5 degrees C. In the infants who started to sweat, evaporation rate increased from 5.6 +/- 2.8 (SD) g/m2/h 15 min before sweating to 15.7 +/- 10.6 g/m2/h (p < 0.05) when sweat became visible and the infants were fed cold water. After feeding of cold water the evaporation rate decreased and within 10 min returned to a value not significantly different from the pre-sweating value. Interscapular skin blood flow had increased by 42% (p < 0.01) at the time of sweating and decreased by 22% (p < 0.01) after feeding cold water. In the infants who did not start to sweat, no increase in evaporation rate was noted and the changes in skin blood flow were not statistically significant. The infants who started to sweat did not differ from those who did not regarding maternal medication during delivery. We conclude that some, but not all, newborn infants start to sweat at a body temperature of 37.5 degrees C. In the infants who start to sweat, sweating and an increase in skin blood flow can be inhibited by feeding cold water. There seem to be individual differences in the regulation of body temperature in newborn infants, possibly due to a delayed change in the central temperature set-point in some infants.
Body Temperature↗
Trigger delay in infant ventilators.
In an experimental study we determined the response trigger delay time of three infant ventilators with a capacity to detect and support spontaneous breathing. We measured this in anaesthetized cats as the time between the start of phrenic nerve activity and the increase in airway pressure caused by the subsequent inflation. Two modes of ventilatory support were used, namely Assist/Control (A/C) and synchronised intermittent mandatory ventilation (SIMV). We found that ventilators equipped with flow sensors close to the free end of the endotracheal tube had a shorter trigger delay than a ventilator which detected breathing with an abdominal sensor. Further, the trigger delay was shorter in SIMV mode than in A/C mode of operation. A higher set sensitivity reduced the response time. We conclude that triggered ventilation may be used in infants, at least when the spontaneous breathing rate is below 60 breaths per minute. This mode of ventilation could be useful when infants are to be weaned off the ventilator.
Animals↗
Hyaluronan production in vitro by fetal lung fibroblasts and epithelial cells exposed to surfactants of N-acetylcysteine.
Fetal human lung fibroblasts and feline lung epithelial cells were exposed to either a surfactant or N-acetylcysteine in various concentrations for 24-48 hours, after which the hyaluronan concentration in the culture medium was determined. Most of the experiments showed no stimulatory effect of either artificial or natural surfactant on hyaluronan synthesis. N-acetylcysteine 5-100 mg/mL induced progressive stimulation of hyaluronan synthesis by human fetal lung fibroblasts, resulting in a maximum hyaluronan concentration six times that released by unexposed cells. A slight increase in hyaluronan synthesis was also observed after exposure of feline fetal lung epithelial cells to N-acetylcysteine 50-100 micrograms/mL.
Acetylcysteine↗
Irregular breathing in young lambs and newborn infants during heat stress.
Ten healthy unanaesthetized full-term lambs, aged 4-12 days, were studied during moderate radiant heat stress, and 21 full-term newborn infants were studied during moderate convective heat stress. The rate of breathing and the breathing pattern were recorded, using strain gauges made of mercury-filled rubber tubing placed around the thorax and abdomen. In both the lambs and the infants the respiratory rate increased during heat stress. When this increase began, both the lambs and infants had short periods of very rapid breathing followed by short apnoeas. The concentrations of carbon dioxide and water in a flow-through system collecting expired air increased during the short periods of rapid breathing and then decreased again during the subsequent short apnoeic period.
Animals↗
Effects of ventilator resistance and compliance on phrenic nerve activity in spontaneously breathing cats.
This study investigates the effects of respiratory mechanical loading and unloading on phrenic nerve activity and ventilation. Ten adult cats were anesthetized, intubated, and connected to a servocontrolled infant ventilator while breathing spontaneously in continuous positive airway pressure mode. The ventilator was then set to decrease the pressure at the airway opening in proportion to the inspiratory airflow or the volume of spontaneous breathing (resistive or elastic loading) or to increase the pressure at the airway opening accordingly (resistive or elastic unloading, also called proportional assist ventilation). When compared with continuous positive airway pressure, both resistive and elastic loading increased the number of phrenic nerve impulses per breath and the mean frequency of impulses (p < 0.01, ANOVA). In contrast, elastic unloading decreased phrenic nerve activity significantly in normal and injured lungs. Resistive unloading in normal lungs did not change phrenic nerve activity significantly. The compensatory response in phrenic nerve activity was not large enough to completely offset effects of loading and unloading on ventilation: elastic and resistive loading decreased ventilation. Unloading had the opposite effect on ventilation, particularly in injured lungs. We conclude that respiratory mechanical loading and unloading have statistically significant, opposite effects on phrenic nerve activity and opposite effects on ventilation.
Airway Resistance↗