Prevention of neonatal cold injury in preterm infants.

UNLABELLED: In many parts of the world neonatal cold injury still contributes to neonatal death in preterm or growth-retarded neonates. Kangaroo Mother Care might improve the situation and is the only effective, affordable and available method to prevent neonatal hypothermia in most developing countries. In developed countries, highly sophisticated incubators and radiant warmers are available but there is increasing concern about the long-term effects of high levels of sound, disturbing light and unplanned procedures which can have a bearing on the use of these tools. A controlled clinical trial of cot-nursing with a heated, water-filled mattress is presented in this issue of Acta Paediatrica. CONCLUSION: The results from the new trial and the recently published systematic reviews by the Cochrane Library of technologies to provide warmth to preterm infants in modem neonatal intensive care units, makes it possible to suggest the place of available tools: incubators, radiant warmers, heated water-filled mattresses and care in skin-to-skin contact.

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.

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.

Assessment of mouth-to-mask ventilation in resuscitation of asphyxic newborn babies. A pilot study.

The aim of the study was to compare the effectiveness of mouth-to-mask ventilation (MM) in neonatal asphyxia with bag-and-mask ventilation (BM). A new mouth-to-mask infant resuscitation system was constructed. The study was performed in two university clinics with different resources. The KEM Hospital in Bombay was well equipped and neonatologists took part in all resuscitations; Muhimbili Medical Centre in Dar es Salaam was understaffed and had no physicians available at resuscitation. Therefore, different protocols had to be used. In Bombay, the study period was limited to 5 minutes. If needed, mask ventilation was then replaced by intubation. In Dar es Salaam, MM ventilation was continued for up to 10 minutes, the inspiratory pressure was adjusted to 30 cmH2O and the ventilation was slow (8-10 breaths/min). In Bombay, 30 babies were allocated to the BM and 24 to the MM groups. In Dar es Salaam 56 were in the BM and 64 in the MM groups. The results for term babies in Bombay and both term and pre-term babies in Dar es Salaam showed no significant differences between the two groups of treatment, as determined by Apgar score > or = 4 at 5 and 10 minutes, number of babies with their first gasp, heart rate > 130 beats/min or pulse oximeter values above 75%, all at 5 minutes. An Apgar score > or = 4 at 5 minutes was achieved in more than 75% of all infants, irrespective of treatment. The rates of early neonatal mortality and neonatal convulsions did not differ between the two methods of resuscitation. In Dar es Salaam, the low respiratory frequency used in both groups was associated with a slow increase in heart rate above 130 beats per min. This result indicates that further studies will be needed before such slow respiratory frequencies are used. We conclude that, if adequate training is provided and the respiratory frequency is kept within the normal range, MM ventilation is an alternative to assisted ventilation when no bag and mask is available. However, further studies are necessary, since this method has proved to be tiring and uncomfortable for the resuscitating health personnel.

Mothers' perceptions of their preterm infants treated in an incubator or on a heated water-filled mattress: a pilot study.

Ten Swedish and 23 Turkish mothers delivering premature infants with a birth weight of less than 2000 g were investigated concerning their attitudes and feelings towards their newborn babies when the infants were treated either in an air-heated incubator or on a heated water-filled mattress (HWM). The first interview took place during the first few days after delivery and the second interview in the case of the Swedish study two weeks later and in the Turkish study one week later. In the first interview, feelings of fear, unreality and insecurity predominated, although significantly more so among the mothers of the incubator group. These feelings had changed strikingly by the time of the second interview among the mothers whose infants were treated on the HWM, but persisted to a large extent among the mothers whose infants remained in an incubator. The results of both investigations indicate that the mothers' perceptions of their infants improves when the prematurely born infant is treated on an HWM instead of in an incubator.

Pulmonary gas exchange during facemask ventilation immediately after birth.

The rate of carbon dioxide production (VCO2), heart rate, and oxygen saturation were recorded during resuscitation in 30 newborn infants. Twenty eight infants were ventilated through a facemask only and two were intubated after initial facemask ventilation. Five neonates were born at full term, eight had a gestational age of 32-36 weeks, and 17 of 27-31 weeks. Towards the end of the five minute study period, the VCO2 in ventilated infants, born after 32 weeks or more, was not different from that of spontaneously breathing infants. Neonates with a gestational age of 27-31 weeks showed a low VCO2, particularly when no reflex response from the baby was recorded, with a significant increase if a reflex response was elicited. Ventilation was found to be satisfactory if the heart rate increased to 130 beats/min or more within 5-15 seconds or if the oxygen saturation, measured in the right hand, was 70% or more.

Pulmonary gas exchange immediately after birth in spontaneously breathing infants.

The pulmonary gas exchange (rate of oxygen consumption, VO2 and rate of carbon dioxide production, VCO2), heart rate, and transcutaneously measured oxygen saturation were measured during the first five minutes after birth in healthy newborn infants. Fifteen full term infants who were vaginally delivered, 15 full term infants born by caesarean section, and 10 preterm infants born by caesarean section were studied. VO2 tended to be slightly higher than VCO2 during the first minutes, with a gradual change to a respiratory exchange ratio above 1.0. VO2 and VCO2 were significantly higher in vaginally delivered infants than in those born by caesarean section during the second minute after birth, partly due to a higher number of cries/minute. During periods of calm breathing, VO2 and VCO2 were significantly higher in vaginally delivered infants than in those born by caesarean section, with low gas exchange levels in infants born by caesarean section during the second minute after birth. Decreased ventilation was reflected by a significant drop in oxygen saturation within 30-45 seconds.

Colonization with coagulase-negative staphylococci in two neonatal units.

Episodes of septicaemia due to coagulase-negative staphylococci (CNS) were more frequent in a level III than in a level II neonatal unit in Stockholm, Sweden. Colonization with CNS during the first 2 weeks of life was investigated in 10 infants from each unit. As the use of antibiotics differed between the two units, the aim was to correlate colonization and antimicrobial resistance patterns to antibiotic usage. Antimicrobial susceptibility of CNS to isoxazolylpenicillins, co-trimoxazole, erythromycin, clindamycin, chloramphenicol and gentamicin was determined. Selected isolates were typed with restriction endonuclease analysis of plasmid DNA and of genomic DNA. Infants were frequently colonized with multiple strains and species of CNS, and transmission of strains from patient to patient occurred within the unit. Qualitative and quantitative differences in antibiotic use were not correlated with colonization. The prevalence of resistant isolates, mostly of Staphylococcus haemolyticus, was higher in the level II unit with lower use of antibiotics. Staphylococcus epidermidis, which is generally more virulent, prevailed in the level III unit, where there were more severely ill children and invasive procedures were more frequently performed.

Assessment of thermal conditions in neonatal care: use of a manikin of premature baby size.

A thermal manikin of the size of a 1 kg premature baby has been constructed. The nonevaporative heat loss from eight different regions and the total heat loss were measured. The measurements of heat loss have high repeatability and the values are in good agreement with measurements of dry heat loss for premature babies, using indirect calorimetry. The heat losses from the manikin in a single-walled, air-heated incubator and on a recently described heated, water-filled mattress have been compared. The total heat loss was found to be 20 to 30 W/m2 with both methods at ambient temperatures between 15 degrees and 25 degrees C. Treatment on a heated, water-filled mattress provides a means of direct conductive heat input to the baby, with a conductive heat transfer coefficient of 0.4 W/degrees C or 21 W/m2 degrees C. The thermal manikin appears to provide an accurate method for assessment of the thermal conditions in neonatal care.

Rewarming preterm infants on a heated, water filled mattress.

Sixty low birthweight infants (1000-2000 g) admitted to a neonatal care unit in Turkey were studied. Those not requiring intensive care were randomly assigned for treatment either in a cot on a heated, water filled mattress kept at 37 degrees C (n = 28) or in air heated incubators with a mean air temperature of 35 degrees C (n = 32). On admission 53 (88.3%) of the infants had body temperatures between 30 degrees and 36 degrees C. There was good correlation between axillary and rectal temperatures in the infants while they were hypothermic. Normal temperatures were achieved within the first day and remained within this range during the subsequent days after admission in all the infants treated on the heated, water filled mattress, whereas they were not achieved until three days later in the incubator group. The neonatal mortality among those treated on the heated, water filled mattress was 21%, and among those treated in the incubator 34%. The heated, water filled mattress provides a good alternative to skin to skin contact with the mother, and to the use of a complex and expensive incubator for rapidly attaining and maintaining normal temperatures in the low birthweight newborn.

Providing warmth for preterm babies by a heated, water filled mattress.

Seventeen healthy preterm babies had extra warmth provided in their cots by thermocontrolled, heated, water filled mattresses. As controls 17 babies of the same weight were nursed in air heated incubators. Both groups were studied for three weeks. No differences were found in minimal oxygen consumption (measured by indirect calorimetry), rectal and mean skin temperatures, or in daily weight gain. The babies were kept just as warm on the heated, water filled mattresses as in air heated incubators but the mattresses had the advantage of giving the mothers easy access to their babies.