TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS

ABSTRACT. In 68 appropriate for gestational age (AGA) and 33 small for gestational age (SGA) infants, transepidermal water loss was studied during the first four weeks after birth. The method used to measure evaporation rate is based on measurement of the water vapour pressure gradient close to the skin surface. All measurements were made at an ambient humidity of 50% and with the infants calm and quiet. At all the investigated post-natal ages in both AGA and SGA infants, an exponential relationship was found between transepidermal water loss (g/m² h) and gestational age, this loss being much higher in the pre-term infants than in those born at term. The transepidermal water loss was generally lower in SGA than in AGA infants during the first week of post-natal life, irrespective of gestational age at birth. There was a gradual decrease in transepidermal water loss with increasing post-natal age in both pre-term AGA and pre-term SGA infants. Three weeks after birth this water loss tended to be higher in pre-term SGA infants than in pre-term AGA infants of corresponding gestational age.     

TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS II. Relation to Activity and Body Temperature

Abstract. Using a method described in a previous article the transepidermal water loss (TEWL) was studied in 10 healthy newborn infants at rest and during activity. On the average TEWL was 37% higher during activity than during rest although no sweating was observed. In 9 infants placed in incubators with an ambient temperature slightly above the thermoneutral range measurements were made as the body temperature rose. TEWL was almost constant until a temperature of 37.1°C was reached whereupon the water loss suddenly increased as the infant started sweating.     

TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS

ABSTRACT. During the first weeks after birth the transepidermal water loss was determined repeatedly in 7 infants born after 25–27 weeks of gestation, in 13 infants born after 28–30 weeks and in 14 full-term infants. All infants were appropriate for gestational age. The very pre-term infants had high evaporative water losses from their skin on their first days after birth. A gradual decrease was then observed, but after four weeks the values were still higher than those in full-term infants. The transepidermal water loss in full-term infants was unchanged during the first two weeks of life, but increased during the subsequent two weeks. The relation between evaporation rate from an interscapular skin area and ambient humidity was studied repeatedly during the first week of life in two very pre-term infants. The magnitude of evaporation decreased with increasing post-natal age, but was still dependent on the ambient relative humidity.     

TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS I. Relation to Ambient Humidity and Site of Measurement and Estimation of Total Transepidermal Water Loss

Abstract. Insensible water loss (IWL) is an important factor in the thermoregulation and water balance of the newborn infant. A method for direct measurement of the rate of evaporation from the skin surface has been developed. The method, which is based on determination of the vapour pressure gradient close to the skin surface, allows free evaporation. From measurements performed on 19 newborns placed in incubators, a linear relation was found between the evaporation rate (ER) and the humidity of the environment at a constant ambient temperature. A 40% lower ER was recorded at a high relative humidity (60%) than at a low one (20%) in the incubator. At measurements on different sites of the body, a high ER was observed on the face and peripheral parts of the extremities, while ER at other sites was relatively low. By determining ER from different parts of the body and calculating the areas of the corresponding surfaces, the total cutaneous insensible water loss for the infant in question could be obtained. The transepidermal water loss (TEWL) for the whole body surface area was calculated to be 8.1 g/m²h. On the basis of measurements performed it was found that the total cutaneous insensible water loss can be estimated with a reasonable degree of accuracy by recording ER from only three easily accessible measurement points.     

TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS

ABSTRACT. The amount of water evaporated from the skin of newborn infants and the temperatures of the skin, of the ambient air, and of the surfaces facing the infants were measured and used as a basis for calculation of the evaporative, radiative and convective heat exchange between the infant and the environment. The infants were of varying gestational ages, from 25 to 39 completed weeks of gestation. Evaporative heat exchange was high in the most preterm infants when nursed at a low ambient humidity, while the high ambient humidity needed to maintain these infants at a stable body temperature led to a low loss of heat through radiation and convection or even a heat gain. In the more mature infants evaporative heat exchange was lower, while radiative and convective heat exchange was higher.     

TRANSEPIDERMAL WATER LOSS IN FULL-TERM AND PRE-TERM INFANTS

Sedin, G., Hammarlund, K. and Strömberg, B. (Department of Paediatrics, University Hospital, Uppsala, Sweden). Transepidermal water loss in full-term and pre-term infants. Acta Paediatr Scand, Suppl. 305: 27–31, 1983.—The amount of water lost from the skin and the relation of the water loss to environmental factors, activity, body temperature, gestational age, nutritional status at birth and post-natal age were studied in full-term and pre-term newborn infants. The method we used was non-invasive and based on determination of the water vapour pressure gradient immediately above the skin surface. We found that the transepidermal water loss per unit time and area (TEWL; g/m2 h) could be calculated by using values from only three measurement sites. TEWL increased with activity and when body temperature was elevated above 37.1C. On the first day after birth TEWL in appropriate for gestational age (AGA) infants was exponentially related to gestational age, with much higher values in the most pre-term infants than in full-term infants. In full-term small for gestational age (SGA) infants TEWL was significantly lower than in full-term AGA infants. In pre-term and full-term AGA infants and in full-term SGA infants we found an inverse linear relationship between ambient humidity and evaporation rate (ER; g/m² h) from the skin. The level of ER and the slope of the relationship depended on the gestational age of the infant, with higher ER in the more pre-term infants. Analysis of the relationship between ambient humidity and ER indicated that there is a gradual change in the permeability of the skin with gestational age. In pre-term infants TEWL gradually decreased during the first weeks of life. In full-term AGA infants TEWL was almost unchanged during these first weeks.     

TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS: IV. Small for Gestational Age Infants

Abstract. Hammarlund, K. and Sedin, G. (Department of Paediatrics, University Hospital, Uppsala, Sweden). Transepidermal water loss in newborn infants. IV. Small for gestational age infants. Ada Paediatr Scand, 69: 377, 1980.—Using a method described earlier, the evaporation rate (ER) from the skin was studied at different ambient humidities in 14 full-term and 10 pre-term small for gestational age (SGA) infants. Transepidermal water loss (TEWL) was estimated in 25 SGA infants born after 30–40 weeks of gestation. Comparisons were made with infants appropriate for gestational age (AGA). A linear relationship was found between ER and ambient humidity in full-term SGA infants, but with lower ER values than in AGA infants. Lower ER values were also found in moderately pre-term SGA infants at different ambient humidities. ER was higher at lower ambient humidities in both SGA and AGA infants. In full-term and moderately pre-term SGA infants TEWL was lower than in corresponding AGA infants.     

TRANSEPIDERMAL WATER LOSS IN NEWBORN INFANTS: V. Evaporation from the Skin and Heat Exchange during the First Hours of Life

Abstract. Hammarlund, K., Nilsson, G. E., öberg, P. Å. and Sedin, G. (Department of Paediatrics, University Hospital, Uppsala, and Department of Biomedical Engineering, Linköping University, Linköping, Sweden). Transepidermal water loss in newborn infants. V. Evaporation from the skin and heat exchange during the first hours of life. Acta Paediatr Scand, 69:385, 1980.—The amount of water evaporated from the skin was studied in 10 healthy newborn infants from their first minute of life, while being taken care of in the delivery room, and in 11 infants treated in incubators from their 30th min of life. The heat lost by evaporation, radiation and convection was calculated. Evaporation from the skin was very high during the first minutes after birth and was the main cause of heat loss during the first 15–30 min of life. Thereafter the amount of heat lost depended on the conditions under which the infant was nursed. Higher convective and radiative heat losses were found in delivery rooms than in incubators.     

WATER EVAPORATION AND HEAT EXCHANGE WITH THE ENVIRONMENT IN NEWBORN INFANTS

Hammarlund, K. and Sedin, G. (Department of Paediatrics, University Hospital, Uppsala, Sweden). Water evaporation and heat exchange with the environment in newborn infants. Acta Paediatr Scand, Suppl. 305: 32–35, 1983.—The amount of water evaporated from the skin of newborn infants and the temperatures of the skin, the ambient air and the surfaces facing the infants were measured and used to calculate the evaporative, radiative and convective heat exchange between the infant and the environment in infants of varying gestational ages. Immediately after birth the evaporative heat exchange was very high but it then decreased gradually. The radiative heat exchange was very high in the delivery room but lower in the incubators. In incubators the evaporative heat exchange was high in the most pre-term infants, especially when nursed at a low ambient humidity. Different modes of heat exchange were interrelated, so that when the pre-term infants had a high evaporation rate, a high ambient temperature was needed and the heat exchange through radiation and convection decreased. Net heat exchange was lowest in very pre-term infants at an ambient humidity of 60%.     

STUDIES ON MATURITY IN NEWBORN INFANTS

ABSTRACT: Finnström, O., Gothefors, L. and Zetterlund, B. (Departments of Paediatrics, University Hospitals, Linköping and Umeå, Sweden). Studies on maturity in newborn infants. VII. Foetal haemoglobin. Acta Paediatr Scand, 64:404, 1975.–Cord blood from 125 newborns of various gestational ages has been analysed for the ratio foetal haemoglobin to total haemoglobin, using an alkali denaturation method. The quotient, percentage of foetal haemoglobin divided by birth weight correlates well with gestational age. Thus the percentage of foetal haemoglobin in cord blood can be used as a method for estimating maturity in newborn infants. Foetal haemoglobin has been compared with other methods for maturity assessments and seems to give the same precision in estimating gestational age as the best of these, which is the scoring of external characteristics. However, the latter method is considerably less time-consuming and more suitable for routine use.     

MOTOR CONDUCTION VELOCITIES IN NEWBORN INFANTS OF VARIOUS GESTATIONAL AGES

The motor conduction velocities, in the ulnar and peroneal nerves of newborn infants, of various postmenstrual ages were studied. It was found that: 1. The conduction velocities, in children of a short gestational age is significantly lower than those of fullterm infants. 2. The conduction velocities, of the peroneal nerve, is slightly but significantly lower than those of the ulnar nerve, in both groups of children. It is also concluded that the determination of motor conduction velocities seems to be an additional method, of value, in assessing the degree of maturity at birth, and in determining the gestational age.     

CIRCULATORY ADAPTATION IN NEWBORN INFANTS OF STRICTLY CONTROLLED DIABETIC MOTHERS

ABSTRACT. Possible relations between neonatal circulatory function and maternal diabetic control were investigated in 22 infants of strictly controlled diabetic mothers during the first 2 days after birth. Eleven infants were delivered vaginally (V) and 11 infants by elective cesarean section (S). Maternal diabetes was more severe in the latter group. Half of the infants had one or more episodes of neonatal morbidity although none presented symptomatic hypoglycemia. Plasma glucose FFA and C-peptide were measured at birth and 3-6 hours later together with skinfold thickness; heart size was determined by X-ray at 24-28 hours; stroke volume and cardiac output were repeatedly determined by transthoracic impedance and ECG. C-peptide at birth was higher in group S than in V. C-peptide in both groups were neither related to glucose or FFA nor to birthweight or skinfold thickness. Infants with neonatal complications including cardiomegaly had the highest C-peptide values. Skinfold was positively correlated to maternal pregnancy glucose level, birthweight percentile and infant heart volume. Mean values for stroke volume and cardiac output were similar in both groups and not different from normal controls when related to body weight. Heart volume and stroke volume were significantly related. ECG abnormalities were seen in 6 infants who showed cardiomegaly on X-ray. We suggest that the present finding of an association between elevated C-peptide concentration at birth and the occurrence of neonatal complications including cardiomegaly and ECG abnormalities could be the consequence of functional hyperinsulinism and that the cardiomegaly is of adaptive type.     

WATER REQUIREMENT OF PREMATURE NEWBORN INFANTS

Bell, E. F. and Oh, W. (Department of Pediatrics, Women and Infants Hospital of Rhode Island, and the Program in Medicine, Brown University, Providence, Rhode Island, USA). Water requirement of premature newborn infants. Acta Paediatr Scand, Suppl. 305: 21–26, 1983.—Two groups of studies related to the water requirement of premature infants are reviewed. The first examined the effects of several environmental factors on insensible water loss (IWL) and oxygen consumption of 20 low-birth-weight infants. Incubator air temperature above the neutral zone increased IWL, as did the use of a radiant heat source instead of a conventional incubator. A plastic heat shield slightly reduced IWL of infants in incubators. The second group of studies examined the effects of excess water intake in premature infants. 170 infants were randomly assigned to receive "low" (average estimated requirement for birth weight and age) or "high" (excess) volume water intake. The high-volume group became dehydrated less often but had a greater incidence of patent ductus arteriosus and necrotizing enterocolitis.     

CEREBROSPINAL FLUID FERRITIN IN NEWBORN INFANTS

ABSTRACT. One hundred and four infants with neurological symptoms or suspected infection during the neonatal period were consecutively investigated with respect to ferritin and albumin concentrations in the cerebrospinal fluid (CSF). In some cases serial determinations of CSF ferritin were performed during the period in the neonatal unit. CSF ferritin was significantly higher in infants that recovered very soon from a transient neonatal disorder (TND) than in apparently healthy adults. No difference in CSF ferritin was found between full-term infants with TND and pre-term infants with TND or asphyxiated infants. Three out of five infants with septicaemia or meningitis showed a marked increase in CSF ferritin during the observation period, and the same finding was made in three infants with intracranial bleeding, in whom CSF ferritin values 100 times the upper reference limit for infants with TND were recorded. In two infants with neonatal convulsions secondary to asphyxia moderate CSF elevations were observed. No correlation was found between ferritin and albumin in CSF, suggesting that other mechanisms than passive penetration from blood into CSF must have been responsible for the ralsed levels of CSF ferritin. More likely the observed ferritin increments reflect ferritin release from macrophages undergoing phagocytosis either induced by cerebral bleeding or due to infectious agents.     

PERIPHERAL CIRCULATORY RESPONSE TO PHOTOTHERAPY IN NEWBORN INFANTS

Calf blood flow (CBF), calf skin temperature, incubator wall and ambient temperature, and respiratory rate, were measured in 8 newborn infants 10 to 127 hours of age, who were treated by phototherapy because of jaundice. During phototherapy (within 30 min) the CBF increased to a range of 30 to 80% above the control values of 8.8 ± 0.9 ml/min/100 g. The CBF is correlated directly with the leg skin temperature (γ= 0.724 and 0.588 at 15 and 30 min after phototherapy respectively). The increase in CBF was associated with a fall in incubator ambient temperature, the latter is a result of the use of servo control unit in monitoring incubator temperature by epigastric skin temperature. The increase in CBF is probably evidence of peripheral vasodilatation to facilitate evaporative heat loss. An increase in respiratory rate was also observed during phototherapy. The observed increase in heat loss (and water loss) from vasodilatation and increased respiratory rate serve as a basis for the increase in insensible water loss as previously reported.     

RESPIRATORY QUOTIENT AND METABOLIC RATE IN NORMAL FULL-TERM AND SMALL-FOR-DATE NEWBORN INFANTS1

Respiratory quotient and gaseous metabolism were measured in normal full-term and small-for-date infants during the first week of life. In both groups RQ dropped during the first day and rose again during the next few days. However, the RQ was lower during the first 5 days in small-for-date infants. The O₂ uptake of the small-for-date babies is initially lower but rises during the first 5 days. Technical problems and clinical implications of the results are discussed.     

BACTERIAL COLONIZATION OF NEWBORN INFANTS IN A NEONATAL INTENSIVE CARE UNIT

ABSTRACT. The bacterial colonization of the nose, unbilicus, perineum and faeces in 85 newborns was studied during one period of high and one of low occupancy in a neonatal intensive care unit. Cultures were taken on admission, at three days, at one week of age, and then weekly during the stay in the unit. Colonization took place early and potential pathogens were responsible for a significant part of the spectrum. At one week of age, more than 50% of the infants had Staphylococcus aureus in the nose and umbilicus, 25% had E. coli and/or Klebsiella enterobacter in the umbilicus, and 60% had Klebsiella enterobacter in the perineum. Neither the occupancy rate in the unit nor the clinical state of the infant seemed to influence the colonization pattern significantly. Changes in flora were frequent in the individual infant. However, the bacterial spectrum remained essentially the same with increasing age during the stay in the unit and during the two periods. Only on two occasions was the same phage type of Staphylococcus aureus found in two infants at the same time. Two cases of septicemia occured in the 85 infants during the three months of the study. Both infants were colonized beforehand with the causative organism. The results may indicate that the clinical state of the infant is of greater importance for risk of septicemia than the pattern of the bacterial colonization.     

THE EFFECT OF CHLORPROMAZINE IN SEVERE HYPOXIA IN NEWBORN INFANTS

ABSTRACT. Eighteen newborn infants with severe hypoxia during the course of idiopathic respiratory distress syndrome, pneumonia, persistent fetal circulation or right diaphragmatic hernia were treated with chlorpromazine with the aim of improving arterial oxygenation by a postulated vasodilatory action on the pulmonary circulation. Fourteen of the infants improved their P_SO2 during the treatment. Nine infants died. The systematic arterial blood-pressure and the urinary output were reduced and some infants were somnolent during the initial period of treatment. No other side effects were noted. Further studies of chlorpromazine as a possible pulmonary vasodilator in newborn infants are justified.