Applied potential tomography in the measurement of gastric emptying in infants.

The aim of this study was to investigate the feasibility of using applied potential tomography (APT), a noninvasive and nonradioactive method, to measure the rate of gastric emptying in preterm babies and infants < 3 months old. APT, a form of electrical impedance tomography, creates tomographic images of tissue resistivity to a small electrical current and has been used to study gastric emptying in adults. The rate of gastric emptying of 53 preterm infants and 29 term infants was measured. The test feed was either milk (formula milk or expressed breast milk) or Dioralyte (a commercial rehydration solution). When a nasogastric tube was present, the results obtained by APT were validated by comparing the volume of feed estimated to be present with the volume that could be aspirated. All infants completed the investigation without any problems. APT demonstrated a slower rate of emptying of milk feeds than Dioralyte and showed that milk and Dioralyte feeds in preterm babies emptied at a similar rate to feeds in term infants. In validation studies, gastric emptying has been observed in 44 of 47 studies, and this finding was confirmed by aspiration of the nasogastric tube. Applied potential tomography is a safe, noninvasive method for measuring gastric emptying in small infants.

Knemometry and the assessment of growth in premature babies.

The characteristics of a knemometer designed for accurate lower leg measurement in babies were assessed. Repeated measurement of a 100 mm Perspex rod gave a mean length of 99.993 mm and a mean SD of 0.058. When used to measure leg length, technical error of the measurement technique was 0.31 with a mean leg length of 98.49 mm (coefficient of variation 0.31%). Leg lengths measured at birth in 324 babies from 23 to 42 weeks' gestation gave an estimated in utero leg length velocity of 0.43 mm/day (95% confidence interval 0.41 to 0.45). Assessment of interobserver variation showed poor agreement in absolute values of leg length, although similar estimates of leg length velocity could be obtained. The neonatal knemometer allows measurements to be made in situations where conventional growth measurements are not possible. It is believed that knemometry has an important role in accurate evaluation of factors that can influence short term bone growth.

Growth retardation after dexamethasone administration: assessment by knemometry.

Knemometry has been used to measure lower leg growth during 32 nine day courses of dexamethasone in 26 babies ranging from 24 to 32 weeks' gestation at birth. Mean leg length velocity was 0.37 mm/day in the 10 days before steroids. Administration of dexamethasone was associated with a decrease in velocity in all babies, and in 15 leg shortening was documented. Mean leg length velocity during steroid treatment was -0.003 mm/day. After the course of dexamethasone was completed there was an immediate increase in leg length velocity to a mean of 0.52 mm/day over the first 10 days then falling to a value similar to the growth velocity observed before treatment. Leg length had reached the value predicted by growth before steroids about 30 days after dexamethasone. The reduction in leg length velocity occurred despite a significant increase in energy intake and decrease in oxygen requirements.

Intussusception in preterm infants.

Two cases of intussusception in infants born at 26 and 30 weeks' gestation are described. The two infants presented in the neonatal period with abdominal distension, intolerance of feeds, and rectal bleeding. An initial diagnosis of necrotising enterocolitis was made and the infants were treated medically. This led to a delay in the diagnosis of the intussusception. Published work on neonatal intussusception is reviewed and attention is drawn to the fact that the presenting signs and symptoms can be similar to those of necrotising enterocolitis. A diagnosis of intussusception should therefore be considered in any preterm infant with suspected necrotising enterocolitis.

Weight, length, and head circumference curves for boys and girls of between 20 and 42 weeks' gestation.

The value of available growth curves for preterm infants is limited because they exclude infants of less than 28 weeks' gestation. We describe growth curves for weight, length, and head circumference for boys and girls of between 20 and 42 weeks' gestation.

The effect of the skull of low-birthweight neonates on applied potential tomography imaging of centralised resistivity changes.

An investigation is presented into the likely effects of the neonatal skull on impedance images produced by applied potential tomography (APT) by imaging impedance changes inside the skull of a human infant of occipito-frontal circumference 30 cm. Measurements have been made with the skull immersed in a tank of saline and electrodes fixed to the perimeter of the tank. Sensitivity measurements have been assessed for imaging a small target close to the centre of the skull as compared with images produced without the skull. The results obtained compare favourably with measurements on a more realistic model of the neonatal head constructed by filling the skull with agar jelly to leave only a thin exterior coating of jelly to simulate the scalp. These experiments suggest that in the central region of the head of a neonate, measured changes by the APT technique are about 44% of that expected from a homogeneous phantom, but that this might vary from 32% to 55% at different points in the image in a very complex manner.

Sudden infant death and cytomegalovirus inclusion disease.

Four infants, apparently thriving and without clinical evidence of disease, died suddenly at ages ranging from 2 to 6 months. Inclusions bearing cells pathognomonic of cytomegalovirus infection were shown microscopically in a small number of extraneural organs. In view of the lack of associated tissue destruction on microscopy and the apparent well being of the infants before death whether the function of these organs had been impaired to any important degree was questionable: such limited disease, consequently, could not have contributed substantially to the cause of death. The brainstem, on the other hand, consistently showed small numbers of glial nodules. Damage to strategically located neurones associated potentially with the organisation of vital function was a possible basis of sudden death. Alternatively, the small number of glial nodules may have represented a residue of previous more severe brainstem disease, which had possibly started while the baby was in the uterus.

Birthweight between 14 and 42 weeks' gestation.

Data representing fetal weight gain between 14 and 42 weeks' gestation are presented; firstly to provide suitable curves enabling the growth of the very immature infant to be monitored and secondly to examine the influence of the improved techniques of paediatric and obstetric assessment developed since the publication of previous studies. Data have been collected from the 57 866 livebirths in Sheffield between 1976 and 1984 and from therapeutically terminated and spontaneously aborted fetuses over the same period. It seems that preterm livebirths do not form a different population with respect to weight from the fetus still in utero, at least until the beginning of the third trimester. Previous studies have reported a bimodality of weight distribution in preterm infants at each gestational age which has been attributed to errors in gestational assessment. The pattern of distribution of weight in this study suggests that early ultrasonography and paediatric assessment techniques have exerted a considerable influence on the accuracy of gestational assessment. The mean weights of the sample differ considerably from those of the Gairdner and Pearson chart which are, therefore, considered to be inappropriate for the Sheffield population.

Total anomalous pulmonary venous drainage associated with tetralogy of Fallot: report of a case.

The association of total anomalous pulmonary venous drainage and Tetralogy of Fallot is a rare occurrence; only six cases have been reported and only in one of these was the pulmonary drainage by the infracardiac route. A further such case is reported in a girl twin, with cleft palate and umbilical hernia and a normal spleen, who died at the age of three weeks and the clinical and post mortem features are described. The masking effect of the pulmonary outflow stenosis on pulmonary venous obstruction is discussed together with the relevance to clinical diagnosis and surgical intervention as "palliative" surgery may be dangerous.

The 'bright brain'.

In this preliminary study we report on a new neonatal cerebral ultrasound appearance consisting of high amplitude echoes that arise diffusely throughout the brain and obscure the echoes of normal structures. This scan appearance was associated with probable cerebral insult and we believe that it is caused by cerebral oedema.

Perforation of the appendix in the neonatal period.

Perforation of the appendix in the neonatal period may be a complication of neonatal necrotizing enterocolitis and should be differentiated from perforating appendicitis in later life. A patient is presented together with a review of the literature to illustrate this concept. Perforation of the appendix occurred in a 12-day-old preterm baby. Th cause of this perforation is assumed to be localized full thickness necrosis of the appendiceal wall, a form of neonatal necrotizing enterocolitis. The similarity between the clinical histories of neonates with so called "appendicitis" and those with necrotizing enterocolitis is pointed out. It is argued that "idiopathic primary peritonitis" probably does not exist, but that the peritonitis may be secondary to similar small perforations of the bowel. The importance of a thorough search for such a perforation is stressed.

Neonatal form of dystrophia myotonica. Five cases in preterm babies and a review of earlier reports.

Five preterm babies with the neonatal form of dystrophia myotonica are reported. In addition to the generally accepted signs and symptoms of the disease, two other features were present in these patients; oedema was notable in all 5 babies and 4 had unexplained haematomas. It is suggested that premature birth may be a result of severe involvement and that prematurity further aggravates the symptoms.

Percutaneous catheterisation of the radial artery in newborn babies using transillumination.

A technique for inserting radial artery catheters percutaneously in newborn babies using transillumination is described. Catheterisation was successful in 69% of the 107 babies in whom it was attempted. In the last 30 attempts there was an 85% success rate with an average useful life of 100 hours. The average weight of these babies was 1405 g, with a range of 620--4250 g. The method has several advantages over previous methods.

Idiopathic infantile arterial calcification in siblings: radiologic diagnosis and successful treatment.

Idiopathic infantile arterial calcification is a disorder of unknown etiology manifested by widespread arterial calcification. This usually leads to early death from coronary artery occlusion. In 12 of the 75 cases in the literature, radiographs were taken and it was possible to make the diagnosis in them all. We present two patients, siblings, in whom the diagnosis was established radiologically. The nature of the calcium deposits was studied in one of the infants and proved to be calcium hydroxyapatite. Therapy with diphosphonate was apparently successful in the other child.