Standard two-compartment formulation for total parenteral nutrition in the neonatal intensive care unit: A fluid tolerance based system

The nutrient requirements of most (pre) term newborns receiving intensive care appear to be relatively fixed. The range of optimal fluid load however, is perceived as being quite narrow and highly variable in time. We designed four amino acid-dextrose mixtures for a standardized neonatal parenteral nutrition, delivering a fixed amount of nutrients in four dilutions with water and corresponding to a fluid load of 90, 110, 130 or 170 ml/kg per day. The addition of a lipid emulsion completes the TPN. In a pilot study, we followed the weight of 30 very low birthweight infants on this parenteral nutrition. After a stabilisation period, the weight gain was found to be similar to the normal fetal weight accretion in utero. We have now infused these solutions in to more than 1000 infants, without significant complications. These formulations proved to have substantial advantages compared to the individualized prescription in terms of availability, safety and time- and cost-effectiveness.

Calcium and phosphorus retention in the preterm infant during total parenteral nutrition. A comparative randomised study between organic and inorganic phosphate as a source of phosphorus

The preterm infant fed parenterally is prone to some demineralisation due in part to insufficient Calcium (Ca) and Phosphorus (P) retention. In an attempt to augment Ca and P retention, we prepared a standardised parenteral solution containing calcium gluconate and glucose-1-phosphate (Phocytan) as source of phosphorus, yielding a daily supply of 75 mg/kg Ca and 45 mg/kg P. 28 very low birthweight infants were randomly assigned to receive either this solution (high Ca P ; n = 15) or a conventional formulation containing calcium gluconate and potassium mono- and dibasic phosphate delivering 42 mg/kg Ca and 36 mg/kg P daily (low Ca P ; n = 13). In the high Ca P daily retention was respectively 80% and 99% for Ca and P whereas in the low Ca P group, retention was 70% and 82%. Serum parathormone levels were significantly lower in the high Ca P group. We conclude that parenteral nutrition with a new high Ca P supplement results in an augmented Ca and P retention in very low birthweight infants. This may help to prevent neonatal bone demineralization.

Cardiorespiratory events recorded on home monitors: the effect of prematurity on later serious events

OBJECTIVE

To describe severe alarms on home-documented monitoring in infants born prematurely.

METHODS

In infants born at a post-menstrual age (PMA) less than 35 weeks, a polysomnography was performed before discharge. A heart rate less than 50 beats per minute (bpm) for more than 3 seconds or an apnea lasting for more than 15 seconds with a heart rate less than 60 bpm were defined as abnormal. These babies were given cardiorespiratory home monitoring with memory. Serious alarms on the home monitor were defined as heart rate less than 50 bpm for more than 3 seconds.

RESULTS

Of 1058 infants, 96 infants needed cardiorespiratory home monitoring. Sixty-one infants showed alarms at home. The mean post-conceptional age (PCA) when alarms stopped was 46 weeks. Seventeen patients had serious alarms above the PCA of 50 weeks. There was a significant negative correlation (r = -0.46 and p = 0.0002 by Spearman's rank correlation) between the PMA at birth and the PCA at which the last alarm was noted

CONCLUSION

Prematurely born infants with an abnormal polysomnography at discharge are at high risk for developing acute events at home. A younger PMA at birth correlates with a higher risk of alarms at a later PCA.

Maturational changes in the in vivo activity of CYP3A4 in the first months of life

OBJECTIVE

To document maturational changes of the in vivo activity of CYP3A4 in the first months of life.

METHODS

The contribution of tramadol (M), O-demethyl tramadol (M1, CYP2D6-mediated) and N-demethyl tramadol (M2, CYP3A4-mediated) to the overall elimination of tramadol and the log M/M2 was assessed in 24-hour urine collections during continuous intravenous tramadol administration. Correlations with perinatal characteristics (postnatal age (PNA) and postmenstrual age (PMA)) were studied.

RESULTS

Of the total amount of tramadol administered in a 24-hour interval to 25 neonates and young infants (PMA 25 - 53 weeks), 34.5% (SD 6.1) were retrieved in the urine as parent compound or metabolite in a 24-hour interval. This retrieved material consisted primarily of tramadol 79% (SD 18), M1 10% (SD 17) and M2 3% (SD 3.4). The contribution of M (r2 = -0.53), M1 (r2 = 0.46) and M2 (r2 = 0.16) to overall M elimination correlated with increasing PMA. The mean log M/M2 was 1.44 (SD 0.46) and there was an inverse correlation between the log M/M2 ratio and PMA (r2 = -0.43, 95% CI for r = -0.84 to -0.34, p = 0.0006) and PNA (r2 = -0.25, 95% CI for r = -0.78 to -0.16, p = 0.008). The maturational half-life of the log M/M2 ratio was 16 - 20 weeks. In a multiple regression model, PMA was the only significant variable accounting for the interindividual variability in log M/M2.

CONCLUSIONS

PMA was found to be the most important maturational change determing the in vivo activity of CYP3A4. The activity of CYP3A4 is relatively delayed in the first months of life compared to the developmental changes in CYP2D6 activity described earlier, however, the overall weak correlations reflect that PMA explains only in part the interindividual variability observed.

Cryotherapy versus laser photocoagulation for threshold retinopathy of prematurity: impact on early postoperative clinical recovery

In a retrospective study in preterms treated with either cryotherapy (n= 16, 2000-2001) or laser photocoagulation (n= 19, 2002-2005) for threshold retinopathy, a significant decrease in duration of postoperative ventilation, in postoperative administration of analgesics and in time until regain of full enteral feeding was documented in infants who received laser photocoagulation. We therefore conclude that - compared to cryotherapy - laser treatment for threshold retinopathy is associated with a faster clinical postoperative recovery.

O-demethylation of tramadol in the first months of life

OBJECTIVE

Assess in vivo O-demethylation activity in the first months of life.

METHODS

Time-concentration profiles of tramadol (M) and O-demethyl tramadol (M1) in plasma and urine were simultaneously collected in the first 24 h of continuous intravenous tramadol administration in neonates and young infants. M and M1 were determined by high performance liquid chromatography. Correlations between perinatal characteristics [postnatal age (PNA), postmenstrual age (PMA)] and the contribution of metabolites (M, M1) to overall tramadol elimination and to the plasma and urine log M/M1 were calculated.

RESULTS

Plasma samples were available in 20/29 and complete 24-h urine collections were available in 25/29 neonates (25-53 weeks PMA). Mean plasma log M/M1 value (>4 h, n=86) was 0.8 (SD 0.4). A significant correlation between plasma log M/M1 and PMA (r=-0.73, P<0.0001) and PNA (r=-0.58, P<0.005) was observed. In a multiple regression model, only PMA remained an independent variable. Mean urine log M/M1 was 0.94 (SD 0.7). Significant correlations of the urine log M/M1 ratio with PMA (r=-0.73, P<0.0001) and PNA (r=-0.56, P=0.0035) were observed. In a multiple regression model with the urine log M/M1 ratio as dependent variable, only PMA remained an independent variable. The maturational half-life of the log M/M1 ratio in early neonatal life in the age range evaluated is about 12-16 weeks without plateau.

CONCLUSIONS

O-demethylation activity was already observed in early neonatal life. A significant correlation with PMA was documented, but PMA can only partially explain the observed variability in O-demethylation activity. Polymorphism therefore likely already contributes to the interindividual variability observed in neonates.

Tramadol disposition in the very young: an attempt to assess in vivo cytochrome P-450 2D6 activity

BACKGROUND

Tramadol is potentially a very useful pain relief medication in neonates and infants. It is primarily metabolized into O-demethyl tramadol (M1) by CYP2D6. Data concerning tramadol disposition and CYP2D6 activity in young infants are not available.

METHODS

A population pharmacokinetic analysis of tramadol and M1 time-concentration profiles was undertaken using non-linear mixed-effects models (NONMEM), based on newly collected data on tramadol and M1 time-concentration profiles in neonates and young infants (n=20) and published studies on intravenous tramadol in children and adults. M1 formation served as a surrogate for CYP2D6 activity.

RESULTS

Tramadol clearance was described using a two-compartment linear model with zero-order input and first-order elimination. Clearance increased from 25 weeks post-conception age (PCA) (5.52 litre h(-1) [70 kg](-1)) to reach 84% of the mature value by 44 weeks PCA (standardized to a 70 kg adult using allometric '1/4 power' models). The central volume of distribution decreased from 25 weeks PCA (256 litre [70 kg](-1)) to reach 120% of its mature value by 87 weeks PCA. Formation clearance to M1 contributed 43% of tramadol clearance, but had no relationship with PCA. There was a weak non-linear relationship between PCA and M1 metabolite clearance.

CONCLUSIONS

Maturational clearance of tramadol is almost complete by 44 weeks PCA. A target concentration of 300 microg litre(-1) is achieved after a bolus of tramadol hydrochloride 1 mg kg(-1) and can be maintained by infusion of tramadol hydrochloride 0.09 mg kg(-1) h(-1) at 25 weeks PCA, 0.14 mg kg(-1) h(-1) at 30 weeks PCA, 0.17 mg kg(-1) h(-1) at 35 weeks PCA, 0.18 mg kg(-1) h(-1) at 40 weeks, 0.19 mg kg(-1) h(-1) at 50 weeks PCA to 1 yr, 0.18 mg kg(-1) h(-1) at 3 yr and 0.12 mg kg(-1) h(-1) in adulthood. CYP2D6 activity was observed as early as 25 weeks PCA, but the impact of CYP2D6 polymorphism on the variability in pharmacokinetics, metabolism and pharmacodynamics of tramadol remains to be established.

Continuous measurement of cerebral blood volume and oxygenation during rewarming of neonates

AIM

To investigate the effect of rewarming in preterm infants presenting with hypothermia at admission.

METHODS

The tissue oxygenation index (TOI), changes in cerebral blood volume (DeltaCBV) and changes in intravascular oxygenation (DeltaHbD) were measured in eight preterm infants, presenting with a temperature less than 35 degrees C at admission.

RESULTS

A significant increase in HbD and TOI was seen in four patients (group A), while a significant increase in CBV and a decrease in HbD was seen in four other patients (group B). Retrospective analysis showed that group A had important signs of peripartal asphyxia.

CONCLUSION

While infants with peripartal asphyxia showed an important increase in oxygenation during rewarming, no significant changes were seen in the non-asphyxiated infants.

Tramadol concentrations in blood and in cerebrospinal fluid in a neonate

Based on blood and cerebrospinal fluid samples collected in a full-term neonate, the penetration of tramadol in the central nervous system is described. Following intravenous administration of tramadol, a lag time of about 4 h was observed until full blood-brain equilibration was achieved. This pharmacokinetic observation is in line with a recent pharmacodynamic evaluation of the central opioid effects of tramadol in adults.

Ibuprofen and cerebral oxygenation and circulation

The effect of prophylactic administration of ibuprofen on the cerebral circulation in preterm babies was measured with near infrared spectroscopy. No significant difference in the change in cerebral blood volume, change in cerebral blood flow, or tissue oxygenation index was found between administration of ibuprofen or placebo.

Clinical pharmacology of non opioid analgesics in neonates

An integrated approach of neonatal analgesia starts with the systematic evaluation of pain and should be followed by effective interventions, mainly based on the appropriate (i.e. safe and effective) administration of analgesics. In contrast to the more potent opioids, data on the pharmacokinetics and -dynamics of non-opioid analgesics in this specific population are still rare or even lacking. We therefore evaluated various aspects of developmental pharmacology of non-opioid analgesics (paracetamol, ibuprofen, acetylsalicyl acid) in neonates. We first performed a single dose propacetamol study in preterm and term neonates. Based on these preliminary findings, a repeated dose administration scheme was developed and tested and maturational aspects from preterm till teenage were documented. Although non-selective COX-inhibitors might be effective in the treatment of postoperative or inflammatory pain syndromes in neonates, potential efficacy should be balanced against the drugs' safety profile. Neonatal renal clearance strongly depends on glomerular filtration rate (GFR) and GFR itself strongly depends on the vaso-dilatative of prostaglandins on the afferent arterioli. We therefore evaluated the impact of the administration of ibuprofen or acetylsalicylic acid on renal clearance in preterm infants and hereby used amikacin clearance as a surrogate marker. We hereby documented the negative effect of ibuprofen on glomerular filtration rate in preterm infants up to 34 weeks and we were able to show that ibuprofen and acetylsalicylic acid had an equal impact on the glomerular filtration rate.

Effects of co-administration of ibuprofen-lysine on the pharmacokinetics of amikacin in preterm infants during the first days of life

The aim of this study was to assess the effects of intravenous co-administration of ibuprofen-lysine on the pharmacokinetics of amikacin during the first days of life in preterm infants. The pharmacokinetics of amikacin were retrospectively calculated in a cohort of 73 neonates (gestational age <31 weeks) who received either ibuprofen-lysine or placebo following inclusion in the multicentre ibuprofen prophylaxis study. Assuming a one-compartment model with instantaneous input and first-order output, there was no significant difference in the median distribution volume (0.63 vs. 0.59 liters/kg), but the median serum half-life (16.4 vs. 12.4 h) of amikacin was significantly longer (p <0.02), and the clearance (0.36 vs. 0.6 ml/kg/min; p <0.005) of amikacin was significantly lower in infants who received ibuprofen-lysine. We conclude that the time interval between consecutive amikacin administrations should be prolonged, if ibuprofen-lysine is co-administered.

Characteristics of respiratory syncytial virus-related apnoea in three infants

Apnoea is a common sign in respiratory syncytial virus (RSV) infections in young infants and can be the first presentation of an acquired RSV infection. We describe polysomnographic recordings of three infants revealing prolonged RSV-related apnoea before RSV infection was diagnosed. The apnoeas were of central origin. The caregivers had not noted any apparent life-threatening events (ALTE) prior to the polysomnography. Cardiorespiratory monitoring after the acute infection did not reveal any further apnoeas.

CONCLUSION

Central, prolonged apnoea can be the first sign of an acquired RSV infection in young infants in the absence of other respiratory symptoms and without any previous observation of apnoea by the caregivers.

Video reveals self-stimulation in infancy

The medical literature on early childhood masturbation is sparse. Only 12 patients who presented with infantile self-stimulation under the age of 1 y are described. During the last 2 y, five girls under 1 y of age presented at our department with self-stimulating behaviour. The diagnosis of this behaviour was difficult, but could be made by watching a video of the attacks. Infantile self-stimulation is often misdiagnosed and unnecessary investigations and useless treatments are often prescribed. Video recording can be of great help to put forward the correct diagnosis. Masturbation is not so uncommon and treatment consists mostly in reassuring the parents. It can, however, be associated with behavioural problems. Few data are available on the clinical outcome of childhood masturbation, but most children seem to develop normally.

CONCLUSION

Infantile self-stimulation should always be considered in the differential diagnosis of "strange episodes or attacks".

Continuous infusion of medications in very low birth weight infants

OBJECTIVE

To develop a safe and accurate method for the administration in the neonatal intensive care unit of several potent medications as a continuous infusion without overloading the infant, especially the very low birth weight (VLBW) infant by diluents.

METHOD

The method designed is based on a weight-adapted solution limiting the diluent administration and allowing for a versatile modulation of dose administration. As this method was initially designed for VLBW infants, the point of departure of this method is a standard maximal fluid load of 0.3 ml/h for each medication, delivered in a low compliant circuit with a high-precision syringe driver. Solutions are made for 24 h, which is a compromise between drug stability and repeated pressure drops in the circuit when changing the syringe and administration set. To translate a prescription into a solution a conversion factor is calculated. In addition to the calculation principle, this conversion factor is given for a number of commonly used drugs in neonatal care.

CONCLUSIONS

In our experience, the method described adds to the safety and accuracy of continuous drug administration in neonatal care.

The use of methohexital during chest tube removal in neonates

BACKGROUND

The aim of the study was the evaluation of the effect of methohexital during chest tube removal (CTR) in neonates.

METHODS

Evaluation was based on the degree of sedation (grades 1-4) and relaxation (grades 1-4) and trends in vital signs heart rate, mean arterial blood pressure (MAP), oxygen saturation at time points (-10, -5, -3, -1, 0, 1, 3, 5, and 10 min) before and after administration of methohexital. A multidimensional pain scale [Leuven Neonatal Pain Scale (LNPS)] was used to evaluate pain expression. Effective sedation and relaxation (grade >2) would enable the physician to perform CTR without difficulties. Paired Wilcoxon was used to compare vital signs and pain expression before and after the procedure.

RESULTS

Twenty-two procedures in 22 infants were recorded. Eleven infants were ventilated and 21 infants were having intravenous analgesics during CTR. Birth weight was 2645 g (range 1235-4500 g). Postnatal age was 6 days (range 1-80 days). Methohexital had no effect on ventilatory weaning, MAP or oxygen saturation. Heart rate increased from 144 (49) to 162 (43) (P = 0.012) b.min(-1). Sedation and relaxation were effective (>grade 2) and lasted for <5 min. No major side effects were documented. Adequate analgesia by LNPS was more difficult to evaluate as clinical pain evaluation was not feasible during full muscular relaxation.

CONCLUSIONS

Administration of methohexital for CTR resulted in adequate sedation and relaxation without major side effects in neonates. This approach should be compared with other strategies.

Retinopathy of prematurity: any difference in risk factors between a high and low risk population?

PURPOSE

To document incidence of and risk factors for development of retinopathy of prematurity (ROP) in a population of low birthweight infants (< 1500 g).

METHODS

The authors registered clinical characteristics (birthweight, gestational age (GA), Clinical Risk Index for Babies (CRIB), Apgar score, respiratory characteristics (intubation, ventilation, respiratory support, supplemental oxygen, oxygenation index), prescription of dopamine, and maximal creatinemia) by retrospective chart review in two consecutive CRIB score-based (< 851 g, 851-1350 g) categories. Chi square and Mann-Whitney U tests were used to compare clinical characteristics in both categories and a stepwise logistic regression was done to document independent risk factors for either stage 3 (< 851 g) or any grade of ROP (851-1350 g).

RESULTS

Incidence of ROP was 65/157 (41%; 76% in < 851 g and 22% in 851-1350 g). Incidence of stage 3 ROP was 25/46 (54%) in the < 851 g and 4/84 (5%) in the 851-1350 g group. Among other risk factors, maximal creatinemia was a risk factor in the 851-1350 g cohort (p < 0.03). In a logistic regression model, only GA (OR 0.42) remained significant in the lowest birthweight category; in the 851-1350 g cohort, GA (OR 0.53) and CRIB score (OR 1.7) were independent risk factors for ROP.

CONCLUSIONS

In relatively more mature infants (851-1350 g), the risk to develop ROP is based on GA and on neonatal severity of disease (CRIB score); in the tiniest infants, GA is the most important risk factor. Microangiopathy might explain the association of maximal creatinemia and the risk of developing ROP.

Threshold retinopathy at threshold of viability: the EpiBel study

AIM

To describe incidence, co-morbidity characteristics, and risk factors associated with threshold retinopathy of prematurity (ROP) in survivors with a gestational age (GA) of < or =26 weeks at birth.

METHODS

Retrospective analysis of perinatal data of all inborn survivors in all perinatal centres of Belgium in the period 1999-2000 (EpiBel cohort) believed to be between 22 and 26 weeks GA at time of delivery. Data on survivors who did and survivors who did not develop threshold ROP were compared (chi(2), Mann-Whitney U) and logistic regression was performed.

RESULTS

Of 303 admitted infants 175 (58%) were discharged alive. Incidence of major retinopathy (> or =stage 3) and of threshold ROP was 25.5% and 19.8% in survivors. Associated central nervous abnormalities were documented in six (17%) and associated chronic lung disease in 19 (54%) threshold ROP infants. Threshold ROP without additional morbidity characteristics at discharge was documented in 14 (40%) infants. Besides often reported risk factors, renal insufficiency (creatinaemia>1.5 mg/dl) was a risk factor to develop threshold ROP (p<0.0015) (chi(2)). Days of respiratory support (OR 1.02; 95% CI 1.002 to 1.039), number of transfusions (OR 1.118; 95% CI 1.030 to 1.214), and renal insufficiency (OR 3.31; 95% CI 1.344 to 8.196) remained independent risk factors to develop threshold ROP in this cohort in a stepwise logistic regression model (MedCalc).

CONCLUSIONS

Incidence of threshold ROP is high at the limits of viability. Renal insufficiency is a risk factor to develop threshold ROP in this cohort.

Pharmacokinetics of single dose intravenous propacetamol in neonates: effect of gestational age

AIM

To investigate the pharmacokinetics and pharmacodynamics of single dose propacetamol in preterm and term infants on the first day of life.

METHODS

Neonates were stratified by gestational age. Preterm (< 37 weeks) and term (37-41 weeks) infants received a single dose of propacetamol in the first 24 hours of life when they had minor, painful procedures or as additional treatment in infants receiving opioids. Blood samples were taken from an arterial line, and pain was evaluated by a multidimensional pain scale. Results were reported as mean (SD). Student's t and Wilcoxon tests were used to compare the groups.

RESULTS

Thirty neonates were included, 10 of which were term infants. Serum half life was 277 (143) minutes in the preterm infants and 172 (59) minutes in the term infants (p < 0.05). Clearance was 0.116 (0.08) litre/kg/h in the preterm infants and 0.170 (0.06) litre/kg/h in the term infants (p < 0.05). Gestational age correlated with serum half life (r = -0.46). No effect of sex or administration of prenatal steroids was found on the pharmacokinetics of paracetamol. In neonates who only received propacetamol (n = 15), the level of analgesia seemed to be associated with the therapeutic (> 5 mg/l) level.

CONCLUSIONS

A correlation was found between gestational age and the serum half life of propacetamol. The maturational trend of clearance and half life in preterm and term neonates is in line with data on the pharmacokinetics of propacetamol beyond the newborn period.

Methemoglobinemia and hemolysis after enteral administration of methylene blue in a preterm infant: relevance for pediatric surgeons

A preterm infant had methaemoglobulinemia and hemolytic anemia after enteral administration of methylene blue. The dye was administered to exclude a tracheoesophageal fistula. Methylene blue is a noxious product, especially in neonates. It should be considered a potential cause of acquired methemoglobulinemia, even after enteral administration.

The respiratory pump: past and present understanding

The history of our understanding of the respiratory system has been long and progressive, probably starting with Galenus who did experimental spinal cord sections, and progressed through the poorly known work of Leonardo da Vinci on the structure-function relation of chest wall components.

CONCLUSION

Despite numerous experiments in the past, the respiratory control system remains complex and poorly integrated because of the diversity of the afferent pathways and of the interacting respiratory centres.

Incidence, perinatal risk factors, visual outcome and management of threshold retinopathy

The incidence of threshold retinopathy, clinical characteristics and risk factors to develop threshold retinopathy are described in a group of preterm infants admitted between 1996 and 2000 in a single tertiary neonatal intensive care unit. A subset of these infants (n = 31) developed threshold retinopathy (ROP). Incidence of threshold ROP in survivors with a birth weight below 1500 g is 6.4%. Pre-, peri- and postnatal characteristics of these infants are described and compared with matched controls of the same gestational age (GA) and admitted in the same unit in an attempt to focus on relevant risk factors of threshold ROP. We also report on visual outcome data in infants who developed threshold retinopathy. Finally, we describe our experience with perioperative management in this cohort.

Cryotherapy for threshold retinopathy: perioperative management in a single center

Perioperative management and complications during and after surgery were reviewed in a population of premature infants who received cryotherapy because of threshold retinopathy by retrospective analysis of medical, anaesthetic, and ophthalmologic files. Infants (n=31) who received cryotherapy between January 1, 1996 and January 1, 2001 and were treated during the neonatal period in the unit were included in the study. Cryotherapy was performed under general anesthesia on the neonatal ward. Neonatal and preoperative characteristics of this cohort point to a vulnerable group of infants with a preoperative weight of 1622 g (1519 to 1862 g), bronchopulmonary dysplasia criteria applying in 29 of 31 patients and methylxanthins prescribed in 26 of 31 patients. No single cryotherapy session had to be interrupted because of systemic complications. Still marked cardiorespiratory instability was documented until 36 hours postoperative in 8 patients. Performing surgical procedures on the neonatal ward is a feasible option. Perioperative management in infants who received cryotherapy is used as an illustration of this approach.

Cerebral tissue oxygenation index in very premature infants

AIM

To describe normal values of the cerebral tissue oxygenation index (TOI) in premature infants.

METHODS

TOI was measured by spatially resolved spectroscopy in preterm infants on the first 3 days of life. Infants with an abnormal cranial ultrasound were excluded. Other simultaneously measured variables were PaO(2), PaCO(2), pH, mean arterial blood pressure, heart rate, haemoglobin, glycaemia, and peripheral oxygen saturation.

RESULTS

Fifteen patients with a median postmenstrual age of 28 weeks were measured. There was a significant increase in median TOI over the first 3 days of life: 57% on day 1, 66.1% on day 2, and 76.1% on day 3. Multiple regression analysis showed no correlation between TOI and postmenstrual age, peripheral oxygen saturation, mean arterial blood pressure, PaO(2), PaCO(2), and haemoglobin concentration.

CONCLUSION

Cerebral TOI increases significantly in the first 3 days of life in premature babies. This increase probably reflects the increase in cerebral blood flow at this time.

Neonatal transthoracic puncture in a case of congenital cystic adenomatoid malformation of the lung

A patient with congenital cystic adenomatoid malformation of the lung (CCAM) is presented who showed severe respiratory deterioration in the neonatal period caused by hyperinflation of the cystic component and compression of the contralateral lung. Transthoracic drainage of the cyst was performed to avoid preoperative artificial ventilation. On aspiration, air and liquid was removed from the cyst. After stabilization, surgical intervention was performed within 24 hours. Postoperative recovery was uneventful, and the child was discharged at day 13.

Effects of non-nutritive sucking on heart rate, respiration and oxygenation: a model-based signal processing approach

Several studies support the idea that the use of pacifiers can reduce the risk of Sudden Infant Death Syndrome. To investigate the effect of non-nutritive sucking (NNS), we measured heart rate, abdominal respiration, EMG and arterial oxygen saturation of 20 neonates. Also, in 10 of these neonates, changes in cerebral hemoglobin concentrations were acquired by means of near-infrared spectroscopy. Using a parametric technique to model the heart rate as a sum of exponentially damped sinusoids, two main frequency components were found in the heart rate during NNS: a frequency of approximately 0.08 Hz due to the alternation of sucking bursts and pauses, and a frequency of approximately 0.8 Hz that reflects the influence of the respiration. Our analysis shows that it is the alternation of bursts and pauses itself that causes the increased heart rate variability, and that this is not due to increased effort. This suggests that the neuronal mechanism regulating NNS also stimulates the heart rate. From our measurements, no effect of NNS on cerebral or peripheral oxygenation could be found. Furthermore, we show that our model-based signal processing technique is well suited for the analysis of non-stationary biomedical signals.

The use of methohexital during neonatal cardioversion

We report on the use of methohexital during elective neonatal direct current cardioversion. In contrast with the available data on cardiac management in neonates with supraventricular tachycardia and the guidelines on anaesthetic management during cardioversion in adults, data on anaesthetic management in neonates are still lacking. Methohexital might be an option for procedural sedation and anaesthesia during elective cardioversion in neonates.

Aneurysm of the ductus arteriosus in a neonate with 13q-deletion

Aneurysm of the ductus arteriosus is a rare abnormality for which different ways of pathogenesis are described. We report the case of a fatal thrombosis of an aneurysm of the ductus arteriosus in an infant presenting feeding difficulties and a mild dysmorphic facies. Karyotype analysis revealed a de novo chromosomal deletion 46,XY, del (13)(q12.3,q22.3). To the best of our knowledge, this is the first case of an aneurysm of the ductus arteriosus associated with a chromosomal aberration.

Fetal growth: boys before girls

At term birth, boys are heavier than girls. This difference is thought to be generated in part by androgen action; its time course has not been deciphered. Androgen action may not only increase weight gain, but may also alter its time course. We have tested this hypothesis by examining the difference in gestational age of 281,894 boys and girls with weights between 500-4,749 g. The age at which children are born with a given weight was found to depend on gender: boys were consistently younger than girls (p < 0.001), the age difference being most pronounced in the lower birth weight classes. Thus, the gender difference in fetal growth appears to be rather pronounced before the third trimester and relatively less marked towards term. In conclusion, the male conceptus seems to grow not only more, but also earlier than the female. Hence, some critical time windows of development may be slightly different in boys and girls, and this phenomenon may be one of the bases for gender differences in the sensitivity to fetal programming. Copyrightz1999S. KargerAG,Basel

Pulmonary sequestration: a comparison between pediatric and adult patients

OBJECTIVE

Modern large single institutional reports on pulmonary sequestration (PS) are extremely rare. We were interested in comparing patients with PS referred by our pediatric versus adult pulmonologists.

METHODS

Hospital notes of all patients operated on between 1978 and 1997 for a congenital broncho-pulmonary malformation were reviewed. In 28 patients, the parenchymal lesion was vascularized by a systemic artery and was separated from the bronchial tree, thus matching the strict definition of PS. Patient characteristics and outcome were analyzed comparing the pediatric group (< or =16 years: n=13; mean age, 3+/-5 years) versus the adult group (>16 years: n=15; mean age, 33+/-13 years).

RESULTS

No significant differences between both groups were observed in sex, side, type of sequestration, pulmonary venous drainage, associated anomalies, hospital and late outcome, and patient's overall score. Patients (n=21) with the intralobar type of sequestration presented significantly more often with an infection when compared with patients (n=7) with the extralobar type (91 versus 14%; P=0.0033). When compared with the pediatric group, patients in the adult group had significantly more respiratory infections (87 versus 38%; P=0.016), and also required a lobectomy more often (67 versus 31%; P=0.056).

CONCLUSIONS

The extralobar type of sequestration often remains asymptomatic, and is usually an incidental finding during infancy. The intralobar type mostly presents with recurrent infections in adulthood resulting in more lobectomies. We believe these findings support our current policy to remove any pulmonary malformation whenever diagnosed in order to: (1), prevent infection and other potentially serious late complications which may compromise the surgical outcome; and (2), enhance the chance of a parenchymal-sparing resection.

Iron supplementation in preterm infants: a study comparing the effect and tolerance of a Fe2+ and a nonionic FeIII compound

The more widely used divalent forms of iron (Fe2+) supplementation often lead to gastrointestinal symptoms in preterm infants although little is known about the use of nonionic trivalent iron preparations (FeIII) in these patients. It is especially under this nonionic form that dietary iron is available. For this reason, a randomized controlled study was undertaken to compare the efficacy and the extent of possible side effects in two groups of preterm infants. In one group, the elemental iron was given in the Fe2+ form, while the other group received a nonionic trivalent iron (FeIII) complexed with polysaccharides of low molecular weight. Both groups received 7.5 mg elemental iron daily. Measured parameters in the two study groups did not differ significantly throughout the study period of 14 weeks. Both forms of iron supplementation were well tolerated. However, vomiting, diarrhea, or constipation occurred slightly more often in the group receiving iron supplementation in the Fe2+ form without reaching statistical difference. The authors found a nonionic trivalent polysaccharide-iron complex given as iron supplementation as effective as the generally more favored ferrous sulphate. Since iron therapy is mandatory in the preterm infant, the use of trivalent iron complexes can be considered as a good alternative.

Right diaphragmatic eventration associated with intralobar pulmonary sequestration: a case report

A case of right diaphragmatic eventration, associated with a lung sequestration, in a 7-month-old infant is presented. Failure to thrive was the initial symptom. X-ray of the chest, made because of mild respiratory distress, revealed an inhomogeneous opacification of the right lower hemithorax, suggesting a diaphragmatic hernia. A right thoracotomy was performed and a diaphragmatic eventration covered by a thick pleuroperitoneal membrane was found, together with sequestration of the lung. The pathologic findings and the embryology are discussed.