Hugo Devlieger

The effects of the addition of sufentanil to 0.125% bupivacaine on the quality of analgesia during labor and on the incidence of instrumental deliveries.

In a double-blinded, randomized, prospective multi-center study of 695 women, we investigated whether epidural injection of sufentanil added to 0.125% bupivacaine with epinephrine (1:800,000) reduces the total amount of local anesthetic required, resulting in less motor blockade and reduced incidence of instrumental deliveries, and improves the quality of analgesia provided by this low concentration of local anesthetic without jeopardizing the safety of the baby. In addition, other potential benefits of sufentanil (such as decrease in the incidence of shivering) and side effects were examined. It was found that adding incremental doses of 10 micrograms sufentanil up to a maximum of 30 micrograms reduced the incidence of instrumental deliveries from 36 to 24% (P less than 0.01) and significantly improved quality and duration of analgesia without depressing the neurobehavioral status of the baby. No other benefits from adding sufentanil were found. The only side effect that occurred more frequently after sufentanil was pruritus. We conclude that epidural injection of 10-30 micrograms sufentanil added to 0.125% bupivacaine with epinephrine (1:800,000) improved the quality of analgesia during labor and reduced the incidence of instrumental deliveries without jeopardizing the safety of the baby.

Use of Tissue Oxygenation Index and Fractional Tissue Oxygen Extraction as Non-Invasive Parameters for Cerebral Oxygenation

Objective: To evaluate the relation between cerebral tissue oxygenation index (TOI), measured with spatially resolved spectroscopy (SRS), and the different oxygenation parameters. To evaluate the relation between a new parameter named fractional tissue oxygen extraction (FTOE) and the cerebral fractional oxygen extraction (FOE). Methods: Six newborn piglets were measured at 33, 35, and 37°C and in hypocapnia. Mean arterial blood pressure (MABP), haemoglobin (Hb), peripheral oxygen saturation (S_aO₂) and P_aCO₂ were measured at each step. Cerebral blood flow (CBF) was measured by injection of coloured microspheres into the left atrium. Jugular bulb oxygen saturation (JVS), cerebral arterial and venous oxygen content (C_aO₂ and C_vO₂) and FOE were calculated. TOI of the brain was calculated and FTOE was introduced as (S_aO₂ – TOI)/S_aO₂. The correlation was calculated with an ANCOVA test. Results: There was a positive correlation (R = 0.4 and p = 0.011) between TOI and JVS. No correlation was found with CBF, MABP or Hb. There was a positive correlation between P_aCO₂ and cerebral TOI (R = 0.24 and p = 0.03). FTOE correlated well with FOE (R = 0.4 and p = 0.016) and there was a negative correlation between FTOE and P_aCO₂ (R = 0.24, p = 0.03). Conclusion: The measurement of TOI and FTOE by SRS correlated well with the cerebral venous saturation and FOE, respectively.

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 patients 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.

Gastric emptying in formula-fed and breast-fed infants measured with the 13C-octanoic acid breath test

BACKGROUND The 13C-octanoic acid breath test, a noninvasive method for measuring gastric emptying, was used to compare the gastric-emptying rate of formula-fed and breast-fed infants. Octanoic acid, a medium-chain fatty acid marked with the stable isotope 13C is immediately absorbed in the duodenum. Because gastric emptying is the rate-limiting step for the absorption of medium-chain fatty acids, the fraction of 13C expired in the breath indicates the rate of gastric emptying. METHODS Twenty-nine newborn infants (16 boys, 13 girls) were investigated, with parental consent. The infants had a mean gestational age at birth of 34.5 weeks (range, 27-41 weeks) and a birth weight of 2148 g (range, 960-4100 g). Their mean weight on the day of the test was 2496 g (range, 1998-4140 g), and their mean age was 23 days (range, 7-74 days). Each infant received a test meal after a maximum fasting period of 3 hours. Fourteen infants were fed formula milk (Nutrilon Premium, NV Nutricia, Zoetermeer, The Netherlands) with 13C-octanoic acid and 15 infants received expressed mothers milk mixed with 13C-octanoic acid. After obtaining two basal breath samples and the feeding, breath samples were collected using a nasal prong, every 5 minutes during the first half hour and every 15 minutes during the next 3.5 hours. Analysis of the expired 13C fraction in the breath samples was performed using isotope-ratio mass spectrometry, and the gastric emptying curve and gastric emptying parameters were determined. RESULTS The mean half-emptying time determined by the 13C-octanoic acid breath test was 65 minutes (range, 27-98 minutes) for the formula fed infants and 47 minutes (range, 16-86 minutes) for the breast-fed infants. The difference between the half-emptying times is significant (t-test, p < 0.05). CONCLUSIONS The results of the 13C-octanoic acid breath test indicated faster gastric emptying of human milk than formula. Our findings are in accordance with those in earlier studies, using the invasive-dilution technique; noninvasive and detailed ultrasonography, which is not easily used because it is operator dependent and the observation time is short; or cineesophago-gastroscintigraphy, which is less suitable for infants (because of the radiation involved). The 13C-octanoic acid breath test is a safe and noninvasive method for measuring gastric emptying in small infants and allows comparison of various feeding methods.

Congenital Parenchymatous Malformations of the Lung

Abstract. Congenital lung malformations, primary and secondary, contribute to an important portion of pediatric thoracic surgery. One purpose of this report is to outline the close relation in terms of embryology and clinical presentation of congenital parenchymatous pulmonary malformations. In a retrospective study we also aim to evaluate our experience with the diagnosis and surgical management of congenital parenchymatous bronchopulmonary malformations and to compare our data with the literature. From January 1979 to December 1996 a series of 48 patients, 30 males (62.5%) and 18 females (37.5%), were operated on for congenital bronchopulmonary malformations. Pulmonary sequestration, bronchogenic cysts, congenital lobar emphysema, and congenital cystic adenomatoid malformation were seen in 16, 13, 5, and 14 patients, respectively. The first clinical symptoms occurred at a mean age of 8.8 years (1 day to 62 years), and the mean age at the time of surgical intervention was 9.3 years (1 day to 62 years). The maximum time between first symptoms and surgical treatment was 27 years. A lobectomy was performed in 22 cases; in the other patients more lung-preserving surgery such as enucleation or sequestrectomy was performed. Only one postoperative death occurred following lobectomy for pulmonary sequestration, and it was due to pulmonary hypoplasia and pulmonary hypertension. Eleven other patients presented with postsurgical complications: pneumothorax (n= 5), pleural effusion (n= 3), prolonged air leak (n= 2), portal vein thrombosis (n= 1), and hemorrhage requiring reintervention (n= 1). We conclude that any thoracic cystic lesion expanding on chest radiography should be an indication for surgical resection, even if asymptomatic, because of the risk of pulmonary compression, infection, or malignant degeneration. In the few cases of a fetal intrathoracic mass, prenatal diagnosis and intrauterine intervention may be indicated, and these indications are also discussed.

L-Thyroxine Treatment of Preterm Newborns: Clinical and Endocrine Effects

Preterm newborns have low serum thyroxine (T4) levels compared with late-gestational fetuses. Low thyroid hormone levels are associated with increased severity of neonatal illness and neurodevelopmental dysfunction. We assessed the endocrine and clinical effects of increasing serum T4 levels in preterm newborns with a gestational age <31 wk. Forty newborns were randomized in a double blind protocol: 20 infants received a daily dose of 20 μg/kg l-T4 for 2 wk, whereas 20 control infants received saline. Serum concentrations of T4, triiodothyronine (T3), reverse T3 (rT3), thyroglobulin (TG), and TSH were measured weekly as well as serum levels of GH, prolactin, and IGF-I. After 2 wk, a TSH-releasing hormone (TRH) test was performed. Neonatal illness and outcome was evaluated by noting heart rate, oxygen requirement, duration of ventilation, development of chronic lung disease, oral fluid intake, and weight gain; a Bayley score was done at the corrected age of 7 mo. l-T4 administration induced a marked increase in serum T4 without apparent change in T3 levels, whereas the postnatal decline in serum rT3 was more gradual. l-T4 treatment was associated with a decrease in serum TG and TSH levels. TRH injection induced a definite rise in serum TSH and T3 in controls, but not in L-T4 treated newborns. Neither l-T4 treatment, nor TRH administration appeared to alter circulating levels of prolactin, GH, or IGF-I. In contrast to the pronounced endocrine effects, no clinical effects of l-T4 administration were detected.

PATHOGENESIS OF CONGENITAL CYSTIC ADENOMATOID MALFORMATION OF THE LUNG

Congenital cystic adenomatoid malformation is a rare developmental abnormality of the lung. In most earlier reported cases, the anatomy of the bronchial tree was poorly documented. We describe four cases studied following autopsy. Post‐mortem bronchography or serial microscopical examination showed segmental bronchial absence or atresia in each of them. Our observations provide further evidence pointing to bronchial atresia as being the primary defect leading to the development of congenital cystic adenomatoid malformation. The morphology of the lesion, i.e. the type of malformation, is determined by the extent of dysplastic lung growth beyond the atretic segment. The aetiology of the bronchial atresia is probably heterogeneous and may either represent a primary malformation, or be the result of vascular disruption.

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.

Short-term use of parenteral nutrition with a lipid emulsion containing a mixture of soybean oil, olive oil, medium-chain triglycerides, and fish oil: a randomized double-blind study in preterm infants.

Background: For premature neonates needing parenteral nutrition (PN), a balanced lipid supply is crucial. The authors hypothesized that a lipid emulsion containing medium-chain triglycerides (MCTs) and soybean, olive, and fish oils would be as safe and well tolerated as a soybean emulsion while beneficially influencing the fatty acid profile. Methods: Double-blind, controlled study in 53 neonates (<34 weeks’ gestation) randomized to receive at least 7 days of PN containing either an emulsion of MCTs and soybean, olive, and fish oils or a soybean oil emulsion. Target lipid dosage was 1.0 g fat/kg body weight [BW]/d on days 1–3, 2 g/kg BW/d on day 4, 3 g/kg BW/d on day 5, and 3.5 g/kg BW/d on days 6–14. Results: Test emulsion vs control, mean ± SD: baseline triglyceride concentrations were 0.52 ± 0.16 vs 0.54 ± 0.19 mmol/L and increased similarly in both groups to 0.69 ± 0.38 vs 0.67 ± 0.36 on day 8 of treatment (P = .781 for change). A significantly higher decrease in total and direct bilirubin vs baseline was seen in the test group compared with the control group P < .05 between groups). In plasma and red blood cell phospholipids, eicosapentaenoic acid and docosahexaenoic acid were higher, and the n-6/n-3 fatty acid ratio was lower in the test group (P < .05 vs control). Conclusions: The lipid emulsion, based on a mixture of MCTs and soybean, olive, and fish oils, was safe and well tolerated by preterm infants while beneficially modulating the fatty acid profile.

Hormone synthesis and storage in the thyroid of human preterm and term newborns: Effect of thyroxine treatment

Iodine and thyroglobulin concentrations, as well as iodine, T3, T4 and sialic acid contents of thyroglobulin, were measured in thyroid glands collected postmortem from 42 human premature or term newborns and infants. Three groups were considered: very preterm newborns (24-32 postmenstrual weeks, < 5 days postnatal life), preterm and term newborns (34-41 postmenstrual weeks, < 5 days postnatal life) and infants (born at term, postnatal age 1-8 months). Five very preterm and seven preterm newborns received a daily dose of 10 microg/kg L-T4 for at least 3 days. Thyroid weight and sialic acid content of thyroglobulin progressed with maturation. Intrathyroidal concentrations of iodine and thyroglobulin did not increase significantly before the 42nd week of postmenstrual age. The level of thyroglobulin iodination increased during the postnatal life, except in the very preterm neonates. T4 and T3 content of thyroglobulin was directly proportional to its degree of iodination and positively related to its sialic acid content. L-T4 treatment of preterm newborns increased thyroglobulin iodination and T4-T3 content, without increasing thyroglobulin concentration in the thyroid. It was concluded that the storage of thyroglobulin and iodine in the thyroid develops around term birth. This, associated with the resulting rapid theoretical turnover of the intrathyroidal pool of T4 in Tg, could be an important factor of increased risk of neonatal hypothyroxinemia in the premature infants. The L-T4 treatment of preterm newborns does not accelerate the maturational process of the thyroid gland.