The kinetic profile of vancomycin in neonates

The pharmacokinetic parameters of vancomycin in a neonatal population have been characterized to enable development of optimum dosage guidelines for neonatal intensive-care units and to examine the relationship between these pharmacokinetic parameters and various demographic, developmental and clinical factors which might be associated with changes in the kinetic profile of vancomycin. Forty-four infants (twenty-five males and nineteen females) with suspected or proven Gram-positive infection and who received intravenous vancomycin between October 1993 and December 1996 were included in this retrospective analysis. Gestational age ranged from 25 to 40 weeks and postconceptional age at the time of the study ranged from 28 to 45 weeks. Sixty case-studies were obtained from the forty-four patients, with one period of study corresponding to one week or one cycle of therapy. Vancomycin pharmacokinetic parameters were determined by use of a one-compartment model. By regression analysis the current weight (g) was shown to be the stronger covariate, and both vancomycin clearance (L h(-1)) and volume of distribution (L) had to be normalized. The vancomycin volume of distribution depended on the postconceptional age with a cut-off at 32 weeks, whereas vancomycin clearance depended on the presence or absence of concomitant treatment with indomethacin or of mechanical ventilation, or both. On the basis of the pharmacokinetic parameters obtained we suggest initial dosage guidelines for vancomycin ranging from 10 mg kg(-1) every 8 h to 10 mg kg(-1) every 12 h, depending on the demographic and clinical characteristics of the patients. The results obtained enabled application of better a priori and a posteriori dosage schedules to infants in neonatal intensive-care units by use of the Bayesian approach, although further prospective study is recommended before direct extrapolation to patients in other settings.

[Clinical and laboratory basis for the diagnosis and understanding of neonatal metabolic diseases]

The authors divide neonatal metabolic diseases into two major groups: intoxication and energy deficiency. The main signs which allow for the suspicion of the diagnosis are indicated for each group. The complementary examinations to be carried out by the Clinical Pathology Service of the Central Hospital and those which must be carried out by the metabolic diseases Reference Centre are reviewed. Based on the clinical framework and on the examination results, the authors establish five syndromatic groups to orientate diagnosis. The authors conclude by presenting differential diagnosis tables based on the original systematic classification by Jean-Marie Saudubray, with up-dated modifications from their own experience.

[Importance of J. Brazy's neurobiological index. Prediction of the number and severity of complications in very low birth weight infants]

The objective of this study was to evaluate the neurodevelopment outcome of Very-Low-Birth-Weight Infants (VLBW), between 1987 and 1993, and correlate these findings with J.Brazy's Neurobiologic Risk Score (NBRS). The minimum corrected age at follow-up was 12 months. The neurodevelopmental assessment was performed using Mary Sheridan and Ruth Griffiths scales, Auditory and Visual Brainstem Evoked Responses and Stycar test. The NBRS was applied to 77 children. According to the score, three groups of risk were defined: Low < or = 4; Intermediate 5-7; High > or = 8. We obtained the following results: children with NBRS < 4, 20% had handicaps (5% of which major); children with NBRS 5-7, 41% had handicaps (23% of which major); in children with NBRS > 8, 95% had handicaps (80% of which major). The incidence of handicaps, (all grades included) was 71.4% for those weighing less than 1000 gr at birth, and 39.2% for those weighing 1000-1499 gr at birth. Major handicaps, mainly motor deficits, occurred in 26.8% of VLBW infants and minor to moderate handicaps were observed in 18.3% of patients in this group. These results were compared to J.Brazy's originals. We concluded that the NBRS, which is simple and objective to perform, is a good predictor of subsquent abnormal development in VLBW infants, allowing the infant's integration as soon as possible in high-risk follow-up programs, to place as soon as possible.

[Extra-lobar pulmonary sequestration with broncho-esophageal fistula]

We describe a case of extra-lobar pulmonary sequestration with broncho-esophageal fistula in a newborn male who presented respiratory distress, cyanosis and feeding difficulties. The diagnosis was made with a swallowed contrast examination, nuclear magnetic resonance, digital subtraction angiography and confirmed by gross and histologic examination. The work of a multidisciplinary team was essential for an early diagnosis and the correct and effective treatment of this Cuncommon condition.

Transplacental exposure to genotoxins. Evaluation in haemoglobin of hydroxyethylvaline adduct levels in smoking and non-smoking mothers and their newborns

The N-(2-hydroxyethyl)valine (HOEtVal) adduct resulting from the interaction of ethylene oxide with the N-terminal valine in haemoglobin, was determined in blood samples taken from non-smoking pregnant women (n = 10) and from pregnant women (n = 13) smoking 15 or more cigarettes a day. The HOEtVal levels were also determined in the haemoglobin from blood samples taken, within 48 h of delivery, from the newborns of these mothers. In the maternal haemoglobins, the average HOEtVal adduct level was increased from a background of 63 +/- 20 (mean +/- SD) pmol/g globin in the non-smoking mothers to 361 +/- 107 (mean +/- SD) pmol/g globin in the smoking mothers. Haemoglobin adducts were also detected in all the babies' blood samples. The concentrations in the newborns from smoking mothers [147 +/- 68 (mean +/- SD) pmol/g globin] was significantly higher (P < 0.01) than the concentrations in the newborns from non-smoking mothers [42 +/- 18 (mean +/- SD) pmol/g globin]. A significant correlation (P < 0.01) was found between newborns and maternal HOEtVal adduct levels.