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Background and aims: Study of lung function in anexperimental model of bronchopulmonary dysplasia(BPD) induced by hyperoxia in newborn rats.Methods: The subjects of this study were twolitters of Sprague-Dawley rats. Group C (Control):exposure to room air. Group H (Hyperoxia): exposureto 60% of Oxygen from birth and during 14 days. The lung function tests were performed on day 15. Respiratory functional evaluation through a systemof total body plethysmography (Buxco Electronics, Troy, NY, USA): non-invasive analysis system, withthe animal conscious and free, housed in a sealedcontainer. Changes of pressure and volume in thecabin due to respiratory movements are monitoredand used to calculate ventilatory parameters usinga computer application.Results: Two litters with 14 offspring each werestudied. Pulmonary function tests showed adecrease in tidal volume (H: 0.098 ml, C: 0.125 ml, p0,000) with offsetting increase in respiratory rate (H:310 rpm; C: 266 rpm; p 0,03) without differences inminute volume (H: 29.92 ml / min, C: 32.75 ml / min;p 0,186). The index of airway obstruction (Penh) isaltered in the litter exposed to oxygen (p 0, 026).Conclusions:- Validation of an experimental model of hyperoxia(DBP) in newborn rats.- Functional respiratory non-invasive test whichmainly showed a decrease in tidal volume withincreased respiratory rate volume.- Non invasive total body plethysmography is anadequate method to study lung function in thisanimal model.

Aim: Infants with Hypoplastic Left Heart Syndrome(HLHS) may suffer inhibited growth. Some papershave shown it in congenital heart disease. Aim:to check if that is true in HLHS. We will also studyother perinatal parameters that can be influencedby this pathology.Methods: We have studied a total number of 173HLHS of which 75 (43,45 %) died in our neonatalunit. We have compared data of maternal, pregnancy and delivery risks, weight, height andcephalic perimeter with normal babies born in thesame period in our hospital,. We also compared theevolution between babies born at our hospital andthose who were referred to us.Results: No difference was obtained betweennormal and HLHS groups on: maternal age, number of previous gestations, abortion and livebabies. There was significant difference in maternalpathology especially due to endocrine alterations(thyroid and diabetic). Also epilepsy was present. Both weight (3216,05 v 2990,39 p< 0,001) andcephalic perimeter (34,26 v 33,41 p< 0,001) wassignificantly different. Height had a p< 0,1. At birthpH, Apgar 1 minute were significantly diminished inthe HLSH group.HLSH born at our hospital had less morbidity andmortality.Conclusions: We think it is important to diagnosepregnancy growth retardation and try to control it. Asother authors have shown aortic arch morphometryduring pregnancy should be controlled. Endocrinepathology or epilepsy in the mother may be a riskfor HLSH. It is advisable that these babies shouldbe born in reference hospitals.

Background and aim: There is controversy in the last years on on surgical closure of the ductus arteriosus in extremely low birth weight infants. Study the possible consequences of surgical closure of the patent ductus arteriosus in the newborn period.Material and methods: 422 preterm newborns born with of less than 1000 gr. were studied, 202 (47,86 %) had symptomatic PDA (Patent Ductus Arteriosus) and received medical therapy with indomethacine., 36 (8,53 %) underwent PDA ligation. We studied the risks of adverse outcomes (Retinopathy (ROP), bronchopulmonary dysplasia (BDP), and Neurosensory Impairment (NI)) between both groups, surgical closure and non surgical treatment.Results: No significant differences between the two groups were found in: Maternal age, gestations, gestacional age, type of delivery, pH at delivery, Apgar score at 1 and 5 minutes, weight, height and cephalic perimeter. ROP, Intracraneal hemorrage, neumothorax, necrotaizing enterocolitis, had no different incidences in both groups. We found augmented risk in surgery closure group : Lenth of stay (LOS) in hospital 99,5±6,46 versus 69,50±3,59 (p< 0,001), NI Odds ratio 3,149 (1,286-7,712) and BDP 2,364 (1,085-5,151).Conclusions: PDA surgical closure seems that can be associated with increased risk of LOS, NI and BDP in this group of infants. We could not demonstrate, like other authors have, its relationship with ROP.

Background: Vascular endothelial growth factor (VEGF), an angiogenic factor secreted by pneumocytes-II, may play a role in the pathogenesis of congenital diaphragmatic hernia (CDH). Studies in rodents suggest that it may accelerate lung growth in hypoplastic lungs induced by prenatal nitrofen administration.Aims: Analysis of pulmonary hypoplasia and quantification of VEGF in fetal lungs rats with CDH induced by administration of nitrofen to pregnant rats and changes after fetal tracheal occlusion (TO).Methods: Timed-pregnant Sprague-Dawley rats treated with nitrofen on embryonic day 9 without further fetal intervention (group 1) and with fetal TO on day 20 (group 2). Control animals were treated with placebo (group 0). Cesarean section was performed on day 21. Fetuses were weighed, lungs dissected, weighed and frozen for subsequent quantification of VEGF by immunoassay.Results: 50% fetuses in groups 1 and 2 developed CDH and none in the control group. Fetuses with CDH had significantly lower lung weight and reduced lung weight index/fetal weight than those who did not have CDH. VEGF quantification in those with CDH was lower (2.67 pg/mg) than in the rest (2.97 pg/gm). A trend to higher VEGF expression was observed after TO (data of 20 more fetuses are pending to confirm these results).Conclusions: With the data available up to date, we found no significant differences in the quantification of lung VEGF, although we observed a trend toward lower expression of this protein in CDH fetuses. TO could improve pulmonary VEGF expression.

Aim: To study cerebral electrical activity and local regional oximetry during cardiopulmonary by-pass (CPB) and determine the periods of time in which the brain is at its most vulnerability.Setting: Neonatal intensive care unit of a tertiary university-affiliated children's hospital.Methods: Prospective observational study of newborns with congenital heart disease needing surgical therapy on CBP. Regional cerebral oxymetry (CrSO2) with near-infrared spectroscopy (NIRS, INVOS) and amplitude integrated electroencephalography (aEEG, CFM Olympic) were continuously monitored.Results: 23 infants were studied. 19/23 underwent cardiac surgery on CPB with deep hypothermic circulatory arrest (DHCA), 2 had selective cerebral perfusion (SCP), 4/23 did not need circulatory arrest. 70.6% presented critical electric activity during circulatory arrest (aEEG) and a rapid fall in cerebral oxymetry (CrSO2 < 40%) during CPB-DHCA. The electrical activity ceased when reentering cardiopulmonary bypass. In cases of CPB with SCP there was no critical electrical activity in the aEEG, nonetheless these patients had critical values of CrSO2 in the postoperative period.Electrical seizures occurred in 19/23 patients (82.6%). During anesthetic induction 2 patients presented seizures (8.7%), 12 (52.2%) during DHCA, 8 (34.8%) during modified ultrafiltration (MUF), 7 (30.4%) during re-warming and 4 (17.4%) during the postoperative period. Only 4 patients (17.4%) didn't have critical electrical activity at any time.Conclusions: Brain activity monitoring with aEEG allows us to identify seizures during CPB, which suggests an inadequate neuro-protection mostly during circulatory arrest.The combined use of aEEG and INVOS allows a rapid detection of high-risk situations for neurological injury and low cardiac output.