Neonatal oxidative stress depends on oxygen blood pressure in umbilical artery.

With advancing gestation, partial pressure of oxygen (pO2) and pH fall significantly. Hypoxia is a main factor inducing free radical generation and thereby oxidative stress (OS). Placental and fetal tissue response when oxygen becomes restricted is complex and partially known. We tested the hypothesis that changes in umbilical artery and vein blood gas concentrations modulate OS occurrence in the newborn. Seventy umbilical artery and vein plasma samples were collected from healthy term newborns immediately after delivery. F2 Isoprostanes (F2-Isop) were measured in all samples as reliable markers of lipid peroxidation. Significantly lower pCO2 and higher pO2 and pH were found in umbilical vein than in artery, as expected. A positive correlation was detected between pH and pO2 only in umbilical artery (p=0.019). F2-Isop levels were no different between artery and vein in cord blood. Significant correlations were found between F2-Isop and pCO2 (p=0.025) as well as between F2-Isop and pH in umbilical vein (p=0.027). F2-Isop correlated with pCO2 (p=0.007) as well as with pO2 values (p=0.005) in umbilical artery blood. Oxidative stress (OS) in newborns depends on oxygen concentrations in umbilical artery. OS biomarkers significantly correlate with pO2 and in umbilical artery but not in umbilical vein. In normoxic conditions fetal-maternal gas exchanges occurring in placenta re-establish normal higher oxygen levels in umbilical vein than artery, with a normal production of free radicals without any deleterious effects.

Pudendal nerve somatosensory evoked potentials in paediatrics: maturation aspects.

Pudendal nerve somatosensory evoked potentials (PN-SSEPs) were recorded in 21 healthy children (age range: 3.3-13.3 years). The dorsal nerve of the penis/clitoris was stimulated and SSEPs were recorded at spinal L1-D12 and at cortical Cz'-Fz. Morphology, latency and amplitude of the cortical SSEPs were evaluated. A cortical response was obtained in all but two subjects. Cortical SSEPs were broader and less defined in shape in the youngest subjects. There was a progressive shortening of the latency of the P and N components during growth. Spinal responses were obtained only in 6 cases. Nine subjects also underwent tibial nerve stimulation. Pudendal and tibial SSEPs differed in their degree of maturation.

Complications of pediatric laparoscopic surgery.

BACKGROUND: Surgical complications of laparoscopy most often occur during Veress needle or primary trocar placement. Veress needle punctures are insignificant and require no further treatment, whereas trocar-induced vascular injuries can be catastrophic. The frequency of vascular and viscus injuries is difficult to calculate because several complications are not reported in the literature. METHODS: During a 10-year-period (1984-1995), at the Division of Pediatric Surgery at "Federico II" University of Naples, 430 laparoscopic procedures were performed in 395 children with a mean age of 5 years. The incidence of complications related to laparoscopy was 1.8% with eight complications, one of which was rather severe. The complications included one abdominal wall hematoma, two perforations of abdominal viscus (stomach, ovary), one umbilical scar complication, one postoperative hydrocele, one subcutaneous emphysema, and one pneumothorax during a Nissen procedure. The only severe complication occurred in a young girl with neurologic problems and a kyphoscoliosis operated on via laparoscopy for a gastroesophageal reflux. She suffered injuries of both right common iliac vessels and several intestinal perforations due to blind introduction of the first umbilical trocar. RESULTS: In this case rapid conversion, complex vascular reconstruction, and multiple intestinal sutures were performed. The Nissen fundoplication with pyloroplasty was performed traditionally and the patient left the hospital free of symptoms after 20 days. The other seven complications were resolved without any problem intra- or postoperatively. CONCLUSIONS: The authors believe that the open approach with a blunt trocar is most important in helping to avoid complications in pediatric laparoscopy.