Department of Endocrinology, Sydney Children's Hospital, Sydney, Australia. kristen.neville@sesiahs.health.nsw.gov.au AIMS: To determine whether the risk of hyponatraemia in children with gastroenteritis receiving intravenous (IV) fluids is decreased by the use of 0.9% saline. METHODS: A prospective randomised study was carried out in a tertiary paediatric hospital. A total of 102 children with gastroenteritis were randomised to receive either 0.9% saline + 2.5% dextrose (NS) or 0.45% saline + 2.5% dextrose (N/2) at a rate determined by their treating physician according to hospital guidelines and clinical judgement. Plasma electrolytes, osmolality, and plasma glucose were measured before (T(0)) and 4 hours after (T(4)) starting IV fluids, and subsequently if clinically indicated. Electrolytes and osmolality were measured in urine samples. Results were analysed according to whether children were hyponatraemic (plasma sodium <135 mmol/l) or normonatraemic at T(0). RESULTS: At T(0), mean (SD) plasma sodium was 135 (3.3) mmol/l (range 124-142), with 37/102 (36%) hyponatraemic. At T(4), mean plasma sodium in children receiving N/2 remained unchanged in those initially hyponatraemic (n = 16), but fell 2.3 (2.2) mmol/l in the normonatraemic group. In contrast, among children receiving NS, mean plasma sodium was 2.4 (2.0) mmol/l higher in those hyponatraemic at baseline (n = 21) and unchanged in the initially normonatraemic children. In 16 children who were still receiving IV fluids at 24 hours, 3/8 receiving N/2 were hyponatraemic compared with 0/8 receiving NS. No child became hypernatraemic. CONCLUSIONS: In gastroenteritis treated with intravenous fluids, normal saline is preferable to hypotonic saline because it protects against hyponatraemia without causing hypernatraemia. PMID: 16352625 [PubMed - indexed for MEDLINE]

Department of Endocrinology, Sydney Children's Hospital, Randwick, Sydney, Australia. nevillek@sesahs.nsw.gov.au OBJECTIVES: Nonosmotic antidiuretic hormone (ADH) activity can cause severe hyponatremia during involuntary fluid administration. We looked for evidence of this before and during intravenous (IV) fluid administration in children treated for gastroenteritis. METHODOLOGY: In this prospective observational study, plasma ADH, electrolytes, osmolality, and glucose were measured in 52 subjects before (T0) and 4 hours after (T4) starting 0.45% saline + 2.5% dextrose and subsequently when indicated. Hormonal markers of stress were measured at T0. Urine samples were collected to measure electrolytes and osmolality. RESULTS: The nonosmotic stimuli of ADH secretion that we identified were vomiting (50 of 52), dehydration (median: 5%; range: 3-8%), hypoglycemia (2 of 52), and raised hormonal markers of stress (mean +/- SD: cortisol, 1094 +/- 589 nmol/L; reverse triiodothyronine, 792 +/- 293 pmol/L). At T0, half the children were hyponatremic (plasma sodium concentration of < 135 mmol/L; n = 27). The median plasma ADH concentration at T0 was significantly elevated (median: 7.4 pg/mL; range: < 1.9-85.6 pg/mL). ADH was high in both hyponatremic and normonatremic children and remained high at T4 in 33 of the 52 children, 22 of whom were concurrently hyponatremic. At T4, mean plasma sodium concentration was unchanged in the hyponatremic children but was 2.6 mmol/L (+/-2.0) lower in those who were initially normonatremic. Urine tonicity was high compared with 0.45% saline in 16 of 19 children at baseline and in 20 of 37 children after 3 to 12 hours of IV fluids. CONCLUSIONS: Nonosmotic stimuli of ADH secretion are frequent in children with gastroenteritis. Their persistence during IV-fluid administration predisposes to dilutional hyponatremia. The use of hypotonic saline for deficit replacement needs to be reassessed.

Seccion de Urgencias Pediatria. Hospital Infantil Gregorio Maranon. Madrid. Espana. cristinaif@hotmail.com Complete aortic thrombosis is rare in neonates. Because it carries high morbidity and mortality, this entity requires aggressive and early treatment. This report describes an 8-day-old healthy and exclusively breast-fed infant, without specific coagulopathy, who developed complete aortic and cerebral venous thrombosis, which was attributed to inadequate breast-feeding and severe hypernatremic dehydration. Early systemic anticoagulation and thrombolytic therapy allowed complete resolution of the problem. PMID: 17020732 [PubMed - indexed for MEDLINE]

Miscarriage and pre-eclampsia are the most common disorders of human pregnancy. Both are placental-related and exceptional in other mammalian species. Ultrasound imaging has enabled events during early pregnancy to be visualized in vivo for the first time. As a result, a new understanding of the early materno-fetal relationship has emerged and, with it, new insight into the pathogenesis of these disorders. Unifying the two is the concept of placental oxidative stress, with associated necrosis and apoptosis of the trophoblastic epithelium of the placental villous tree. In normal pregnancies, the earliest stages of development take place in a low oxygen (O2) environment. This physiological hypoxia of the early gestational sac protects the developing fetus against the deleterious and teratogenic effects of O2 free radicals (OFRs). In miscarriage, development of the placento-decidual interface is severely impaired leading to early and widespread onset of maternal blood flow and major oxidative degeneration. This mechanism is common to all miscarriages, with the time at which it occurs in the first trimester depending on the aetiology. In contrast, in pre-eclampsia the trophoblastic invasion is sufficient to allow early pregnancy phases of placentation but too shallow for complete transformation of the arterial utero-placental circulation, predisposing to a repetitive ischaemia-reperfusion (I/R) phenomenon. We suggest that pre-eclampsia is a three-stage disorder with the primary pathology being an excessive or atypical maternal immune response. This would impair the placentation process leading to chronic oxidative stress in the placenta and finally to diffuse maternal endothelial cell dysfunction. PMID: 16682385 [PubMed - indexed for MEDLINE]

Department of Paediatrics, Umea University, Umea, Sweden. fredrik.serenius.us@vll.se AIM: To determine major neonatal morbidity in surviving infants born at 23-25 weeks, and to identify maternal and infant factors associated with major morbidity. METHODS: The medical records of 224 infants who were delivered at two tertiary care centres in 1992-1998 were reviewed retrospectively. At these centres, policies of active perinatal and neonatal management were universally applied. Of the 213 liveborn infants, 140 (66%) survived to discharge. Data were analysed by gestational age and considered in three time periods. Logistic regression models were used to identify factors associated with morbidity. RESULTS: Of the survivors, 6% had intraventricular haemorrhage grade > or = 3 (severe IVH) or periventricular leukomalacia (PVL), 15% retinopathy of prematurity > or = stage 3 (severe ROP) and 36% bronchopulmonary dysplasia (BPD). On logistic regression analysis, severe IVH or PVL was associated with duration of mechanical ventilation (odds ratio, OR: 1.53 per 1-wk increment in duration; 95% confidence interval, CI: 1.01-2.33). Severe ROP was associated with the presence of a patent ductus arteriosus (PDA) (OR: 3.31; 95% CI: 1.11-9.90) and birth in time period 3 versus time periods 1 and 2 combined (OR: 6.28; 95% CI: 2.10-18.74). BPD was associated with duration of mechanical ventilation (OR: 2.71 per 1-wk increment in duration; 95% CI: 1.76-4.18) and with the presence of any obstetric complication (OR: 2.67; 95% CI: 1.07-6.65). Gestational age and birthweight were not associated with major morbidity. Of all survivors, 81% were discharged home without severe IVH, PVL or severe ROP. CONCLUSIONS: Increased survival as a result of active perinatal and neonatal management was associated with favourable morbidity rates compared with those in recent studies. Among survivors born at 23-25 weeks, neither gestational age nor birthweight was a significant determinant of major morbidity. PMID: 15456201 [PubMed - indexed for MEDLINE]

Department of Paediatrics, Umea University, Umea, Sweden. AIM: To determine neonatal survival rates based on both foetal (stillborn) and neonatal deaths among infants delivered at 23-25 wk, and to identify maternal and neonatal factors associated with survival. METHODS: The medical records of 224 infants who were delivered in two tertiary care centres in 1992-1998 were reviewed retrospectively. At these centres, policies of active perinatal and neonatal management were universally applied. Data were analysed by gestational age groups and considered in three time periods. Logistic regression models were used to identify factors associated with survival. RESULTS: The rate of foetal death was 5%. Of infants born alive, 63% survived to discharge. Survival rates including foetal deaths in the denominator at 23, 24 and 25 wk were 37%, 61% and 74%, respectively, and survival rates excluding foetal deaths were 43%, 63% and 77%, respectively. Of infants born with 1-min Apgar scores of 0-1, 43% survived. In the total cohort, survival rates including foetal deaths in the denominator increased from 52% in time period 1 to 61% in time period 2 and 74% in time period 3 (p < 0.02). On multivariate logistic regression analysis, higher birthweight (OR: 1.91 per 100 g increment; 95% CI: 1.45-2.52), female gender (OR: 3.33; 95% CI: 1.65-6.75), administration of antenatal steroids (OR: 2.95; 95% CI: 1.46-5.98) and intrauterine referral from a peripheral hospital (OR: 2.35; 95% CI: 1.18-4.68) were associated with survival. Apgar score < or = 3 at 1 min (OR: 0.46; 95% CI: 0.22-0.95) was associated with decreased survival. The use of antenatal steroids was protective at 23-24 wk (OR: 5.2; 95% CI: 2.0-13.7), but not at 25 wk. CONCLUSIONS: Active perinatal management that included universal initiation of neonatal intensive care virtually eliminated intrapartum stillbirths and delivery room deaths, and resulted in survival rates that compare favourably with those of recent studies. However, the policies of active care postponed death in non-survivors. Individual variations in outcome in relation to the infant's condition at birth as reflected by the Apgar scores preclude the making of treatment decisions in the delivery room. PMID: 15456200 [PubMed - indexed for MEDLINE]

Health Surveillance and Epidemiology Division, Centre for Health Promotion, Public Health Agency of Canada, Ottawa, Ont. Shiliang_Liu@phac-aspc.gc.ca BACKGROUND: The rate of elective primary cesarean delivery continues to rise, owing in part to the widespread perception that the procedure is of little or no risk to healthy women. METHODS: Using the Canadian Institute for Health Information's Discharge Abstract Database, we carried out a retrospective population-based cohort study of all women in Canada (excluding Quebec and Manitoba) who delivered from April 1991 through March 2005. Healthy women who underwent a primary cesarean delivery for breech presentation constituted a surrogate "planned cesarean group" considered to have undergone low-risk elective cesarean delivery, for comparison with an otherwise similar group of women who had planned to deliver vaginally. RESULTS: The planned cesarean group comprised 46,766 women v. 2,292,420 in the planned vaginal delivery group; overall rates of severe morbidity for the entire 14-year period were 27.3 and 9.0, respectively, per 1000 deliveries. The planned cesarean group had increased postpartum risks of cardiac arrest (adjusted odds ratio [OR] 5.1, 95% confidence interval [CI] 4.1-6.3), wound hematoma (OR 5.1, 95% CI 4.6-5.5), hysterectomy (OR 3.2, 95% CI 2.2-4.8), major puerperal infection (OR 3.0, 95% CI 2.7-3.4), anesthetic complications (OR 2.3, 95% CI 2.0-2.6), venous thromboembolism (OR 2.2, 95% CI 1.5-3.2) and hemorrhage requiring hysterectomy (OR 2.1, 95% CI 1.2-3.8), and stayed in hospital longer (adjusted mean difference 1.47 d, 95% CI 1.46-1.49 d) than those in the planned vaginal delivery group, but a lower risk of hemorrhage requiring blood transfusion (OR 0.4, 95% CI 0.2-0.8). Absolute risk increases in severe maternal morbidity rates were low (e.g., for postpartum cardiac arrest, the increase with planned cesarean delivery was 1.6 per 1000 deliveries, 95% CI 1.2-2.1). The difference in the rate of in-hospital maternal death between the 2 groups was nonsignificant (p = 0.87). INTERPRETATION: Although the absolute difference is small, the risks of severe maternal morbidity associated with planned cesarean delivery are higher than those associated with planned vaginal delivery. These risks should be considered by women contemplating an elective cesarean delivery and by their physicians. PMID: 17296957 [PubMed - indexed for MEDLINE]