David J Henderson‐Smart

Delayed umbilical cord clamping in preterm infants: a feasibility study.

Objectives: To assess: (i) the size of placental transfusion following a 30 s delay in cord clamping following vaginal and Caesarean births; and (ii) the feasibility of delaying cord clamping in the labour ward and particularly in the operating theatre.

Autonomic Reflexes in Preterm Infants

ABSTRACT. Some autonomic nervous reflexes often tested in adult medicine have been studied in 21 preterm infants (25‐37 gestational weeks). The aim was to develop such tests for preterm infants and see if there were any differences in babies with recurrent apnea and bradycardia and babies who had been exposed to sympathicolytic drugs before birth. To test sympathetic nervous activity the peripheral vascular resistance was measured before and during 45° of head‐up tilting. To test parasympathetic nervous activity the degree of bradycardia was measured in response to cold face test (application of an ice‐cube on the fore‐head) and laryngeal stimulation with saline. Finally the heart rate changes after a sudden noise (85 dB) were studied as an indicator of both sympathetic and vagal activity. The peripheral resistance was found to be relatively low in these preterm infants, particularly in some infants tested at the postnatal age of about two months. Heart rate and mean blood pressure did not change during tilting, while the peripheral resistance increased significantly mainly due to lowered limb blood flow. The median decrease of the heart rate during the cold face test was 20.0% and during laryngcal receptor stimulation 23.7%. The sudden noise usually caused a biphasic heart rate response. An autonomic nervous reflex score was calculated and found to be negative (parasympathetic) in infants with recurrent prolonged apnea and bradycardia and positive in infants with clinical signs of increased sympathetic nervous activity.

Prenatal predictors of chronic lung disease in very preterm infants

Objective: To identify prenatal risk factors for chronic lung disease (CLD) at 36 weeks postmenstrual age in very preterm infants. Population: Data were collected prospectively as part of the ongoing audit of the Australian and New Zealand Neonatal Network (ANZNN) of all infants born at less than 32 weeks gestation admitted to all tertiary neonatal intensive care units in Australia and New Zealand. Methods: Prenatal factors up to 1 minute of age were examined in the subset of infants born at gestational ages 22–31 weeks during 1998–2001, and who survived to 36 weeks postmenstrual age (n = 11 453). Factors that were significantly associated with CLD at 36 weeks were entered into a multivariate logistic regression model. Results: After adjustment, low gestational age was the dominant risk factor, with an approximate doubling of the odds with each week of decreasing gestational age from 31 to less than 25 weeks (trend p<0.0001). Birth weight for gestational age also had a dose-response effect: the lower the birth weight for gestational age, the greater the risk, with infants below the third centile having 5.67 times greater odds of CLD than those between the 25th and 75th centile (trend p<0.0001). There was also a significantly increased risk for male infants (odds ratio 1.51 (95% confidence interval 1.36 to 1.68), p<0.0001). Conclusions: These population based data show that the prenatal factors low gestational age, low birth weight for gestational age, and male sex significantly predict the development of chronic respiratory insufficiency in very preterm infants and may assist clinical decision about delivery.

Caesarean section in four South East Asian countries: reasons for, rates, associated care practices and health outcomes

BackgroundCaesarean section is a commonly performed operation on women that is globally increasing in prevalence each year. There is a large variation in the rates of caesarean, both in high and low income countries, as well as between different institutions within these countries. This audit aimed to report rates and reasons for caesarean and associated clinical care practices amongst nine hospitals in the four South East Asian countries participating in the South East Asia-Optimising Reproductive and Child Health in Developing countries (SEA-ORCHID) project.MethodsData on caesarean rates, care practices and health outcomes were collected from the medical records of the 9550 women and their 9665 infants admitted to the nine participating hospitals across South East Asia between January and December 2005.ResultsOverall 27% of women had a caesarean section, with rates varying from 19% to 35% between countries and 12% to 39% between hospitals within countries. The most common indications for caesarean were previous caesarean (7.0%), cephalopelvic disproportion (6.3%), malpresentation (4.7%) and fetal distress (3.3%). Neonatal resuscitation rates ranged from 7% to 60% between countries. Prophylactic antibiotics were almost universally given but variations in timing occurred between countries and between hospitals within countries.ConclusionRates and reasons for caesarean section and associated clinical care practices and health outcomes varied widely between the four South East Asian countries.

Reducing the risk of sudden infant death syndrome : A review of the scientific literature

In March 1997 a multidisciplinary forum was convened by the National SIDS Council of Australia to review recent evidence concerning risk factors of sudden infant death syndrome (SIDS) and to revise and refine the current guidelines for reducing the risk of SIDS. The forum provided an assessment of the evidence for recommendations to reduce the risk of SIDS using an evidence‐based process. Strong evidence has now accumulated that the intervention campaigns to reduce prone sleeping during infancy have been followed by SIDS rate declines. Recent data indicate that the supine position is not associated with an increase in significant morbidity outcomes and provides greater protection for SIDS than the side position, which may be unstable. Covering of the baby’s head by bedding is strongly related to SIDS. The infant’s sleeping environment should be carefully set up to ensure that the baby’s head, including the face, cannot be obstructed during sleep.

Ventilatory Response of the Newborn Infant to Mild Hypoxia

The transition from an immature (biphasic) to a mature (sustained hyperpneic) response to a brief period of sustained hypoxia is believed to be well advanced by postnatal day 10 for newborn infants. However, a review of the supporting evidence convinced us that this issue warranted further, more systematic investigation. Seven healthy term infants aged 2 days to 8 weeks were studied. The ventilatory response (VR) elicited by 5 min breathing of 15% O2 was measured during quiet sleep. Arterial SaO2 (pulse oximeter) and minute ventilation (expressed as a change from control, ΔV′i) were measured continuously. Infants were wrapped in their usual bedding and slept in open cots at room temperature (23°–25°).

Using hospital discharge data for determining neonatal morbidity and mortality: a validation study.

BackgroundDespite widespread use of neonatal hospital discharge data, there are few published reports on the accuracy of population health data with neonatal diagnostic or procedure codes. The aim of this study was to assess the accuracy of using routinely collected hospital discharge data in identifying neonatal morbidity during the birth admission compared with data from a statewide audit of selected neonatal intensive care (NICU) admissions.MethodsValidation study of population-based linked hospital discharge/birth data against neonatal intensive care audit data from New South Wales, Australia for 2,432 babies admitted to NICUs, 1994–1996. Sensitivity, specificity and positive predictive values (PPV) with exact binomial confidence intervals were calculated for 12 diagnoses and 6 procedures.ResultsSensitivities ranged from 37.0% for drainage of an air leak to 97.7% for very low birthweight, specificities all exceeded 85% and PPVs ranged from 70.9% to 100%. In-hospital mortality, low birthweight (≤1500 g), retinopathy of prematurity, respiratory distress syndrome, meconium aspiration, pneumonia, pulmonary hypertension, selected major anomalies, any mechanical ventilation (including CPAP), major surgery and surgery for patent ductus arteriosus or necrotizing enterocolitis were accurately identified with PPVs over 92%. Transient tachypnea of the newborn and drainage of an air leak had the lowest PPVs, 70.9% and 83.6% respectively.ConclusionAlthough under-ascertained, routinely collected hospital discharge data had high PPVs for most validated items and would be suitable for risk factor analyses of neonatal morbidity. Procedures tended to be more accurately recorded than diagnoses.

Continuous Positive Airway Pressure Therapy for Infants With Respiratory Distress in Non–Tertiary Care Centers: A Randomized, Controlled Trial

OBJECTIVE. Our objective was to determine whether continuous positive airway pressure therapy would safely reduce the need for up-transfer of infants with respiratory distress from nontertiary centers. METHODS. We randomly assigned 300 infants at >30 weeks of gestation with respiratory distress to receive either Hudson prong bubble continuous positive airway pressure therapy or headbox oxygen treatment (standard care). The primary end point was “up-transfer or treatment failure.” Secondary end points included death, length of nursery stay, time receiving oxygen therapy, cost of care, and other measures of morbidity. RESULTS. Of 151 infants who received continuous positive airway pressure therapy, 35 either were up-transferred or experienced treatment failure, as did 60 of the 149 infants given headbox oxygen treatment. There was no difference in the length of stay or the duration of oxygen treatment. For every 6 infants treated with continuous positive airway pressure therapy, there was an estimated cost saving of

Variation in rates of severe retinopathy of prematurity among neonatal intensive care units in the Australian and New Zealand Neonatal Network

10000. Pneumothorax was identified for 14 infants in the continuous positive airway pressure group and 5 in the headbox group. There was no difference in any other measure of morbidity or death. CONCLUSIONS. Hudson prong bubble continuous positive airway pressure therapy reduces the need for up-transfer of infants with respiratory distress in nontertiary centers. There is a clinically relevant but not statistically significant increase in the risk of pneumothorax. There are significant benefits associated with continuous positive airway pressure use in larger nontertiary centers.

Analysing differences in clinical outcomes between hospitals

Aim: To analyse variations in rates of severe retinopathy of prematurity (ROP) among neonatal intensive care units (NICUs) in the Australian and New Zealand Neonatal Network (ANZNN), adjusting for sampling variability and for case mix. Methods: 25 NICUs were included in the study of 2105 infants born at less than 29 weeks in 1998 and 1999, who survived to 36 weeks post-menstrual age and were examined for ROP. The observed NICU rates of severe ROP were adjusted for case mix using logistic regression on gestation, weight for gestational age and sex, and for sampling variability using shrinkage estimates. The corrected rate in the best 20% of NICUs was identified and NICU variations in rates were compared with those in 2000–1. Results: The overall (unadjusted) rate of severe ROP in the NICUs was 9.6% (interquartile range 5.4−12.8%). After adjusting for both case mix and sampling variability there remained significant variation among the NICUs. 20% of NICUs had a rate of severe ROP ⩽5.9%. Variation in rates among NICUs showed a similar pattern in both time periods. If the overall network rate was reduced to 5.9%, the 20th centile of the adjusted rates, there would be 79 fewer cases in a 2 year period, in contrast with 26 fewer if rates in the two units with excess rates improved to the average. Conclusions: Considerable variation in rates of severe ROP among NICUs remained after adjustment for case mix and sampling variability. These data will facilitate investigation of potentially better practices associated with a reduced risk of severe ROP.