Dwell time and risk of central-line-associated bloodstream infection in neonates.

BACKGROUND: Umbilical venous catheters (UVCs) or peripherally inserted central catheters (PICCs), widely used in high-risk neonates, may have a threshold dwell time for subsequent increased risk of central-line-associated bloodstream infection (CLABSI). AIM: To evaluate the CLABSI risks in neonates having either UVC, PICC, or those having both sequentially. METHODS: The study included 3985 infants who had UVC or PICC inserted between 2007 and 2009 cared for in 10 regional neonatal intensive care units: 1392 having UVC only (group 1), 1317 PICC only (group 2), and 1276 both UVC and PICC (group 3). FINDINGS: There were 403 CLABSIs among 6000 venous catheters inserted, totalling 43,302 catheter-days. CLABSI rates were higher in group 3 infants who were of lowest gestation (16.9 per 1000 UVC-days and 12.5 per 1000 PICC-days; median: 28 weeks) when compared with group 1 (3.3 per 1000 UVC-days; 37 weeks) and group 2 (4.8 per 1000 PICC-days; 30 weeks). Life table and Kaplan-Meier hazard analysis showed that UVC CLABSI rate increased stepwise to 42 per 1000 UVC-days by day 10, with the highest rate in group 3 (85 per 1000 UVC-days). PICC CLABSI rates remained relatively stable at 12-20 per 1000 PICC-days. Compared to PICC, UVC had a higher adjusted CLABSI risk controlled for dwell time. Among group 3, replacing UVC electively before day 4 may have a trend of lower CLABSI risk than late replacement. CONCLUSION: There was no cut-off duration beyond which PICC should be removed electively. Early UVC removal and replacement by PICC before day 4 might be considered.

Perinatal characteristics and outcome of preterm singleton, twin and triplet infants in NSW and the ACT, Australia (1994-2005).

OBJECTIVE: To compare the perinatal characteristics, neonatal morbidity and mortality of preterm singletons, twins and triplets born at 22-31 weeks' gestation and admitted to neonatal intensive care units (NICU) in New South Wales and Australian Capital Territory between 1994 and 2005. METHODS: Perinatal characteristics and neonatal outcome data were obtained from the regional NICUS data collection to test for a priori hypothesis. The 10 068 very premature infants studied included 7304 (72.5%) singletons, 2444 (24.2%) twins and 320 (3.2%) triplets. RESULTS: Assisted conception was associated with a higher maternal age and increased twins and triplets admissions into NICU than spontaneous conceptions (twins OR 6.9, 95% CI 6.1 to 8.0; and triplets OR 35.6, 95% CI 27.6 to 45.8). Major neonatal morbidities were similar between the three groups of singletons, twins or triplets. While twins of 22-27 weeks' gestation (adjusted OR 1.39, 95% CI 1.12 to 1.72) had higher mortality compared with singletons, mortality only diverged below 24 weeks' gestation. Mortality was predicted by decreasing gestational age, male gender and lack of antenatal steroids, whereas assisted conception was protective against mortality (adjusted OR 0.69, 95% CI 0.57 to 0.86). CONCLUSIONS: Assisted conception contributed to higher very premature NICU admissions of twins and triplets. Preterm twins at the very extreme of viability had higher mortality compared with singletons. The protective effect of assisted conception against mortality requires further research.

Softening of the stiffness of bottle-brush polymers by mutual interaction.

We study bottle-brush macromolecules in a good solvent by small-angle neutron scattering (SANS), static light scattering (SLS), and dynamic light scattering (DLS). These polymers consist of a linear backbone to which long side chains are chemically grafted. The backbone contains about 1600 monomer units (weight average) and every second monomer unit carries side chains with approximately 60 monomer units. The SLS and SANS data extrapolated to infinite dilution lead to the form factor of the polymer that can be described in terms of a wormlike chain with a contour length of 380 nm and a persistence length of 17.5 nm. An analysis of the DLS data confirms these model parameters. The scattering intensities taken at finite concentration can be modeled using the polymer reference interaction site model. It reveals a softening of the bottle-brush polymers caused by their mutual interaction. We demonstrate that the persistence decreases from 17.5 nm down to 5 nm upon increasing the concentration from dilute solution to the highest concentration (40.59 gl) under consideration. The observed softening of the chains is comparable to the theoretically predicted decrease of the electrostatic persistence length of linear polyelectrolyte chains at finite concentrations.

Severe conjugated hyperbilirubinaemia and neonatal haemolysis.

We report two neonates, one with Rh anti-C isoimmunisation and the other with hereditary pyropoikilocytosis. Both presented with severe, early onset conjugated hyperbilirubinaemia.

Postnatal changes in maternal and neonatal plasma antioxidant vitamins and the influence of smoking.

OBJECTIVE: To study the postnatal changes in the plasma concentrations of fat soluble antioxidant vitamins and malondialdehyde (MDA) in mothers and their newborns and their relation to smoking. DESIGN: Prospective cohort study. SETTING: Tertiary perinatal centre. SUBJECTS: Eighteen non-smoking and 14 smoking mothers and 33 infants. MAIN OUTCOME MEASURES: Plasma concentrations of vitamins E, A, and beta-carotene and MDA were measured in mothers and infants at delivery and on day 4 post partum. RESULTS: Neonatal plasma levels of vitamins E, A, and beta-carotene were significantly lower than maternal levels both at delivery and on day 4 in both groups. There was a significant postnatal increase in plasma vitamin E levels in smoking mothers and neonates of both groups. A significant postnatal increase in maternal, but not neonatal, plasma vitamin A was noted in both groups. Cord plasma vitamin E levels were significantly lower in infants of smoking mothers (mean 4.7 v 6.5 micromol/l, p = 0.041). Plasma MDA was paradoxically lower in smoking mothers at delivery (3.19 v 4.01 micromol/l, p = 0.03) and on day 4 (1.37 v 3.29 micromol/l, p = 0.005) and in infants of the smoking group on day 4 (2.18 v 3.12 micromol/l, p = 0.014). Also, there was a significant postnatal fall in plasma MDA levels on day 4 in mothers and infants in the smoking group. CONCLUSIONS: The postnatal changes in plasma vitamin E were more pronounced in the smoking group. The postnatal changes in plasma vitamins A and beta-carotene were similar in both groups. The rapid decline in plasma MDA in smoking mothers and their infants suggests withdrawal of oxidative stress from smoking around delivery. This coincided with the increase in plasma vitamin E.

The profile of substance-using pregnant mothers and their newborns at a regional rural hospital in New South Wales.

We conducted an audit study of identified substance-using mothers and their neonates at Lismore Base Hospital in the Northern Rivers region of New South Wales between January 1995 and December 1999. Women using marijuana and/or alcohol only were excluded. The average number of total births during the study period was 1,363 per year. Forty-nine mothers were identified as substance users with an incidence of seven per 1,000 total births. Twenty-three (47%) were methadone users, 14 (29%) methadone and intravenous heroin users, 11 (22%) heroin users, and one (2%) used amphetamines. Twenty-seven (55%) had irregular antenatal visits. Forty-one (89%) were hepatitis C positive. Forty-seven neonates were live-born and there were two stillbirths. Thirty-seven (79%) required admission to the special care nursery, 40% of them for withdrawal alone. Twenty-seven (55%) babies had neonatal withdrawal and 23 (49%) required medication for withdrawal. The incidence of substance abuse among the pregnant women in this region is ten times higher than the previously quoted figures in metropolitan areas of Australia.

Neonatal amniotic fluid aspiration syndrome underdiagnosed?

Aspiration of uncontaminated amniotic fluid as a cause of significant respiratory distress in neonates is not well documented. We report a term neonate who presented with severe respiratory distress soon after birth. The diagnosis of amniotic fluid aspiration was confirmed at autopsy. Implications of this diagnosis in the management of neonates with respiratory distress are discussed.

A regional study of underlying congenital diseases in term neonates with necrotizing enterocolitis.

AIM OF THE STUDY: The aetiology of necrotizing enterocolitis (NEC) remains poorly understood in infants of all gestation, particularly when it occurs at term. We hypothesize that NEC in term infants is rare but often associated with underlying congenital illnesses. METHOD: Records of all term infants hospitalized with radiologically or surgically proven NEC in the 10 tertiary centres of two geographical regions of Australia during a 6.5-y period were reviewed. Regional birth data were obtained and a special care nursery survey was conducted. RESULTS: Twenty-nine infants had proven NEC giving a population incidence of 0.05 per 1000 live births. Nineteen (66%) of them had underlying congenital diseases. Five (17%) infants had endocrine disorders, which included panhypopituitarism, hypothyroidism, hypoparathyroidism and congenital adrenal hyperplasia. Ten infants had congenital heart disease, eight being cyanotic. Six of them developed NEC prior to any invasive cardiac procedures. Seven of the other nine infants without any congenital diseases had perinatal risk factors associated with NEC. The severity of illness was not different amongst the three groups. All infants, except two, survived. CONCLUSION: NEC in term infants is commonly secondary to or preceded by underlying congenital diseases. A considerable proportion of NEC cases had co-existing endocrine illnesses.

Randomised controlled trial of cisapride in feed intolerance in preterm infants.

AIM: To assess the efficacy of cisapride in reducing the time required to establish enteral feeds in preterm infants. METHODS: A randomised, double blind, placebo controlled trial was conducted of 34 infants of < or = 32 weeks of gestation, assigned to receive either cisapride 0.2 mg/kg/dose four times daily (n = 18) or placebo (n = 16). RESULTS: The time taken by the babies to tolerate full enteral feeds was not significantly different between the groups (median 9.5 days vs 10 days). There was a significantly lower incidence of large gastric residuals and regurgitation in the treated group compared with the placebo group. The number of episodes of large gastric residuals per infant was also significantly less. No adverse effects were noted. CONCLUSION: The routine use of cisapride in preterm infants cannot be recommended to decrease the time to establish enteral feeds. Its use may be justified for clinically significant gastric stasis or regurgitation.

Vitamin K in preterm breastmilk with maternal supplementation.

Six healthy lactating mothers who gave birth to preterm infants at a median post conceptional age of 29.5 (range 26-30) weeks were given 2.5 mg phylloquinone (vitamin K1) orally daily for 2 weeks beginning at a median postconceptional age of 31.5 (range 28-32) weeks. Phylloquinone was measured in the breastmilk daily for 14 d. Trough plasma phylloquinone concentrations were also determined on four occasions. Phylloquinone levels in the breastmilk increased from a baseline of 3 +/- 2.3 ng ml(-1) to 22.6 +/- 16.3 ng ml(-1) (mean +/- SD) after the first dose (p < 0.05); a gradual increase was noted until phylloquinone levels reached a plateau of 64.2 +/- 31.4 ng ml(-1) after the sixth daily dose.