A Survey of Neonatal Nurses on Mydriatic Regimens Used in Neonatal Retinopathy of Prematurity Eye Examinations.

OBJECTIVE: This study was aimed to determine mydriatic regimen(s) used in neonatal units in Aotearoa, New Zealand (NZ), and Australia and to estimate the frequency of adverse drug events following mydriatic administration in preterm neonates. STUDY DESIGN: A cross-sectional survey was sent to neonatal nursing staff listed in the Australian and New Zealand Neonatal Network contact list. Participants were asked to state what mydriatic regimen they use, and to estimate the frequency of adverse drug events when eye drops were administered for retinopathy of prematurity eye examinations (ROPEE). RESULTS: Thirteen different mydriatic regimens were identified; phenylephrine 2.5% and cyclopentolate 0.5% (1 standard drop of each) was the most commonly used regimen. Two of the regimens exceeded adult doses and five regimens included a mydriatic that is equivalent to an adult dose. Following mydriatic instillation, the three most common adverse effects were apnea, tachycardia, and periorbital pallor. CONCLUSION: Low-concentration single-microdrop regimens are currently in use and resulting in successful ROPEE, yet doses exceeding adult doses are in use throughout Aotearoa, NZ, and Australian units. We know from this dataset that neonates are experiencing unwanted and potentially preventable, adverse effects associated with mydriatics, and every effort should be made to minimize this risk. KEY POINTS: · Thirteen different regimens are in use in Aotearoa, NZ, and Australia.. · Three regimens use doses in excess of adult doses.. · Phenylephrine 2.5% and cyclopentolate 0.5% (one standard drop of each) is the most common regimen.

Plasma ammonia concentrations in extremely low birthweight infants in the first week after birth: secondary analysis from the ProVIDe randomized clinical trial.

BACKGROUND: Little is known about normative ammonia concentrations in extremely low birthweight (ELBW) babies and whether these vary with birth characteristics. We aimed to determine ammonia concentrations in ELBW babies in the first week after birth and relationships with neonatal characteristics and protein intake. METHODS: Arterial blood samples for the measurement of plasma ammonia concentration were collected within 7 days of birth from ProVIDe trial participants in six New Zealand neonatal intensive care units. RESULTS: Three hundred and twenty-two babies were included. Median (range) gestational age was 25.7 (22.7-31.6) weeks. Median (interquartile range (IQR)) ammonia concentration was 102 (80-131) µg/dL. There were no statistically significant associations between ammonia concentrations and birthweight or sex. Ammonia concentrations were weakly correlated with mean total (Spearman's rs = 0.11, P = 0.047) and intravenous (rs = 0.13, P = 0.02) protein intake from birth, gestational age at birth (rs = -0.13, P = 0.02) and postnatal age (rs = -0.13, P = 0.02). CONCLUSIONS: Plasma ammonia concentrations in ELBW babies are similar to those of larger and more mature babies and only weakly correlated with protein intake. Currently, recommended thresholds for investigation of hyperammonaemia are appropriate for ELBW babies. Protein intake should not be limited by concerns about potential hyperammonaemia.

Standardised neonatal parenteral nutrition formulations - Australasian neonatal parenteral nutrition consensus update 2017.

BACKGROUND: The first consensus standardised neonatal parenteral nutrition formulations were implemented in many neonatal units in Australia in 2012. The current update involving 49 units from Australia, New Zealand, Singapore, Malaysia and India was conducted between September 2015 and December 2017 with the aim to review and update the 2012 formulations and guidelines. METHODS: A systematic review of available evidence for each parenteral nutrient was undertaken and new standardised formulations and guidelines were developed. RESULTS: Five existing preterm Amino acid-Dextrose formulations have been modified and two new concentrated Amino acid-Dextrose formulations added to optimise amino acid and nutrient intake according to gestation. Organic phosphate has replaced inorganic phosphate allowing for an increase in calcium and phosphate content, and acetate reduced. Lipid emulsions are unchanged, with both SMOFlipid (Fresenius Kabi, Australia) and ClinOleic (Baxter Healthcare, Australia) preparations included. The physicochemical compatibility and stability of all formulations have been tested and confirmed. Guidelines to standardise the parenteral nutrition clinical practice across facilities have also been developed. CONCLUSIONS: The 2017 PN formulations and guidelines developed by the 2017 Neonatal Parenteral Nutrition Consensus Group offer concise and practical instructions to clinicians on how to implement current and up-to-date evidence based PN to the NICU population.

Genomic Analysis of Multiresistant Staphylococcus capitis Associated with Neonatal Sepsis.

Coagulase-negative staphylococci (CoNS), such as Staphylococcus capitis, are major causes of bloodstream infections in neonatal intensive care units (NICUs). Recently, a distinct clone of S. capitis (designated S. capitis NRCS-A) has emerged as an important pathogen in NICUs internationally. Here, 122 S. capitis isolates from New Zealand (NZ) underwent whole-genome sequencing (WGS), and these data were supplemented with publicly available S. capitis sequence reads. Phylogenetic and comparative genomic analyses were performed, as were phenotypic assessments of antimicrobial resistance, biofilm formation, and plasmid segregational stability on representative isolates. A distinct lineage of S. capitis was identified in NZ associated with neonates and the NICU environment. Isolates from this lineage produced increased levels of biofilm, displayed higher levels of tolerance to chlorhexidine, and were multidrug resistant. Although similar to globally circulating NICU-associated S. capitis strains at a core-genome level, NZ NICU S. capitis isolates carried a novel stably maintained multidrug-resistant plasmid that was not present in non-NICU isolates. Neonatal blood culture isolates were indistinguishable from environmental S. capitis isolates found on fomites, such as stethoscopes and neonatal incubators, but were generally distinct from those isolates carried by NICU staff. This work implicates the NICU environment as a potential reservoir for neonatal sepsis caused by S. capitis and highlights the capacity of genomics-based tracking and surveillance to inform future hospital infection control practices aimed at containing the spread of this important neonatal pathogen.

tuf Gene Sequence Variation in Bifidobacterium longum subsp. infantis Detected in the Fecal Microbiota of Chinese Infants.

Members of the bacterial genus Bifidobacterium generally dominate the fecal microbiota of infants. The species Bifidobacterium longum is prevalent, but the B. longum subsp. longum and B. longum subsp. infantis strains that are known to colonize the infant bowel are not usually differentiated in microbiota investigations. These subspecies differ in their capacities to metabolize human milk oligosaccharides (HMO) and may have different ecological and symbiotic roles in humans. Quantitative PCR provides a quick analytical method by which to accurately ascertain the abundances of target species in microbiotas and microcosms. However, amplification targets in DNA extracted from samples need to be dependably differential. We evaluated the tuf gene sequence as a molecular target for quantitative PCR measurements of the abundances of B. longum subsp. infantis and B. longum subsp. longum in fecal microbiotas. This approach resulted in the detection of a tuf gene variant (operational taxonomic unit 49 [OTU49]) in Chinese infants that has sequence similarities to both B. longum subsp. infantis and B. longum subsp. longum We compared the genome sequence and growth and transcriptional characteristics of an OTU49 isolate cultured in HMO medium to those of other B. longum subsp. infantis cultures. We concluded from these studies that OTU49 belongs to B. longum subsp. infantis, that dependable quantitative PCR (qPCR) differentiation between the B. longum subspecies cannot be achieved by targeting tuf gene sequences, and that functional genes involved in carbohydrate metabolism might be better targets because they delineate ecological functions.IMPORTANCE High-throughput DNA sequencing methods and advanced bioinformatics analysis have revealed the composition and biochemical capacities of microbial communities (microbiota and microbiome), including those that inhabit the gut of human infants. However, the microbiology and function of natural ecosystems have received little attention in recent decades, so an appreciation of the dynamics of gut microbiota interactions is lacking. With respect to infants, rapid methodologies, such as quantitative PCR, are needed to determine the prevalences and proportions of different bifidobacterial species in observational and microcosm studies in order to obtain a better understanding of the dynamics of bifidobacterial nutrition and syntrophy, knowledge that might be used to manipulate the microbiota and perhaps ensure the better health of infants.

Oxygen saturation and outcomes in preterm infants.

BACKGROUND: The clinically appropriate range for oxygen saturation in preterm infants is unknown. Previous studies have shown that infants had reduced rates of retinopathy of prematurity when lower targets of oxygen saturation were used. METHODS: In three international randomized, controlled trials, we evaluated the effects of targeting an oxygen saturation of 85 to 89%, as compared with a range of 91 to 95%, on disability-free survival at 2 years in infants born before 28 weeks' gestation. Halfway through the trials, the oximeter-calibration algorithm was revised. Recruitment was stopped early when an interim analysis showed an increased rate of death at 36 weeks in the group with a lower oxygen saturation. We analyzed pooled data from patients and now report hospital-discharge outcomes. RESULTS: A total of 2448 infants were recruited. Among the 1187 infants whose treatment used the revised oximeter-calibration algorithm, the rate of death was significantly higher in the lower-target group than in the higher-target group (23.1% vs. 15.9%; relative risk in the lower-target group, 1.45; 95% confidence interval [CI], 1.15 to 1.84; P=0.002). There was heterogeneity for mortality between the original algorithm and the revised algorithm (P=0.006) but not for other outcomes. In all 2448 infants, those in the lower-target group for oxygen saturation had a reduced rate of retinopathy of prematurity (10.6% vs. 13.5%; relative risk, 0.79; 95% CI, 0.63 to 1.00; P=0.045) and an increased rate of necrotizing enterocolitis (10.4% vs. 8.0%; relative risk, 1.31; 95% CI, 1.02 to 1.68; P=0.04). There were no significant between-group differences in rates of other outcomes or adverse events. CONCLUSIONS: Targeting an oxygen saturation below 90% with the use of current oximeters in extremely preterm infants was associated with an increased risk of death. (Funded by the Australian National Health and Medical Research Council and others; BOOST II Current Controlled Trials number, ISRCTN00842661, and Australian New Zealand Clinical Trials Registry numbers, ACTRN12605000055606 and ACTRN12605000253606.).

Why do parents decline newborn intramuscular vitamin K prophylaxis?

OBJECTIVE: To explore the influencing factors and reasoning of parents who opt out of intramuscular vitamin K prophylaxis for their newborn. DESIGN: We conducted a qualitative study with 15 families from the Otago/Southland region of New Zealand. Semistructured interviews explored their choice to opt out of intramuscular vitamin K prophylaxis and thematic analysis was used to elucidate themes that captured important aspects of this parental decision-making process. RESULTS: Parents opt out of intramuscular vitamin K for a variety of reasons. These were clustered into three main themes: parents' beliefs and values (philosophy and spirituality), concerns about their child's welfare (pain and potential side effects) and external influencing factors (family, friends, media and health professionals). As part of a wider family hesitancy towards medical intervention, the majority of parents also raised concerns regarding other perinatal or childhood interventions. CONCLUSION: Many factors influence parental decision making and lead to a decision to opt out of newborn intramuscular vitamin K prophylaxis. Due to strong parallels with other common childhood interventions, these findings have relevance for vitamin K prophylaxis and for other healthcare interventions in childhood.

Effect of gestational age and blood glucose on C-peptide excretion rate and clearance in neonates.

AIMS: The aim of this study was to measure urinary C-peptide concentrations, and then calculate C-peptide clearance (Cl), and excretion rate (UER) in neonates. In addition, the effect of gestational age (GA) and blood glucose levels (BGL) on C-peptide UER were investigated. METHODS: Insulin concentrations in plasma and C-peptide concentrations were measured in plasma and urine, in 20 neonates. Chemiluminescent immunoassays were used for insulin and C-peptide measurements, with urine diluted to 40% with bovine serum albumin 1% in phosphate buffered saline. Urine volume and time of collection were recorded and used to calculate UER and Cl. RESULTS: The mean Cl of C-peptide was 0.309 ± 0.329 mL/min/kg, and UER was 0.0329 ± 0.0342 pmol/min/kg. Correlations between Cl or UER and GA were not significant (P > 0.05). No significant correlation was shown between Cl or UER and BGL (P > 0.05). CONCLUSIONS: Both Cl and UER were highly variable in neonates, but were not correlated with GA. Additionally, BGL did not appear to affect C-peptide UER and Cl. As GA and BGL did not appear to affect Cl and UER, urinary C-peptide may provide a non-invasive method of measuring insulin production in neonates.

Declining newborn intramuscular vitamin K prophylaxis predicts subsequent immunisation refusal: A retrospective cohort study.

AIM: Low rates of childhood immunisation are linked to outbreaks of infectious disease. Identifying and addressing barriers to immunisation may lead to improved immunisation rates. Immunisation and newborn vitamin K prophylaxis have many similarities. We aimed to investigate whether parents who decline newborn vitamin K are also more likely to decline subsequent childhood immunisations. METHODS: We undertook a retrospective cohort study, examining the relationship between vitamin K administration and immunisation uptake by parents of babies born over a 2-year period (January 2010-December 2011) in Dunedin, New Zealand (NZ). Both written and electronic data from a single birthing unit and the NZ National Immunisation Register (NIR) were analysed to ascertain the relationship between declining newborn vitamin K prophylaxis and subsequent immunisation uptake. RESULTS: Records for 3575 babies were examined. Ninety-two per cent of infants received intramuscular, and 5% received oral vitamin K. An increased risk ratio for non-immunisation of 14.1 (95% confidence interval 7.8-25.9) for babies whose parents declined vitamin K was identified. Receiving oral vitamin K was also associated with subsequent non-immunisation, with a risk ratio of 3.5 (95% confidence interval 1.7-7.3). CONCLUSIONS: Parents who decline newborn vitamin K are more likely to decline immunisation for their child. These parents, as well as those that elect for oral vitamin K, are a small but easily identifiable group to whom additional education about the benefits of immunisation could be offered. This is especially pertinent at a time when there is a resurgence of immunisation preventable diseases.

Randomized controlled trial of oxygen saturation targets in very preterm infants: two year outcomes.

OBJECTIVE: To assess whether an oxygen saturation (Spo2) target of 85%-89% compared with 91%-95% reduced the incidence of the composite outcome of death or major disability at 2 years of age in infants born at <28 weeks' gestation. STUDY DESIGN: A total 340 infants were randomized to a lower or higher target from <24 hours of age until 36 weeks' gestational age. Blinding was achieved by targeting a displayed Spo2 of 88%-92% using a saturation monitor offset by ±3% within the range 85%-95%. True saturations were displayed outside this range. Follow-up at 2 years' corrected age was by pediatric examination and formal neurodevelopmental assessment. Major disability was gross motor disability, cognitive or language delay, severe hearing loss, or blindness. RESULTS: The primary outcome was known for 335 infants with 33 using surrogate language information. Targeting a lower compared with a higher Spo2 target range had no significant effect on the rate of death or major disability at 2 years' corrected age (65/167 [38.9%] vs 76/168 [45.2%]; relative risk 1.15, 95% CI 0.90-1.47) or any secondary outcomes. Death occurred in 25 (14.7%) and 27 (15.9%) of those randomized to the lower and higher target, respectively, and blindness in 0% and 0.7%. CONCLUSIONS: Although there was no benefit or harm from targeting a lower compared with a higher saturation in this trial, further information will become available from the prospectively planned meta-analysis of this and 4 other trials comprising a total of nearly 5000 infants.

Medical and midwifery attitudes towards vitamin K prophylaxis in New Zealand neonates.

AIM: Neonates are at risk for potentially life-threatening vitamin K deficiency bleeding. This can be readily prevented with prophylactic vitamin K following delivery. In this context, most vitamin K-deficiency bleeding occurs in those whose parents decline newborn vitamin K. One factor influencing parental decision-making is information received from health professionals. This study examined attitudes and perceptions towards newborn vitamin K in relevant health-care professionals. METHODS: A literature review and one-on-one semi-structured interviews were conducted to inform questionnaire design. Midwives and selected medical staff employed in the South Island of New Zealand were then invited to complete an anonymous survey exploring attitudes and perceptions towards vitamin K prophylaxis in newborns. RESULTS: The survey achieved an overall response rate of 57%. Almost all responding medical staff and 76% of midwives agreed with the current New Zealand Ministry of Health vitamin K guideline. All medical staff but only 55% of midwives feel that all babies should receive vitamin K. Differences were also seen between professionals with respect to vitamin K education and risks. CONCLUSION: This is the first study to examine attitudes and perceptions of midwives and doctors to vitamin K prophylaxis in neonates. Considerable discrepancies in attitude are evident, and in some midwives, a lack of confidence in this intervention is apparent. How this affects education to families is unknown. Increased understanding of this phenomenon, along with improved education and communication to professionals and families, is required.

Neonatal extravasation injury: prevention and management in Australia and New Zealand-a survey of current practice.

BACKGROUND: Extravasation injury remains an important cause of iatrogenic injury in neonatal intensive care. This study aims to describe the current approach to extravasation injury (EI) prevention and management in Neonatal Intensive Care Units (NICUs) in Australia and New Zealand. METHODS: A literature review regarding extravasation injury in the newborn was carried out to inform questionnaire design. An internet-based survey was then conducted with the clinical directors of the 27 tertiary NICUs in Australia and New Zealand. RESULTS: The survey received a 96% response rate. Approximately two thirds of Australian and New Zealand NICUs have written protocols for prevention and management of extravasation injury. Considerable practice variation was seen for both prevention and treatment of EI. 92% of units had experienced cases of significant EI. CONCLUSIONS: Australian and New Zealand tertiary neonatal units clearly recognise EI as an important cause of iatrogenic morbidity and mortality. Significant variation still exists among units with regards to guidelines for both prevention and management of EI. We recommend that neonatal staff should remain vigilant, ensuring that guidelines for the prevention and treatment of EI are available, and rigorously followed.

Low dose or very low dose phenylephrine and cyclopentolate microdrops for retinopathy of prematurity eye examinations (The Little Eye Drop Study): a randomised controlled non-inferiority trial.

OBJECTIVE: To determine if very low dose (VLD, 0.5% phenylephrine, 0.1% cyclopentolate) mydriatic microdrop (approximately 7 µL) administration (up to three doses) is non-inferior to low dose (LD, 1% phenylephrine, 0.2% cyclopentolate) mydriatic microdrop administration for ophthalmologist-determined successful retinopathy of prematurity eye examination (ROPEE). DESIGN: Multicentre, prospective, randomised controlled, non-inferiority clinical trial. SETTING: Four neonatal intensive care units in Aotearoa, New Zealand from October 2019 to September 2021. PATIENTS: Infants with a birth weight less than 1250 g or gestational age less than 30+6 weeks and who required a ROPEE. INTERVENTIONS: The intervention: microdrop (approximately 7 µL) of VLD (0.5% phenylephrine and 0.1% cyclopentolate) to both eyes, or the comparison: microdrop of LD (1% phenylephrine and 0.2% cyclopentolate) to both eyes. Up to three doses could be administered. MAIN OUTCOME MEASURES: The primary outcome measure was an ophthalmologist-determined successful ROPEE. RESULTS: One hundred and fifty preterm infants (LD mean GA=27.4±1.8 weeks, mean birth weight=1011±290 g, VLD mean GA=27.5±1.9 weeks, mean birth weight=1049±281 g,) were randomised. Non-inferiority for successful ROPEE was demonstrated for the VLD group compared with the LD group (VLD successful ROPEE=100%, LD successful ROPEE=100%, 95% CI no continuity correction -0.05 to 0.05) and for Maori (95% CI no continuity correction -0.02 to 0.19). CONCLUSION: VLD microdrops enable safe and effective screening for ROPEE in both Maori and non-Maori preterm infants. TRIAL REGISTRATION NUMBER: ACTRN12619000795190.

Premedication for neonatal intubation in Australia and New Zealand: a survey of current practice.

AIM: This study aims to describe the current approach to intubation premedication in neonatal intensive care units (NICUs) in Australia and New Zealand. METHODS: A literature review regarding intubation premedication in the newborn was carried out to inform questionnaire design. A web-based survey of 28 NICUs and two neonatal emergency transport services was conducted and supplemented by telephone contact to ensure completion. RESULTS: All the tertiary NICUs and neonatal emergency transport services in Australia and New Zealand use premedication for elective intubation of neonates. Eighty per cent of units have a written policy. There were 28 of 30 units (93%) that use muscle relaxants, mostly suxamethonium. The choice of sedative medication is varied. CONCLUSIONS: Australian and New Zealand neonatal units have a high use of intubation premedication including muscle relaxants, but vary considerably in their choice of sedative medication.

Randomised controlled pilot trial comparing low dose and very low- dose microdrop administration of phenylephrine and cyclopentolate for retinopathy of prematurity eye examinations in neonates.

AIMS: To determine ifVery low dose mydriatic eye microdrop regimen sufficiently dilates the pupil (above 4.1 mm) compared with the currently used low dose mydriatic eye microdrop regimen.Cardiovascular, gastrointestinal and respiratory adverse effects occur following eye drop instillation. METHODS: Seventeen premature infants were recruited into this prospective, randomised controlled pilot trial in January 2017 to November 2018. Data were collected from the single-centre Neonatal Intensive Care Unit, Dunedin Hospital, New Zealand. The inclusion criteria were birth weight less than 1500 g or gestational age less than 31 weeks, or any premature infant requiring red reflex testing. Infants were randomised to receive either phenylephrine 1% or 0.5% and cyclopentolate 0.2% or 0.1%, 1 microdrop in both eyes. Efficacy outcome measures were pupil size at retinopathy of prematurity eye examination (ROPEE) and ophthalmologist rating of ease of screen. RESULTS: All participants had sufficient pupillary dilation for a successful ROPEE. Ophthalmologists rated the ROPEE as easy for 90% of all examinations. Pupil dilation measurements at the time of examination, mean±SD, 4.8±0.2 (95% CI 4.5 to 5.2) mm for treatment A and 5±0.2 (95%CI 4.6 to 5.4) mm for treatment B (p=0.61). There were no statistically significant differences between the groups for safety data. CONCLUSIONS: Very low dose microdrop administration of phenylephrine and cyclopentolate appears to be effective at sufficiently dilating the neonatal pupil for ROPEEs. Low dose and very low dose microdrop mydriatic regimens may also reduce the risk of unwanted adverse effects associated with these medicines. TRIAL REGISTRATION NUMBER: Australian New Zealand Clinical Trials Registry (reference ACTRN12616001266459p).

Probiotics for Prevention of Severe Necrotizing Enterocolitis: Experience of New Zealand Neonatal Intensive Care Units.

Introduction: Necrotizing enterocolitis (NEC) affects mainly preterm infants, has a multifactorial etiology and is associated with intestinal dysbiosis and disordered immunity. Use of probiotics for prophylaxis is beneficial with studies indicating reduction in NEC ≥ stage 2, late onset sepsis (LOS) and mortality. However, not all studies have shown a reduction, there are questions regarding which probiotic to use, whether infants <1,000 g benefit and the risk of probiotic sepsis. All neonatal intensive care units in New Zealand (NZ) use probiotics and contribute to an international database (Australian and New Zealand Neonatal Network or ANZNN). Objective: To use ANZNN data to investigate the experience of NZ neonatal units with probiotics for NEC prevention in a setting where the baseline incidence of severe NEC was low, to compare results of 2 commonly used probiotic regimes and report on the extremely low birth weight subgroup. Method: Outcomes before (Pre group 2007-2010) and after (Probiotic group 2013-2015) starting routine probiotics for preterm infants <1,500 g or <32 weeks were compared. Clinicians reviewed cases to ensure they met database criteria. Five units used Infloran (Bifidobacterium bifidum and Lactobacillus acidophilus) and 1 unit used Lactobacillus GG (LGG) and bovine lactoferrin (bLF). Results: Four thousand five hundred and twenty nine infants were included and Pre and Probiotic groups were well-balanced with regard to gestation, birth weight and gender. The incidence of NEC in the Probiotic group was 1.6 and 2.7% in the pre group (corrected OR 0.62 CI 0.41-0.94). There was one case of probiotic sepsis. There was no significant difference between the Infloran and LGG/bLF combinations in regard to observed NEC rates. Late onset sepsis rates were significantly lower in the Probiotic group (p < 0.01). Conclusions: Introduction of probiotics for preterm infants in NZ has been associated with significant reductions in NEC and late onset sepsis.

Risk factors for Staphylococcus capitis pulsotype NRCS-A colonisation among premature neonates in the neonatal intensive care unit of a tertiary-care hospital: a retrospective case-control study.

BACKGROUND: A S. capitis strain called NRCS-A (S. capitis NRCS-A) has emerged as a cause of bloodstream infections and sepsis in neonatal intensive care units (NICUs) worldwide. AIM: To identify risk factors for S. capitis NRCS-A colonisation among neonates, Dunedin Hospital NICU, Dunedin, New Zealand, from September 2013 through March 2015. METHODS: Weekly axillary swabs categorised eligible neonates as a case or a control. A case was defined as a week ending with a neonate's first positive swab for S. capitis NRCS-A and a control as a week in which a neonate remained negative. Weekly exposures were abstracted from hospital medical records. Analyses were performed using conditional logistic regression. FINDINGS: The median (range) gestational age at birth of participants was 32.7 (23.1-41.3) weeks. Participants contributed 26 weeks of case data and 177 weeks of control data. On adjusted analysis compared with matched controls, cases had higher odds of requiring invasive mechanical ventilation (OR 3.6, 95% CI: 1.1-11.6, p=0.035) and of a patent ductus arteriosus (PDA) (OR 3.0, 95% CI: 1.0-9.0, p=0.044). Cases had lower odds of being part of a multiple birth (OR 0.24, 95% CI 0.08-0.73, p=0.001), having an area of inflamed skin (OR 0.31, 95% CI: 0.13-0.75, p=0.009), and specifically an area of inflamed axillary skin (OR 0.08, 95% CI: 0.01-0.50, p=0.006). CONCLUSIONS: We found that premature neonates with invasive mechanical ventilation and PDA had greater odds for S. capitis NRCS-A colonisation. Transmission may be mediated by increased staff contact, but prospective research is needed to confirm this.

Individualised dosing of amikacin in neonates: a pharmacokinetic/pharmacodynamic analysis.

PURPOSE: To examine the pharmacokinetics of amikacin and its pharmacokinetic pharmacodynamic (PKPD) relationship in neonates. To develop an alternative dosing strategy for amikacin in neonates. METHODS: A population PKPD analysis was performed using data collected from 80 neonates with gestational ages from 24 to 41 weeks. The final pharmacokinetic model analysed 358 amikacin concentrations. All neonates were > 72 hours postnatal age. Simulations were performed to develop a new dosing strategy. RESULTS: The final covariate model was clearance = 0.23 x (current weight/2)(0.691) x (postmenstrual age/40)(3.23) and volume of distribution = 0.957 x (current weight/2)(0.89). Following the logistic regression analysis of treatment failure, new amikacin target concentrations were estimated and used in development of an alternative dosing strategy. CONCLUSION: Simulation of a new dosing regimen yielded the following recommendations: 15 mg/kg at 36-h intervals, 14 mg/kg at 24-h intervals and 15 mg/kg at 24-h intervals for neonates < or = 28 weeks, 29-36 weeks and > or = 37 weeks postmenstrual age respectively.