ORCID Profile
0000-0001-5648-468X
Current Organisations
University of Sydney
,
Western Sydney Local Health District
,
University of New South Wales
,
University of Otago
,
Royal Australasian College of Physicians
,
University of London
,
Australasian Society for Ultrasound in Medicine
,
London School of Hygiene and Tropical Medicine
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Publications
Liberal hemoglobin threshold affects cerebral arterial pulsed Doppler and cardiac output, not cerebral tissue oxygenation: a prospective cohort study in anemic preterm infants
Publisher: Wiley
Date: 16-07-2019
DOI: 10.1111/TRF.15452
Abstract: Red blood cell (RBC) transfusion is a standard treatment for anemia of prematurity. Cerebral tissue oxygenation and blood flow velocities improve when a restrictive transfusion threshold is followed, but little is known about the effect of practicing a liberal transfusion threshold on cerebral tissue oxygenation, cerebral blood flow velocities, and cardiac output measurements. A prospective observational study of preterm infants under 32 weeks' gestation who received RBC transfusion. Monitoring was performed immediately before, immediately after, and 24 hours after transfusion. Data obtained included physiologic parameters, cerebral tissue oxygenation index (TOI), anterior and middle cerebral artery pulsed Doppler ultrasound measurements, and cardiac output measurements. Data were analyzed using analysis of variance for repeated measures. Fifty RBC transfusion episodes in 40 preterm infants were monitored. The mean gestational age was 26.72 weeks (±1.6 weeks), and the mean birth weight was 855.25 g (±190.7 g). We did not observe significant changes in cerebral TOI (pretransfusion mean TOI = 70.5 [11.54], immediately after transfusion = 71.38 [12.51], [p = 0.924 95% confidence interval (CI), -4.64 to 6.39], and 24 hours after transfusion = 75.64 [14.4] [p = 0.07 95% CI, -0.37 to 10.65]), cerebral fractional tissue oxygen extraction (pretransfusion = 0.25 [0.12], immediately after transfusion = 0.24 [0.13], and 24 hours after transfusion = 0.20 [0.15]), cerebral resistive index, cerebral pulsatility index, or right ventricular output. Statistically significant changes were observed immediately after transfusion in peak systolic velocity, end-diastolic velocity and time-averaged maximum velocity in the cerebral arterial circulation. Left ventricular output (pretransfusion = 374.32 mL/kg/min, immediately after transfusion = 346.67 mL/kg/min [p = 0.000 95% CI, -39.61 to -15.68], and 24 hours after transfusion = 361.17 mL/kg/min [p = 0.027 95% CI, -25.11 to -1.18]) and heart rate (pretransfusion = 163.37 [9.49], immediately after transfusion = 157.29 [10.2] [p = 0.000 95% CI, -8.96 to -3.20], and 24 hours after transfusion = 160.40 [10.4] [p = 0.041 95% CI, -5.85 to -0.09]) showed statistically significant changes throughout the monitoring period. Our findings show that practicing liberal transfusion thresholds did not improve cerebral TOI in preterm infants who have mild anemia, but it did improve the compensatory response in cerebral arterial blood flow and cardiac output.
Are there changes to regional tissue oxygenation and circulation following umbilical artery catheter placement? A prospective cohort study in newborn infants
Publisher: Wiley
Date: 12-11-2019
DOI: 10.1111/JPC.14679
Abstract: The use of umbilical arterial catheters (UACs) is a standard of care in monitoring critically unwell infants. Serious vascular complications are rare but when they do occur, they can be associated with significant morbidity, risking limb loss or even death. Near infra-red spectroscopy has the potential to monitor limb perfusion. Our study investigates changes in tissue oxygenation and perfusion in the abdominal and leg circulation following UAC insertion. A prospective observational study performing ultrasound pulsed Doppler measurements in the coeliac, superior mesenteric artery, renal arteries and the femoral arteries as well as near infrared spectroscopy measurements of both thighs at three time points (immediately before = Time 1, 1 h after = Time 2 and 24 h after UAC insertion = Time 3). We monitored 30 infants, the mean gestational age was 30 weeks (24-41) and the mean birthweight was 1720 g (600-4070 g). We observed statistically significant changes (P < 0.05) in pulse Doppler measurements in coeliac (mean peak systolic velocity (PSV): Time 1 = 70.51, Time 2 = 61.75 resistive index (RI): Time 1 = 0.75, Time 2 = 0.67), superior mesenteric (PSV: Time 1 = 41.72, Time 2 = 36.10 RI: Time 1 = 0.92, Time 2 = 0.87), renal (same side end-diastolic velocity: Time 1 = 1.98, Time 2 = 3.80 RI: Time 1 = 0.93, Time 2 = 0.87 opposite side end-diastolic velocity: Time 1 = 2.62, Time 2 = 3.84 RI: Time 1 = 0.92, Time 2 = 0.85) and femoral arteries (same side PSV: Time 1 = 72.75, Time 2 = 62.18 opposite side PSV: Time 1 = 81.89, Time 2 = 62.74). Tissue oxygenation in lower limbs remained unaffected (same side (mean): Time 1 = 68.59, Time 2 = 68.99, Time 3 = 66.40, opposite side: Time 1 = 67.72, Time 2 = 66.92, Time 3 = 65.40). All infants on clinical examination had normal lower limb perfusion, lower limb arterial pulses and normal perfusion to the gluteal region before and after insertion of UAC. While sub-clinical changes in perfusion occur in abdominal and leg circulation, these changes are not consistent across vessels and regional tissue oxygenation remains unaffected.
Ventilator-delivered mask ventilation compared with three standard methods of mask ventilation in a manikin model
Publisher: BMJ
Date: 07-06-2011
Abstract: Little is known regarding the variations in effective ventilation during bag and mask resuscitation with standard methods compared with that delivered by ventilator-delivered mask ventilation (VDMV). To measure the variations in delivered airway pressure, tidal volume (TV), minute ventilation (MV) and inspiratory time during a 3-min period of mask ventilation comparing VDMV with three commonly used hand-delivered methods of bag and mask ventilation: Laerdal self-inflating bag (SIB) anaesthetic bag and T-piece Neopuff. A modified resuscitation manikin was used to measure variation in mechanical ventilation during 3-min periods of mask ventilation. Thirty-six experienced practitioners gave positive pressure mask ventilation targeting acceptable chest wall movement with a rate of 60 inflations/min and when pressures could be targeted or set, a peak inspiratory pressure (PIP) of 18 cm water, positive end-expiratory pressure (PEEP) of 5 cm water, for 3 min with each of the four mask ventilation methods. Each mode was randomly sequenced. A total of 21 136 inflations were recorded and analysed. VDMV achieved PIP and PEEP closest to that targeted and significantly lower variation in all measured parameters (p<0.001) other than with PIP. SIB delivered TV and MV over twice that delivered by VDMV and Neopuff. During 3-min periods of mask ventilation on a manikin, VDMV produced the least variation in delivered ventilation. SIB produced wide variation and unacceptably high TV and MV in experienced hands.
Women's experiences of transfer from primary maternity unit to tertiary hospital in New Zealand: part of the prospective cohort Evaluating Maternity Units study
Publisher: Springer Science and Business Media LLC
Date: 12-2015
Randomised study of a new inline respiratory function monitor (Juno) to improve mask seal and delivered ventilation with neonatal manikins
Publisher: Cold Spring Harbor Laboratory
Date: 13-09-2023
Admission of term infants to neonatal intensive care: a population-based study
Publisher: Wiley
Date: 14-11-2007
Incomplete Exhalation during Resuscitation—Theoretical Review and Examples from Ventilation of Newborn Term Infants
Publisher: MDPI AG
Date: 28-06-2023
Abstract: Background: Newborn resuscitation guidelines recommend positive pressure ventilation (PPV) for newborns who do not establish effective spontaneous breathing after birth. T-piece resuscitator systems are commonly used in high-resource settings and can additionally provide positive end-expiratory pressure (PEEP). Short expiratory time, high resistance, rapid dynamic changes in lung compliance and large tidal volumes increase the possibility of incomplete exhalation. Previous publications indicate that this may occur during newborn resuscitation. Our aim was to study ex les of incomplete exhalations in term newborn resuscitation and discuss these against the theoretical background. Methods: Ex les of flow and pressure data from respiratory function monitors (RFM) were selected from 129 term newborns who received PPV using a T-piece resuscitator. RFM data were not presented to the user during resuscitation. Results: Ex les of incomplete exhalation with higher-than-set PEEP-levels were present in the recordings with visual correlation to factors affecting time needed to complete exhalation. Conclusions: Incomplete exhalation and the relationship to expiratory time constants have been well described theoretically. We documented ex les of incomplete exhalations with increased PEEP-levels during resuscitation of term newborns. We conclude that RFM data from resuscitations can be reviewed for this purpose and that incomplete exhalations should be further explored, as the clinical benefit or risk of harm are not known.
Newborn self-inflating manual resuscitators: precision robotic testing of safety and reliability
Publisher: BMJ
Date: 18-10-2019
DOI: 10.1136/ARCHDISCHILD-2018-315391
Abstract: A controlled bench test was undertaken to determine the performance variability among a range of neonatal self-inflating bags (SIB) compliant with current International Standards Organisation (ISO). Use of SIB to provide positive pressure ventilation during newborn resuscitation is a common emergency procedure. The United Nations programmes advocate increasing availability of SIB in low-income and middle-income nations and recommend devices compliant with ISO. No systematic study has evaluated variance in different models of neonatal SIB. 20 models of SIB were incrementally compressed by an automated robotic device simulating the geometry and force of a human hand across a range of precise distances in a newborn lung model. Significance was calculated using analysis of variance repeated measures to determine the relationship between distance of SIB compression and delivered ventilation. A pass/fail was derived from a composite score comprising: minimum tidal volume coefficient of variation (across all compression distances) peak pressures generated and functional compression distance. Ten out of the 20 models of SIB failed our testing methodology. Two models could not provide safe minimum tidal volumes (2.5–5 mL) six models exceeded safety inflation pressure limit cm H 2 O, representing 6% of their inflations five models had excessive coefficient of variation ( % averaged across compression distances) and three models did not deliver inflation volumes .5 mL until approximately 50% of maximum bag compression distance was reached. The study also found significant intrabatch variability and forward leakage. Compliance of SIBs with ISO standards may not guarantee acceptable or safe performance to resuscitate newborn infants.
Neonatal endotracheal intubation: How to make it more baby friendly
Publisher: Wiley
Date: 05-2016
DOI: 10.1111/JPC.13192
Abstract: Neonatal endotracheal intubation is commonly accompanied by significant disturbances in physiological parameters. The procedure is often poorly tolerated, and multiple attempts are commonly required before the airway is secured. Adverse physiological effects include hypoxemia, bradycardia, hypertension, elevation in intracranial pressure and possibly increase in pulmonary vascular resistance. Use of premedications to facilitate intubation has been shown to reduce but not eliminate these effects. Other important preventative factors include adequate training of the operators and guidelines to limit the duration of attempts. Pre-intubation stabilisation with optimal bag and mask ventilation should allow for better neonatal tolerance of the procedure. Recent research has described significant mask leak and airway obstruction compromising efficacy of neonatal mask ventilation. Further research should help in elucidating mask ventilation techniques which minimise mask leak and airway obstruction.
Postnatal lactate as an early predictor of short-term outcome after intrapartum asphyxia
Publisher: Springer Science and Business Media LLC
Date: 22-12-2004
T-piece resuscitators: how do they compare?
Publisher: BMJ
Date: 04-05-2019
DOI: 10.1136/ARCHDISCHILD-2018-314860
Abstract: The T-piece resuscitator (TPR) has seen increased use as a primary resuscitation device with newborns. Traditional TPR design uses a high resistance expiratory valve to produce positive end expiratory pressure (PEEP) or continuous positive airway pressure (CPAP) at resuscitation. A new TPR device that uses a dual flow ratio valve (fluidic flip) to produce PEEP/CPAP is now available (rPAP). We aimed to compare the measured ventilation performance of different TPR devices in a controlled bench test study. Single operator provided positive pressure ventilation to an incremental testlung compliance (Crs) model (0.5–5 mL/cmH 2 O) with five different brands of TPR device (Atom, Neopuff, rPAP, GE Panda warmer and Draeger Resuscitaire). At recommended peak inflation pressure (PIP) 20 cmH 2 O, PEEP of 5 cmH 2 O and rate of 60 inflations per minute. 1864 inflations were analysed. Four of the five devices tested demonstrated inadvertent elevations in mean PEEP (5.5–10.3 cmH 2 O, p .001) from set value as Crs was increased, while one device (rPAP) remained at the set value. Measured PIP exceeded the set value in two infant warmer devices (GE and Draeger) with inbuilt TPR at Crs of 0.5 (24.5 and 23.5 cmH 2 O, p .001). Significant differences were seen in tidal volumes across devices particularly at higher Crs (p .001). Results show important variation in delivered ventilation from set values due to inherent TPR device design characteristics with a range of lung compliances expected at birth. Device-generated inadvertent PEEP and overdelivery of PIP may be clinically deleterious for term and preterm newborns or infants with larger Crs during resuscitation.
Caseload midwifery care versus standard maternity care for women of any risk: M@NGO, a randomised controlled trial
Publisher: Elsevier BV
Date: 11-2013
Spectral analysis of systemic and cerebral cardiovascular variabilities in preterm infants: relationship with clinical risk index for babies (CRIB)
Publisher: IOP Publishing
Date: 02-11-2011
DOI: 10.1088/0967-3334/32/12/003
Abstract: Frequency spectrum analysis of circulatory signals has been proposed as a potential method for clinical risk assessment of preterm infants by previous studies. In this study, we examined the relationships between various spectral measures derived from systemic and cerebral cardiovascular variabilities and the clinical risk index for babies (CRIB II). Physiological data collected from 17 early low birth weight infants within 1-3 h after birth were analysed. Spectral and cross-spectral analyses were performed on heart rate variability, blood pressure variability and cerebral near-infrared spectroscopy measures such as oxygenated and deoxygenated haemoglobins (HbO(2) and HHb) and tissue oxygenation index (TOI). In addition, indices related to cardiac baroreflex sensitivity and cerebral autoregulation were derived from the very low, low- and mid-frequency ranges (VLF, LF and MF). Moderate correlations with CRIB II were identified from mean arterial pressure (MAP) normalized MF power (r = 0.61, P = 0.009), LF MAP-HHb coherence (r = 0.64, P = 0.006), TOI VLF percentage power (r = 0.55, P = 0.023) and LF baroreflex gain (r = -0.61, P = 0.01 after logarithmic transformation), with the latter two parameters also highly correlated with gestational age (r = -0.75, P = 0.0005 and r = 0.70, P = 0.002, respectively). The relationships between CRIB II and various spectral measures of arterial baroreflex and cerebral autoregulation functions have provided further justification for these measures as possible markers of clinical risks and predictors of adverse outcome in preterm infants.
Mask leak in one-person mask ventilation compared to two-person in newborn infant manikin study
Publisher: BMJ
Date: 11-11-2011
Abstract: To compare a new two-person method (four hands) of delivering mask ventilation with a standard one-person method using the Laerdal self-inflating bag (SIB) and the Neopuff (NP) infant resuscitator in a manikin model. Recent studies of simulated neonatal resuscitation using bag and mask ventilation techniques have shown facemask leak levels of 55-57% in expert hands. 48 participants were randomly paired and instructed to give mask ventilation for a 2-min period as single-person resuscitators, then as two-person paired resuscitators at set pressures for NP and set parameters for SIB. Airway pressure, flow, inspiratory tidal volume, expiratory tidal volume and mask leak were recorded. A total of 21 578 inflations were recorded and analysed. For SIB, mask leak was greater (11.5%) with single-person compared to two-person (5.4% mean difference 6.1%, 95% CI 1.5 to 10.7, p<0.01). For NP, mask leak was greater for single-person (22.2%) compared to two-person (9.1% mean difference 13.1% 95% CI 3.6 to 22.6, p<0.01). For single-person mask ventilation, mask leak was greater with NP (22.2%) compared to SIB (11.5% mean difference 10.7%, 95% CI 1.4 to 19.7, p<0.01). For two-person mask ventilation, mask leak was greater for NP (9.1%) compared to SIB (5.4% mean difference 3.7%, 95% CI 0.1 to 6.4, p<0.05). Two-person mask ventilation technique reduces mask leak by approximately 50% compared to the standard one-person mask ventilation method. NP mask ventilation has higher mask leak than Laerdal SIB for both single- and two-person technique mask ventilation.
Cardiovascular impact of intravenous caffeine in preterm infants
Publisher: Wiley
Date: 23-05-2019
DOI: 10.1111/APA.14382
Abstract: To evaluate the acute effect of intravenous caffeine on heart rate and blood pressure variability in preterm infants. We extracted and compared linear and nonlinear features of heart rate and blood pressure variability at two time points: prior to and in the two hours following a loading dose of 10 mg/kg caffeine base. We studied 31 preterm infants with arterial blood pressure data and 25 with electrocardiogram data, and compared extracted features prior to and following caffeine administration. We observed a reduction in both scaling exponents (α 1 , α 2 ) of mean arterial pressure from detrended fluctuation analysis and an increase in the ratio of short‐ ( SD 1) and long‐term ( SD 2) variability from Poincare analysis ( SD 1/ SD 2). Heart rate variability analyses showed a reduction in α 1 (mean ( SD ) of 0.92 (0.21) to 0.86 (0.21), p 0.01), consistent with increased vagal tone. Following caffeine, beat‐to‐beat pulse pressure variability ( SD ) also increased (2.1 (0.64) to 2.5 (0.65) mmHg, p 0.01). This study highlights potential elevation in autonomic nervous system responsiveness following caffeine administration reflected in both heart rate and blood pressure systems. The observed increase in pulse pressure variability may have implications for caffeine administration to infants with potentially impaired cerebral autoregulation.
Maternal and perinatal outcomes amongst low risk women giving birth in water compared to six birth positions on land. A descriptive cross sectional study in a birth centre over 12 years
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.MIDW.2012.07.002
Abstract: the option of giving birth in water is available to most women in birth centres in Australia but there continues to be resistance in mainstream delivery wards due to safety concerns. Women in birth centres are more likely to give birth in upright positions and be attended by experienced midwives and obstetricians who are comfortable facilitating normal birth. The aim of this study was to determine rates of perineal trauma, postpartum haemorrhage and five-minute Apgar scores amongst low risk women in a birth centre who gave birth in water compared to six birth positions on land. this was a descriptive cross sectional study of births occurring in a large alongside Sydney birth centre from January 1996 to April 2008. Handwritten records were kept by midwives on each birth in the birth centre over twelve and a half years (n=6,144). Descriptive statistics and logistic regression were applied controlling for risk factors for perineal trauma, postpartum haemorrhage and the five-minute Apgar score. waterbirth (13%) and six main birth positions on land were identified: kneeling/all fours (48%), semi-recumbent (12%), lateral (5%), standing (8%), birth stool (10%) and squatting (3%). Compared to waterbirth, birth on a birth stool led to a higher rate of major perineal trauma (second, third, fourth degree tear and episiotomy) (OR 1.40 [1.12-1.75]) and postpartum haemorrhage (OR 2.04 [1.44-2.90]). Compared to waterbirth, babies born in a semi-recumbent position had a significantly greater incidence of five-minute Apgar scores <7 (OR 4.61 [1.29-16.52]). waterbirth does not lead to more infants born with Apgar score <7 at 5 mins when compared to other birth positions. Waterbirth provides advantages over the birth stool for maternal outcomes of major perineal trauma and postpartum haemorrhage.
Removal of sinks and bathing changes to control multi-drug resistant Gram negative bacteria in a neonatal intensive care unit: a retrospective investigation
Publisher: Elsevier BV
Date: 04-2020
Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model
Publisher: Wiley
Date: 10-03-2014
DOI: 10.1111/APA.12573
Abstract: To determine changes in respiratory mechanics when chest compressions are added to mask ventilation, as recommended by the International Liaison Committee on Resuscitation (ILCOR) guidelines for newborn infants. Using a Laerdal Advanced Life Support leak-free baby manikin and a 240-mL self-inflating bag, 58 neonatal staff members were randomly paired to provide mask ventilation, followed by mask ventilation with chest compressions with a 1:3 ratio, for two minutes each. A Florian respiratory function monitor was used to measure respiratory mechanics, including mask leak. The addition of chest compressions to mask ventilation led to a significant reduction in inflation rate, from 63.9 to 32.9 breaths per minute (p < 0.0001), mean airway pressure reduced from 7.6 to 4.9 cm H2 O (p < 0.001), minute ventilation reduced from 770 to 451 mL/kg/min (p < 0.0001), and there was a significant increase in paired mask leak of 6.8% (p < 0.0001). Adding chest compressions to mask ventilation, in accordance with the ILCOR guidelines, in a manikin model is associated with a significant reduction in delivered ventilation and increase in mask leak. If similar findings occur in human infants needing an escalation in resuscitation, there is a potential risk of either delay in recovery or inadequate response to resuscitation.
The effect of caffeine loading on cerebral autoregulation in preterm infants
Publisher: Wiley
Date: 10-12-2019
DOI: 10.1111/APA.14636
Abstract: To evaluate cerebral autoregulation changes in preterm infants receiving a loading dose of caffeine base. In a cohort of 30 preterm infants, we extracted measures of cerebral autoregulation using time and frequency domain techniques to determine the correlation between mean arterial pressure (MAP) and tissue oxygenation index (TOI) signals. These measures included the cerebral oximetry index (COx), cross‐correlation and coherence measures, and were extracted prior to caffeine loading and in the 2 hours following administration of 10 mg/kg caffeine base. We observed acute reductions in time domain correlation measures, including the cerebral oximetry index (linear mixed model coefficient −0.093, standard error 0.04 p = 0.028) and the detrended cross‐correlation coefficient (ρ 5 coefficient −0.13, standard error 0.055 p = 0.025). These reductions suggested an acute improvement in cerebral autoregulation. Features from detrended cross‐correlation analysis also showed greater discriminative value than other methods in identifying changes prior to and following caffeine administration. We observed a reduced correlation between MAP and TOI from near‐infrared spectroscopy following caffeine administration. These findings suggest an acute enhanced capacity for cerebral autoregulation following a loading dose of caffeine in preterm infants, contributing to our understanding of the physiological impact of caffeine therapy.
Evaluating Midwifery Units (EMU): A prospective cohort study of freestanding midwifery units in New South Wales, Australia
Publisher: BMJ
Date: 10-2014
DOI: 10.1136/BMJOPEN-2014-006252
Abstract: To compare maternal and neonatal birth outcomes and morbidities associated with the intention to give birth in two freestanding midwifery units and two tertiary-level maternity units in New South Wales, Australia. Prospective cohort study. 494 women who intended to give birth at freestanding midwifery units and 3157 women who intended to give birth at tertiary-level maternity units. Participants had low risk, singleton pregnancies and were at less than 28 +0 weeks gestation at the time of booking. Primary outcomes were mode of birth, Apgar score of less than 7 at 5 min and admission to the neonatal intensive care unit or special care nursery. Secondary outcomes were onset of labour, analgesia, blood loss, management of third stage of labour, perineal trauma, transfer, neonatal resuscitation, breastfeeding, gestational age at birth, birth weight, severe morbidity and mortality. Women who planned to give birth at a freestanding midwifery unit were significantly more likely to have a spontaneous vaginal birth (AOR 1.57 95% CI 1.20 to 2.06) and significantly less likely to have a caesarean section (AOR 0.65 95% CI 0.48 to 0.88). There was no significant difference in the AOR of 5 min Apgar scores, however, babies from the freestanding midwifery unit group were significantly less likely to be admitted to neonatal intensive care or special care nursery (AOR 0.60 95% CI 0.39 to 0.91). Analysis of secondary outcomes indicated that planning to give birth in a freestanding midwifery unit was associated with similar or reduced odds of intrapartum interventions and similar or improved odds of indicators of neonatal well-being. The results of this study support the provision of care in freestanding midwifery units as an alternative to tertiary-level maternity units for women with low risk pregnancies at the time of booking.
Stitch in time: life-saving thoracotomy for treatment of neonatal haemothorax
Publisher: Wiley
Date: 05-2011
Rates of obstetric intervention among low-risk women giving birth in private and public hospitals in NSW: a population-based descriptive study
Publisher: BMJ
Date: 2012
Does caffeine impair cerebral oxygenation and blood flow velocity in preterm infants?
Publisher: Wiley
Date: 17-08-2000
DOI: 10.1111/J.1651-2227.2010.01828.X
Abstract: The aim of the study is to assess the effects of an intravenous 10 mg/kg loading dose of caffeine base in cerebral oxygenation, cerebral Doppler blood flow velocity and cardiac output in preterm infants. Preterm neonates <34 weeks gestation were investigated at 1 and 4 h following the loading dose of caffeine using Doppler cerebral sonography, cardiac echocardiography and cerebral spatially resolved near-infrared spectroscopy. Forty infants were studied with a mean gestational age (mean ± standard deviation) of 27.7 (±2.5) weeks, birth weight of 1155 (±431) g and a postnatal age of 2.8 (±2.2) days. Mean Anterior Cerebral Artery peak and time average mean blood flow velocity fell significantly by 14% and 17.7%, respectively at 1 h post-caffeine loading dose, which recovered partially by 4 h. Cerebral Tissue Oxygenation Index fell from pre-dose levels by 9.5% at 1 h with partial recovery to 4.9% reduced at 4 h post-dose. There were no significant changes in left or right ventricular output, transcutaneous oxygen saturation, transcutaneous PCO(2) or total vascular resistance. A loading dose of 10 mg/kg caffeine base resulted in significant reduction at 1 h post-dose in cerebral oxygenation and cerebral blood flow velocity with partial recovery at 4 h.
Does model of maternity care make a difference to birth outcomes for young women? A retrospective cohort study
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1016/J.IJNURSTU.2015.04.011
Abstract: Adolescent pregnancy is associated with adverse outcomes including preterm birth, admission to the neonatal intensive care unit, low birth weight infants, and artificial feeding. To determine if caseload midwifery or young women's clinic are associated with improved perinatal outcomes when compared to standard care. A retrospective cohort study. A tertiary Australian hospital where routine maternity care is delivered alongside two community-based maternity care models specifically for young women aged 21 years or less: caseload midwifery (known midwife) and young women's clinic (rostered midwife). All pregnant women aged 21 years or less, with a singleton pregnancy, who attended a minimum of two antenatal visits, and who birthed a baby (without congenital abnormality) at the study hospital during May 2008 to December 2012. Caseload midwifery and young women's clinic were each compared to standard maternity care, but not with each other, for four primary outcomes: preterm birth (<37 weeks gestation), low birth weight infants (<2500g), neonatal intensive care unit admission, and breastfeeding initiation. Two analyses were performed on the primary outcomes to examine potential associations between maternity care type and perinatal outcomes: intention-to-treat (model of care at booking) and treatment-received (model of care on admission for labour/birth). 1908 births were analysed by intention-to-treat and treatment-received analyses. Young women allocated to caseload care at booking, compared to standard care, were less likely to have a preterm birth (adjusted odds ratio 0.59 (0.38-0.90, p=0.014)) or a neonatal intensive care unit admission adjusted odds ratio 0.42 (0.22-0.82, p=0.010). Rates of low birth weight infants and breastfeeding initiation were similar between caseload and standard care participants. Participants allocated to young women's clinic at booking, compared to standard care, were less likely to have a low birth weight infant adjusted odds ratio 0.49 (0.24-1.00, p=0.049), however when analysed by treatment-received, this finding was not significant. There was no difference in the other primary outcomes. Young women who were allocated to caseload midwifery at booking, and/or were receiving caseload midwifery at the time of admission for birth, were less likely to experience preterm birth and neonatal intensive care unit admission.
Estimation of cardiac output and total peripheral resistance in preterm infants by arterial waveform analysis
Publisher: IEEE
Date: 07-2013
The impact of caseload midwifery, compared with standard care, on women's perceptions of antenatal care quality: Survey results from the M@NGO randomized controlled trial for women of any risk
Publisher: Wiley
Date: 23-06-2019
DOI: 10.1111/BIRT.12436
Abstract: The measurement and interpretation of patient experience is a distinct dimension of health care quality. The Midwives @ New Group practice Options (M@NGO) randomized control trial of caseload midwifery compared with standard care among women regardless of risk reported both clinical and cost benefits. This study reports participants' perceptions of the quality of antenatal care within caseload midwifery, compared with standard care for women of any risk within that trial. A trial conducted at two Australian tertiary hospitals randomly assigned participants (1:1) to caseload midwifery or standard care regardless of risk. Women were sent an 89-question survey at 6 weeks postpartum that included 12 questions relating to pregnancy care. Ten survey questions (including 7-point Likert scales) were analyzed by intention to treat and illustrated by participant quotes from two free-text open-response items. From the 1748 women recruited to the trial, 58% (n = 1017) completed the 6-week survey. Of those allocated to caseload midwifery, 66% (n = 573) responded, compared with 51% (n = 444) of those allocated to standard care. The survey found women allocated to caseload midwifery perceived a higher level of quality care across every antenatal measure. Notably, those women with identified risk factors reported higher levels of emotional support (aOR 2.52 [95% CI 1.87-3.39]), quality care (2.94 [2.28-3.79]), and feeling actively involved in decision-making (3.21 [2.35-4.37]). Results from the study show that in addition to the benefits to clinical care and cost demonstrated in the M@NGO trial, caseload midwifery outperforms standard care in perceived quality of pregnancy care regardless of risk.
Skin antisepsis survey in Australia-New Zealand neonatal nurseries
Publisher: Wiley
Date: 12-2013
DOI: 10.1111/JPC.12274
A randomised controlled trial of caseload midwifery care: M@NGO (Midwives @ New Group practice Options)
Publisher: Springer Science and Business Media LLC
Date: 26-10-2011
Freestanding midwifery units: Maternal and neonatal outcomes following transfer
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.MIDW.2017.01.006
Abstract: the viability of freestanding midwifery units in Australia is restricted, due to concerns over their safety, particularly for women and babies who, require transfer. to compare the maternal and neonatal birth outcomes of women who planned, to give birth at freestanding midwifery units and subsequently, transferred to a tertiary maternity unit to the maternal and neonatal, outcomes of a low-risk cohort of women who planned to give birth in, tertiary maternity unit. a descriptive study compared two groups of women with low-risk singleton, pregnancies who were less than 28 weeks pregnant at booking: women who, planned to give birth at a freestanding midwifery unit (n=494) who, transferred to a tertiary maternity unit during the antenatal, intrapartum or postnatal periods (n=260) and women who planned to give, birth at a tertiary maternity unit (n=3157). Primary outcomes were mode, of birth, Apgar score of less than 7 at 5minutes and admission to, special care nursery or neonatal intensive care. the proportion of women who experienced a caesarean section was lower, among the freestanding midwifery unit women who transferred during the, intrapartum ostnatal period compared to women in the tertiary maternity, unit group (16.1% versus 24.8% respectively). Other outcomes were, comparable between the cohorts. Rates of primary outcomes in relation to, stage of transfer varied when stratified by parity. these descriptive results support the provision of care in freestanding, midwifery units as an alternative to tertiary maternity units for women, with low risk pregnancies at the time of booking. A larger study, powered, to determine statistical significance of any differences in outcomes, is, required.
Prediction of intraventricular haemorrhage in preterm infants using time series analysis of blood pressure and respiratory signals
Publisher: Springer Science and Business Media LLC
Date: 24-04-2017
DOI: 10.1038/SREP46538
Abstract: Despite the decline in mortality rates of extremely preterm infants, intraventricular haemorrhage (IVH) remains common in survivors. The need for resuscitation and cardiorespiratory management, particularly within the first 24 hours of life, are important factors in the incidence and timing of IVH. Variability analyses of heart rate and blood pressure data has demonstrated potential approaches to predictive monitoring. In this study, we investigated the early identification of infants at a high risk of developing IVH, using time series analysis of blood pressure and respiratory data. We also explore approaches to improving model performance, such as the inclusion of multiple variables and signal pre-processing to enhance the results from detrended fluctuation analysis. Of the models we evaluated, the highest area under receiver-operator characteristic curve (5th, 95th percentile) achieved was 0.921 (0.82, 1.00) by mean diastolic blood pressure and the long-term scaling exponent of pulse interval (PI α 2 ), exhibiting a sensitivity of % at a specificity of 75%. Following evaluation in a larger population, our approach may be useful in predictive monitoring to identify infants at high risk of developing IVH, offering caregivers more time to adjust intensive care treatment.
Dangerous Pressurization and Inappropriate Alarms during Water Occlusion of the Expiratory Circuit of Commonly Used Infant Ventilators
Publisher: Public Library of Science (PLoS)
Date: 26-04-2016
Neopuff T-piece resuscitator: does device design affect delivered ventilation?
Publisher: BMJ
Date: 19-09-2017
DOI: 10.1136/ARCHDISCHILD-2016-311164
Abstract: The T-piece resuscitator (TPR) is in common use worldwide to deliver positive pressure ventilation during resuscitation of infants <10 kg. Ease of use, ability to provide positive end-expiratory pressure (PEEP), availability of devices inbuilt into resuscitaires and cheaper disposable options have increased its popularity as a first-line device for term infant resuscitation. Research into its ventilation performance is limited to preterm infant and animal studies. Efficacy of providing PEEP and the use of TPR during term infant resuscitation are not established. The aim of this study is to determine if delivered ventilation with the Neopuff brand TPR varied with differing (preterm to term) test lung compliances (Crs) and set peak inspiratory pressures (PIP). A single operator experienced in newborn resuscitation provided positive pressure ventilation in a randomised sequence to three different Crs models (0.5, 1 and 3 mL/cmH A total of 1087 inflations were analysed. The delivered mean PEEP was Crs dependent across set PIP range, rising from 4.9 to 8.2 cmH As Crs increases, the Neopuff TPR can produce clinically significant levels of auto-PEEP and thus may not be optimal for the resuscitation of term infants with healthy lungs.
Neopuff T-piece resuscitator mask ventilation: Does mask leak vary with different peak inspiratory pressures in a manikin model?
Publisher: Wiley
Date: 04-07-2017
DOI: 10.1111/JPC.13609
Abstract: The aim of this study was to compare mask leak with three different peak inspiratory pressure (PIP) settings during T-piece resuscitator (TPR Neopuff) mask ventilation on a neonatal manikin model. Participants were neonatal unit staff members. They were instructed to provide mask ventilation with a TPR with three PIP settings (20, 30, 40 cm H A total of 12 749 inflations delivered by 40 participants were analysed. There were no statistically significant differences (P > 0.05) in the mask leak with the three PIP settings. No statistically significant differences were seen in respiratory rate and inspiratory time with the three PIP settings. There was a significant rise in PEEP as the PIP increased. Failure to achieve the desired PIP was observed especially at the higher settings. In a neonatal manikin model, the mask leak does not vary as a function of the PIP when the flow rate is constant. With a fixed rate and inspiratory time, there seems to be a rise in PEEP with increasing PIP.
Cerebral near-infrared spectroscopy analysis in preterm infants with intraventricular hemorrhage
Publisher: IEEE
Date: 08-2011
Neonatologist performed point‐of‐care bowel ultrasound: Is the time right?
Publisher: Wiley
Date: 12-09-2018
DOI: 10.1002/AJUM.12114
Neopuff T-piece mask resuscitator: is mask leak related to watching the pressure dial?
Publisher: Wiley
Date: 17-08-2010
DOI: 10.1111/J.1651-2227.2010.01816.X
Abstract: The aim of the study is to compare mask leak and delivered ventilation during Neopuff (NP) mask ventilation in two modes: (i) with NP pressure dial hidden and resuscitator watching chest wall (CW) rise with, (ii) CW movement hidden and resuscitator watching NP pressure dial. Thirty-six participants gave mask ventilation to a modified manikin designed to measure mask leak and delivered ventilation for two minutes in each mode randomly assigned. Paired t-tests were used to analyse differences in mean values. Linear regression was used to determine the association of mask leak with delivered ventilation. Of 7277 inflations analysed, 3621 were observing chest wall mode (CWM) and 3656 observing NP mode (NPM). Mask leak was similar between the groups 31.6% for CWM and 31.5% (p = 0.56) for NPM. There were no significant differences in airways pressures and expired tidal volumes (TVe) between modes. Mask leak was strongly associated with TVe (R = -0.86 p < 0.0001) and with peak inspiratory pressure (PIP) (R = -0.51 p < 0.0001). TVe was associated with PIP (R = 0.51 p < 0.0001). This study provides reassurance that NP mask leak is not greater when resuscitators watch the NP pressure dial. Mask leak is related to TVe. Mask ventilation training with manikins should include tidal volume measurements.
Emergence and control of an outbreak of infections due to Panton-Valentine leukocidin positive, ST22 methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit
Publisher: Elsevier BV
Date: 07-2013
Advanced analyses of physiological signals in the neonatal intensive care unit
Publisher: IOP Publishing
Date: 21-09-2017
Abstract: Management and monitoring of infants within the neonatal intensive care unit represents a unique challenge. It involves an array of life-threatening diseases, procedures with potentially lifelong impacts, co-morbidities associated with preterm birth and risk of infection from prolonged exposure to the hospital environment. With the integration of monitoring systems and increasing accessibility of high-resolution data, there is a growing interest in the utility of advanced data analyses in predictive monitoring and characterising patterns of disease. Such analyses may offer an opportunity to identify infants at high risk of certain conditions and to detect the onset of disease prior to manifestation of clinical signs. This allows caregivers more time to respond and mitigate any abnormal or potentially fatal changes. We review techniques for variability analysis as they have been or have the potential to be applied to neonatal intensive care, the disease conditions in which they have been tested, and technical as well as clinical challenges relevant to their application.
The effect of medical and operative birth interventions on child health outcomes in the first 28 days and up to 5 years of age: A linked data population-based cohort study
Publisher: Wiley
Date: 25-03-2018
DOI: 10.1111/BIRT.12348
A validation study: assessing the reliability of the hand held StatStripXPress lactate meter to test lactate in amniotic fluid
Publisher: Springer Science and Business Media LLC
Date: 2014
On-demand Virtual Neonatal Intensive Care units supporting rural, remote and urban healthcare with Bush Babies Broadband
Publisher: Elsevier BV
Date: 11-2007
Can Ambu self-inflating bag and Neopuff infant resuscitator provide adequate and safe manual inflations for infants up to 10 kg weight?
Publisher: BMJ
Date: 23-12-2017
DOI: 10.1136/ARCHDISCHILD-2016-311830
Abstract: Manual resuscitation devices for infants and newborns must be able to provide adequate ventilation in a safe and consistent manner across a wide range of patient sizes (0.5-10 kg) and differing clinical states. There are little comparative data assessing biomechanical performance of common infant manual resuscitation devices across the manufacturers' recommended operating weight ranges. We aimed to compare performance of the Ambu self-inflating bag (SIB) with the Neopuff T-piece resuscitator in three resuscitation models. Five experienced clinicians delivered targeted ventilation to three lung models differing in compliance, delivery pressures and inflation rates Preterm (0.5 mL/cmH 3309 inflations were collected and analysed with analysis of variance for repeated measures. The Neopuff was unable to reach set peak inflation pressures and exhibited seriously elevated positive end expiratory pressure (PEEP) with all inflow gas rates (p<0.001) in this infant model. The Ambu SIB accurately delivered targeted pressures in all three models. The Ambu SIB was able to accurately deliver targeted pressures across all three models from preterm to infant. The Neopuff infant resuscitator was unable to deliver the targeted pressures in the infant model developing clinically significant levels of inadvertent PEEP which may pose risk during infant resuscitation.
Detrended fluctuation analysis of blood pressure in preterm infants with intraventricular hemorrhage
Publisher: Springer Science and Business Media LLC
Date: 29-05-2013
DOI: 10.1007/S11517-013-1083-0
Abstract: Very preterm infants are at high risk of death and serious permanent brain damage, as occurs with intraventricular hemorrhage (IVH). Detrended fluctuation analysis (DFA) that quantifies the fractal correlation properties of physiological signals has been proposed as a potential method for clinical risk assessment. This study examined whether DFA of the arterial blood pressure (ABP) signal could derive markers for the identification of preterm infants who developed IVH. ABP data were recorded from a prospective cohort of 30 critically ill preterm infants in the first 1-3 h of life, 10 of which developed IVH. DFA was performed on the beat-to-beat sequences of mean arterial pressure (MAP), systolic blood pressure (SBP) and pulse interval, with short-term exponent (α1, for timescale of 4-15 beats) and long-term exponent (α2, for timescale of 15-50 beats) computed accordingly. The IVH infants were found to have higher short-term scaling exponents of both MAP and SBP (α1 = 1.06 ± 0.18 and 0.98 ± 0.20) compared to the non-IVH infants (α1 = 0.84 ± 0.25 and 0.78 ± 0.25, P = 0.017 and 0.038, respectively). The results have demonstrated that fractal dynamics embedded in the arterial pressure waveform could provide useful information that facilitates early identification of IVH in preterm infants.
How do different brands of size 1 laryngeal mask airway compare with face mask ventilation in a dedicated laryngeal mask airway teaching manikin?
Publisher: BMJ
Date: 11-08-2018
DOI: 10.1136/ARCHDISCHILD-2017-312766
Abstract: International neonatal resuscitation guidelines recommend the use of laryngeal mask airway (LMA) with newborn infants (≥34 weeks’ gestation or kg weight) when bag-mask ventilation (BMV) or tracheal intubation is unsuccessful. Previous publications do not allow broad LMA device comparison. To compare delivered ventilation of seven brands of size 1 LMA devices with two brands of face mask using self-inflating bag (SIB). 40 experienced neonatal staff provided inflation cycles using SIB with positive end expiratory pressure (PEEP) (5 cmH 2 O) to a specialised newborn/infant training manikin randomised for each LMA and face mask. All subjects received prior education in LMA insertion and BMV. 12 415 recorded inflations for LMAs and face masks were analysed. Leak detected was lowest with i-gel brand, with a mean of 5.7% compared with face mask (triangular 42.7, round 35.7) and other LMAs (45.5–65.4) (p .001). Peak inspiratory pressure was higher with i-gel, with a mean of 28.9 cmH 2 O compared with face mask (triangular 22.8, round 25.8) and other LMAs (14.3–22.0) (p .001). PEEP was higher with i-gel, with a mean of 5.1 cmH 2 O compared with face mask (triangular 3.0, round 3.6) and other LMAs (0.6–2.6) (p .001). In contrast to other LMAs examined, i-gel had no insertion failures and all users found i-gel easy to use. This study has shown dramatic performance differences in delivered ventilation, mask leak and ease of use among seven different brands of LMA tested in a manikin model. This coupled with no partial or complete insertion failures and ease of use suggests i-gel LMA may have an expanded role with newborn resuscitation as a primary resuscitation device.
Evaluating Maternity Units: a prospective cohort study of freestanding midwife-led primary maternity units in New Zealand-clinical outcomes
Publisher: BMJ
Date: 08-2017
DOI: 10.1136/BMJOPEN-2017-016288
Abstract: To compare maternal and neonatal birth outcomes and morbidities associated with the intention to give birth in a freestanding primary level midwife-led maternity unit (PMU) or tertiary level obstetric-led maternity hospital (TMH) in Canterbury, Aotearoa/New Zealand. Prospective cohort study. 407 women who intended to give birth in a PMU and 285 women who intended to give birth at the TMH in 2010–2011. All of the women planning a TMH birth were ‘low risk’, and 29 of the PMU cohort had identified risk factors. Mode of birth, Apgar score of less than 7 at 5 min and neonatal unit admission. Secondary outcomes: labour onset, analgesia, blood loss, third stage of labour management, perineal trauma, non-pharmacological pain relief, neonatal resuscitation, breastfeeding, gestational age at birth, birth weight, severe morbidity and mortality. Women who planned a PMU birth were significantly more likely to have a spontaneous vaginal birth (77.9%vs62.3%, adjusted OR (AOR) 1.61, 95% CI 1.08 to 2.39), and significantly less likely to have an instrumental assisted vaginal birth (10.3%vs20.4%, AOR 0.59, 95% CI 0.37 to 0.93). The emergency and elective caesarean section rates were not significantly different (emergency: PMU 11.6% vs TMH 17.5%, AOR 0.88, 95% CI 0.55 to 1.40 elective: PMU 0.7% vs TMH 2.1%, AOR 0.34, 95% CI 0.08 to 1.41). There were no significant differences between the cohorts in rates of 5 min Apgar score of (2.0%vs2.1%, AOR 0.82, 95% CI 0.27 to 2.52) and neonatal unit admission (5.9%vs4.9%, AOR 1.44, 95% CI 0.70 to 2.96). Planning to give birth in a primary unit was associated with similar or reduced odds of intrapartum interventions and similar odds of all measured neonatal well-being indicators. The results of this study support freestanding midwife-led primary-level maternity units as physically safe places for well women to plan to give birth, with these women having higher rates of spontaneous vaginal births and lower rates of interventions and their associated morbidities than those who planned a tertiary hospital birth, with no differences in neonatal outcomes.
Rates of obstetric intervention and associated perinatal mortality and morbidity among low-risk women giving birth in private and public hospitals in NSW (2000-2008): a linked data population-based cohort study
Publisher: BMJ
Date: 05-2014
Physiological Signal Analysis Techniques for Preterm Infants in Detecting Adverse Outcomes: A Review (Preprint)
Publisher: JMIR Publications Inc.
Date: 02-03-2023
Abstract: omputational signal pre-processing is a prerequisite for developing data-driven predictive models for clinical decision support. Thus, identifying the best practices that adhere to clinical principles is critical to ensure transparency and reproducibility which will drive clinical adoption. his review focuses on the Neonatal intensive care unit (NICU) setting and summarises the state-of-the-art computational methods used for pre-processing neonatal clinical physiological signals for the development of machine learning models in predicting the risk of adverse outcomes. ive databases (Pubmed, Web of Science, Scopus, IEEE, ACM Digital Library) were searched using a combination of keywords and MeSH terms. 3,585 papers from the year 2013 to January 2023 were identified based on the defined search terms and inclusion criteria. After removing duplicates, 2,994 papers were screened by title and abstract, and 81 were selected for full-text review. Of these, 52 were eligible for inclusion in the detailed analysis. he papers included in the review were heterogeneous in design and the selection of adverse outcomes modelled. We found a partial or complete lack of transparency in reporting the setting and the methods used for signal pre-processing. This includes reporting methods to handle missing data, segment size for considered analysis, and details regarding the modification of the state-of-the-art methods for physiological signal processing to align with the clinical principles for neonates. he review found heterogeneity in techniques and inconsistent reporting of parameters and procedures used for pre-processing neonatal physiological signals, which is necessary to confirm their adherence to clinical practices, usefulness and choice of the best practices. Improving this aspect will ensure transparent reporting and hence facilitate the interpretation and reproducibility of the studies as well as accelerate their clinical adoption. /A
Caseload midwifery compared to standard or private obstetric care for first time mothers in a public teaching hospital in Australia: a cross sectional study of cost and birth outcomes
Publisher: Springer Science and Business Media LLC
Date: 24-01-2014
Spontaneous preterm birth of liveborn infants in women at low risk in Australia over 10 years: a population-based study
Publisher: Wiley
Date: 16-05-2007
DOI: 10.1111/J.1471-0528.2007.01323.X
Abstract: To describe a 10-year trend in preterm birth. Population-based study. Australia. All women who gave birth during 1994-03. The proportion of spontaneous preterm births (greater than or equal to 22 weeks of gestation and less than 37 completed weeks of gestation) was calculated by iding the number of women who had a live spontaneous preterm birth (excluding elective caesarean section and induction of labour) by the total number of women who had a live birth after spontaneous onset of labour (excluding elective caesarean section and induction of labour). This method was repeated for the selected population of women at low risk. Preterm birth rates among the overall population of women preterm birth among all women with a spontaneous onset of labour and preterm birth in a selected population of women who were either primiparous or multiparous, non-Indigenous aged 20-40 years and who gave birth to a live singleton baby after the spontaneous onset of labour. Over the 10-year study period, the proportion of all women having a live preterm birth in Australia increased by 12.1% (from 5.9% in 1994 to 6.6% in 2003). Among women with a spontaneous onset of labour, there was an increase of 18.3% (from 5.7 to 6.7%). Among the selected population of low-risk women after the spontaneous onset of labour, the rate increased by 10.7% (from 5.6 to 6.2%) among first time mothers and by 19.2% (4.4-5.2%) among selected multiparous women. Over the 10-year period of 1994-03, the rate of spontaneous preterm birth among low-risk women having a live singleton birth has risen in Australia.
The effectiveness of Ambu neonatal self-inflating bag to provide consistent positive end-expiratory pressure
Publisher: BMJ
Date: 19-01-2016
DOI: 10.1136/ARCHDISCHILD-2015-308649
Abstract: The self-inflating bag (SIB) is the most common device used to resuscitate newborn infants worldwide. Delivering positive end-expiratory pressure (PEEP) may be important in infant resuscitation and limited research using one brand (Laerdal) SIB has led to international guidelines stating SIBs 'often deliver inconsistent positive end-expiratory pressure'. To measure delivered PEEP using disposable and reusable Ambu SIBs fitted with Ambu PEEP valve and manometer comparing different rates of 20, 40 and 60 inflations per minute (IPM) and test lung compliance. Three experienced neonatal medical staff provided positive pressure ventilation each using different disposable and reusable Ambu SIBs, targeting peak inflation pressure of 30-35 cm H2O at three different set PEEP levels of 5, 7.5 and 10 cm H2O on test lungs of compliance of 0.5 and 3.0 mL/cm H2O. Inflation data were captured with Florian Monitor and analysed by analysis of variance for repeated measures. A total of 3265 inflations were analysed. The delivered PEEP was rate and lung compliance dependent. At set PEEP of 5 cm H2O, the adjusted measured PEEP was 3.6, 4.4 and 4.8 cm H2O at rates 20, 40 and 60 IPM, respectively, while at set PEEP of 10 cm H2O, the adjusted measured PEEP was 7.0, 8.8 and 9.8 cm H2O. The delivered PEEP was statistically higher with more compliant test lungs. The Ambu SIB with Ambu PEEP valve can deliver consistent mean levels of PEEP close to the operator set PEEP. The performance of SIB with PEEP valves is likely brand specific and requires further evaluation.
Ensemble Approach on Deep and Handcrafted Features for Neonatal Bowel Sound Detection
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2023
The motivation and capacity to go 'above and beyond': Qualitative analysis of free-text survey responses in the M@NGO randomised controlled trial of caseload midwifery
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.MIDW.2017.03.012
Abstract: to explore whether women allocated to caseload care characterise their midwife differently to those allocated to standard care. multi-site unblinded, randomised, controlled, parallel-group trial. the study was conducted in two metropolitan teaching hospitals across two Australian cities. women of all obstetric risk were eligible to participate. Inclusion criteria were: 18 years or older, less than 24 week's gestation with a singleton pregnancy. Women already booked with a care provider or planning to have an elective caesarean section were excluded. participants were randomised to caseload midwifery or standard care. The caseload model provided antenatal, intrapartum and postnatal care from a primary midwife or 'back-up' midwife as well as consultation with obstetric or medical physicians as indicated by national guidelines. The standard model included care from a general practitioner and/or midwives and obstetric doctors. participants' responses to open-ended questions were collected through a 6-week postnatal survey and analysed thematically. A total of 1748 women were randomised between December 2008 - May 2011 871 to caseload midwifery and 877 to standard care. The response rate to the 6-week survey including free text items was 52% (n=901). Respondents from both groups characterised midwives as Informative, Competent and Kind. Participants in the caseload group perceived midwives with additional qualities conceptualised as Empowering and 'Endorphic'. These concepts highlight some of the active ingredients that moderated or mediated the effects of the midwifery care within the M@NGO trial. caseload midwifery attracts, motivates and enables midwives to go Above and Beyond such that women feel empowered, nurtured and safe during pregnancy, labour and birth. the concept of an Endorphic midwife makes a useful contribution to midwifery theory as it enhances our understanding of how the complex intervention of caseload midwifery influences normal birth rates and experiences. Defining personal midwife attributes which are important for caseload models has potential implications for graduate attributes in degree programs leading to registration as a midwife and selection criteria for caseload midwife positions.
Logistic regression models for predicting intraventricular haemorrhage in preterm infants using respiratory and blood pressure signals
Publisher: IEEE
Date: 10-2016
Evaluating midwifery units (EMU): lessons from the pilot study
Publisher: Elsevier BV
Date: 08-2013
DOI: 10.1016/J.MIDW.2012.08.012
Abstract: this paper describes the pilot study that was undertaken to test the feasibility of the recruitment plan designed to recruit women who booked to give birth in two freestanding midwifery units in NSW, Australia. The pilot preceded the full prospective cohort study, Evaluating Midwifery Units (EMU), which aimed to examine the antenatal, birth and postnatal outcomes of women planning to give birth in freestanding midwifery units compared to those booked to give birth in tertiary level maternity units in Australia and New Zealand. a prospective cohort study with two mutually-exclusive cohorts. two freestanding midwifery units in NSW and their corresponding tertiary referral hospitals. a total of 146 women with few identified risk factors recruited between 13 September 2009 and 31 March 2010 whose planned place of birth was either a freestanding midwifery unit or tertiary maternity unit. the pilot study identified the feasibility of relying on the booking midwife to recruit eligible women from several antenatal booking clinics to the study. Low rates of eligible women were invited resulting in a lower than expected consent rate. In addition, although mostly only low-risk women were invited to participate, some women requiring medical consultation at the time of booking were inadvertently recruited into the study. The results of this pilot study led us to revise the study protocol to find ways of including the outcomes of all women without identified risk factors who booked at either the freestanding midwifery units or the tertiary referral hospital in that area. This paper describes the revisions that were made to the study plan. five lessons were learned from the pilot study. We found that recruitment protocols employed for the cohort study were too complicated and required simplification to maximise the potential of the study. The study protocol needed to be changed for the main study to ensure a larger s le size and to ensure the risk profile of each cohort was as similar as possible. Sources of data needed to be expanded to produce a complete data set. pilot studies are extremely useful tools in testing methods to inform research protocols. We found that the first months spent undertaking a pilot study ensured a stronger design with the potential to show more meaningful results.
The presence of vaginal Lactobacillus species does not contribute to a measureable difference in amniotic fluid lactate levels collected from the vaginal tract of laboring women
Publisher: Wiley
Date: 06-03-2017
DOI: 10.1111/AOGS.13089
Abstract: Amniotic fluid lactate research is based on the hypothesis that a relationship exists between fatigued uterine muscles and raised concentrations of the metabolite lactate, which is excreted into the amniotic fluid during labor. To assess potentially confounding effects of lactate-producing organisms on amniotic fluid lactate measurements, we aimed to determine if the presence of vaginal Lactobacillus species was associated with elevated levels of amniotic fluid lactate, measured from the vaginal tract of women in labor. Results from this study contribute to a large prospective longitudinal study of amniotic fluid lactate at a teaching hospital in Sydney, Australia. Amniotic fluid lactate measurement was assessed at the time of routine vaginal examination, after membranes had ruptured, using a hand-held lactate meter StatStripXPress (Nova Biomedical). Vaginal swab s les were collected at the time of the first amniotic fluid lactate measurement and stored for later detection and quantification of Lactobacillus species using a TaqMan real-time PCR assay. Swab s le and amniotic fluid lactate results were paired and analyzed. The PCR assay detected Lactobacillus species in 48 of 388 (12%) vaginal swab specimens (8% positive, 4% low positive) collected from women in labor after membranes had ruptured. There was no significant difference in median and mean (respectively) amniotic fluid lactate levels with (8.35 mmol/L 8.95 mmol/L) or without (8.5 mmol/L 9.08 mmol/L) Lactobacillus species detected. There was no association between the presence or level of vaginal Lactobacillus species and the measurement of amniotic fluid lactate collected from the vaginal tract of women during labor.
A pilot study to determine the feasibility of collecting amniotic fluid samples from women during labour and measuring amniotic fluid lactate at point of care
Publisher: Springer Science and Business Media LLC
Date: 26-03-2013
Related Organisations
University Of London
Location: United Kingdom of Great Britain and Northern Ireland
London School Of Hygiene And Tropical Medicine
Location: United Kingdom of Great Britain and Northern Ireland
Related Funding Activities
No related grants have been discovered for Mark Tracy.