One-person versus two-person mask ventilation in preterm infants at birth: a pilot randomised controlled trial.

BACKGROUND: Mask leak and airway obstruction are common with mask ventilation in newborn infants, leading to suboptimal ventilation. We aimed to perform a pilot study measuring respiratory mechanics during one-person and two-person mask ventilation in preterm infants at birth. METHODS: Infants less than 30 weeks' gestation were eligible for the study. In the two-person method, one person holds the mask in place and the other provides positive pressure ventilation compared with the standard one-person mask hold. A respiratory function monitor was used in line with a T-piece resuscitator to measure mask leak and airway obstruction. Deferred consent was obtained. RESULTS: Twenty-five infants were recruited. The mean (SD) birth weight was 920.4 g (188.3), and mean (SD) gestational age was 27.3 weeks (3.0). Percentage mask leak was higher in the one-person mask method (26.4±18.5) compared with the two-person mask method (17.6±9.3) (p=0.018). The mean (SD) expired tidal volume (VTe, mL) in breaths with leak was 3.9 (1.57) in the one-person method compared with 3.05 (1.0) the two-person method (p=0.31). A significantly lower mean (SD) end-tidal carbon dioxide (EtCO2, mm Hg) was measured at 25.3 (9.9) in breaths with mask leak, compared with 30.8 (12.1) in breaths without leak. The breaths with airway obstruction had lower mean EtCO2 (25.9 vs 30.8, p=0.003) and lower mean VTe (1.71 vs 6.95, p<0.001). CONCLUSION: Mask leak and airway obstruction are common in resuscitation of preterm infants at birth. The use of the two-person mask technique is effective and it could be a useful option if mask ventilation with the one-person method is not effective. TRIAL REGISTRATION NUMBER: ACTRN12614000245695.

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.

BACKGROUND: 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. METHODS: 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. RESULTS: 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]). CONCLUSIONS: 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.

Cardiovascular impact of intravenous caffeine in preterm infants.

AIM: To evaluate the acute effect of intravenous caffeine on heart rate and blood pressure variability in preterm infants. METHODS: 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. RESULTS: 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 (α1 , α2 ) of mean arterial pressure from detrended fluctuation analysis and an increase in the ratio of short- (SD1) and long-term (SD2) variability from Poincare analysis (SD1/SD2). Heart rate variability analyses showed a reduction in α1 (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). CONCLUSION: 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.

Newborn self-inflating manual resuscitators: precision robotic testing of safety and reliability.

AIM: 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). INTRODUCTION: 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. METHODS: 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. RESULTS: 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 >45 cm H2O, representing 6% of their inflations; five models had excessive coefficient of variation (>30% averaged across compression distances) and three models did not deliver inflation volumes >2.5 mL until approximately 50% of maximum bag compression distance was reached. The study also found significant intrabatch variability and forward leakage. CONCLUSION: Compliance of SIBs with ISO standards may not guarantee acceptable or safe performance to resuscitate newborn infants.

The effect of caffeine loading on cerebral autoregulation in preterm infants.

AIM: To evaluate cerebral autoregulation changes in preterm infants receiving a loading dose of caffeine base. METHODS: 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. RESULTS: 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 (ρ5 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. CONCLUSION: 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.

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.

INTRODUCTION: 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. MATERIAL AND METHODS: 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 samples 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 sample and amniotic fluid lactate results were paired and analyzed. RESULTS: 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. CONCLUSION: 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.

Women's experiences of transfer from primary maternity unit to tertiary hospital in New Zealand: part of the prospective cohort Evaluating Maternity Units study.

BACKGROUND: There is worldwide debate regarding the appropriateness and safety of different birthplaces for well women. The Evaluating Maternity Units (EMU) study's primary objective was to compare clinical outcomes for well women intending to give birth in either a tertiary level maternity hospital or a freestanding primary level maternity unit. Little is known about how women experience having to change their birthplace plans during the antenatal period or before admission to a primary unit, or transfer following admission. This paper describes and explores women's experience of these changes-a secondary aim of the EMU study. METHODS: This paper utilised the six week postpartum survey data, from the 174 women from the primary unit cohort affected by birthplace plan change or transfer (response rate 73%). Data were analysed using descriptive statistics and thematic analysis. The study was undertaken in Christchurch, New Zealand, which has an obstetric-led tertiary maternity hospital and four freestanding midwife-led primary maternity units (2010-2012). The 702 study participants were well, pregnant women booked to give birth in one of these facilities, all of whom received continuity of midwifery care, regardless of their intended or actual birthplace. RESULTS: Of the women who had to change their planned place of birth or transfer the greatest proportion of women rated themselves on a Likert scale as unbothered by the move (38.6%); 8.8% were 'very unhappy' and 7.6% 'very happy' (quantitative analysis). Four themes were identified, using thematic analysis, from the open ended survey responses of those who experienced transfer: 'not to plan', control, communication and 'my midwife'. An interplay between the themes created a cumulatively positive or negative effect on their experience. Women's experience of transfer in labour was generally positive, and none expressed stress or trauma with transfer. CONCLUSIONS: The women knew of the potential for change or transfer, although it was not wanted or planned. When they maintained a sense control, experienced effective communication with caregivers, and support and information from their midwife, the transfer did not appear to be experienced negatively. The model of continuity of midwifery care in New Zealand appeared to mitigate the negative aspects of women's experience of transfer and facilitate positive birth experiences.

A validation study: assessing the reliability of the hand held StatStripXPress lactate meter to test lactate in amniotic fluid.

BACKGROUND: The level of lactate in amniotic fluid may provide useful clinical information when assessing whether a woman in labour is experiencing labour dystocia. If so, a rapid, reliable method to assess the concentration of amniotic fluid lactate at the bedside will be required in order to be clinically relevant. To assess efficacy, we compared the hand held StatStripXPreass lactate meter (Nova Biomedical) to the reference laboratory analyser ABX Pentra 400 (Horiba) in a controlled environment. Baseline biological lactate concentration was measured in triplicate and samples of a known quantity of thawed amniotic fluid spiked with lactate substrate (62 mmol/L) from the LDH12 kit (Roche, SUI) to yield a predetermined lactate concentration above baseline then measured in triplicate. Deming Regression was used to determine the linear agreement and a Bland Altman plot used to determine the paired agreement across the range of values. FINDINGS: The mean difference with Bland-Altman plot between hand held meter and lab instrument was -1.0 mmol/L (SD 3.0 mmol/L) with 95% CI limits of agreement between -6.9 mmol/L to 4.9 mmol/L. The Deming regression co-efficient or slope of agreement was 0.91 (SD of 0.21). CONCLUSION: The measurement of amniotic fluid lactate using the StatStripXPress hand held meter was reliable compared to reference laboratory methods for measuring lactate levels in amniotic fluid.

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.

BACKGROUND: In many countries midwives act as the main providers of care for women throughout pregnancy, labour and birth. In our large public teaching hospital in Australia we restructured the way midwifery care is offered and introduced caseload midwifery for one third of women booked at the hospital. We then compared the costs and birth outcomes associated with caseload midwifery compared to the two existing models of care, standard hospital care and private obstetric care. METHODS: We undertook a cross sectional study examining the risk profile, birth outcomes and cost of care for women booked into one of the three available models of care in a tertiary teaching hospital in Australia between July 1st 2009 December 31st 2010. To control for differences in population or case mix we described the outcomes for a cohort of low risk first time mothers known as the 'standard primipara'. RESULTS: Amongst the 1,379 women defined as 'standard primipara' there were significant differences in birth outcome. These first time 'low risk' mothers who received caseload care were more likely to have a spontaneous onset of labour and an unassisted vaginal birth 58.5% in MGP compared to 48.2% for Standard hospital care and 30.8% with Private obstetric care (p < 0.001). They were also significantly less likely to have an elective caesarean section 1.6% with MGP versus 5.3% with Standard care and 17.2% with private obstetric care (p < 0.001). From the public hospital perspective, over one financial year the average cost of care for the standard primipara in MGP was $3903.78 per woman. This was $1375.45 less per woman than those receiving Private obstetric care and $1590.91 less than Standard hospital care per woman (p < 0.001). Similar differences in cost were found in favour of MGP for all women in the study who received caseload care. CONCLUSIONS: Cost reduction appears to be achieved through reorganising the way care is delivered in the public hospital system with the introduction of Midwifery Group Practice or caseload care. The study also highlights the unexplained clinical variation that exists between the three models of care in Australia.

Mask leak increases and minute ventilation decreases when chest compressions are added to bag ventilation in a neonatal manikin model.

AIM: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Estimation of cardiac output and total peripheral resistance in preterm infants by arterial waveform analysis.

This study investigated whether arterial blood pressure waveform analysis could be useful for estimating left ventricular outflow (LVO) and total peripheral resistance (TPR) in preterm infants. A cohort of 27 infants were studied, with 89 measurements of left ventricular outflow (LVO) using Doppler echocardiography and arterial pressure using catheters, performed in 0, 12, 24 and 36 hours after birth. TPR was computed as mean arterial pressure divided by LVO. The diastolic decay rate (1/τ) was obtained via fitting an exponential function to the last one third of each arterial pulse, with the mean rate computed from 50 pulses selected from each infant. This decay rate was considered to be inversely related to TPR while positively related to LVO. The results of regression analysis have confirmed that the diastolic decay rate had significant positive and negative relationships with LVO and TPR respectively(r = 0.383, P = 0.0002 and r = -0.379, P = 0.0002 respectively). These preliminary results demonstrated the potential utility of arterial pressure waveform analysis for estimating LVO and TPR in preterm infants, but more advanced multi-parameter models may be needed to improve accuracy of the estimation.

Caseload midwifery care versus standard maternity care for women of any risk: M@NGO, a randomised controlled trial.

BACKGROUND: Women at low risk of pregnancy complications benefit from continuity of midwifery care, but no trial evidence exists for women with identified risk factors. We aimed to assess the clinical and cost outcomes of caseload midwifery care for women irrespective of risk factors. METHODS: In this unblinded, randomised, controlled, parallel-group trial, pregnant women at two metropolitan teaching hospitals in Australia were randomly assigned to either caseload midwifery care or standard maternity care by a telephone-based computer randomisation service. Women aged 18 years and older were eligible if they were less than 24 weeks pregnant at the first booking visit. Those who booked with another care provider, had a multiple pregnancy, or planned to have an elective caesarean section were excluded. Women allocated to caseload care received antenatal, intrapartum, and postnatal care from a named caseload midwife (or back-up caseload midwife). Controls received standard care with rostered midwives in discrete wards or clinics. The participant and the clinician were not masked to assignment. The main primary outcome was the proportion of women who had a caesarean section. The other primary maternal outcomes were the proportions who had an instrumental or unassisted vaginal birth, and the proportion who had epidural analgesia during labour. Primary neonatal outcomes were Apgar scores, preterm birth, and admission to neonatal intensive care. We analysed all outcomes by intention to treat. The trial is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12609000349246. FINDINGS: Publicly insured women were screened at the participating hospitals between Dec 8, 2008, and May 31, 2011. 1748 pregnant women were randomly assigned, 871 to caseload and 877 to standard care. The proportion of caesarean sections did not differ between the groups (183 [21%] in the caseload group vs 204 [23%] in the standard care group; odds ratio [OR] 0·88, 95% CI 0·70-1·10; p=0·26). The proportion of women who had elective caesarean sections (before onset of labour) differed significantly between caseload and standard care (69 [8%] vs 94 [11%]; OR 0·72, 95% CI 0·52-0·99; p=0·05). Proportions of instrumental birth were similar (172 [20%] vs 171 [19%]; p=0·90), as were the proportions of unassisted vaginal births (487 [56%] vs 454 [52%]; p=0·08) and epidural use (314 [36%] vs 304 [35%]; p=0·54). Neonatal outcomes did not differ between the groups. Total cost of care per woman was AUS$566·74 (95% 106·17-1027·30; p=0·02) less for caseload midwifery than for standard maternity care. INTERPRETATION: Our results show that for women of any risk, caseload midwifery is safe and cost effective. FUNDING: National Health and Medical Research Council (Australia).

Detrended fluctuation analysis of blood pressure in preterm infants with intraventricular hemorrhage.

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.

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.

BACKGROUND: The level of lactate in amniotic fluid may provide useful clinical information when assessing progress of a woman's labour and if so, a rapid, reliable method to assess amniotic fluid lactate is required in order to be clinically relevant. However, measuring lactate levels in amniotic fluid, using portable, handheld lactate meters may be less accurate than reference laboratory instruments designed to measure lactate levels in aqueous solutions. Prior to conducting a large study, we assessed recruitment, consent and sampling procedures, and the accuracy of a handheld lactate meter to measure lactate in amniotic fluid. We compared amniotic fluid lactate results obtained using the hand held Lactate Pro (Arkray) to results obtained using reference laboratory methods ABX Pentra 400 (Horiba). RESULTS: We recruited 35 nulliparous women during their antenatal hospital visits and tested amniotic fluid samples collected from 20 labouring women. The handheld Lactate Pro meter was found accurate from 9-20 mmol/L with a Passing & Bablok regression of y = 0.18 + 0.97x (95% CI 0.76-1.45). Amniotic fluid lactate results remained reliable in the presence of potential contaminants commonly encountered during labour; obstetric lubricant, blood and meconium. CONCLUSION: The measurement of amniotic fluid lactate using the Lactate Pro meter was reliable compared to reference laboratory methods for measuring lactate levels in amniotic fluid. The pilot study enabled the refinement of information, recruitment, consenting and sampling procedures prior to commencing a large cohort study.

Spectral analysis of systemic and cerebral cardiovascular variabilities in preterm infants: relationship with clinical risk index for babies (CRIB).

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.

Cerebral near-infrared spectroscopy analysis in preterm infants with intraventricular hemorrhage.

Near-infrared spectroscopy (NIRS) for cerebral circulation monitoring has gained popularity in the neonatal intensive care setting, with studies showing the possibility of identifying preterm infants with intraventricular hemorrhage (IVH) by transfer function analysis of arterial blood pressure (BP) and NIRS measures. In this study, we examined a number of NIRS-derived measures in a cohort of preterm infants with IVH (n = 5) and without IVH (n = 12) within 1-3 hours after birth. The IVH infants were found to have significantly higher tissue oxygenation index (TOI), lower fractional tissue oxygen extraction (FTOE) and lower coherence between arterial BP and deoxygenated hemoglobin (HHb) in the very low frequency range (VLF, 0.02-0.04 Hz). Further studies with larger sample size are warranted for a more complete understanding of the clinical utility of these NIRS measures for early identification of IVH infants.

Neopuff T-piece mask resuscitator: is mask leak related to watching the pressure dial?

AIM: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Admission of term infants to neonatal intensive care: a population-based study.

BACKGROUND: Neonatal intensive care and special care nurseries provide a level of care that is both high in cost and low in volume. The aim of our study was to determine the rate of admission of term babies to neonatal intensive care in association with each method of giving birth among low-risk women. METHODS: We examined the records of 1,001,249 women who gave birth in Australia during 1999 to 2002 using data from the National Perinatal Data Collection. Among low-risk women, we calculated the adjusted odds of admission to neonatal intensive care at term separated for each week of gestational age between 37 and 41 completed weeks. We also calculated the odds of admission to neonatal intensive care in association with cesarean section before or after the onset of labor, and vacuum or instrumental birth compared with unassisted vaginal birth at 40 weeks' gestation. RESULTS: The overall rate of admission to neonatal intensive care of term babies was 8.9 percent for primiparas and 6.3 percent for multiparas. After a cesarean section before the onset of labor, the adjusted odds of admission among low-risk primiparas at 37 weeks' gestation were 12.08 (99% CI 8.64-16.89); at 38 weeks, 7.49 (99% CI 5.54-10.11); and at 39 weeks, 2.80 (99% CI 2.02-3.88). At 41 weeks, the adjusted odds were not significantly higher than those at 40 weeks' gestation. Among low-risk multiparas who had a cesarean section before the onset of labor, the adjusted odds of admission to neonatal intensive care at 37 weeks' gestation were 15.40 (99% CI 12.87-18.43); at 38 weeks, 12.13 (99% CI 10.37-14.19); and at 39 weeks, 5.09 (99% CI 4.31-6.00). At 41 weeks' gestation, the adjusted odds of admission were significantly lower than those at 40 weeks (AOR 0.64, 99% CI 0.47-0.88). Babies born after any operative method of birth were at increased odds of being admitted to neonatal intensive care compared with those born after unassisted vaginal birth at 40 weeks' gestation. CONCLUSIONS: The adjusted odds of admission to neonatal intensive care for babies of low-risk women were increased after birth at 37 weeks' gestation. In a climate of rising cesarean sections, this information is important to women who may be considering elective procedures.

Birth centers in Australia: a national population-based study of perinatal mortality associated with giving birth in a birth center.

BACKGROUND: Perinatal mortality is a rare outcome among babies born at term in developed countries after normal uncomplicated pregnancies; consequently, the numbers involved in large databases of routinely collected statistics provide a meaningful evaluation of these uncommon events. The National Perinatal Data Collection records the place of birth and information on the outcomes of pregnancy and childbirth for all women who give birth each year in Australia. Our objective was to describe the perinatal mortality associated with giving birth in "alongside hospital" birth centers in Australia during 1999 to 2002 using nationally collected data. METHODS: This population-based study included all 1,001,249 women who gave birth in Australia during 1999 to 2002. Of these women, 21,800 (2.18%) gave birth in a birth center. Selected perinatal outcomes (including stillbirths and neonatal deaths) were described for the 4-year study period separately for first-time mothers and for women having a second or subsequent birth. A further comparison was made between deaths of low-risk term babies born in hospitals compared with deaths of term babies born in birth centers. RESULTS: The total perinatal death rate attributed to birth centers was significantly lower than that attributed to hospitals (1.51/1,000 vs 10.03/1,000). The perinatal mortality rate among term births to primiparas in birth centers compared with term births among low-risk primiparas in hospitals was 1.4 versus 1.9 per 1,000; the perinatal mortality rate among term births to multiparas in birth centers compared with term births among low-risk multiparas in hospitals was 0.6 versus 1.6 per 1,000. CONCLUSIONS: This study using Australian national data showed that the overall rate of perinatal mortality was lower in alongside hospital birth centers than in hospitals irrespective of the mother's parity.