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Background: Care for infants born at 22-24 weeks' gestation varies globally, with an increasing willingness to provide survival-focused ('active') care for infants born at 22 weeks' gestation in recent years. This study aims to report changes in care for infants born at 22-24 weeks before and after the introduction of a statewide guideline for extreme prematurity (EP)., Methods: A retrospective cohort study was conducted, including all live births at 22-24 weeks in tertiary perinatal centres from 1 January 2015 to 31 December 2022 in Victoria, Australia. Medical records were reviewed to obtain antenatal history and perinatal outcomes. Data on in utero referral and transfer to tertiary perinatal centres were sourced from the statewide perinatal emergency retrieval service (Paediatric Infant Perinatal Emergency Retrieval, PIPER) database. Changes in PIPER referrals and transfers, survival-focused care and survival at 28 days preguideline and postguideline were assessed using logistic regression., Results: Following the guideline, at 22 weeks' gestation, there was an increase in referrals to PIPER and a 3.31 (95% CI 1.84 to 5.95) higher likelihood of in utero transfer to tertiary centres.Following the guideline, infants had a 6.67 (95% CI 1.40 to 31.72) higher likelihood of receiving survival-focused care at 22 weeks, and a 5.57 (95% CI 1.22 to 25.44) higher likelihood at 23 weeks. All 24-week live births received survival-focused care at birth. The 28-day survival for infants who received survival-focused care was unchanged preguideline and postguideline., Conclusion: Following the publication of the EP guideline in Victoria, in utero referrals and transfers at 22 weeks' gestation have increased, as has survival-focused management of inborn live births at 22-24 weeks., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Despite providing intensive care to more infants born <24 weeks' gestation, data on school-age outcomes, critical for counselling and decision-making, are sparse., Objective: To compare major neurosensory, cognitive and academic impairment among school-aged children born extremely preterm at 22-23 weeks' gestation (EP22-23) with those born 24-25 weeks (EP24-25), 26-27 weeks (EP26-27) and term (≥37 weeks)., Design: Three prospective longitudinal cohorts., Setting: Victoria, Australia., Participants: All EP live births (22-27 weeks) and term-born controls born in 1991-1992, 1997 and 2005., Main Outcome Measures: At 8 years, major neurosensory disability (any of moderate/severe cerebral palsy, IQ <-2 SD relative to controls, blindness or deafness), motor, cognitive and academic impairment, executive dysfunction and poor health utility. Risk ratios (RRs) and risk differences between EP22-23 (reference) and other gestational age groups were estimated using generalised linear models, adjusted for era of birth, social risk and multiple birth., Results: The risk of major neurosensory disability was higher for EP22-23 (n=21) than more mature groups (168 EP24-25; 312 EP26-27; 576 term), with increasing magnitude of difference as the gestation increased (adjusted RR (95% CI) compared with EP24-25: 1.39 (0.70 to 2.76), p=0.35; EP26-27: 1.85 (0.95 to 3.61), p=0.07; term: 13.9 (5.75 to 33.7), p<0.001). Similar trends were seen with other outcomes. Two-thirds of EP22-23 survivors were free of major neurosensory disability., Conclusions: Although children born EP22-23 experienced higher rates of disability and impairment at 8 years than children born more maturely, many were free of major neurosensory disability. These data support providing active care to infants born EP22-23., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Many clinicians overestimate mortality and disability rates in infants born extremely preterm. We developed a digital tool ('NIC-PREDICT') that predicts infant mortality and survival with and without major disability in infants born 23-27 weeks' gestation., Aims: To determine if clinicians could use NIC-PREDICT accurately, and if their perceptions of infant outcomes improved after its release in 2021., Materials and Methods: Midwives, nurses, obstetricians, neonatologists and paediatricians working in tertiary and non-tertiary hospitals in Victoria were asked to use NIC-PREDICT to estimate three mutually exclusive outcomes: (i) mortality; (ii) survival free of major disability; and (iii) survival with major disability for six different scenarios where a liveborn infant was offered survival-focused care after birth. The proportions who completed the survey (responded to all six scenarios) and the proportions able to provide 100% accurate results for all scenarios were determined. Estimates of the three outcomes were compared with true rates., Results: A total of 85 clinicians responded: 70 (82%) completed the survey, with an overall accuracy of 76%. Overall, predictions of mortality were accurate (mean difference from true value 0.7% (95% confidence interval (CI) -0.7, 2.1) P = 0.33), as were predictions of survival without major disability (mean difference - 0.7 (95% CI -3.0, 1.7) P = 0.58). However, survival with major disability was overestimated by 4.9% ((95% CI 1.7, 8.0) P = 0.003)., Conclusions: Most perinatal clinicians who responded used NIC-PREDICT correctly to estimate expected outcomes in infants born extremely preterm who are offered intensive care. Undue pessimism about survival with major disability remains an ongoing concern., (© 2024 The Authors. Australian and New Zealand Journal of Obstetrics and Gynaecology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Background: Extremely preterm infants often require invasive mechanical ventilation, and clinicians aim to extubate these infants as soon as possible. However, extubation failure occurs in up to 60% of extremely preterm infants and is associated with increased mortality and morbidity. Nasal continuous positive airway pressure (nCPAP) is the most common post-extubation respiratory support, but there is no consensus on the optimal nCPAP level to safely avoid extubation failure in extremely preterm infants. We aimed to determine if higher nCPAP levels compared with standard nCPAP levels would decrease rates of extubation failure in extremely preterm infants within 7 days of their first extubation., Methods: In this multicentre, randomised, open-label controlled trial done at three tertiary perinatal centres in Australia, we assigned extremely preterm infants to extubation to either higher nCPAP (10 cmH 2 O) or standard nCPAP (7 cmH 2 O). Infants were eligible if they were born at less than 28 weeks' gestation, were receiving mechanical ventilation via an endotracheal tube, and were being extubated for the first time to nCPAP. Eligible infants must have received previous treatment with exogenous surfactant and caffeine. Infants were ineligible if they were planned to be extubated to a mode of respiratory support other than nCPAP, if they had a known major congenital anomaly that might affect breathing, or if ongoing intensive care was not being provided. Parents or guardians provided prospective, written, informed consent. Infants were maintained within an assigned nCPAP range for a minimum of 24 h after extubation (higher nCPAP group 9-11 cmH 2 O and standard nCPAP group 6-8 cmH 2 O). Randomisation was stratified by both gestation (22-25 completed weeks or 26-27 completed weeks) and recruiting centre. The primary outcome was extubation failure within 7 days and analysis was by intention to treat. This trial was prospectively registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12618001638224., Findings: Between March 3, 2019, and July 31, 2022, 483 infants were born at less than 28 weeks and admitted to the recruiting centres. 92 infants were not eligible, 172 were not approached, 65 families declined to participate, and 15 consented but were not randomly assigned. 139 infants were enrolled and randomly assigned, 70 to the higher nCPAP group and 69 to the standard nCPAP group. One infant in the higher nCPAP group was excluded from the analysis because consent was withdrawn after randomisation. 104 (75%) of 138 mothers were White. The mean gestation was 25·7 weeks (SD 1·3) and the mean birthweight was 777 grams (201). 70 (51%) of 138 infants were female. Extubation failure occurred in 24 (35%) of 69 infants in the higher nCPAP group and in 39 (57%) of 69 infants in the standard nCPAP group (risk difference -21·7%, 95% CI -38·5% to -3·7%). There were no significant differences in rates of adverse events between groups during the primary outcome period. Three patients died (two in the higher nCPAP group and one in the standard nCPAP group), pneumothorax occurred in one patient from each group, spontaneous intestinal perforation in three patients (two in the higher nCPAP group and one in the standard nCPAP group) and there were no events of pulmonary interstitial emphysema., Interpretation: Extubation of extremely preterm infants to higher nCPAP significantly reduced extubation failure compared with extubation to standard nCPAP, without increasing rates of adverse effects. Future larger trials are essential to confirm these findings in terms of both efficacy and safety., Funding: National Health and Medical Research Council Centre for Research Excellence in Newborn Medicine, number 1153176., Competing Interests: Declaration of interests Outside of the submitted work, AMK, BJM, PGD, AM, and SMD report receipt of funding from the National Health and Medical Research Council, Australia. BJM, PGD, AM, and SMD report receipt of funding from the Medical Research Future Fund, Australia. BJM reports receipt of an investigator-initiated grant for medical supplies within a trial from Chiesi Farmaceutici, Italy. AM reports receipt of funding from Cerebral Palsy Alliance, National Stem Cell Foundation of Australia, Lions Cord Blood Foundation, Monash Health Foundation, and Inner Wheel Australia. FB reports receipt of funding from the Mater Foundation, and the Royal Australasian College of Physicians, Australia. RB and RAB declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: To determine the diagnostic accuracy of small-for-gestational-age (SGA; <10th centile) status for infant mortality and adverse school-age outcomes in infants born extremely preterm (EP; <28 weeks' gestation)., Design: Geographical cohort studies., Setting: The state of Victoria, Australia., Patients: For mortality, live births 22-27 weeks' gestation from 2009 to 2017 offered active care after birth. For school-age outcomes, survivors to 8 years' corrected age born in 1991-1992, 1997 or 2005., Exposures: SGA <10th centile on four commonly used growth references: three derived from neonatal data (Fenton, UK-WHO and Intergrowth Newborn Size) and one from fetal data (Intergrowth Estimated Fetal Weight)., Main Outcome Measures: (a) Infant mortality; (b) major neurodevelopmental disability, and poor performance on tests of IQ, academic achievement, motor function, and executive function., Results: Infant mortality data were available for 2040 infants, and neurodevelopmental data for 499 children. Diagnostic accuracy of SGA status was low overall and varied with the growth reference. Positive predictive values for infant mortality ranged from 18% to 21%, only marginally higher than its 18% prevalence. Compared with a prevalence of 17%, positive predictive values for major neurodevelopmental disability ranged from 30% to 38% for the neonatal growth references but was only 20% for Intergrowth Estimated Fetal Weight. SGA status was also associated with lower IQ, poor academic achievement and poor motor performance., Conclusions: Among infants born EP, the diagnostic accuracy of SGA status was low for both infant mortality and adverse neurodevelopmental outcomes at school age, but importantly varied with the growth reference used to identify SGA status., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Although outcomes for infants born extremely low birthweight (ELBW; <1000 g birthweight) have improved over time, it is important to document survival and morbidity changes following the advent of modern neonatal intensive care in the 1990s., Objective: To describe trends in survival, perinatal outcomes and neurodevelopment to 2 years' corrected age over time across six discrete geographic cohorts born ELBW between 1979 and 2017., Methods: Analysis of data from discrete population-based prospective cohort studies of all live births free of lethal anomalies with birthweight 500-999 g in the state of Victoria, Australia, over 6 eras: 1979-80, 1985-87, 1991-92, 1997, 2005 and 2016-17. Perinatal data collected included survival, duration and type of respiratory support, neonatal morbidities and two-year neurodevelopmental outcomes., Results: More ELBW live births were inborn (born in a maternity hospital with a neonatal intensive care unit) over time (1979-80, 70%; 2016-17, 84%), and more were offered active care (1979-80, 58%; 2016-17, 90%). Survival to 2 years rose substantially, from 25% in 1979-80 to 80% in 2016-17. In survivors, rates of any assisted ventilation rose from 75% in 1979-80 to 99% in 2016-17. Cystic periventricular leukomalacia, severe retinopathy of prematurity and blindness improved across eras. Two-year data were available for 95% (1054/1109) of survivors. Rates of cerebral palsy, deafness and major neurodevelopmental disability changed little over time. The annual numbers with major neurodevelopmental disability increased from 12.5 in 1979-80 to 30 in 2016-17, but annual numbers free of major disability increased much more, from 31 in 1979-80 to 147 in 2016-17., Conclusions: Active care and survival rates in ELBW children have increased dramatically since 1979 without large changes in neonatal morbidities. The numbers of survivors free of major neurodevelopmental disability have increased more over time than those with major disability., (© 2022 John Wiley & Sons Ltd.)

Background: Decision-making for infants born at 23-25 weeks involves counselling parents about survival and major disability risks. Accurate information is needed for parents to make informed decisions about their baby's care., Aims: To determine if perinatal clinicians had accurate perceptions of outcomes of infants born at 23-25 weeks' gestation, and if accuracy had changed over a decade., Materials and Methods: A web-based survey was sent to midwives, nurses, neonatologists, and obstetricians working in tertiary and non-tertiary hospitals, and the neonatal retrieval service in the state of Victoria in 2020. A similar survey had been completed in 2010. Clinicians' estimates of survival and major neurodevelopmental disability rates were compared with true rates for actively managed infants overall, and by infant birthplace and gestational age, and professional workplace and discipline. Accuracy of outcomes was compared between eras., Results: Overall, 165 surveys were received. Participants underestimated survival (absolute mean difference [%] -14.4%; [95% confidence interval (CI) -16.6 to -12.3]; P < 0.001) and overestimated major disability (absolute mean difference 32.7%; [95% CI 29.7 to 35.8]; P < 0.001) rates overall, and at each week of gestation, and were worse for outborn compared with inborn infants. Perceptions of clinicians in tertiary centres were similar to those of non-tertiary clinicians. Nurses/midwives were more pessimistic, and paediatricians were more optimistic. Clinicians' perceptions of outcome were less accurate in 2020 than in 2010., Conclusions: Most perinatal clinicians underestimate survival and overestimate major disability of infants born at 23-25 weeks' gestation, which may translate into overly pessimistic counselling of parents., (© 2021 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

This systematic review investigated the effects of weight-loss diets before elective surgery on preoperative weight loss and postoperative outcomes in people with obesity. Electronic databases were searched from inception to May 2021. Inclusion criteria were prospective cohort or randomised controlled studies that compared effects of weight-loss diets to standard care on postoperative outcomes in adults with obesity awaiting surgery. Participants with cancer or undergoing bariatric surgery were excluded. Data on preoperative weight change, length of stay, postoperative complications and patient-reported outcome measures were extracted and synthesised in meta-analyses. One randomised controlled trial involving total knee arthroplasty and two that investigated general surgery were eligible that included 173 participants overall. Each study compared low-calorie diets using meal replacement formulas to usual care. There is very-low-quality evidence of a statistically significant difference favouring the intervention for preoperative weight loss (mean difference [MD] -6.67 kg, 95% confidence interval [CI] -12.09 to -1.26 kg; p = 0.02) and low-quality evidence that preoperative weight-loss diets do not reduce postoperative complications to 30 days (odds ratio [OR] 0.34, 95% CI 0.08-1.42; p = 0.14) or length of stay (MD -3.72 h, 95% CI -10.76 to 3.32; p = 0.30). From the limited data that is of low quality, weight loss diets before elective surgery do not reduce postoperative complications., (© 2021 The Authors. Clinical Obesity published by John Wiley & Sons Ltd on behalf of World Obesity Federation.)

Extremely preterm birth before 28 weeks' gestation accounts for less than 1% of births in high-income countries but is associated with high rates of perinatal and infant mortality, and of neurodevelopmental disability in surviving children. Survival rates have increased over time, both overall, and within each week of gestational age since the introduction of exogenous surfactant into clinical care in the early 1990s. However, rates of major neurodevelopmental disability in survivors, whether they be in early childhood or at school-age, have not clearly improved in parallel with the increases in survival. An important strategy to improve survival free of major neurodevelopmental disability is to birth extremely preterm infants in a tertiary perinatal center, where specialist obstetric care for the mother and ongoing intensive care for the infant can both be provided without the potential morbidities associated with postnatal transfer., Competing Interests: Declaration of Competing Interest The authors have no conflicts to declare, real or perceived., (Crown Copyright © 2021. Published by Elsevier Inc. All rights reserved.)

Importance: Survival of infants born extremely preterm (EP) (<28 weeks' gestation) has increased since the early 1990s. It is necessary to know whether increased survival is accompanied by increased neurodevelopmental disability., Objective: To examine changes in major (ie, moderate or severe) neurodevelopmental disability and survival free of major neurodevelopmental disability at 2 years in infants born EP., Design, Setting, and Participants: Four prospective longitudinal cohort studies comprising all EP live births at 22 to 27 weeks' gestation from April 1, 2016, to March 31, 2017, and earlier eras (1991-1992, 1997, and 2005), and contemporaneous term-born controls in the state of Victoria, Australia. Among 1208 live births during the periods studied, data were available for analysis of 2-year outcomes in 1152 children: 422 (1991-1992), 215 (1997), 263 (2005), and 252 (2016-2017). Data analysis was performed from September 17, 2020, to April 15, 2021., Exposures: Extreme preterm live birth., Main Outcomes and Measures: Survival, blindness, deafness, cerebral palsy, developmental delay, and neurodevelopmental disability at 2 years' corrected age. Developmental delay comprised a developmental quotient less than -1 SD relative to the control group means on the Bayley Scales for each era. Major neurodevelopmental disability comprised blindness, deafness, moderate to severe cerebral palsy, or a developmental quotient less than -2 SDs. Individual neurodevelopmental outcomes in each era were contrasted relative to the 2016-2017 cohort using logistic regression adjusted for gestational age, sex, birth weight z score, and sociodemographic variables. Changes in survival free of major neurodevelopmental disability over time were also assessed using logistic regression., Results: Survival to 2 years was highest in 2016-2017 (73% [215 of 293]) compared with earlier eras (1991-1992: 53% [225 of 428]; 1997: 70% [151 of 217]; 2005: 63% [170 of 270]). Blindness and deafness were uncommon (<3%). Cerebral palsy was less common in 2016-2017 (6%) than in earlier eras (1991-1992: 11%; 1997: 12%; 2005: 10%). There were no obvious changes in the rates of developmental quotient less than -2 SDs across eras (1991-1992: 18%; 1997: 22%; 2005: 7%; 2016-2017: 15%) or in rates of major neurodevelopmental disability (1991-1992: 20%; 1997: 26%; 2005: 15%; 2016-2017: 15%). Rates of survival free of major neurodevelopmental disability increased steadily over time: 42% (1991-1992), 51% (1997), 53% (2005), and 62% (2016-2017) (odds ratio, 1.30; 95% CI, 1.15-1.48 per decade; P < .001)., Conclusions and Relevance: These findings suggest that survival free of major disability at age 2 years in children born EP has increased by an absolute 20% since the early 1990s. Increased survival has not been associated with increased neurodevelopmental disability.

Background: Management of livebirths at 22-24 weeks' gestation in high-income countries varies widely and has changed over time., Aims: Our aim was to determine how rates of active management and infant survival of livebirths at 22-24 weeks varied with perinatal variables known at birth, and over time in Victoria, Australia., Materials and Methods: We conducted a population-based cohort study of all 22-24 weeks' gestation live births, free of lethal congenital anomalies in 2009-2017. Rates of active management and survival to one year of age were reported. 'Active management' was defined as receiving resuscitation at birth or nursery admission for intensive care., Results: Over the nine-year period, there were 796 eligible live births. Overall, 438 (55%) were actively managed: 5% at 22 weeks, 45% at 23 weeks and 90% at 24 weeks' gestation, but rates of active management did not vary substantially over time. Of livebirths actively managed, 263 (60%) survived to one year: 0% at 22 weeks, 50% at 23 weeks and 66% at 24 weeks. Apart from gestational age, being born in a tertiary perinatal centre and increased size at birth were associated with survival in those actively managed, but sex and plurality were not. Survival rates of actively managed infants rose over time (adjusted odds ratio 1.09 per year; 95% CI 1.01-1.18; P = 0.03)., Conclusions: Although active management rates did not change substantially over time in Victoria, an overall increase in infant survival was observed. With increasing gestational age, rates of active management and infant survival rapidly rose., (© 2021 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Background: Magnesium sulphate was introduced for fetal neuroprotection in Australia in 2010. The aim of this study was to determine how often antenatal magnesium sulphate is used currently and its association with cerebral palsy in children born <28 weeks' gestation., Materials and Methods: Participants comprised all survivors born <28 weeks' gestational age in the state of Victoria in 2016-17, and earlier, in 1991-92, 1997, 2005. Rates of cerebral palsy, diagnosed at two years for the 2016-17 cohort, and at eight years in the earlier cohorts, were compared across eras. Within 2016-17, the proportions of children exposed to antenatal magnesium sulphate were determined, and rates of cerebral palsy were compared between those with and without exposure to magnesium sulphate., Results: Overall, cerebral palsy was present in 6% (11/171) of survivors born in 2016-17, compared with 12% (62/499) of survivors born in the three earlier eras (odds ratio (OR) 0.48, 95% confidence interval (CI) 0.25-0.94; P = 0.032). Data were available for 213/215 (99%) survivors born in 2016-17, of whom 147 (69%) received magnesium sulphate. Data on cerebral palsy at two years were available for 171 (80%) survivors with magnesium data. Cerebral palsy was present in 5/125 (4%) children exposed to magnesium sulphate and in 6/46 (13%) of those not exposed (OR 0.28, 95% CI 0.08-0.96; P = 0.043)., Conclusions: Antenatal magnesium sulphate is being translated into clinical practice for infants born <28 weeks' gestation, but there is room for improvement. It is associated with lower rates of cerebral palsy in survivors., (© 2021 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Introduction: Respiratory distress syndrome is a complication of prematurity and extremely preterm infants born before 28 weeks' gestation often require endotracheal intubation and mechanical ventilation. In this high-risk population, mechanical ventilation is associated with lung injury and contributes to bronchopulmonary dysplasia. Therefore, clinicians attempt to extubate infants as quickly and use non-invasive respiratory support such as nasal continuous positive airway pressure (CPAP) to facilitate the transition. However, approximately 60% of extremely preterm infants experience 'extubation failure' and require reintubation. While CPAP pressures of 5-8 cm H2O are commonly used, the optimal CPAP pressure is unknown, and higher pressures may be beneficial in avoiding extubation failure. Our trial is the Extubation CPAP Level Assessment Trial (ÉCLAT). The aim of this trial is to compare higher CPAP pressures 9-11 cm H2O with a current standard pressures of 6-8 cmH2O on extubation failure in extremely preterm infants., Methods and Analysis: 200 extremely preterm infants will be recruited prior to their first extubation from mechanical ventilation to CPAP. This is a parallel group randomised controlled trial. Infants will be randomised to one of two set CPAP pressures: CPAP 10 cmH2O (intervention) or CPAP 7 cmH2O (control). The primary outcome will be extubation failure (reintubation) within 7 days. Statistical analysis will follow standard methods for randomised trials on an intention to treat basis. For the primary outcome, this will be by intention to treat, adjusted for the prerandomisation strata (GA and centre). We will use the appropriate parametric and non-parametric statistical tests., Ethics and Dissemination: Ethics approval has been granted by the Monash Health Human Research Ethics Committees. Amendments to the trial protocol will be submitted for approval. The findings of this study will be written into a clinical trial report manuscript and disseminated via peer-reviewed journals (on-line or in press) and presented at national and international conferences. Trial registration number ACTRN12618001638224; pre-results., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To determine predictors and outcomes of extubation failure in extremely preterm (EP) infants born <28 weeks' gestational age (GA)., Methods: Retrospective clinical audit across two tertiary-level neonatal intensive care units in Melbourne, Australia. Two-hundred and four EP infants who survived to their first extubation from mechanical ventilation. Extubation failure (re-intubation) within 7 days after the first extubation., Results: Lower GA (odds ratio [OR] 0.71, 95% confidence interval (CI), 0.61-0.89, P < 0.001) and higher pre-extubation measured mean airway pressure (MAP) on the mechanical ventilator (OR 1.9 [95% CI 1.41-2.51], P < 0.001) predicted extubation failure. The area under a receiver operating characteristic curve for GA and MAP was 0.77 (95% CI 0.70-0.82). After adjustment for GA, infants who experienced extubation failure had higher rates of bronchopulmonary dysplasia (P < 0.001), post-natal systemic corticosteroid treatment (P < 0.001), airway trauma (P < 0.003), longer durations of treatment with mechanical ventilation (P < 0.001), non-invasive respiratory support (P < 0.001), supplemental oxygen therapy (P = 0.05) and longer hospitalisation (P = 0.025)., Conclusions: Lower GA and higher pre-extubation measured MAP were predictive of extubation failure within 7 days in extremely preterm infants. Extubation failure was associated with increased morbidity and extended periods of respiratory support and hospitalisation., (© 2021 Paediatrics and Child Health Division (The Royal Australasian College of Physicians).)

Objectives: It is unclear how newer methods of respiratory support for infants born extremely preterm (EP; 22-27 weeks gestation) have affected in-hospital sequelae. We aimed to determine changes in respiratory support, survival and morbidity in EP infants since the early 1990s., Design: Prospective longitudinal cohort study., Setting: The State of Victoria, Australia., Participants: All EP births offered intensive care in four discrete eras (1991-1992 (24 months): n=332, 1997 (12 months): n=190, 2005 (12 months): n=229, and April 2016-March 2017 (12 months): n=250)., Outcome Measures: Consumption of respiratory support, survival and morbidity to discharge home. Cost-effectiveness ratios describing the average additional days of respiratory support associated per additional survivor were calculated., Results: Median duration of any respiratory support increased from 22 days (1991-1992) to 66 days (2016-2017). The increase occurred in non-invasive respiratory support (2 days (1991-1992) to 51 days (2016-2017)), with high-flow nasal cannulae, unavailable in earlier cohorts, comprising almost one-half of the duration in 2016-2017. Survival to discharge home increased (68% (1991-1992) to 87% (2016-2017)). Cystic periventricular leukomalacia decreased (6.3% (1991-1992) to 1.2% (2016-2017)), whereas retinopathy of prematurity requiring treatment increased (4.0% (1991-1992) to 10.0% (2016-2017)). The average additional costs associated with one additional infant surviving in 2016-2017 were 200 (95% CI 150 to 297) days, 326 (183 to 1127) days and 130 (70 to 267) days compared with 1991-1992, 1997 and 2005, respectively., Conclusions: Consumption of resources for respiratory support has escalated with improved survival over time. Cystic periventricular leukomalacia reduced in incidence but retinopathy of prematurity requiring treatment increased. How these changes translate into long-term respiratory or neurological function remains to be determined., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Decisions regarding provision of intensive care and post-discharge follow-up for infants born extremely preterm (<28 weeks' gestation) are based on the risks of mortality and neurodevelopmental disability. We aimed to elucidate the changes in probability of three outcomes (death, survival with major disability, and survival without major disability) with postnatal age in extremely preterm infants offered intensive care, and the effect of postnatal events on the probability of survival without major disability., Methods: In this prospective observational study, we used data from three geographical cohorts composed of all extremely preterm livebirths offered intensive care at birth during three distinct periods (1991-92, 1997, and 2005) in Victoria, Australia. Participants were assessed at 8 years' corrected age for major neurodevelopmental disability, defined as moderate or severe cerebral palsy, general intelligence more than 2 SDs below term-born control means, blindness, or deafness. Probabilities of outcomes conditional on survival to different postnatal ages were calculated by logistic regression. Multivariable logistic regression was used to assess factors predictive of survival with major disability., Findings: 751 (82%) of 915 extremely preterm livebirths free of lethal anomalies were offered intensive care, of whom 546 (73%) survived to age 8 years. Of the 499 survivors assessed, 86 (17%) had a major disability. With increasing gestational age at birth or days of postnatal survival, the probability of death decreased and of survival without major disability increased. By contrast, the probability of survival with major disability varied little with gestational age or postnatal survival. In survivors, major disability was associated with the occurrence of four important postnatal events: grade 3 or 4 intraventricular haemorrhage (odds ratio 2·61 [95% CI 1·11-6·15]), cystic periventricular leukomalacia (9·17 [3·57-23·53]), postnatal corticosteroid use (1·99 [1·03-3·85]), and surgery (2·78 [1·51-5·13]). 241 survivors (48%) had no major postnatal events during the newborn period, and had the lowest prevalence of major disability (17 participants [7%]). The probability of survival without major disability decreased with increasing number of major events (0·93 [0·89-0·96] for no events vs 0·31 [0·11-0·59] for three or more events)., Interpretation: Long-term prognosis in terms of death and major neurodevelopmental disability changes rapidly after birth for extremely preterm infants. Counselling of families and post-discharge planning should be individualised to changing circumstances following birth., Funding: National Health and Medical Research Council of Australia., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objectives: Pre-eclampsia (PE) is associated with significant risks of adverse perinatal outcomes, often necessitating transfer to a higher level of care for specialist perinatal management. In Victoria, Australia, the Paediatric Infant Perinatal Emergency Retrieval (PIPER) coordinates in-utero transfers of high-risk pregnancies. Our objectives were to report the clinical features and outcomes of women referred to PIPER with a primary diagnosis of PE, and subsequently transferred in-utero., Study Design: A retrospective audit of consecutive pregnancies referred to PIPER in 2013-2014 with a primary diagnosis of pre-eclampsia, ≥20 weeks' gestation and transferred in-utero., Main Outcome Measures: Severity of disease, gestational age, transfer details and outcome until 7 days post transfer., Results: Over two years, 244 women were referred to PIPER with PE; 199 (82%) were subsequently transferred in-utero. Severe PE was diagnosed in 146 (73%) women. Overall, 64% presented 'early' (<32 weeks' gestation). Only 6% were ≥37 weeks. All but 2 women <32 weeks were transferred to a tertiary perinatal centre, compared with 39% of women ≥32 weeks. Within 7 days, 153/199 (77%) delivered, 10% remained in-patients and 12.5% were discharged. There were 165 livebirths and 3 stillbirths, with a mean gestational age of 30.7 weeks (SD 3.3 weeks). Twenty-nine women required high dependency or intensive care admission. No maternal deaths were reported., Conclusion: Women referred to PIPER predominantly presented with early onset, severe PE and most delivered within 7 days of transfer. Data from this study provides important information for obstetric service planning in Victoria and comparable regions., (Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.)

Background: Our aim was to report perinatal characteristics of very preterm births before arrival (BBAs) at a hospital, and perinatal and infant mortality rates up to one year, comparing BBAs with births in a hospital., Materials and Methods: A population-based cohort study of 22-31 weeks' gestation births in the state of Victoria, Australia from 1990-2009. BBAs were defined as unintentional births at home or on route to hospital. Perinatal data were obtained from the Department of Health and Human Services, Victoria. Perinatal and infant mortality data comparing BBAs with births in hospitals were analysed by logistic regression, adjusted for gestational age, birthweight and sex., Results: One hundred and thirty-three BBAs were recorded: 51 (38%) stillbirths and 82 (62%) livebirths. Compared with births in a hospital, BBAs were less mature (26.3 weeks (SD 2.9) vs 27.7 weeks (SD 2.8), P < 0.001) and a higher proportion were born to teenagers: 13% versus 5% (adjusted odds ratio (aOR) 2.86, P < 0.001). BBAs were significantly more likely to be stillborn (aOR 2.13, 95% confidence interval (CI) 1.41, 3.23, P < 0.001) die within 28 days of livebirth (aOR 2.97, 95% CI 1.54, 5.73, P = 0.001) or die within a year of livebirth (aOR 2.87, 95% CI 1.51, 5.46, P = 0.001) compared with hospital births. Overall, 54 BBAs survived to one year (41% all BBAs, 67% liveborn BBAs), compared with 69% of hospital births (87% of livebirths)., Conclusions: Very preterm birth before arrival is more common in teenagers and is associated with significantly increased risks of perinatal and infant mortality compared with birth in a hospital., (© 2017 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Objectives: To compare mortality and serious morbidity rates between outborn and inborn livebirths at 22-27 weeks' gestation., Design: Population-based cohort study., Setting: Victoria, Australia., Patients: Livebirths at 22-27 weeks' gestation free of major malformations in 2010-2011., Interventions: Outcome data for outborn (born outside a tertiary perinatal centre) infants compared with inborn (born in a tertiary perinatal centre) infants were analysed by logistic regression, adjusted for gestational age, birth weight and sex., Main Outcome Measures: Infant mortality and serious morbidity rates to hospital discharge., Results: 541 livebirths free of major malformations were recorded. By 1 year, 49 (58%) outborns and 140 (31%) inborns died (adjusted OR (aOR) 2.78, 95% CI 1.52 to 5.09, p=0.001). In total, 445 infants were admitted to neonatal intensive care unit (NICU); 93 died by 1 year (14/49 outborns and 79/396 inborns), (aOR 1.75, 95% CI 0.87 to 3.55, p=0.12). There were no significant differences in rates of necrotising enterocolitis, intraventricular haemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia (BPD) or the combined outcome of death or BPD in outborn infants compared with inborn infants. Outborns had an increased risk of cystic periventricular leukomalacia (cPVL) compared with inborns (12.2% vs 2.8%, respectively; aOR 5.34, 95% CI 1.84 to 15.54, p=0.002)., Conclusions: Mortality rates remained higher for outborn livebirths at 22-27 weeks' gestation compared with inborn peers in 2010-2011. Outborn infants admitted to NICU did not have substantially different rates of mortality or serious morbidity compared with inborns, with the exception of cPVL. Longer-term health consequences of outborn birth before 28 weeks' gestation need to be determined., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background: Parent counselling and decision-making regarding the management of preterm labour and birth are influenced by information provided by healthcare professionals regarding potential infant outcomes., Aim: The aim of this study was to determine whether perinatal healthcare providers had accurate perceptions of survival and major neurosensory disability rates of very preterm infants born in non-tertiary hospitals ('outborn') and tertiary perinatal centres ('inborn')., Materials and Methods: A web-based survey was distributed to midwives, nurses, obstetricians and neonatologists working in non-tertiary and tertiary maternity hospitals, and the perinatal/neonatal emergency transport services in Victoria, Australia., Main Outcome Measures: Estimates of survival rates at 24 and 28-weeks' gestation were compared with actual survival rates of a population-based cohort of 24 and 28-weeks' gestation infants, born free of lethal anomalies in Victoria in 2001-2009. Estimates of major neurosensory disability rates in 24 and 28-week survivors were compared with actual disability rates in 24 and 28-week children born in Victoria averaged over three eras: 1991-1992, 1997 and 2005., Results: Response rates varied as follows: 83% of non-tertiary midwives, 4% of obstetricians, 55% of tertiary centre staff and 68% of transport team staff responded (total of 30%). Overall, respondents underestimated survival and overestimated major neurosensory disability rates in both outborn and inborn 24 and 28-week infants. Outborn infants were perceived to have much worse prospects for survival and for survival with major disability compared with inborn peers., Conclusion: Many clinicians overestimated rates of adverse outcomes. These clinicians may be misinforming parents about their child's potential for a favourable outcome., (© 2016 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Background: Very preterm infants born in non-tertiary hospitals ('outborn') are known to have higher mortality rates compared with infants 'inborn' in tertiary centres., Aim: The aim of this study was to report changes over time in the incidence of outborn livebirths, 22-31 weeks and infant mortality rates for outborn compared with inborn births., Methods: We conducted a population-based cohort study of consecutive livebirths, 22-31 weeks' gestation in Victoria from 1990 to 2009. The relationship between birthplace, gestational age, birthweight, sex and infant mortality were analysed by logistic regression., Results: There were 13,760 livebirths, 22-31 weeks: 14% were outborn. The proportion of outborn livebirths fell from 19% in 1991 to a nadir of 9% in 1997, but climbed to 17% by 2009. At all times, outborns had higher mortality rates compared with inborns. The overall infant mortality rate was 250.6 per 1000 outborn compared with 113.3 per 1000 inborn livebirths (adjusted odds ratio (aOR) 2.76 (95% CI 2.32, 3.27, P < 0.001). There were no differences between outborn and inborn mortality risks for 22-week livebirths (OR 7.04, 95% CI 0.87, 56.8, P = 0.067), but there were at 23-27 weeks (aOR 3.16, 95% CI 2.52, 3.96, P < 0.001) and at 28-31 weeks (aOR 1.66, 95% CI 1.19, 2.31, P = 0.003). Over time, mortality rates fell for inborn 23-27 week infants. Mortality rates fell for outborn 23-27 week infants in 1990-2005, but rose in 2006-2009., Conclusions: Outborn livebirths at 22-31 weeks' gestation occur too frequently and are associated with a significantly increased risk of mortality. Strategies to reduce outborn livebirths are required., (© 2015 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.)

Background: The aim of this study was to determine if the National Institute of Child Health and Human Development (NICHD) calculator, designed to predict mortality or neurosensory disability in infants 22-25 weeks' gestation, was valid for contemporary Australian infants., Method: Outcome data at 2 years of age for 114 infants who were liveborn in Victoria, Australia, in 2005, between 22 and 25 completed weeks' gestation, weighing 401-1000 g at birth, and free of lethal anomalies, were entered into the NICHD online calculator. Predicted outcomes were then compared with the actual outcomes., Results: Of the 114 infants, 99 (87%) were inborn and 15 (13%) were outborn. The overall prediction of death for inborn infants was 47.1% compared with the actual death rate to 2 years of age of 49.5%. The area under the curve (AUC) was 0.803 (95% CI 0.718 to 0.888; p<0.001) for mortality, comparable with the AUC for the NICHD study (AUC: 0.753; 95% CI 0.737 to 0.769; p<0.001). The accuracy for predicting death was not as precise for outborn infants (AUC: 0.643; 95% CI 0.337 to 0.949; p=0.36). The calculator overestimated the combined outcome of death or survival with major disability at 72.0%, compared with an actual rate of 60.5%., Conclusions: The NICHD outcome estimator was helpful in predicting mortality for inborn infants, 22-25 weeks' gestation, but was less precise for outborn infants. It overestimated the combined outcome of death or major disability in infants born in Victoria, Australia, in 2005.

Introduction: In this study we investigated the changes in axonal excitability and the generation of neurological symptoms in response to focal nerve compression (FNC) of the median nerve in carpal tunnel syndrome (CTS)., Methods: Sensory excitability recordings were undertaken in 11 CTS patients with FNC being applied at the wrist using a custom-designed electrode., Results: During FNC, refractoriness increased significantly (62.4 ± 3.4%; P < 0.001), associated with a rapid reduction in superexcitability (16.9 ± 2.8%; P < 0.001) and sensory nerve action potential amplitude (SNAP) (32.4 ± 3.9%; P < 0.001), consistent with axonal depolarization. Associated with these changes, paresthesiae steadily increased throughout FNC, as did numbness. Reductions in SNAP amplitude and superexcitability developed more rapidly for CTS patients during FNC compared with controls, and these changes were associated with more marked symptoms., Conclusions: Axonal responses to compression are impaired in CTS. This may suggest a greater reliance on axonal membrane Na(+) /K(+) -ATPase function., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: Lymphedema of hand after breast cancer treatment causes significant loss of hand function. Although there are several ways of assessing limb volume, measuring hand volume has been problematic due to technical difficulties associated with assessment of finger volumes. The aim of this study was to investigate the criterion validity and reliability of Perometer™ for measuring hand volume in woman with and without lymphedema., Methods and Results: Hand volume of forty women with (n = 20) and without lymphedema (n = 20) was assessed twice by one rater and once by another rater using the Perometer, and once by one rater using the water volumetry method. Intra- and inter-rater reliability was determined from the intraclass correlation coefficients and Percent Close Agreement. Agreement between the Perometer and water volumetry was determined using a limit of agreement and Lin's concordance correlation. The Perometer had high intra [ICC(2,1) = 0.989 (95% CI: 0.98-0.99)] and inter-rater reliability [ICC(2,1) = 0.993 (95% CI: 0.99-1.0)]. Percent close agreement revealed that 80% of the measures were within 9 ml for inter-rater reliability and within 15 ml for intra-rater reliability. In addition, there was high concordance between hand volumes obtained with the Perometer and water volumetry method (R(c) = 0.88). However, the Perometer overestimated the volume of hand compared to water volumetry method (bias: 7.5%)., Conclusions: The Perometer can be used with high reliability to measure hand volume but caution should be exercised when data are compared with measures derived from the water volumetry method.

The mechanisms underlying spinal shock have not been clearly defined. At present, clinical assessment remains the mainstay to describe progression through spinal shock following traumatic spinal cord injury. However, nerve excitability studies in combination with conventional nerve conduction and clinical assessments have the potential to investigate spinal shock at the level of the peripheral axon. Therefore, peripheral motor axon excitability was prospectively and systematically evaluated in more than 400 studies of 11 patients admitted to hospital after traumatic spinal cord injury, with cord lesions above T9 (nine cervical, two thoracic). Recordings commenced within 15 days of admission from the median nerve to abductor pollicis brevis in the upper limb and the common peroneal nerve to tibialis anterior in both lower limbs, and were continued until patient discharge from hospital. Excitability was assessed using threshold tracking techniques and recordings were compared with data from healthy controls. In addition, concurrent clinical measures of strength, serum electrolytes and nerve conduction were collected. High threshold stimulus-response relationships were apparent from the early phase of spinal shock that coincided with depolarization-like features that reached a peak on Day 16.9 (± 2.7 standard error) for the common peroneal nerve and Day 11.8 (± 2.0 standard error) for the median nerve. Overall, changes in the common peroneal nerve were of greater magnitude than for the median nerve. For both nerves, the most significant changes were in threshold electrotonus, which was 'fanned in', and during the recovery cycle superexcitability was reduced (P < 0.001). However, refractoriness was increased only for the common peroneal nerve (P < 0.05). Changes in the spinal injured cohort could not be explained on the basis of an isolated common peroneal nerve palsy. By the time patients with spinal injury were discharged from hospital between Days 68 and 215, excitability for upper and lower limbs had returned towards normative values, but not for all parameters. Electrolyte levels and results for nerve conduction studies remained within normal limits throughout the period of admission. Contrary to prevailing opinion, these data demonstrate that significant changes in peripheral motor axonal excitability occur early during spinal shock, with subsequent further deterioration in axonal function, before recovery ensues.

Our objective was to evaluate the neurophysiological index (NI) as a biomarker for amyotrophic lateral sclerosis (ALS) and to assess the validity of linear mixed effects models for describing longitudinal changes. Functional assessment and nerve conduction studies were undertaken in 58 ALS patients. Neurophysiological data were collected on four occasions over 12 weeks (baseline, weeks 4, 8 and 12). The NI was calculated for the abductor digiti minimi and ulnar nerve at the wrist. NI declined at a rate of 0.04 per week (S.E. 0.006, p < 0.0001). Patients with bulbar-onset disease had 0.88 greater NI than patients with upper limb-onset disease over the follow-up period (S.E. 0.39, p = 0.03). There were no differences in the rates of decline among patients with different disease phenotypes. Rates of change in NI and functional impairment were weakly correlated (Spearman's p = 0.29, p = 0.03). Linear mixed effects models were appropriate for detailing the longitudinal changes in NI. The present findings support incorporation of NI as an outcome measure for ALS clinical trials conducted over short time periods.

The aim of the present study was to establish the changes in nerve excitability and symptom generation associated with the application of focal nerve compression (FNC). FNC was applied at the wrist by means of a custom-designed electrode in 10 healthy subjects, and was maintained for 24 min. Symptoms of paraesthesiae and signs of numbness were recorded every 30 s. Despite apparently minimal changes in axonal threshold, FNC was associated with prolongation in latency by 14.5 +/- 2.1% (P < 0.001) and reduction in compound sensory action potential (CSAP) amplitude by 34.3 +/- 5.1% (P < 0.001), with two subjects developing conduction block. The reduction in CSAP was associated with abolition of superexcitability, and an increase in refractoriness of 295.2 +/- 55.5% (P < 0.005) and strength-duration time constant (SDTC) by 48.1 +/- 10.3% (P < 0.005), all consistent with axonal depolarization. With release of FNC, threshold rapidly increased above pre-compression levels (P < 0.01), consistent with the development of axonal hyperpolarization. Associated with these changes in axonal excitability, paraesthesiae and numbness steadily increased throughout FNC and reached a peak at the termination of FNC, followed by a gradual recovery on release of FNC. When compared to previous studies that utilised the effects of more generalised limb ischaemia, the changes in axonal excitability recorded during FNC were qualitatively and quantitatively alike, suggesting that similar biophysical mechanisms contributed to the changes observed with both manoeuvres.

Respiratory impairment, due to respiratory muscle weakness, is a major cause of morbidity and mortality in patients with amyotrophic lateral sclerosis/motor neuron disease (ALS/MND). Threshold loading may strengthen the inspiratory muscles and thereby improve patient prognosis. A phase II, double-blind, randomized-controlled trial was undertaken to determine whether a 12-week inspiratory muscle training programme attenuated the decline in respiratory function and inspiratory muscle strength in patients with ALS/MND. Nine patients were randomized to inspiratory muscle training and 10 to sham training. Primary endpoints were respiratory function (forced vital capacity, vital capacity), lung volumes and inspiratory muscle strength. Patients were assessed before, during and immediately after a 12-week training period, and at eight weeks follow-up. While improvements in inspiratory muscle strength were observed in both treatment arms, there was a non-significant increase in maximum inspiratory pressure of 6.1% in the experimental group compared to controls (standard error of mean, 6.93%; 95% confidence interval -8.58 -20.79; p=0.39). The gains in inspiratory muscle strength were partially reversed during a period of training cessation. In conclusion, inspiratory muscle training may potentially strengthen the inspiratory muscles and slow the decline in respiratory function in patients with ALS/MND.

Although carpal tunnel syndrome (CTS) is the most common human entrapment neuropathy characterized by paraesthesiae and numbness with nocturnal exacerbation, the mechanisms underlying the generation of these symptoms remain unclear. Consequently, the aim of the present study was to investigate the relationship between changes in axonal excitability and the development of neurological symptoms in response to an ischaemic insult in CTS patients. Sensory and motor excitability were measured in 10 CTS patients and compared with 10 healthy controls, with participants asked to report symptom generation and intensity during the development of limb ischaemia. To induce ischaemia, a sphygmomanometer was inflated above the elbow and maintained at 200 mmHg for 10 min. During ischaemia there were decreases in axonal threshold, with less overall reduction in CTS patients when compared with controls. Associated with these differences in threshold, both sensory (p < 0.001) and motor (p < 0.05) refractoriness increased dramatically in CTS patients. This prominent increase in refractoriness was accompanied by a significant reduction in compound sensory action potentials and compound motor action potentials amplitudes for CTS patients when compared with controls (p < 0.05). These changes in axonal excitability resulted in a higher intensity of numbness and paraesthesiae reported by CTS patients during ischaemia. The present study has established differences in the nerve excitability and symptom development during ischaemia for patients with mild and moderate CTS, and may suggest that axons in the median nerve of CTS patients have an altered functional capacity to respond to an ischaemic insult, further contributing to nocturnal exacerbation of their symptoms.

The aim of the study was to investigate whether a combination of selected provocative manoeuvres and sensory testing could improve the accuracy of clinical diagnosis of carpal tunnel syndrome (CTS). Prospective studies were undertaken in 43 of 296 consecutive patients who were referred with suspected CTS and had undergone nerve conduction studies (NCS). Responses to Phalen's test, a modified carpal compression test (MCCT), and sensory testing over the thenar eminence were assessed for each patient. For each test (Phalen's; MCCT), sensitivity (0.64; 0.14), specificity (0.75; 0.96), positive likelihood ratio (PLR) (2.54; 3.64) and negative likelihood ratio (NLR) (0.49; 0.89) were calculated. The inclusion of sensory testing did not improve sensitivity (0.55; 0.13), specificity (0.75; 0.96), PLR (2.22; 3.29) or NLR (0.60; 0.91). These data indicate that assessment of thenar sensation does not improve the diagnostic accuracy of CTS. However, a positive Phalen's test is more likely to be associated with NCS changes that are consistent with CTS.

Objective: To assess changes in peripheral motor excitability after traumatic spinal cord injury (SCI)., Methods: Conventional nerve conduction and nerve excitability studies were longitudinally investigated in a patient diagnosed as C6 American Spinal Injury Association (ASIA) C incomplete. Recordings were undertaken from the peroneal nerve to tibialis anterior, and the median nerve to abductor pollicus brevis throughout the period of hospital admission., Results: Recordings were acutely abnormal in common peroneal axons 6 days after injury. Threshold electrotonus was "fanned in"; during the recovery cycle superexcitability was abolished, and refractoriness at 2.5ms was increased (patient 152.84%; controls 37.13+/-3.83%). All parameters recovered briefly after surgical stabilization on day 9, before regressing by day 13. Excitability values recovered by day 68 when the patient was discharged ambulant as ASIA D. Recordings remained relatively unaffected in median axons throughout the admission period., Conclusions: Decentralisation after SCI had significant effects on lower limb axons, not attributable to direct trauma. Conversely, median axons remained spared. Modeling of the lower limb excitability changes suggested that interruption of energy-dependent processes contributed to the peripheral abnormalities, perhaps through involvement of upstream transynaptic processes., Significance: These findings may suggest the potential for plasticity of peripheral axonal excitability in response to acute SCI.

Objective: To identify the sensitivity and the patterns of change in sensory excitability that accompany an ischaemic insult., Methods: Sensory excitability studies were undertaken in 10 subjects (mean age 36), and monitored throughout ischaemia and following its release. Ischaemia was induced using a sphygmomanometer inflated to 200mm/Hg above the elbow., Results: During ischaemia there was reduction in threshold (P<0.001), associated with a significant increase in refractoriness (106+/-6.62%; P<0.001), reduction in superexcitability (30.4+/-0.42%; P<0.001), and 'fanning in' of threshold electrotonus, all indicative of axonal depolarization. Paraesthesiae were minimal during ischaemia, but became severe on release, at which stage numbness was prominent. Late subexcitability in sensory axons was completely abolished by a relatively shorter period of ischaemia than previously observed in motor axons., Conclusions: The present study has successfully developed a template for changes in sensory axonal excitability parameters that accompany ischaemia, and established their relative sensitivity to an ischaemic change. Further, it is proposed that the inhibition of the Na+/K+ pump, in the setting of increased persistent Na+ currents and abolition of late subexcitability may underlie the development of paraesthesiae during ischaemia., Significance: Changes in axonal excitability induced by ischaemia may serve as a tool to identify and interpret changes in axonal membrane potential recorded in neuropathic patients.

Objective: To explore the basis for the Riche-Cannieu anastomosis (RCA) and specifically whether this anomaly is an hereditary characteristic., Methods: Three individuals from the same family were evaluated after initial studies in the index case indicated an RCA. Nerve conduction, needle electromyography (EMG), and axonal excitability studies of the median and ulnar nerves were undertaken in each case., Results: In all subjects onset thresholds for CMAPs from abductor pollicis brevis (APB) were lower with ulnar nerve stimulation, but of similar latencies when compared with median nerve stimulation. Larger CMAP amplitudes were obtained with ulnar nerve stimulation, at lower stimulus intensities. No sensory anomalies were detected. Needle EMG confirmed dual innervation of APB by both median and ulnar nerves. Nerve excitability studies recorded from APB following ulnar nerve stimulation were within previously established normative limits for the median nerve. In the index case, no innervation anomaly was visible on magnetic resonance imaging from the forearm to hand., Conclusions: Dual innervation of APB by the median and ulnar nerves consistent with RCA was demonstrated in all 3 family members without co-existent sensory anomalies., Significance: These findings infer an hereditary basis for RCA, consistent with an autosomal dominant pattern of inheritance.

Background: Measurements of volume are taken in the clinical environment to determine the extent of swelling and to evaluate the effects of treatment interventions. In the research setting, volume measurements are taken to determine experimental outcomes. Water displacement and figure-of-eight methods are highly reliable for measuring foot and ankle volumes, but the responsiveness of the two methods has not been compared. This study was designed to investigate effects of manipulating hydrostatic and blood pressures on foot and ankle volume and responsiveness of the two methods to induced changes in foot and ankle volume., Methods: Intervention effects on volume were compared using water displacement and tape (figure-of-eight) methods. Foot and ankle volume was measured in each of the 30 participants while they were supine, sitting, and sitting with a sphygmomanometer cuff inflated around the lower thigh to occlude blood flow into the leg. These variations allowed manipulation of the hydrostatic and blood pressures acting on the foot and ankle., Results: Data from the water displacement method showed that a significant increase in volume of 31 mL (p < 0.002) occurred with the cuff in place, but this was not detected using the figure-of-eight method. No significant difference (p > 0.136) between the sitting and supine positions was detected using either method., Conclusions: Limb dependency while sitting or lying had no effect on measures from either method, but volumetry had a higher responsiveness to changes induced by application of the cuff. This effect was interpreted as arterial leakage past the cuff., Clinical Relevance: The figure-of-eight tape method and the water displacement technique for measuring ankle and foot volume may not be interchangeable. Changes in volume of the ankle and foot are better measured by the water displacement technique, but for measurements of ankle volume alone, the tape method is appropriate. The responsiveness of the tape method to changes in volume is yet to be determined.