Dementia, dementia's risk factors and premorbid brain structure are concentrated in disadvantaged areas: National register and birth-cohort geographic analyses

INTRODUCTION

Dementia risk may be elevated in socioeconomically disadvantaged neighborhoods. Reasons for this remain unclear, and this elevation has yet to be shown at a national population level.

METHODS

We tested whether dementia was more prevalent in disadvantaged neighborhoods across the New Zealand population (N = 1.41 million analytic sample) over a 20-year observation. We then tested whether premorbid dementia risk factors and MRI-measured brain-structure antecedents were more prevalent among midlife residents of disadvantaged neighborhoods in a population-representative NZ-birth-cohort (N = 938 analytic sample).

RESULTS

People residing in disadvantaged neighborhoods were at greater risk of dementia (HR per-quintile-disadvantage-increase = 1.09, 95% confidence interval [CI]:1.08-1.10) and, decades before clinical endpoints typically emerge, evidenced elevated dementia-risk scores (CAIDE, LIBRA, Lancet, ANU-ADRI, DunedinARB; β's 0.31-0.39) and displayed dementia-associated brain structural deficits and cognitive difficulties/decline.

DISCUSSION

Disadvantaged neighborhoods have more residents with dementia, and decades before dementia is diagnosed, residents have more dementia-risk factors and brain-structure antecedents. Whether or not neighborhoods causally influence risk, they may offer scalable opportunities for primary dementia prevention.

Public opinion on global COVID-19 vaccine procurement and distribution policies: A nationally representative survey in Aotearoa New Zealand 2022

The World Health Organisation and many health experts have regarded vaccine nationalism, a "my country first" approach to vaccines procurement, as a critical pandemic response failure. However, few studies have considered public opinion in this regard. This study gauged public support for vaccine nationalism and vaccine internationalism in a representative survey in New Zealand (N = 1,135). Support for vaccine internationalism (M (mean rating) = 3.64 on 5-point scales) was significantly stronger than for vaccine nationalism (M = 3.24). Additionally, support for openly sharing COVID-19 vaccine manufacturing knowledge and technology (M = 4.17 on 5-point scales) was significantly stronger than support for safeguarding vaccine manufacturers' intellectual property (M = 2.66). The public also supported a utilitarian approach that would see distributions based on need (M = 3.76 on 5-point scales) over an equal proportional international distribution (M = 3.16). Akin to the few preceding studies, the present observations suggest that the public is likely to be more supportive of pandemic responses that are globally equitable and long-term orientated. Our findings have substantial implications for pandemic preparedness as the congruence or lack thereof of public vaccine-related values with government policies can affect public trust, which, in turn, can affect public cooperation. It may pay for governments to invest in proactive public engagement efforts before and during a pandemic to discuss critical ethical issues and inequities in global vaccine procurement and distributions.

Proximity of alcohol outlets and presentation to hospital by young people after self-harm: A retrospective geospatial study using the integrated data infrastructure

OBJECTIVES

There is a well-established association between alcohol use, misuse, intoxication and self-harm, the latter of which is associated with suicide. This study aimed to better understand the association between proximity to alcohol outlets and the likelihood of young people presenting to hospital following self-harm.

METHODS

This was a nationwide retrospective geospatial study using data from the New Zealand Integrated Data Infrastructure using population-level data for 10-29-year-olds for the 2018 and 2017 calendar years. Presentations to hospital following self-harm were identified using the national minimum data set. Proximity to alcohol outlets was defined in road network distance (in kilometres) and ascertained using Integrated Data Infrastructure geospatial data. Alternative measures of proximity were employed in sensitivity analyses. Complete-case two-level random intercept logistic regression models were used to estimate the relationship between alcohol outlet proximity and hospital presentation for self-harm. Adjusted models included sex, age, ethnicity, area-level deprivation, urbanicity and distance to nearest medical facility. Analyses were also stratified by urbanicity.

RESULTS

Of the 1,285,368 individuals (mean [standard deviation] age 20.0 [5.9] years), 7944 (0.6%) were admitted to hospital for self-harm. Overall, the odds of presenting to hospital for self-harm significantly decreased as the distance from the nearest alcohol outlet increased, including in adjusted models (adjusted odds ratio 0.980; 95% confidence interval = [0.969-0.992]); the association was robust to changes in the measure of alcohol proximity. The effect direction was consistent across all categorisations of urbanicity, but only statistically significant in large urban areas and rural areas.

CONCLUSIONS

The findings of this study show a clear association between young people's access to alcohol outlets and presentation to hospital for self-harm and may provide a mandate for government policies and universal interventions to reduce young people's access to alcohol outlets. Further research regarding causative mechanisms is needed.

Measuring Māori Health, Wellbeing, and Disability in Aotearoa Using a Web-Based Survey Methodology

High-quality evidence on the prevalence and impact of health, wellbeing, and disability among Māori, and other Indigenous peoples, is crucial for mitigating health inequities. Current surveys are predominantly centred within a biomedical paradigm, with the constructs mismatched with Indigenous worldviews. We aimed to develop and deploy an accessible and culturally grounded survey exploring Māori health, wellbeing, and disability using a Kaupapa Māori Research methodology. An extensive codesign process with Māori community partners interrogated all aspects of the design to ensure the process and outcomes met the needs of Māori. A large-scale, nationally representative survey of people of Māori descent was conducted. We used a multi-modal deployment approach that included online and alternate methods of completion. Our analysis included a novel dual-weighting system to ensure generalisability of results to the national Māori population. This achieved a survey of 7230 participants, a sample size comparable with government-administered surveys. The response rate was 11.1%, with 7.3% opting for alternate methods. A high completion rate of 93.4% was observed. This approach demonstrated a high level of engagement, resulting in an unprecedented collection of Māori health, wellbeing, and disability data. This highlights the importance of Indigenous codesign for ensuring accessible and culturally appropriate survey methods.

Are trajectories of social isolation from childhood to mid-adulthood associated with adult depression or suicide outcomes

PURPOSE

Social isolation has been shown to have negative effects on mental health outcomes though little is known about trajectories across the life course. We examined the relationship between trajectory groups and selected mental health outcomes in mid-adulthood.

METHODS

We previously created a typology of social isolation based on onset during the life course and persistence into adulthood, using group-based trajectory analysis of longitudinal data from a New Zealand birth cohort. The typology comprises four groups: 'never-isolated', 'adult-only', 'child-only', and 'persistent (child-adult) isolation'. We undertook logistic regression analyses of three mental health outcomes with trajectory group as the predictor, adjusting for sex and a range of familial and child-behavioural factors.

RESULTS

Lifetime suicide attempt, and depression and suicide ideation in mid-adulthood were each associated with adult-only but not child-only social isolation. Depression in mid-adulthood was also associated with persistent child-adult social isolation.

CONCLUSION

Although our findings are associational and not causal, they indicate that interrupting persistent social isolation may help to prevent adult depression whereas halting adult social isolation may ameliorate both depression and suicide outcomes.

Anthropause appreciation, biophilia, and ecophilosophical contemplations amidst a global pandemic

In 2020, COVID-19 mitigation measures, including lockdowns and travel bans to curtail disease transmission, inadvertently led to an "Anthropause" - a unique global pause to anthropogenic activities. While there was a spike in ecological studies measuring Anthropause effects on environmental indicators, people's experiences of the Anthropause or its potential to inspire change were hardly considered. Hence, we aimed to measure people's appreciation of the environmental outcomes of the Anthropause, ecophilosophical contemplations about the pandemic, and experiences of lockdown-triggered biophilia (human's innate love for and draw towards nature) and test the hypothesis that these experiences would be consistently more prominent among the already environmentally inclined. To that end, we developed and tested three measures on a representative sample of 993 New Zealanders. Anthropause Appreciation received the highest overall mean ratings, followed by Lockdown-Biophilia and Eco-Contemplation. Pre-existing pro-environmental dispositions and behaviours did not consistently influence our three measures as expected. Demographic variables had little influence, while experiences of financial and mental health impacts due to COVID-19 had no influence. We interpreted the limited influence of explanatory variables as indicative of a degree of uniformity in people's experiences. High appreciation of Anthropause benefits suggests that the public may be supportive of policies and ways of living that can lead to similar outcomes post-pandemic - offering environmental policymakers and communicators a basis for action. Ecophilosophical contemplations and biophilic draw among the public suggest an awareness of the significance of the human-nature relationship - offering a symbolic global keystone for communicating and advocating conservation and the many values of pauses in life to connect with nature. Building women's environmental leadership capabilities and the ongoing greening of Christianity may be essential steps for global post-pandemic environmental behaviour transformations.

Mental health inequities for Māori youth: a population-level study of mental health service data

AIM

To examine specialist mental health service, hospital discharge, and pharmaceutical dispensing data for emotional conditions (anxiety, depression), substance use, and self-harm for Māori compared to non-Māori/non-Pasifika (NMNP) youth.

METHODS

A novel population-level case identification method using New Zealand's Integrated Data Infrastructure for 232,845 Māori and 627,891 NMNP aged 10-24 years. Descriptive statistics on mental health conditions were generated and stratified by Māori/NMNP. Unadjusted and adjusted risk ratios (RRs) of mental health conditions were generated using generalised linear regression.

RESULTS

Māori were less likely to be identified for anxiety (ARR=0.88; 95% CI 0.85-0.90) or depression (ARR=0.92; 95% CI 0.90-0.95) than NMNP. They were more likely to be identified for substance problems (ARR)=2.66; 95% CI 2.60-2.71) and self-harm (ARR=1.56; 95% CI 1.50-1.63). Māori living in high deprivation areas were significantly more likely to be identified for substance problems, but less likely for emotional conditions, than Māori in least deprived areas.

CONCLUSION

Despite known high levels of mental health concerns for rangatahi Māori, administrative data suggests significant under-reporting, assessment, and treatment of emotional conditions relative to NMNP. These differences were exacerbated by deprivation. Māori were more likely to be referred to services for externalised symptoms of distress (substance use and self-harm).

Adaption and implementation of the engage programme within the early childhood curriculum

Poor self-regulation has been associated with an array of adverse outcomes including difficulties with school transition, educational attainment, and social functioning in childhood, and employment, mental health, physical health, relationships, and criminal activity in adulthood. Enhancing Neurobehavioural Gains with the Aid of Games and Exercises (ENGAGE) is a play-based intervention fostering the development of self-regulation in pre-schoolers and has led to improvements within the home setting. The aim for this study was to ascertain whether ENGAGE can be implemented within an Early Childhood Education (ECE) group setting and whether this leads to improved self-regulation. This trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR); trial number ACTRN12622000364774; trial web address: https://www.anzctr.org.au/ACTRN12622000364774.aspx . 668 children aged 3-5 years and their teachers, across 28 ECEs participated. Children's self-regulation skills were assessed via scores on the Hyperactivity, Aggression, and Attention Problems subscales of BASC-2. Results indicted no significant changes in self-regulation skills across a 10-week waitlist period. Following 10 weeks of the ENGAGE programme, significant improvements in self-regulation were reported, and these were maintained at 2- and 6-month follow-up. These findings indicate that ENGAGE translates well into the ECE setting and has the potential to have population-based impacts which could lead to more positive societal outcomes.

Medication dispensing among Māori and non-Māori screened for preschool ADHD

AIMS

To investigate whether tamariki Māori screened for attention-deficit/hyperactivity disorder (ADHD) concerns in the B4 School Check (B4SC) between 2011 to 2018 are as likely to receive ADHD medication as non-Māori children.

METHODS

Using population-level data from the Integrated Data Infrastructure, we investigated whether ADHD medication dispensing differed for tamariki Māori screened for ADHD concerns relative to non-Māori children. Analyses were also stratified by area-level deprivation and urban/rural profile of residence.

RESULTS

In our cohort of 414,171 children, 2.8% of Māori and 1.6% of non-Māori were screened as showing ADHD concerns. Among those with ADHD concerns, tamariki Māori had a lower likelihood of ADHD medication dispensing following the B4SC (10.8%) relative to non-Māori children (14.9%), but this effect was only significant among those living in the most deprived quintile and outside of major urban areas.

CONCLUSION

Our study indicates that inequities to accessing ADHD treatment may exist for tamariki Māori living in highly deprived neighbourhoods or outside of major urban areas. Further research is needed to understand what the specific barriers may be to accessing ADHD medication treatment for Māori in these areas.

'As Long as It's Used for Beneficial Things': An Investigation of non-Māori, Māori and Young People's Perceptions Regarding the Research use of the Aotearoa New Zealand Integrated Data Infrastructure (IDI)

The Aotearoa New Zealand Integrated Data Infrastructure (IDI) is a national database containing a wide range of data about people and households. There is limited information about public views regarding its use for research.A qualitative study was undertaken to examine the views of forty individuals attending a large hospital in Auckland, including those of Māori ethnicity and young people. Semi-structured interview data were analysed using Braun and Clarke's method of thematic analysis.Seven key themes emerged: 1) Limited knowledge about medical data held in national databases; 2) Conditional support for the use of the IDI, including for research; 3) Concerns regarding the misuse of IDI data; 4) The importance of privacy; 5) Different views regarding consent for use of data for research; 6) Desire for access to personal data and the results of research; and 7) Concerns regarding third party and commercial use. Young people and those of Māori ethnicity were more wary of data misuse than others.Although there is reasonable support for the secondary use of public administrative data in the IDI for research, there is more work to be done to ensure ethical and culturally appropriate use of this data via improved consent privacy management processes and researcher training.

Different Approaches to requesting Consent for Routine data linkage in Neonatal follow-up (ACORN): protocol for a 2×2 factorial randomised trial

INTRODUCTION

Routinely collected data can be linked to research data to create a rich dataset and inform practice. However, consent is normally required to link identifiable data. Reported rates of consent to data linkage for children ranged from 21% to 96%, but no studies have investigated different approaches to seeking consent for data linkage for school-age children.

METHODS AND ANALYSIS

The Approaches to Consent for Routine Data Linkage in Neonatal Follow-up (ACORN) trial is a 2×2 factorial randomised trial to assess whether, for children who participated in neonatal randomised trials (pre-hypoglycaemia Prevention with Oral Dextrose Gel (hPOD), hPOD and The Impact of Protein Intravenous Nutrition on Development in Extremely Low Birth Weight Babies (ProVIDe)) and are approached to participate in an in-person assessment at 6-7 years of age, parental consent to data linkage is higher if consent is sought (1) after the in-person assessment (delayed) or concurrently and (2) for health and education data combined or separately. The primary outcomes will be rates of consent to linkage of (1) either health or education data and (2) both health and education data. A pilot study indicates the potentially available cohort size of 2110 (80% follow-up of the neonatal trial cohorts) would be adequate to detect an absolute difference of 6%-5%-4% from a baseline consent rate of 70%-85%-90%, respectively (2-tailed alpha 0.05, 90% power). With at least 1136 participants, the ACORN trial would have 90% power to detect an absolute difference of 5% in the primary outcome for each factor, assuming a consent rate of 90% in the control groups and alpha 0.05. Data are categorical and will be presented as number and per cent. The effects of factors will be tested using generalised linear models and presented as ORs and 95% CIs.

ETHICS AND DISSEMINATION

Ethics approval by the New Zealand Health and Disability Ethics Committee (19/STH/202). Dissemination will be via peer-reviewed publications, scientific meetings, educational sessions and public fora.

TRIAL REGISTRATION NUMBER

ACTRN12621000571875 (Australian New Zealand Clinical Trials Registry).

Social attitudes and activities associated with loneliness: Findings from a New Zealand national survey of the adult population

There has been growing recognition of the harmful consequences of loneliness for health and well-being, and the need for community intervention, particularly in times of global crisis such as the Covid-19 pandemic with its imperatives of distancing, isolation, and quarantine. Social capital and a sense of social cohesion are known to have roles in buffering against the effects of adverse life circumstances. Our study sought to investigate the association of a range of social attitudes and activities - as proxies for social capital - with loneliness while taking into account socio-demographic factors. We undertook a national survey on a stratified random sample of the New Zealand (NZ) adult population aged 18+ in 2017 (n = 1,358), data from which included the requisite variables. The prevalence of loneliness was highest in young adults (18-30), falling with age until a slight rise in older people (76+). Loneliness was associated with socio-demographic factors, being more prevalent in the more disadvantaged groups: the deprived, Māori (the indigenous people of NZ), the non-partnered, and the less educated. Controlling for these socio-demographic factors, pro-social attitudes (that is towards political efficacy, trust in others, not feeling exploited, or being committed to family) and participation in social activities (that is being employed or being involved in recreation groups) - were protective against loneliness. Our study supports asset-based approaches to tackling loneliness - with implications for health and social care - that emphasise mobilising existing social resources, building social capital, and raising social cohesion in our communities. Such intervention on loneliness would help to prevent and ameliorate its detrimental consequences for public health.

Prevalence of antidepressant use and unmedicated depression in pregnant New Zealand women

BACKGROUND

Throughout pregnancy, women are at an increased risk of depression, with prevalence estimates between 6.5% and 18%. Global prevalence of antenatal antidepressant use is considerably lower at 3%.

OBJECTIVE

The present study determined the proportion of women taking antidepressants across pregnancy in New Zealand. We investigated whether variation exists across age bands, area-level deprivation and ethnicities, and identified how many women experienced unmedicated depression.

METHOD

Antenatal data (n = 6822) consisted of primarily third-trimester interviews conducted with mothers participating in Growing Up in New Zealand, a longitudinal study investigating child development. Women were asked about their antidepressant intake during pregnancy and assessed on antenatal depression symptoms using the Edinburgh Postnatal Depression Scale. Antidepressant use data were also compared to population-level data from Statistics New Zealand's Integrated Data Infrastructure.

RESULTS

Antidepressant prevalence across pregnancy was 3.2%, with a 2.7% prevalence in trimester one and 2.6% following the first trimester. There was no significant difference in usage within age bands and area-level deprivation quintiles. Ethnicity-specific data revealed that Pasifika and Asian ethnicities had the lowest antidepressant use, and New Zealand Europeans the highest. The rate of unmedicated depression, where women met the Edinburgh Postnatal Depression Scale criteria for significant depressive symptoms but did not receive antidepressants during pregnancy, was 11.8%, indicating that antenatal depression treatment may be inadequate. Greater rates of unmedicated depression were seen for younger women (⩽24 years), those living in high deprivation areas and mothers of Pasifika, Asian and Māori ethnicities.

CONCLUSIONS

Antenatal antidepressant use in New Zealand follows global prevalence estimates and highlights possible undertreatment of antenatal depression in New Zealand. Future research including other treatment types (e.g. behavioural therapy) is needed to evaluate whether undertreatment occurs across all treatment options.

Criminal justice system interactions among young adults with and without autism: A national birth cohort study in New Zealand

While sensationalist headlines and highly publicised criminal cases have led many to believe there is a link between autism and criminal behaviour, extant literature presents an unresolved debate. We sought to address this issue by examining the prevalence of criminal justice system interactions among young adults with and without autism, and by assessing whether offence types differ between these groups. This was a national birth cohort study using linked health and criminal justice system data. Cox proportional hazard models were employed to compare criminal justice system interactions between young adults with and without autism, controlling for important socio-demographic characteristics. Data were acquired for 1197 people with autism and 147,879 without autism. Young adults with autism had significantly lower rates of being proceeded against by police, charged in court, and convicted in court compared to those without autism. However, those charged with an offence were significantly more likely to be charged with serious and violent offences, offences against the person and against property. Our findings indicate that, although young people with autism were not over-represented in the criminal justice system, disparities in offence types and incarceration rates among those charged with an offence suggest the importance of identification and appropriate response to autism within the criminal justice system.

Mental Disorders Forecast Alzheimer’s Disease and Related Dementias in 1.7 Million New Zealanders

Neurodegenerative conditions, including Alzheimer’s disease and related dementias (ADRD), have an outsized impact on disability and loss of independence in older adults. As such, there is a growing need to identify modifiable risk factors for ADRD at the population level. We conducted a nationwide administrative-register study to investigate mental disorders as a potential preventable risk factor for later-life ADRD. Data were drawn from the New Zealand Integrated Data Infrastructure, a collection of whole-of-population administrative data sources linked at the individual level by a common spine. We identified all individuals born in New Zealand between 1928-1967 and followed them for three decades (N = 1,711,386; observation period = 1988-2018; age at baseline = 21-60 years). Diagnoses of mental disorders were ascertained from public-hospital records. Diagnoses of ADRD were ascertained from public-hospital records, mortality records, and pharmaceutical records. Individuals with a mental disorder were at elevated risk for developing Alzheimer’s disease and related dementias relative to those without a mental disorder. This prospective association was evident in both men and women, across age, and after accounting for pre-existing physical diseases. If associations are causal, ameliorating mental disorders could extend population healthspan and reduce the societal burden of neurodegenerative diseases.

Do socially isolated children become socially isolated adults?

Social isolation - the lack of social contacts in number and frequency - has been shown to have a negative impact on health and well-being. Using group-based trajectory analysis of longitudinal data from a New Zealand birth cohort, we created a typology of social isolation based on onset during the life course and persistence into adulthood. We then characterized each type according to risk factors related to family environment and child behavior that have been shown previously to be associated with social isolation. Based on fit statistics and distinctness of trajectories we considered the four-class model to be the most appropriate: (1) 'never isolated' (71.6 % of the cohort), (2) 'adult only' (10.1 %), (3) 'child only' (14.3 %), and (4) 'persistent isolation' (4.0 %). Family-environmental factors - i.e. having a teen-aged mother, having a single parent, frequent changes in residence, or maltreatment - tended to be associated with both child and adult onset and persistence of social isolation, whereas child-behavioral factors - i.e. self-control or internalizing symptoms - applied more to the child onset of social isolation. Sensitivity analyses using empirically defined groups - based on 15 % 'cut-offs' for isolation in childhood and adulthood - produced similar life-course groupings and similar associations. Our findings provide insights into the development of social isolation and demonstrate the changeability of social isolation across almost four decades of the life span. They also suggest family-based and child-based interventions could address child onset and the persistence of social isolation into adulthood.

Short-run effects of poverty on asthma, ear infections and health service use: analysis of the Longitudinal Study of Australian Children

BACKGROUND

Many studies have reported an inferred causal association of income poverty with physical health among children; but making causal inference is challenging due to multiple potential sources of systematic error. We quantified the short-run effect of changes in household poverty status on children's health (asthma and ear infections) and service use (visits to the doctor and parent-reported hospital admissions), using a national longitudinal study of Australian children, with particular attention to potential residual confounding and selection bias due to study attrition.

METHODS

We use four modelling approaches differing in their capacity to reduce residual confounding (generalized linear, random effects (RE), hybrid and fixed effects (FE) regression modelling) to model the effect of income poverty (<60% of median income) on health for 10 090 children surveyed every 2nd year since 2004. For each method, we simulate the potential impact of selection bias arising due to attrition related to children's health status.

RESULTS

Of the 10 090 children included, 20% were in families in poverty at survey baseline (2004). Across subsequent years, ∼25% experienced intermittent and <2% persistent poverty. No substantial associations between poverty and child physical health and service use were observed in the FE models least prone to residual confounding [odds ratio (OR) 0.94, 95% confidence interval (CI) 0.81-1.10 for wheeze], in contrast to RE models that were positive (consistent with previous studies). Selection bias causing null findings was unlikely.

CONCLUSIONS

While poverty has deleterious causal effects on children's socio-behavioural and educational outcomes, we find little evidence of a short-run causal effect of poverty on asthma, ear infections and health service use in Australia.

The Association Between Mode of Delivery and Later Educational Outcomes

IntroductionCaesarean section (C-section) is becoming increasingly prevalent worldwide. It can be a life-saving intervention when medical complications arise, but may cause adverse consequences for the mothers when it is not medically necessary. The upwards trend of C-section is becoming a general concern as it might be associated with a wide range of child outcomes such as immune diseases, respiratory diseases and developmental problems. One underlying mechanism of such association is through gut microbiota. Mode of delivery is a signification factor which determines the gut bacterial environment in early days of life. Gut microbiota can impact cognitive development via microbiota gut brain axis. Objectives and ApproachThis study investigated the association between mode of delivery and later educational outcomes of the children, using linked data from New Zealand Integrated Data Infrastructure. The participants consisted of children born in New Zealand between 1Jan1996 and 31Dec1998. All birth information were retrieved from Department of Internal Affairs and were linked to Ministry of Health data to obtain delivery methods from mothers’ diagnosis records. Once delivery modes were identified, the data was then linked to records from Ministry of Education to obtain children’s educational outcomes at secondary school. Three outcome variables were chosen: University Entrance, Highest Endorsement Level and National Certificate of Educational Achievement Level 2 Percentile Score. ResultsThe results have shown that C-section and assisted vaginal delivery were associated with better secondary school educational achievement, comparing to unassisted vaginal delivery. The results persisted after adjusting for sociodemographic factors such as household income, maternal education and deprivation index; infant factors such as birth weight, gestational age and ethnicity. However, when within family variation was further controlled for in the sibling fixed effects analysis, C-section was no longer associated with improved educational achievement. Conclusion / ImplicationsThis indicated that the impact of delivery mode might be negligible on later educational achievement.

Medication dispensing for attention-deficit/hyperactivity disorder to New Zealand youth

AIMS

Global trends show an increase in medication dispensing for attention-deficit/hyperactivity disorder (ADHD) in young people over time. The current study aimed to examine whether similar trends were observed in New Zealand youth over the period of 2007/08 to 2016/17.

METHODS

We estimated the prevalence in ADHD medication dispensing using national pharmaceutical data for each fiscal year from 2007/08 to 2016/17 in approximately 2.4 million New Zealand youth aged 1-24 years. We also examined whether trends varied by sociodemographic factors.

RESULTS

The total dispensing prevalence almost doubled from 516 per 100,000 to 996 per 100,000 over the study period. Males had a consistently higher dispensing prevalence relative to females. Young people aged 7-17 years had the highest dispensing prevalence. The most deprived quintile had a slightly lower dispensing prevalence relative to other quintiles. Ethnic differences in dispensing prevalence were apparent, with deprivation differences also existing within most ethnic groups.

CONCLUSIONS

Overall, our study showed an increase in ADHD medication use by young people in New Zealand, similar to international findings. Further research is needed into why disparities in dispensing prevalence occur across ethnic and socioeconomic groups.

Autism spectrum disorder/Takiwātanga: An Integrated Data Infrastructure-based approach to autism spectrum disorder research in New Zealand

New Zealand has few estimates of the prevalence of autism spectrum disorder and no national registry. The use of administrative data sources is expanding and could be useful in autism spectrum disorder research. However, the extent to which autism spectrum disorder can be captured in these data sources is unknown. In this study, we utilised three linked administrative health data sources from the Integrated Data Infrastructure to identify cases of autism spectrum disorder among New Zealand children and young people. We then investigated the extent to which a range of mental health, neurodevelopmental and related problems co-occur with autism spectrum disorder. In total, 9555 unique individuals aged 0–24 with autism spectrum disorder were identified. The identification rate for 8-year-olds was 1 in 102. Co-occurring mental health or related problems were noted in 68% of the autism spectrum disorder group. The most common co-occurring conditions were intellectual disability, disruptive behaviours and emotional problems. Although data from the Integrated Data Infrastructure may currently undercount cases of autism spectrum disorder, they could be useful for monitoring service and treatment-related trends, types of co-occurring conditions and for examining social outcomes. With further refinement, the Integrated Data Infrastructure could prove valuable for informing the national incidence and prevalence of autism spectrum disorder and the long-term effectiveness of clinical guidelines and interventions for this group.

How universal are universal preschool health checks? An observational study using routine data from New Zealand's B4 School Check

OBJECTIVES

We aimed to estimate how many children were attending a universal preschool health screen and to identify characteristics associated with non-participation.

DESIGN

Analysis of population-level linked administrative data.

PARTICIPANTS

Children were considered eligible for a B4 School Check for a given year if:(1) they were ever resident in New Zealand (NZ),(2) lived in NZ for at least 6 months during the reference year, (3) were alive at the end of the reference year, (4) either appeared in any hospital (including emergency) admissions, community pharmaceutical dispensing or general practitioner enrolment datasets during the reference year or (5) had a registered birth in NZ. We analysed 252 273 records over 4 years, from 1 July 2011 to 30 June 2015.

RESULTS

We found that participation rates varied for each component of the B4 School Check (in 2014/2015 91.8% for vision and hearing tests (VHTs), 87.2% for nurse checks (including height, weight, oral health, Strengths and Difficulties Questionnaire [SDQ] and parental evaluation of development status) and 62.1% for SDQ - Teacher [SDQ-T]), but participation rates for all components increased over time. Māori and Pacific children were less likely to complete the checks than non-Māori and non-Pacific children (for VHTs: Māori: OR=0.60[95% CI 0.61 to 0.58], Pacific: OR=0.58[95% CI 0.60 to 0.56], for nurse checks: Māori: OR=0.63[95% CI 0.64 to 0.61], Pacific: OR=0.67[95% CI 0.69 to0.65] and for SDQ-T: Māori: OR=0.76[95% CI 0.78 to 0.75], Pacific: OR=0.37[95% CI 0.38 to 0.36]). Children from socioeconomically deprived areas, with younger mothers, from rented homes, residing in larger households, with worse health status and with higher rates of residential mobility were less likely to participate in the B4 School Check than other children.

CONCLUSION

The patterns of non-participation suggest a reinforcing of existing disparities, whereby the children most in need are not getting the services they potentially require. There needs to be an increased effort by public health organisations, community and whānau/family to ensure that all children are tested and screened.

Awake tracheal intubation for blunt airway trauma

A 64-year-old man sustained blunt trauma to the anterior neck following a mechanical fall resulting in an isolated laryngeal fracture of the left cricoarytenoid complex. Although there was no acute airway compromise, he developed worsening airway oedema which necessitated tracheal intubation. He underwent oral awake tracheal intubation with a flexible bronchoscope to facilitate formation of a tracheostomy under general anaesthesia. The challenges encountered in the clinical management of this case relate to decision making for the patient with airway trauma in the absence of the need for emergency tracheal intubation. We describe the advantages and pitfalls of various airway management strategies in the context of blunt airway trauma.

The Efficacy of Preschool Developmental Indicators as a Screen for Early Primary School-Based Literacy Interventions

Literacy success lays the foundation for children's later educational, health, and well-being outcomes. Thus, early identification of literacy need is vital. Using data from New Zealand's national preschool health screening program for fiscal years 2010/2011-2014/2015, demographic and health variables from 255,090 children aged 4 years were related to whether they received a literacy intervention in early primary school. Overall, 20,652 (8.1%) children received an intervention. Time-to-event analysis revealed that all considered variables were significantly related to literacy intervention (all p < .01), but the full model lacked reasonable predictive power for population screening purposes (Harrell's c-statistic = .624; 95% CI [.618, .629]). Including more direct literacy measures in the national screening program is likely needed for improvement.

Childhood to Early-Midlife Systolic Blood Pressure Trajectories: Early-Life Predictors, Effect Modifiers, and Adult Cardiovascular Outcomes

Previous studies examining blood pressure change over time have modeled an average population trajectory. Recent research among older adults suggests there may be subgroups with different blood pressure trajectories. Identifying subgroups at risk of developing adult hypertension early in life can inform effective risk reduction efforts. We sought to identify different systolic blood pressure trajectories from childhood, their correlated risk factors, and early-midlife cardiovascular outcomes. Blood pressure data at ages 7, 11, 18, 26, 32, and 38 years from a longitudinal, representative birth cohort study (n=975) were used to identify 4 distinct trajectory groups via group-based trajectory modeling: normal (21.8%), high-normal (43.3%), prehypertensive (31.6%), and hypertensive (4.2%). The categories refer to blood pressure beginning at the age of 7 years and most recently measured at the age of 38 years. Family history of high blood pressure (odds ratio [OR], 43.23; 95% confidence interval [CI], 5.27-354.65), male sex (OR, 109.48; 95% CI, 26.82-446.96), being first born (OR, 2.5; 95% CI, 1.00-8.69) and low birth weight (OR, 2.79; 95% CI, 2.49-3.09) were associated with hypertensive group membership (compared with the normal group). Higher body mass index and cigarette smoking resulted in increasing blood pressure across trajectories, particularly for the higher blood pressure groups. Prehypertensive and hypertensive trajectory groups had worse cardiovascular outcomes by early midlife. Harmful blood pressure trajectories are identifiable in childhood, associated with both antecedent and modifiable risk factors over time, and predict adult cardiovascular disease risk. Early detection and subsequent targeted prevention and intervention may reduce the lifecourse burden associated with higher blood pressure.

Determinants and disparities: a simulation approach to the case of child health care

Though there is much agreement on the importance of the social determinants of health, debate continues on suitable empirically-based models to underpin efforts to tackle health and health care disparities. We demonstrate an approach that uses a dynamic micro-simulation model of the early life course, based on longitudinal data from a New Zealand cohort of children born in 1977, and counterfactual reasoning applied to a range of outcomes. The focus is on health service use with a comparison to outcomes in non-health domains, namely educational attainment and antisocial behaviour. We show an application of the model to test scenarios based on modifying key determinants and assessing the impact on putative outcomes. We found that appreciable improvement was only effected by modifying multiple determinants; structural determinants were relatively more important than intermediary ones as potential policy levers; there was a social gradient of effect; and interventions bestowed the greatest benefit to the most disadvantaged groups with a corresponding reduction in disparities between the worst-off and the best-off. Our findings provide evidence on how public policy initiatives might be more effective acting broadly across sectors and across social groups, and thus make a real difference to the most disadvantaged.

Can patient safety indicators monitor medical and surgical care at New Zealand public hospitals?

INTRODUCTION

Increasing interest has focused on the safety of hospital care. The AusPSIs are a set of indicators developed from Australian administrative data to reliably identify inpatient adverse events in hospitals. The main aim of this study was to explore the application of the AHRQ/AusPSIs to New Zealand administrative hospital data related to medical and surgical care. Variation over time and across hospitals were also considered for a subset of the more common indicators.

METHOD

AHRQ/AusPSIs were adapted for use with New Zealand National Minimum Dataset administrative data for the period 2001-9. Crude positive event rates for each of the 16 indicators were assessed across New Zealand public hospitals. Variation over time for six more common indicators is presented using statistical control charts. Variation between hospitals was explored using rates adjusted for differences in patient variables including age, sex, ethnicity, rurality of residence, NZDep score and comorbidities.

RESULTS

The AHRQ/AusPSIs were applied to New Zealand administrative hospital data and some 99,366 admissions were associated with a positive indicator event. However rates for some indicators were low (<1% of denominator admissions). Over the study period considerable variation in the rate of positive events was evident for the six most common indicators. Likewise there was substantial variation between hospitals in relation to risk adjusted positive event rates

DISCUSSION

Patient safety indicators can be applied to New Zealand administrative hospital data. While infrequent rates hinder the use of some of the indicators, several could now be readily employed as warning flags to help monitor rates of adverse events at particular hospitals. In conjunction with other established or emerging tools, such as audit and trigger tools, the PSIs are now available to promote ongoing quality improvement activities in New Zealand hospitals.

Low doses of alpha 2-adrenoceptor antagonists augment spinal morphine analgesia and inhibit development of acute and chronic tolerance

BACKGROUND AND PURPOSE

Ultra-low doses of opioid receptor antagonists augment spinal morphine antinociception and block the induction of tolerance. Considering the evidence demonstrating functional and physical interactions between the opioid and alpha(2)-adrenoceptors, this study investigated whether ultra-low doses of alpha(2)-adrenoceptor antagonists also influence spinal morphine analgesia and tolerance.

EXPERIMENTAL APPROACH

Effects of low doses of the competitive alpha(2)-adrenoceptor antagonists-atipamezole (0.08, 0.8 ng), yohimbine (0.02, 2 ng), mirtazapine (0.02 ng) and idazoxan (0.08 ng) were investigated on intrathecal morphine analgesia, as well as acute and chronic morphine antinociceptive tolerance using the rat tail flick and paw pressure tests.

KEY RESULTS

At doses markedly lower than those producing alpha(2)-adrenoceptor blockade, atipamezole, yohimbine, mirtazapine and idazoxan, prolonged the antinociceptive effects of morphine. When co-administered with repeated acute spinal injections of morphine, all four agents blocked the induction of acute tolerance. Co-injection of atipamezole with morphine for 5 days inhibited the development of tolerance in a chronic treatment paradigm. Spinal administration of atipamezole also reversed established antinociceptive tolerance to morphine as indicated by the restoration of morphine antinociceptive potency. The effects of atipamezole on spinal morphine tolerance were not influenced by treatment with 6-hydroxydopamine.

CONCLUSIONS AND IMPLICATIONS

Low doses of competitive alpha(2)-adrenoceptor antagonists can augment acute morphine analgesia and block or reverse tolerance to spinal administration of morphine. These actions are interpreted in terms of their interaction with an opioid-alpha(2)-adrenoceptor complex, whose activity may have a function in the genesis of analgesic tolerance.

A replicated molecular genetic basis for subtyping antisocial behavior in children with attention-deficit/hyperactivity disorder

CONTEXT

Attention-deficit/hyperactivity disorder (ADHD) is a heterogeneous neurodevelopmental disorder that in some cases is accompanied by antisocial behavior.

OBJECTIVE

To test if variations in the catechol O-methyltransferase gene (COMT) would prove useful in identifying the subset of children with ADHD who exhibit antisocial behavior.

DESIGN

Three independent samples composed of 1 clinical sample of ADHD cases and 2 birth cohort studies.

PARTICIPANTS

Participants in the clinical sample were drawn from child psychiatry and child health clinics in England and Wales. The 2 birth cohort studies included 1 sample of 2232 British children born in 1994-1995 and a second sample of 1037 New Zealander children born in 1972-1973.

MAIN OUTCOME MEASURES

Diagnosis of ADHD and measures of antisocial behavior.

RESULTS

We present replicated evidence that the COMT valine/methionine polymorphism at codon 158 (COMT Val158Met) was associated with phenotypic variation among children with ADHD. Across the 3 samples, valine/valine homozygotes had more symptoms of conduct disorder, were more aggressive, and were more likely to be convicted of criminal offenses compared with methionine carriers.

CONCLUSIONS

The findings confirm the presence of genetic heterogeneity in ADHD and illustrate how genetic information may provide biological evidence pointing to clinical subtypes.

Augmentation of spinal morphine analgesia and inhibition of tolerance by low doses of mu- and delta-opioid receptor antagonists

BACKGROUND AND PURPOSE

Ultralow doses of naltrexone, a non-selective opioid antagonist, have previously been found to augment acute morphine analgesia and block the development of tolerance to this effect. Since morphine tolerance is dependent on the activity of micro and delta receptors, the present study investigated the effects of ultralow doses of antagonists selective for these receptor types on morphine analgesia and tolerance in tests of thermal and mechanical nociception.

EXPERIMENTAL APPROACH

Effects of intrathecal administration of mu-receptor antagonists, CTOP (0.01 ng) or CTAP (0.001 ng), or a delta-receptor antagonist, naltrindole (0.01 ng), on spinal morphine analgesia and tolerance were evaluated using the tail-flick and paw-pressure tests in rats.

KEY RESULTS

Both micro and delta antagonists augmented analgesia produced by a sub-maximal (5 microg) or maximal (15 microg) dose of morphine. Administration of the antagonists with morphine (15 microg) for 5 days inhibited the progressive decline of analgesia and prevented the loss of morphine potency. In animals exhibiting tolerance to morphine, administration of the antagonists with morphine produced a recovery of the analgesic response and restored morphine potency.

CONCLUSIONS AND IMPLICATIONS

Combining ultralow doses of micro- or delta-receptor antagonists with spinal morphine augmented the acute analgesic effects, inhibited the induction of chronic tolerance and reversed established tolerance. The remarkably similar effects of micro- and delta-opioid receptor antagonists on morphine analgesia and tolerance are interpreted in terms of blockade of the latent excitatory effects of the agonist that limit expression of its full activity.

The Dunedin Multidisciplinary Health and Development Study: are its findings consistent with the overall New Zealand population?

AIMS

To compare the health of the Dunedin Multidisciplinary Health and Development Study members with people of the same age in the nationally representative New Zealand Health and National Nutrition Surveys.

METHOD

Where similar information was obtained, means or proportions and confidence intervals were generated for both the age 26 assessment of the Dunedin sample and for the 25-26 year old participants in the national surveys. The populations were considered to differ when confidence intervals did not overlap.

RESULTS

For smoking habit, body mass index, waist-hip ratio, general practitioner and medical specialist consultations, and hospital admissions, the findings of the Dunedin Study were not significantly different to the nationally representative surveys. The Dunedin Study members also did not differ from their national counterparts on SF-36 subscales measuring physical functioning, bodily pain, general health, vitality, and mental health. They had better scores on the three interference subscales of the SF-36 compared to the national sample, and men in the Dunedin Study spent a little more time doing vigorous physical activity.

DISCUSSION

For most outcomes, the Dunedin Study members were very similar to the nationally representative samples. There was little evidence that the repeated assessments in the Dunedin Study had significantly altered the Study members' health, either in terms of responses to questionnaires or on physiological measures of health status. Findings from the Dunedin Study are likely to be generalisable to most young New Zealanders. However, the Dunedin Study is under-representative of Maori and Pacific peoples, so these findings need to be interpreted with caution in this context. Implications for the proposed national Longitudinal Study of New Zealand Children and Families are discussed.

Facilitation of spinal morphine analgesia in normal and morphine tolerant animals by neuropeptide SF and related peptides

Neuropeptide FF and related synthetic amidated peptides have been shown to elicit sustained anti-nociceptive responses and potently augment spinal anti-nociceptive actions of spinal morphine in tests of thermal and mechanical nociception. Recent studies have described the occurrence of another octapeptide, neuropeptide SF (NPSF) in the spinal cord and the cerebrospinal fluid and demonstrated its affinity for the NPFF receptors. This study examined the effects of NPSF and two putative precursor peptides, EFW-NPSF and NPAF, on the spinal actions of morphine in normal and opioid tolerant rats using the tailflick and pawpressure tests. In normal rats, NPSF demonstrated weak intrinsic activity but sub-effective doses of the peptide significantly increased the magnitude and duration of spinal morphine anti-nociception in both tests. A low-dose of NPSF also augmented the spinal actions of a delta receptor agonist, deltorphin. The morphine-potentiating effect of NPSF was shared by EFW-NPSF and the octadecapeptide NPAF. In animal rendered tolerant by continuous intrathecal infusion of morphine for 6 days, low dose NPSF itself elicited a significant anti-nociceptive response and potently increased morphine-induced response in both tests. In animals made tolerant by repeated injections of intrathecal morphine, administration of NPSF, EFW-NPSF, and NPAF with morphine reversed the loss of the anti-nociceptive effect and restored the agonist potency. The results demonstrate that in normal animals NPSF and related peptides exert strong potentiating effect on morphine anti-nociception at the spinal level and in tolerant animals these agents can reverse the loss of morphine potency.

Mannitol but not dantrolene prevents myocardial dysfunction following intra-cranial hypertension in rats

Cardiac complications stemming from intra-cranial hypertension may result from impaired intra-cellular Ca(2+) homeostasis. The aim of this study was to examine the effects of dantrolene, a blocker of sarcoplasmic reticulum (SR) Ca(2+) release, on myocardial dysfunction associated with intra-cranial hypertension in rats. Dantrolene (10 mg) with and without 15% mannitol was administered to halothane-anesthetized rats prior to induction of intra-cranial hypertension by subdural balloon inflation. Its effects were compared to 3% and 15% mannitol and 5% Pentaspan. Dantrolene with mannitol or 15% mannitol alone prevented the transient intra-cranial hypertension-induced hyperdynamic response and ensuing circulatory collapse that was found in animals pre-treated with 3% mannitol solution or pentaspan. Moreover, hemodynamic function was preserved irrespective of TnI cleavage. However, only animals treated with high dose 15% mannitol exhibited lower lipid peroxidation content in the heart. In contrast, pre-treatment with dantrolene alone did not prevent the cardiac complications associated with intra-cranial hypertension. In conclusion, 15% mannitol attenuated the cardiopulmonary complications associated with intra-cranial hypertension. Dantrolene without mannitol was without effect. Since mannitol exhibits free radical scavenging properties, protection could be the result of a decrease in oxidative stress after intra-cranial hypertension.

Children's behavioral styles at age 3 are linked to their adult personality traits at age 26

We observed 1,000 3-year-old children who exhibited five temperament types: Undercontrolled, Inhibited, Confident, Reserved, and Well-adjusted. Twenty-three years later, we reexamined 96% of the children as adults, using multiple methods of comprehensive personality assessment, including both self- and informant-reports. These longitudinal data provide the longest and strongest evidence to date that children's early-emerging behavioral styles can foretell their characteristic behaviors, thoughts, and feelings as adults, pointing to the foundations of the human personality in the early years of life.

Prevalence and correlates of irritable bowel symptoms in a New Zealand birth cohort

AIM

To determine the prevalence and correlates of bowel symptoms and the irritable bowel syndrome (IBS) in a birth cohort of young New Zealanders.

METHODS

Participants in the Dunedin Multidisciplinary Health and Development Study at age 26 completed a validated Bowel Disease Questionnaire expressing their experience of clearly defined symptoms over the previous 12 months.

RESULTS

980 participants (499 male, 481 female, comprising 96% of the birth cohort) completed the questionnaire. Sixty four per cent had at least one of the measured symptoms; abdominal pain was reported in 46.5%, chronic constipation in 9.1%, and chronic diarrhoea in 17.1%. A diagnosis of IBS could be made by using two or more of Manning's diagnostic criteria in 18.8%, three or more criteria in 10.3%, and more than three in 3.3%. Symptoms were more than twice as frequent and severe in females than males.

CONCLUSIONS

Bowel-related abdominal symptoms, including those required for a diagnosis of IBS, are very common in 26-year-old New Zealanders; the prevalence of these symptoms is very similar to that recorded previously in Europe and the USA.

The release of spinal prostaglandin E2 and the effect of nitric oxide synthetase inhibition during strychnine-induced allodynia

The removal of spinal glycinergic inhibition by intrathecal strychnine produces an allodynia-like state in rodents. Our objective was to measure spinal prostaglandin E2 (PGE2) release during strychnine-allodynia and examine the effects of Nomega-nitro-L-arginine (L-NOARG), an inhibitor of nitric oxide synthetase. Under halothane, rats were fitted with intrathecal and spinal microdialysis catheters, and microelectrodes implanted into the locus coeruleus for measurement of catechol oxidation current (CAOC) using voltammetry. Animals were then administered urethane and treated as follows: 1) baseline control 10 min, intrathecal strychnine (40 microg) 10 min, 10 min of hair deflection, and 2) 10-min control followed by intrathecal strychnine (40 microg) with hair deflection for 60 min. Spinal dialysate samples were collected for PGE2 levels determined by using immunoassay. In separate experiments, the effect of intrathecal strychnine (40 microg) followed by hair deflection was studied in rats pretreated with intrathecal l-NOARG (50 nmol). After intrathecal strychnine, hair deflection significantly increased spinal PGE2 release (619% +/- 143%), locus coeruleus CAOC (181% +/- 6%), and mean arterial pressure (123% +/- 2%) P < 0.05. Pretreatment with intrathecal l-NOARG significantly inhibited strychnine-allodynia. In this model, hair deflection evokes spinal PGE2 release, locus coeruleus activation, and an increase in mean arterial pressure. L-NOARG pretreatment attenuated the locus coeruleus CAOC, a biochemical index of strychnine-allodynia, suggesting a mediator role of nitric oxide. A mediator role of nitric oxide is also implicated, helping to explain the pathophysiology of this allodynic pain.

Informed consent for labour epidurals: what labouring women want to know

PURPOSE

To determine A) what a labouring woman expects to hear about epidural analgesia before consenting, B) if she feels able to understand the risks and thereby assess if we are obtaining informed consent.

METHODS

Sixty actively labouring women were surveyed immediately after requesting an epidural. Demographic, labour, epidural and consent information were included in the questionnaire. Answers were categorical (yes/no, multiple choice) or scored on a scale from 0 to 10 (visual analogue scale).

RESULTS

The majority of parturients wanted all potential epidural complications but not their incidences disclosed in the consent process. However, a discussion of risks would not dissuade women from consenting to an epidural in the majority of cases. Labouring women have a moderate understanding of epidural risks. The ability to understand risks was not affected by labour pain, anxiety, opioid premedication, duration of labour pain, desire for an epidural, previous epidural experience, level of education or age.

CONCLUSION

This prospective survey characterizes what 60 reasonable labouring women wanted to know about labour epidural analgesia. Parturients wanted all risks of epidural analgesia disclosed in the informed consent process. The majority of women did not want the incidences quoted. This study suggests that labouring patients are as able to give informed consent as are other members of our patient population.

Management of prolonged QT interval during a massive transfusion: calcium, magnesium or both?

PURPOSE

This case report describes the intra-operative management of a prolonged QT interval in the setting of massive transfusion.

CLINICAL FEATURES

A previously healthy, 45-yr-old man presented for repair of a class IV thoraco-abdominal aneurysm. The initial stages of the operation were relatively uneventful, with the exception of an estimated blood loss of 5.0 L. At this point the patient's QT interval became markedly prolonged, and subsequently narrowed in response to supplemental calcium and magnesium. A blood sample taken just before QT prolongation revealed an ionized calcium of 0.98 mmol x L(-1) and an ionized magnesium of 0.37 mmol x L(-1), indicating, that low magnesium may have contributed to the QT interval prolongation.

CONCLUSION

This case illustrates the importance of following both ionized calcium and magnesium in the setting of a massive transfusion.

Autonomic circulatory and cerebrocortical responses during increasing depth of propofol sedation/hypnosis in humans

PURPOSE

To describe the relative effects of graded central nervous system (CNS) depression, using increasing propofol infusion rates, on neurovegetative brainstem-mediated circulatory control mechanisms and higher cortical activity in healthy humans.

METHODS

Propofol was administered using an infusion scheme designed to achieve three target blood concentrations in ten healthy volunteers. Blood propofol concentrations and sedation scores were determined at baseline, during the three propofol infusion levels, and 30 min into the recovery period. Electroencephalographic (EEG) power was measured in three frequency bands to quantify cortical activity, and autonomic heart rate control was quantified using spontaneous baroreflex assessment and power spectral analysis of pulse interval.

RESULTS

Sedation scores closely paralleled propofol blood concentrations (0, 0.53 +/- 0.34, 1.24 +/- 0.21, 3.11 +/- 0.80, and 0.96 +/- 0.42 microg x mL(-1) at baseline, three infusion levels and recovery respectively), and all subjects were unconscious at the deepest level. Indices of autonomic heart rate control were decreased only at the deepest levels of CNS depression, while EEG effects were apparent at all propofol infusion rates. These EEG effects were frequency specific, with power in the beta band being affected at light levels of sedation, and alpha and delta power altered at deeper levels.

CONCLUSIONS

The results of this study support a relative preservation of neurovegetative circulatory control mechanisms during the early stages of CNS depression using gradually increasing rates of infusion of propofol. Indices of circulatory control did not reliably reflect depth of sedation.