bluuebunny/crossref_metadata_2025_split huggingface dataset:
P020 Exploring the Roles of Individual Rapid Eye Movement Sleep Parameters in Emotional Memory Processing
Authors: Zeng Z , Schenker M , Jordan A 
Published: October 2023

Abstract

Background
Maladaptive emotional memory processing is thought to underpin intrusion symptoms experienced by individuals with post-traumatic stress disorder (PTSD). Curtailment of rapid eye movement sleep (REMS) impairs emotional memory consolidation (EMC) and is proposed to contribute to the development of PTSD. However, the effects of altered REMS quality remain less explored. The present study aims to investigate the potential ability of REM percentage, REM latency, and REMS fragmentation to predict EMC.

Methods
The study forms part of a larger study investigating the effects of suvorexant and temazepam on REMS and EMC. Healthy participants view a series of emotionally positive, negative and neutral images, undergo overnight polysomnography with a study drug or placebo, and are assessed for recognition 48 hours after viewing the images. REMS architecture metrics are derived from polysomnographic data. EMC is calculated based on signal detection theory (d′ = z(hit rate) − z(false alarm rate)).

Results
Data collection is ongoing with 11 participants’ data being collected. A one-way ANOVA reveals a main effect of valence, with positive and negative images being recognised better than the neutral (p(positive-neutral) = .039, p(negative-neutral) = .039). REMS parameters do not significantly predict EMC when accounting for image valence, possibly due to low statistical power.

Discussion
Given existing literature supporting the contribution of REMS on emotional memory processing, promoting high-quality REMS may help facilitate adaptive EMC. Further data is required to examine this effect.
P023 Patient experience and care needs within a Motor Neurone Disease Multidisciplinary Clinic
Authors: Goffinet C , Erigadoo S 
Published: October 2023

Abstract

Background
The Sunshine Coast Hospital and Health Service (SCHHS) Motor Neurone Disease (MND) Multidisciplinary Clinic has been running since early 2020 and is the only one of its kind north of Brisbane. Patients with MND have complex care needs and are thought to benefit from the collaborative nature of such clinics. We seek to directly assess the patient experience of our MND Clinic through the use of a patient questionnaire, which addresses both access to appropriate health professionals at Clinic appointments as well as whether specific MND care needs are being addressed through the multidisciplinary team, with reference to the National Institute for Health and Care Excellence (NICE) MND Assessment and Management Guidelines.

Methods
This is a prospective quality assurance project designed to collect anonymous responses from patients currently attending the SCHHS MND Multidisciplinary Clinic. Questionnaires will be distributed to patients both via e-mail and when attending their clinic appointment, and the results will be collated into a password protected database for analysis.

Progress to date
Ethics approval is in progress and questionnaires are expected to be distributed in the next few months.

Intended outcome and impact
This quality assurance project will be used as part of an audit of the SCHHS MND Multidisciplinary Clinic, in order to assess patient satisfaction and identify priority areas for expansion.
P025 Atypical N3 Sleep: A Biomarker for Altered Mental Status in Lewy Body Disease?
Authors: Levendowski D , Neylan T , Lee-Iannotti J , Tsuang D , Walsh C , Berka C , Mazeika G , Boeve B , St. Louis E 
Published: October 2023

Abstract

Introduction
Atypical N3 sleep (AN3=delta waves with limited theta and sigma) has been associated with ICU delirium and sepsis and averaged 25% of sleep time in Japanese ICU patients. We were interested in exploring whether AN3 might be a marker of cerebral dysfunction in ambulatory patients across a range of neurodegenerative disorders, including those with a dementia diagnosis.

Methods
After ethics review and with informed consent, patients with Lewy body disease (DLB/PDD: n=20,male=90%,age=70 + 6.2), Alzheimers disease dementia (AD: n=29,male=79%,age=75 + 6.7), Parkinson disease (PD: n=16,male=69%,age=67 + 8.7), mild cognitive impairment (MCI: n=41,male=63%,age=70 + 8.5), isolated REM sleep behavior disorder (iRBD: n=19,male=74%,age=64 + 9.6) and a control group (CG: n=61,male=47%,age=65 + 8.3) were studied with the Sleep Profiler and auto-detected AN3 computed. Between-group comparisons were assessed with Mann-Whitney U and Chi-square tests.

Results
The mean percentages of sleep time with AN3 were significantly greater in DLB/PDD (8 + 12.3) vs. PD (4 + 10.8), AD (2 + 3.7), MCI (2 + 2.3), iRBD (1 + 1.6), and CG (1 + 2.4)(all p&lt;0.02). The proportions of records with abnormal AN3 (&gt;5% of sleep time) were significantly greater in those with DLB/PDD=35% vs. MCI=10%, iRBD=5% and CG=5% (all p&lt;0.05), but not AD=17% and PD=13%.

Conclusions
Further investigations are needed to determine if abnormal AN3 may be a biomarker that distinguishes patients with Lewy body spectrum diseases from alternative pathologies and/or could be helpful in monitoring the side effects of CNS-acting medications
P035 Investigating the Relationship Between Dietary Timing and Obstructive Sleep Apnoea.
Authors: Huddle S , Young A , Bonham M , Choi T , O'Driscoll D 
Published: October 2023

Abstract

Introduction
Late night eating is associated with obstructive sleep apnoea (OSA) and may increase obesity risk. Time Restricted Eating (TRE) involves shifting the eating window to 8-12 continuous hours per day, prompting energy intake to earlier in the day without any complex dietary prescription, and has metabolic benefits. We aimed to investigate timing of food intake in patients with OSA and assess their openness to trial TRE.

Methods
Adults undergoing in-laboratory diagnostic polysomnography (PSG, n=138, 67 male) completed a dietary questionnaire outlining typical eating habits, including timing of meals, frequency of getting up overnight, and frequency of eating/drinking overnight. Questionnaire responses were reviewed with demographics and PSG variables. Proportions of responses were compared across categories of OSA severity using z-tests.

Results
Patients with moderate/severe OSA (AHI&gt;15events/h, n=77) were more likely to report getting up at night “often” or “always” compared to patients with no/mild OSA (n=61) (63.6% v 47.5%, p=0.08), more likely to report getting up multiple times (66.2% v 47.5%, p=0.04), and more likely to report eating/drinking overnight (42.9% v 18.0%, p=0.003). 71.0% of all patients indicated they would consider trying a TRE diet, and 71.7% could incorporate a TRE diet into their lifestyle.

Conclusion
Moderate/severe OSA is associated with an increased likelihood of getting up multiple times overnight, and getting up to eat and drink. Patients in this clinical cohort reported a willingness to trial TRE. Future research should investigate the efficacy of implementing TRE in OSA and evaluating its effect on weight loss and sleep quality.
P037 The Big Sleep ACT Project: Developing a Modern Dataset to Support Sleep Research
Authors: Malagutti N , Chen L , Miller S 
Published: October 2023

Abstract

Background
Limitations in scale, population diversity, technical quality, data curation methods and accessibility of existing data resources have been recognised as limiting factors for the advancement of sleep clinical research through big data approaches. To bridge this gap, this study introduces a new sleep dataset which seeks to capture a data-rich, longitudinal snapshot of a representative Australian clinical sleep cohort.

Methods
Retrospective collation of de-identified sleep clinical records from adult patients who underwent at least one in-lab Type-1 polysomnography between 2012 and 2018 at Canberra Sleep Clinic. We extracted polysomnography raw signals and annotations, as well as medical record information including basic demographics, comorbidities, medications, examination findings, diagnoses, therapy settings and follow-up observations throughout subjects’ time in the Clinic’s care. Records were organised according to a graph database structure, embedding SNOMED terminology encodings wherever possible.

Results
N=6,777 subjects were included. Gender split (M/F: 62%/38%) and age (51.7±15.3 years) distribution were consistent with typical clinical sleep cohorts. Polysomnography recordings included diagnostic (n=6,635) and non-invasive ventilation titration/therapy (n=2,834), as well as MSLT (n=270) and MWT (n=25) studies. Clinical subgroups featured healthy, Obstructive Sleep Apnea (OSA) and non-OSA dyssomnia patients, as well as small cohort of parasomnia cases. Follow-up duration varied among cases (&lt;3 months to &gt;5 years).

Discussion
Despite limitations associated with retrospective data extraction, the data-richness and scale of Big Sleep ACT compare favourably with world-leading sleep datasets. Careful data organisation makes this dataset well placed to support innovative data-driven research into precise diagnoses, personalised interventions, and automation in sleep medicine.
P048 Does Sleep Reduce Intrusive Memories after Analogue Trauma? Recent findings of Experimental Sleep Manipulations using the Trauma Film Paradigm
Authors: Ogden J , Jobson L , Drummond S 
Published: October 2023

Abstract

Introduction
Intrusive memories are common in the aftermath of trauma, and these can develop into a pervasive, distressing symptom of posttraumatic stress disorder (PTSD). Sleep disturbances have also been shown to contribute to later development and maintenance of overall PTSD symptoms. Recent evidence suggests there is a relationship between sleep disturbance and intrusive memories following experimental analogue trauma. However there has been conflicting findings regarding the direction of the effect; whether sleep following analogue trauma results in increased or decreased frequency of later intrusive memories.

Methods
We conducted a narrative review summarising research examining the role of sleep in the development of trauma-related intrusive memories, using the trauma film paradigm. This included recent meta-analyses of experimental studies.

Results
While there have been initial conflicting results across a small number of studies, meta-analytic results suggest sleep following exposure to analogue trauma leads to a reduced number of intrusive memories in the following week.

Discussion
The relationship between sleep following experimental analogue trauma and reduction in intrusive memory frequency may be due to the role of sleep in the consolidation and integration of traumatic memories into existing autobiographical knowledge. However, more research is needed to investigate the mechanism of action for this relationship. Future studies should attempt to disentangle to what degree consolidation, executive control over spontaneous cognition, or other mechanisms are affected by sleep and contribute to the development of intrusive memories.
P050 Process O (onset/offset) cause of the 90-min sleep cycle
Authors: Lack L 
Published: October 2023

Abstract
The ubiquitous sleep cycles across a normal sleep of approximately 90 minute period length were originally suggested to be a reflection of a 90-minute basic rest-activity cycle (BRAC) operating across the full circadian cycle of wakefulness and sleep. The evidence for a BRAC during the wakeful period is sparce requiring other explanations for the prominent 90min cycles during sleep.
Recently another process, Process O (onset/offset), has been suggested in addition to Processes S (homeostatic) and C (circadian). It was hypothesised in order to account for the recuperative effects of a brief power nap, inexplicable by the other two processes.
Process O hypothesises a development of inhibition to any ongoing state (wake, NREM, REM). The inhibition develops rapidly over 1-2 hours to a plateaued limited level and then, following the cessation of that state, dissipates rapidly (5-15 minutes). Thus, a “power” nap brings improved alertness because of the short break from wakefulness allowing the dissipation of wakefulness Process O inhibition. It is suggested that Process O inhibition accumulates also to periods of NREM sleep and REM sleep.
The ‘sleep switch’ accounting for bi-stable states of sleep or awake is hypothesised to include REM and NREM as separate states accounting for stability and mutual inhibition between 3 rather than just 2 states. Thus Process O inhibition developing to an ongoing state tips the balance to other states (REM or NREM) resulting in the alternation between them of the sleep cycles and allowing longer sleep epochs after brief awakenings.
P053 A Chrononutrition Questionnaire to capture sleep, temporal patterns of eating, and chronotype: Reliability and Validity
Authors: Phoi Y , Rogers M , Dorrian J , Bonham M , Coates A 
Published: October 2023

Abstract
Chrononutrition investigates temporal patterns of eating. Irregular patterns in shift workers and evening chronotypes adversely affect cardiometabolic health. We investigated the test-retest reliability and convergent validity of a Chrononutrition Questionnaire that aims to capture temporal patterns of eating and chronotype in shift and non-shift workers. 58 non-shift and 47 shift workers completed the study. Outcomes include: 1) chronotype, 2) sleep: wake/sleep/mid-sleep time and sleep duration, 3) temporal eating patterns: meal/snack regularity and frequency, times of first/last/largest eating occasions (EO), main meal (MM) 1/2/3, and duration of eating window (DEW) on work and work-free days (non-shift) and morning/afternoon/night/work-free days (shift workers). Test-retest reliability (intraclass correlation coefficients and weighted kappa), and convergent validity was determined against food and sleep diaries (Spearman Rank Coefficients). Reliability was acceptable for chronotype, sleep, and all temporal eating patterns except morning (last EO) and night shifts (last EO, DEW). Convergent validity was good for chronotype and sleep except for wake times and/or sleep duration on work-free days after morning and afternoon shifts. Meal/snack regularity and frequency showed good validity for non-shift but not shift workers. Times of first/last EO, MM1/2/3 and DEW generally showed good validity except for on work-free days, morning shifts, and night shifts. Time of largest EO was poorly correlated except for night shifts. The Chrononutrition Questionnaire has good test-retest reliability and acceptable convergent validity.
P063 Long-term Non-invasive Ventilation in Patients with COPD: A Retrospective Cohort Study.
Authors: Broadhead R , Mukherjee S , Aiyappan V , Chai-Coetzer C , Ullah S , Walker A 
Published: October 2023

Abstract

Introduction
Domiciliary long-term non-invasive ventilation (LT-NIV) is an accepted therapy for patients with severe chronic obstructive pulmonary disease (COPD) and chronic hypercapnia. This study aimed to characterise patients with COPD who were commenced on LT-NIV.

Methods
A retrospective analysis was performed of all patients prescribed LT-NIV with a primary physician-diagnosis of COPD, between June 2016 and March 2022 at an Australian tertiary hospital.

Results
333 patients were commenced on LT-NIV, of whom 67 (20%) had COPD.
Inpatient LT-NIV Initiation: 53/67 (79%) were commenced on LT-NIV during an inpatient admission with acute exacerbation of COPD. Patients were elderly (age, mean 69± SD 9.5 years), predominantly female (60%) with moderate-severe COPD (FEV1 37±18%) and mild-moderate comorbidity burden (Charlson Comorbidity Index Score 2.1±1.4).
Prior to LT-NIV, 64% patients had a sleep study with 15% having severe OSA (AHI≥30 or ODI≥30). 30% previously required acute NIV. Pre-admission non-exacerbated PaCO2 was 58±7.3mmHg
During admission, all inpatients demonstrated hypercapnia (PaCO2≥45mmHg). Peak inpatient PaCO2 was 87±20mmHg, with persistent hypercapnia on discharge 58±9.0mmHg. On discharge, IPAP and EPAP settings were 17±3.8 and 7.7cm±2.7cmH2O respectively.
There was a non-significant reduction in respiratory-related and all-cause hospitalizations in the 12-months following LT-NIV initiation (p=0.66 and 0.53 respectively).
Outpatient LT-NIV Initiation: [Further data collection in progress]

Discussion
This study illustrates the real-world prescription of LT-NIV for COPD at our centre, with the majority being initiated in the inpatient setting, rather than early outpatient reassessment. A prospective multi-centre analysis is required to better understand the nuances of LT-NIV prescription in patients with COPD.
P064 Predictive Value of Awake Supine Pulse Oxygen Saturation in Detecting Resting Hypercapnoea Prior to Polysomnography
Authors: Metti F , Cho J , Lambert S , Wheatley J 
Published: October 2023

Abstract

Introduction
Arterial blood gases (ABG) are used during polysomnography (PSG) to assess gas exchange abnormalities in patients at risk of hypercapnoea. ABG sampling may cause discomfort and can be difficult to obtain. Normal, awake, supine finger pulse oxygen saturation (SpO2) immediately prior to PSG may reduce the need for ABG sampling.

Aim
To determine if an awake supine evening SpO2 cutoff value can exclude awake hypercapnoea measured with ABG testing.
Methods : Prospective observational study of all patients referred for diagnostic or treatment PSGs with ABG at Westmead Sleep Laboratory between January 2019 and December 2021. ABGs were requested to exclude hypercapnoea and were collected awake, supine and breathing room air prior to PSG with simultaneous SpO2 measurement. We defined resting hypercapnoea as PaCO2 &gt; 45mmHg. We used 2x2 tables for SpO2 values of 93% to 98% to determine the negative predictive values (NPV) for SpO2 cutoffs and construct a receiver operating characteristic (ROC) curve.

Results
We analysed 146 patients (60±17 years; 68% male; Body-mass Index 32.7±12.0 kg/m2; mean±SD) and 36 patients (25%) had hypercapnoea. The NPVs for hypercapnoea on the ABG with cut off SpO2 values of 96%, 95%, 94% and 93% were 92%, 92%, 89% and 83%, respectively. The ROC area under curve was 0.75.

Conclusion
Resting supine oxygen saturation of ≥95% was able to exclude hypercapnoea in 92% of subjects within this sleep population at high risk of hypercapnoea. Thus, an accurate, awake, supine SpO2 ≥95% will fail to diagnose hypercapnoea in ~8% of high risk patients.
P066 The Relationship between Chronic Breathlessness and Perceived Sleep Quality in Adult Australian
Authors: Toson B , Loffler K , Reynolds A , Li J , Kochovska S , Currow D , Adams R , Eckert D 
Published: October 2023

Abstract

Introduction
This study aimed to explore the relationship between breathlessness (severity and chronicity) and poor sleep quality.

Methods
Analysis of an Australia-wide, online cross-sectional survey carried out between 12 July - 2 August 2021. Community-dwelling adults were recruited from a web-based survey panel, with recruitment based on age, gender, and state of residence quotas to match the Australian 2016 census population data. Participants self-reported breathlessness using the modified Medical Research Council (mMRC) scale, as well as their perceived sleep quality and other demographic and health measures.

Results
Sleep quality was available for 9,877 responders (52% females, mean age 46, SD=19 years, BMI 27 SD=7 kg/m2). Sleep quality in the previous month was reported as “very good”, “fairly good”, “fairly bad” and “very bad” by 16, 49, 25%, and 10% of participants respectively. Breathlessness (mMRC 1–4), chronic breathlessness (mMRC 1–4 for longer than 3 months) and severe breathlessness (mMRC 2–4) were 42, 29 and 11% respectively. Respondents with perceived poor sleep quality were more likely to be breathless, younger, with a higher BMI, and higher likelihood of identifying as female. All measures of breathlessness were associated with increased odds of poor sleep quality [adjusted models with gender, age and BMI, OR (95% confidence interval): 2.6 (2.4 to 2.9), 3.1 (2.8 to 3.5) and 3.4 (2.9 to 3.9) for breathlessness, chronic and severe breathlessness respectively]. There were no significant interactions between any breathlessness measure and age.

Discussion
There is a strong association between breathlessness and perceived poor sleep quality.
P068 Factors affecting sleep quality in hospitalised respiratory medicine patients
Authors: Koshy K , Gibney M , O'Driscoll D , Ogeil R , Young A 
Published: October 2023

Abstract

Background & Aim
Hospitalised patients are at increased risk of poor sleep which can negatively impact on recovery and quality of life. This study aimed to assess sleep quality in hospitalised patients and explore the factors associated with poorer sleep.

Methods
A hospital-wide questionnaire completed at discharge as asked patients to rate their sleep quality during their admission. Results were compared between respiratory and non-respiratory inpatients. A more detailed questionnaire rating sleep quality and factors disrupting sleep was completed by respiratory ward inpatients at discharge and combined with medical record review of co-morbidities that may impact on sleep.

Results
The hospital-wide questionnaire was completed by 619 patients.28% of respiratory ward inpatients reported poor or very poor quality sleep compared to 20% of patients in a general medicine or other subspecialty ward. 83 respiratory inpatients have completed the more detailed questionnaire to date with recruitment ongoing. Sixteen patients (19.3%) reported poor or very poor sleep. These patients were compared to those who reported fair, good, or very good sleep. Age, gender distribution and BMI were similar between both groups. Noise rating was a significantly different between the groups and may predict sleep quality.

Conclusion
A high proportion of hospitalised patients reported poor sleep quality at our tertiary centre particularly on the respiratory inpatient ward where noise was a significant factor. Further research is needed to determine whether strategies to reduce noise will improved sleep quality and clinical outcomes.