bluuebunny/crossref_metadata_2025_split huggingface dataset:
P116 Increased airflow limitation during nocturnal respiratory events is associated with increased psychomotor vigilance task lapses in obstructive sleep apnoea patients
Authors: Staykov E , Mann D , Duce B , Kainulainen S , Leppänen T , Töyräs J , Sands S , Terrill P 
Published: November 2022

Abstract

Introduction
Impaired daytime vigilance is common in obstructive sleep apnoea (OSA) patients. However, the apnoea-hypopnea index (AHI) has been shown to have a weak correlation with daytime vigilance. This may be because the AHI only quantifies respiratory event frequency. Thus, we aimed to test our hypothesis that increased airflow limitation during nocturnal respiratory events is associated with daytime vigilance impairment.

Methods
495 OSA patients (AHI≥5) completed a psychomotor vigilance task (PVT) and in-lab polysomnographic recording. The number of lapses (response time &gt;500ms) was the primary outcome. Airflow limitation was quantified from nasal airflow using a validated algorithm. Linear regression models were adjusted for age, sex, and body mass index.

Results
The percentage of flow-limited breaths during respiratory events was associated with the number of PVT lapses (R=0.119, p&lt;0.05); AHI was not (p&gt;0.05). One standard deviation (SD, 20%) increase in the percentage of flow-limited breaths during respiratory events increased the number of lapses by 2.5. This effect-size was greater than that for age (one SD increase, 12.5 years, increased the number of lapses by 1.3). These results were similar after adjusting for AHI, arousal index, and desaturation event area. Similar findings were observed using the percentage of flow-limited breaths during all sleep.

Discussion
Increased airflow limitation during nocturnal respiratory events was associated with decreased daytime vigilance in OSA patients. This association appeared to be independent of respiratory event frequency, arousal frequency, and hypoxaemia severity. This suggests that disproportionately large ventilatory drive versus achieved ventilation (i.e. flow-limitation) contributes to daytime vigilance impairment.
P121 Turnaround times for the submission of information using a novel suite of fully online patient forms
Authors: Teuwen P , Eriksson N , Scott A 
Published: November 2022

Abstract

Purpose
To assess the turnaround times for a newly implement suite of online patient questionnaires and forms returned to a private Thoracic and Sleep outpatient service over a two-week period.

Methods
This study included all online patient forms submitted to the Wesley Hospital Sleep Disorders Centre and Wesley Hospital Lung Function Lab between the 16th and 30th June (n= 120). Age, gender and turnaround times were included in the data set.

Results
The average turnaround time for form submission was 2.7 days. 95% of forms were returned within 7 days, 43.3% were returned the same day. On Average women submitted their forms (2.5 days) faster than men (2.8 days). Patients aged under 40 had the shortest average turnaround time (2.53 days). However, when gender is considered we found that women aged over 60 had the fastest turnaround time (2.0 days) and women aged between 40 and 60 had the slowest average turnaround time (3.5 days).

Discussion
It is clear that online form completion and submission are no barrier to the rapid provision of information to and from patients. While failed submission attempts were not included in this analysis, anecdotally we found that most patients had little to no difficulty with completing an online form. The sample size of this study may have limited some of the findings, particularly when assessing the sub-groups that included both age and gender combined.
P124 Differences in OSA pathophysiological traits between mandibular advancement therapy responders versus non-responses and the influence of obesity
Authors: Tong B , Chiang A , Naik G , Osman A , Bull C , Donegan M , Pinczel A , Rawson G , Pitcher G , Brown E , Kwan B , Mukherjee S , Adams R , Eckert D 
Published: November 2022

Abstract
Mandibular advancement therapy (MAS) is a recognised second-line therapy for obstructive sleep apnoea (OSA). However, MAS treatment outcomes vary and are difficult to predict. Recent studies have investigated the role of OSA endotypes to predict MAS therapy outcomes. However, whether OSA endotype predictors differ between obese and non-obese people with OSA is unknown. Thus, this study aimed to compare OSA endotypes between responders and non-responders to MAS therapy in obese and non-obese individuals.
90 people with OSA (AHI&gt;10events/h) were studied. OSA was confirmed via in-laboratory polysomnography. A detailed physiology night was subsequently performed prior to MAS therapy. OSA endotypes were estimated from the detailed physiology polysomnography using a custom-designed, validated, semiautomated script. OSA endotypes were compared between responders (residual AHI&lt;10events/h) and non-responders to MAS therapy. Further comparisons were made between obese and non-obese groups.
Responders to MAS therapy had a less collapsible upper airway; Vpassive: 93[88,96]vs.85[62,94]%Veupnea,p=0.003); Vactive: 103[95,112]vs.98[16,104] %Veupnea,p=0.008), better pharyngeal muscle compensation Vcomp: 9.8[4.3,19.6]vs.3.3[-19.1,18.6]%Veupnea,p=0.02), lower arousal threshold (114[109,144]vs. 142 [117, 177]%Veupnea,p=0.006) and tended to also have lower loop gain (0.48 ±0.1vs. 0.42±0.1,p=0.05). . These findings were similar in obese versus non-obese individuals although loop gain was significantly lower in responders versus non-responders in the non-obese (p=0.01) but not the obese group (0.97).
MAS therapy was most beneficial in people with a less collapsible upper airway, good pharyngeal muscle compensation, lower arousal threshold and loop gain at baseline. Prospective assessment of OSA endotypic traits may therefore help guide treatment decisions and improve MAS therapy outcomes.
P126 The impact of inadequate sleep and breaking up sitting during the day on simulated driving performance
Authors: Tuckwell G , Vincent G , Gupta C , Ferguson S 
Published: November 2022

Abstract

Introduction
Inadequate sleep and prolonged sitting are both associated with a reduction in psychomotor functioning, a cognitive process crucial for the safety critical task of driving. Regular bouts of light-intensity physical activity have been shown to improve psychomotor function. However, it is unknown if breaking up sitting during the day can improve psychomotor functioning for the task of driving, particularly during the commute home when drivers may be at a higher risk of fatigue.

Method
Healthy participants (n=81, 49%female, age 23.6 ± 4.5 years ) participated in a 7-day laboratory study (1 adaptation, 5 experimental, 1 recovery). Participants were randomly allocated to a condition: sitting and 9-h sleep (Sit9; n=22), breaking up sitting 9-h sleep (Sit9; n=19), sitting and 5-h sleep (Sit5; n=21) and breaking up sitting 5-h sleep (Break5; n=19). Participants allocated the breaking up sitting conditions completed 3-min of light-intensity walking every 30 minutes between 09:00-17:00h, while participants in the sitting group remained seated. Driving performance was measured via speed and lane variability during a 20-min simulated drive at 08:10 and 17:30 for the 5 experimental days.

Results
Mixed model analyses revealed no significant interaction effects between condition and time of commute between Sit9, Break9, Sit5 and Break5 for driving performance.

Discussion
Breaking up sitting did not improve driving performance during the commute home. These findings highlight that light-intensity walking may not be adequate to overcome the effects of inadequate sleep on diving performance. Future studies should explore if higher intensity physical activity produce changes in driving performance.
P127 Study protocol for examining the role of REM sleep in trauma-recovery mechanisms: REM fragmentation and fear inhibition in adults with insomnia disorder before and after cognitive behavioural therapy for insomnia (CBT-I)
Authors: Vuong V , Mellor A , Risbrough V , Bei B , Drummond S 
Published: November 2022

Abstract

Introduction
Insomnia has been shown to increase by 2.5-3 fold the risk of developing posttraumatic stress disorder (PTSD) after a traumatic event. The mechanism underlying this increased risk, however, remains unknown. We postulate insomnia may be contributing to PTSD by disrupting rapid eye movement (REM) sleep in the same way it has been shown to impair fear inhibitory processes, which are central to the natural recovery from trauma. To test this, the following protocol aims to: (1) examine the relationship between REM sleep fragmentation and fear inhibition in insomnia; and (2) examine whether correcting REM fragmentation by treating the insomnia, in turn, improves fear inhibition.

Methods
Ninety-two adults with insomnia disorder will be randomly allocated to an active treatment or waitlist control condition. Active treatment involves 7 weekly sessions of cognitive behavioural therapy for insomnia (CBT-I) with a clinician via telehealth. REM fragmentation and fear inhibition (i.e., safety learning and extinction recall) will be assessed pre- and post-treatment in a 4night/3day testing protocol via at-home polysomnography and the fear-potentiated startle paradigm, respectively.

Discussion
This study aims to be the first to test an underlying mechanism potentially explaining why insomnia greatly increases PTSD risk, while demonstrating an existing clinical intervention (CBT-I) can be used to improve this mechanism. Findings will have potential clinical implications for novel approaches in the prevention, early intervention, and treatment of PTSD.
P128 Effect of acute exercise on stress and working memory following sleep restriction
Authors: Wallace-Webb J , Michiel C , Service T , Watkinson O , Harding D , Mulligan G , Stuart-Hill L 
Published: November 2022

Abstract

Introduction
Cognitive impairment poses a serious risk to worker safety. We investigated the interacting effects of acute exercise and sleep restriction (SR) on stress and working memory (WM).

Methods
Our randomized crossover design had 14 adults (10 M, 23 ± 3 years) complete two sessions under different sleep conditions (normal sleep (NS)=8h; restricted sleep (RS)=4h). Sleep duration was verified by validated wrist-worn actigraphy (Fitbit tracker). Salivary cortisol levels (stress indicator) and WM (via n-back task performance) were measured before and after high-intensity exercise on a cycle ergometer. Data was collected at the same time of day for each participant and a washout interval of at least 72-hours separated experimental conditions.

Results
A two-factor repeated measure ANOVA revealed sleep condition to have a significant effect on cortisol levels (F(1,13)=7.78, p&lt;0.05) and n-back reaction time (RT) (F(1,13) = 10.54, p&lt;0.01), but not response accuracy. Post-hoc dependent t-tests showed that RS lead to slower RTs compared to the NS condition (t(27)=3.32, p&lt;0.01), as well as higher cortisol levels both before (t(13)=2.22, p&lt;0.05) and after (t(13)=2.64, p&lt;0.05) exercise. Acute exercise did not affect cortisol levels, but did appear to have a facilitative effect on response accuracy (t(27)=2.13, p&lt;0.05), as well as RT in both sleep conditions (

ES
t(13)=2.32, p&lt;0.05.

RS
t(13)=2.2, p&lt;0.05).

Discussion
These findings suggest that RS may lead to increased stress and impaired cognitive function, while acute exercise may serve as an effective tool for counteracting the negative cognitive effects induced by SR.
P131 Factors associated with Referral to Sleep Clinic and Diagnosis of Obstructive Sleep Apnoea in Pregnant People with Class III Obesity
Authors: Warhurst S , Sethna F , Georgousopoulou E , Huang C 
Published: November 2022

Abstract

Background
Obstructive Sleep Apnoea (OSA) in pregnancy is associated with increased maternal and neonatal morbidity. Evidence supporting use of traditional screening tools (e.g. Epworth Sleepiness Scale and STOP-BANG) in pregnancy is inconsistent, especially for people with class III obesity. This study aims to determine factors associated with referral to sleep clinic and diagnosis of OSA in pregnant people with class III obesity.

Method
Retrospective audit of records for people with class III obesity seen in high-risk pregnancy clinic at Canberra Hospital between 1/7/20 and 30/6/21. It will a) describe patient factors associated with referral to sleep clinic and b) describe patient factors associated with diagnosis of OSA (apnoea-hypopnoea index ≥5).

Progress to date
Approval to proceed as quality improvement project by ACT Health Ethics Committee. Data collection will be completed in 4-8 weeks. Preliminary results will be available by September-October 2022.

Intended outcome and impact
Clinical parameters associated with sleep clinic referral will be presented and compared to existing evidence. Initial data screening suggests that referral rates to sleep clinic are low and reasons for this will be explored. Clinical features associated with a diagnosis of OSA in those who proceeded for polysomnography will also be presented. Our results will inform local practice to determine if pregnant people with class III obesity are being appropriately referred to sleep clinic and objectively assessed for OSA. Our research will add to the limited research in this area and inform further prospective studies on effective screening in this population.
P134 Sleep Laboratory contact in adults commencing CPAP: a post-hoc analysis of the AHEAD trial
Authors: Webster K , Ellender C 
Published: November 2022

Abstract

Background
CPAP used for &gt;4hrs/night effectively treats obstructive sleep apnoea(OSA), however CPAP adherence is often poor. A randomised control trial from our department demonstrated improved CPAP adherence at 12 months in patients receiving video education (VE), compared with standard of care education (SOCE) at CPAP commencement. This follow-on study aimed to evaluate 12-month clinic utilisation of patients in the AHEAD trial, hypothesizing that increased unscheduled contact by patients in the intervention arm may contribute to improved CPAP adherence.

Methods
Post-hoc analysis of data from the AHEAD trial was performed. The AHEAD trial included 195 patients recruited from a large trial protocol and randomised to either SOCE or SOCE+VE. Demographics including age, gender, education level and socioeconomic indices were collected. CPAP usage was assessed at 2-, 6-, and 12-months post randomisation. Adequate adherence was defined as usage &gt;4hours/night. Further data on number of scheduled and unscheduled visits at 12-months post randomisation was collected. The primary outcome was number of unscheduled visits in intervention vs control arm.

Progress to date
Study groups were well-matched at baseline. The proportion with adequate CPAP usage at 12mths was higher in the VE group (33, 33% versus 48, 50% p=0.01). Preliminary analysis suggests there are no significant differences in number of unscheduled visits at 12-month follow up between SOCE vs SOCE+VE (mean0.29 vs 0.43 p=0.18). Further analysis will investigate predetermined subgroups – including low educational level / socioeconomic status.

Intended outcome and impact
This study will inform strategies to improve CPAP adherence in patients with OSA.
P135 Intervention adherence and usefulness as predictors of the efficacy of Cognitive Behavioural Therapy for Insomnia during perinatal periods
Authors: Wellecke C , Cassera L , Quin N , Pinnington D , Spina M , Bei B 
Published: November 2022

Abstract

Introduction
One third of birthing parents experience insomnia symptoms during perinatal periods. Cognitive Behavioural Therapy for Insomnia (CBT-I) is effective for perinatal insomnia. However, it is unclear how adherence to and perceived usefulness of individual CBT-I components predict treatment efficacy.

Methods
76 nulliparous birthing parents (age M±SD=33.07±3.10) with prenatal insomnia received CBT-I from two randomised controlled trials. Insomnia symptoms, sleep-related impairment, dysfunctional beliefs and attitudes about sleep (DBAS), and adherence and usefulness were self-reported at 30 and 35-weeks gestation, and 2 and 6-months postpartum. Linear regressions assessed whether adherence and usefulness predicted sleep-related outcomes, controlling for age, mental health history and social support.

Results
Adherence and perceived usefulness decreased over time across all components. “Cognitive restructuring” and “sleep hygiene” had the highest usefulness and adherence ratings, while “relaxation and mindfulness” was the least useful and adhered to. Controlling for covariates, higher adherence to “sleep hygiene” predicted lower DBAS at 35-weeks gestation (p=.024). At 6-months postpartum, higher usefulness of “relaxation and mindfulness” predicted lower DBAS (p=.032), and higher usefulness/adherence to “managing sleep deprivation, sleepiness, and fatigue” predicted lower insomnia symptoms (usefulness p=.003; adherence p=.029) and lower sleep-related impairment (usefulness p=.007). No significant relationships were found between sleep-related outcomes and usefulness/adherence to other CBT-I components (i.e., psychoeducation, cognitive restructuring, and stimulus control).

Conclusion
Individual CBT-I components play different roles in treatment efficacy as birthing parents navigate diverse sleep challenges in perinatal periods. Strategies to enhance adherence to and perceived usefulness of relevant treatment components for specific perinatal milestones may enhance efficacy.
P136 Sleep Quality and Obesity: an investigation into the relationship between obesity and poor sleep quality as measured by polysomnography
Authors: Wells S , Inman D , Huang H 
Published: November 2022

Abstract

Background
Studies have demonstrated a link between obesity and poor sleep quality. However, definitions of sleep quality vary, and are often subjective. Furthermore, these studies do not explore whether this link is independent of comorbidities associated with obesity. We aim to establish whether an independent link exists between poor sleep and obesity, with sleep quality measured objectively through polysomnography.

Methods
A retrospective observational study of patients undergoing level 1 or 2 diagnostic polysomnography over one year. We recorded demographics, body mass index (BMI), comorbidities; and polysomnography data including apnoea-hypopnoea index, total sleep time (TST), percentage slow-wave sleep (%SWS) and percentage rapid eye movement (%REM) sleep. Primary outcome was %SWS, with secondary outcomes TST, %REM sleep and O2 nadir. Linear regression analysis was used to investigate correlations between variables and the outcomes proposed.

Progress to Date
297 patients were included. The average BMI was 37.9 (17.8-79.5). BMI was not significantly correlated with %SWS. Howevere, a significant negative correlation was found between BMI and %REM (β = -0.196, p = 0.013), BMI and TST (β = -0.199, p = 0.018) as well as BMI and O2 nadir (β = -0.140, p = 0.054). Statistical analysis is ongoing, and additional interesting correlations are being explored.

Intended Outcome and Impact
To investigate if an independent correlation between obesity and abnormal sleep architecture exists. To explore if commonly associated obesity comorbidities are significantly correlated with polysomnographic indices of sleep quality, to help target interventions aimed at both investigating and improving sleep quality.
P137 Diagnosis of nocturnal hypoventilation in children with neuromuscular disorders by polysomnography – a survey of clinical practice in Australia and New Zealand
Authors: Withers A , Downs J , Wilson A , Hall G 
Published: November 2022

Abstract

Background
Diagnosis of nocturnal hypoventilation requires measurement of pCO2 during sleep, which can occur via exhaled gas (capnography) or transcutaneous methods. Different national and international definitions of hypoventilation exist, which may contribute to significant variation in clinical practice.

Methods
An electronic survey was completed by pediatric sleep physicians in Australia and New Zealand to determine how pCO2 was measured during polysomnography, what pCO2 data was available to reporting physicians/included in the report and which definitions of hypoventilation physicians use.

Results
More than two thirds (70%) of physicians indicated that in their centre pCO2 was collected via transcutaneous measurement only and 30% by both transcutaneous and end-tidal measurement. Twelve definitions of hypoventilation were used, including published definitions from the American Academy of Sleep Medicine manual and the pediatric Australasian Sleep Association/Australasian Sleep Technologists Association recommendations. The most commonly used definition was an increase in pCO2 &gt;50mmHg for &gt;25% total sleep time. The percentage of total sleep time with pCO2 &gt;50mmHg was routinely included in the report and/or easily available in the raw data for 70% of physicians.

Discussion
There was significant variation and lack of standardisation within Australia and New Zealand when measuring and reporting pCO2 during polysomnography as well as definitions of hypoventilation used by pediatric sleep physicians. The Australasian Sleep Association/Australasian Sleep Technologists Association recommendations were not frequently used, possibly due to relevant information not being available to reporting physicians, recommendations being irrelevant and/or outdated and excessive cognitive load associated with remembering multiple definitions.
P140 Non-invasive Ventilation prior to Adenotonsillectomy
Authors: Wood C , Aristobil-Adele S , Wittwer J , Gray K , Waters K 
Published: November 2022

Abstract

Introduction
Prolonged wait times to ENT surgery, combined with the risk for post-operative respiratory events in children with severe OSA led to a clinical pathway of implementing CPAP therapy in children with severe OSA whilst on waiting lists for adenotonsillectomy. This study evaluated the impact of this pathway on the clinical care of these patients.

Methods
A retrospective review of medical records of patients under 18yrs of age diagnosed with OSA and initiated on CPAP whilst awaiting review by ENT / Adenotonsillectomy, between January 2019 and December 2020.

Results
36 patients were identified, age 4.3 ± 3.2 years, 86% male, and 80.6% had comorbidities. 16 (44.4%) were overweight or obese, and for 8 (22.2%) obesity was the primary comorbidity. Mean delays: Sleep study to Referral = 4.5 ± 10.5 weeks, Referral to NIV initiation 5.6 ± 8.7 weeks, and NIV to ENT surgery 13.6 ± 13.6 weeks. Total delay from referral to the surgery was 19.6 ± 19.4 weeks. 31 (86%) children were initiated on therapy in hospital, and five (13.9%) patients were non-compliant with the therapy.

Discussion
Current delays to ENT surgery for children identified with OSA on sleep study average 5 months. Where OSA is sufficient to recommend ENT surgery, the majority (80%) of children tolerated CPAP therapy while they await surgery. We suggest that the benefits obtained are that therapy can be instituted more rapidly than surgery, and where children are able to use CPAP therapy it reduced the requirement for high-dependency or intensive care admission post-operatively.