Keith Wong - Academia.edu (original) (raw)

Papers by Keith Wong

Research paper thumbnail of Wang Sleep Med 2011

Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process an... more Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process and is considered a state of recuperation. SWS is reduced in obstructive sleep apnea (OSA) patients, but SWS has not been specifically studied in respiratory failure patients. The aim of this study is to investigate SWS in predominantly hypercapnic respiratory failure patients. Methods: We analyzed sleep and arterial blood gas records of all 97 respiratory failure patients who underwent polysomnography and bilevel non-invasive ventilation (NIV) treatment in our laboratory from 2008 to July 2009. We also analyzed 32 initial diagnostic study data from these 97 patients. Results: The 97 patients had an average age of 58 ± 15 (SD) years. Total sleep time was 320.3 ± 82.8 (SD) min of which 32.9% ± 15.4 (%) was spent in SWS. This high percentage SWS correlated positively with awake arterial CO 2 pressure (PCO 2 ) in both the 97 treatment studies (r = 0.35, p = 0.001) and the 32 initial diagnostic studies (r = 0.40, p = 0.025). The relationship was particularly apparent in patients with obesity hypoventilation syndrome or overlap syndrome. Statistical modelling identified three significant predictor variables for SWS across both diagnostic and NIV nights: PCO 2 , arousal index and female gender. Conclusions: Patients with respiratory failure have a high percentage of EEG assessed SWS which is in part determined by disease specific variables such as hypercapnia as well as by traditional SWS determinants such as sleep fragmentation and gender.

Research paper thumbnail of A comparison of screening methods for sleep disorders in Australian community pharmacies: a randomized controlled trial

PloS one, 2014

Community pharmacies may potentially assist in screening for chronic conditions such as sleep dis... more Community pharmacies may potentially assist in screening for chronic conditions such as sleep disorders, which remain both under-diagnosed and untreated. We aimed to compare a subjective risk-assessment-only questionnaire (RAO) for common sleep disorder screening against the same risk-assessment questionnaire plus a nasal flow monitor as an objective marker of possible underlying obstructive sleep apnea (OSA) (RA+) in a community pharmacy setting. The primary outcome was the number of participants identified in RAO or RA+ group who were likely to have and consequently be diagnosed with OSA. Further outcomes included the number of participants identified as being at risk for, referred for, taking-up referral for, and then diagnosed with OSA, insomnia, and/or restless legs syndrome (RLS) in either group. In a cluster-randomized trial, participants were recruited through 23 community pharmacies. Using validated instruments, 325 (RAO = 152, RA+ = 173) participants were screened for OSA,...

Research paper thumbnail of Consolidating innovative practice models: The case for obstructive sleep apnea services in Australian pharmacies

Research in social & administrative pharmacy : RSAP, Jan 27, 2014

Pharmacists in Australia have pioneered an innovative role in providing obstructive sleep apnea (... more Pharmacists in Australia have pioneered an innovative role in providing obstructive sleep apnea (OSA) services in community pharmacies. A professional practice framework is yet to be established for this novel service area. To explore the practices and experiences of Australian pharmacy staff providing OSA services. Semi-structured telephone interviews were conducted using an interview guide to explore a priori areas of interest. Interviews were audio recorded, transcribed verbatim and thematically analyzed using a framework approach. Interviews were completed with 22 practitioners from demographically diverse pharmacies. Key themes emerging from the interviews included motivation for providing the service, current practice frameworks, determinants for sustaining the service and future directions for the profession. Participants reflected on the professional satisfaction they derived from providing the service and being able to contribute to an important public health area. However,...

Research paper thumbnail of Obstructive sleep apnoea: does one treatment not fit all?

The Lancet. Respiratory medicine, 2014

Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY revi... more Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY reviewed the papers. KW, BY and RG contributed equally to writing the manuscript.

Research paper thumbnail of How do pharmacists respond to complaints of acute insomnia? A simulated patient study

International Journal of Clinical Pharmacy, 2011

Objective It is known that many people with insomnia choose to self medicate and present at commu... more Objective It is known that many people with insomnia choose to self medicate and present at community pharmacies, particularly in cases of acute insomnia. The objective of this study is to investigate how community pharmacists respond to complaints of acute insomnia from people who seek self treatment and determine the factors affecting this response. Setting Community pharmacies in New South Wales, Australia. Method A simulated patient study was conducted in 100 randomly selected pharmacies located in Newcastle and Sydney, Australia. A standardized scenario of acute sleep onset insomnia and a scoring system was used in each pharmacy. Main outcome measures Main outcome measures included supply/non supply of an over the counter sleep aid to the simulated patient, and scores for pharmacists for skills in eliciting information prior to supply of medication (Pre Supply Score), counseling about medication (Supply Score), or about sleep (Sleep Score). Results Of the 100 pharmacies, upon simulated patient presentation, 96% supplied a product, the remaining 4% referred to a physician. Non-pharmacological advice was provided in 42%. Pharmacists scored highly on advice provided with supply of a medication (Supply scores/4, 3.1 ± 0.9), but lower on skills in eliciting information prior to supply (Pre-supply score/8, 3.6 ± 1.9) and sleep related counselling (Sleep Score/9, 2.1 ± 1.7). Lower estimated pharmacist age, being in a chain type pharmacy, and having a visible symbol of quality accreditation were found to significantly improve (P \ 0.05 the Sleep Score outcome. Lower estimated pharmacist age as also significantly associated with higher Supply Score (P \ 0.05); whilst both lower estimated age an visible quality assurance signage were associated with higher Pre-Supply scores (P \ 0.05). Conclusion The results of this study suggest that many pharmacists are responding appropriately to complaints of sleeplessness in terms of eliciting insomnia type and counseling about medicines use. However more education for pharmacists would help to further promote good sleep health, and address behaviors including reliance on medicines taking that can progressively worsen insomnia.

Research paper thumbnail of CPAP use, weight change and metabolic outcomes: Data from 3 randomised controlled trials

Obesity Research & Clinical Practice, 2014

Research paper thumbnail of Screening for Sleep Apnoea in Mild Cognitive Impairment: The Utility of the Multivariable Apnoea Prediction Index

Sleep Disorders, 2014

properly cited.

Research paper thumbnail of Comparing the effect of hypercapnia and hypoxia on the electroencephalogram during wakefulness

Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2015

Hypoxia has been postulated as a key mechanism for neurocognitive impairment in sleep-disordered ... more Hypoxia has been postulated as a key mechanism for neurocognitive impairment in sleep-disordered breathing. However, the effect of hypoxia on the electroencephalogram (EEG) is not clear. We examined quantitative EEG recordings from 20 normal volunteers under three 5-min ventilatory control protocols: progressive hypercapnia with iso-hyperoxia (pO2=150mmHg) (Protocol 1), progressive hypercapnia with iso-hypoxia (pO2=50mmHg) (Protocol 2), and progressive hypoxia with a CO2 scrubber in the circuit (Protocol 3). Each protocol started with a 5-min session of breathing room air as baseline. In Protocol 1, compared to its baseline, iso-hyperoxia hypercapnia led to a lower Alpha% and higher Delta/Alpha (D/A) ratio. Similarly, in Protocol 2, the iso-hypoxia hypercapnia induced a higher Delta%, a lower Alpha% and higher D/A ratio. No difference was found in any EEG spectral band including the D/A ratio when Protocols 1 & 2 were compared. In Protocol 3, the Delta%, Alpha% and D/A ratio recorde...

Research paper thumbnail of Hypercapnia is a Key Correlate of EEG Activation and Daytime Sleepiness in Hypercapnic Sleep Disordered Breathing Patients

Journal of Clinical Sleep Medicine, 2000

ABG arterial blood gas AHI apnoea-hypopnoea index BMI body mass index COPD chronic obstructive pu... more ABG arterial blood gas AHI apnoea-hypopnoea index BMI body mass index COPD chronic obstructive pulmonary disease CPAP continuous positive airway pressure D/A ratio Delta/Alpha ratio ECG electrocardiogram EEG electroencephalography ESS Epworth Sleepiness Scle ODI oxygen desaturation index OHS obesity hypoventilation syndrome OSA obstructive sleep apnoea PSG polysomnography PtcCO 2 transcutaneous PCO 2 REM rapid eye movement sleep SDB sleep-disordered breathing SpO 2 oxygen saturation T90 total sleep time with SpO 2 <90% TST total sleep time ABSTRACT Background: The key determinants of daytime drowsiness in sleep-disordered breathing (SDB) are unclear. Hypercapnia has not been examined as a potential contributor due to the lack of reliable measurement during sleep. To overcome this limitation, we studied predominantly on hypercapnic SDB patients to investigate the role of hypercapnia on EEG activation and daytime sleepiness. Methods: We measured overnight polysomnography (PSG), arterial blood gases, and Epworth Sleepiness Scale in 55 severe SDB patients with obesity hypoventilation syndrome or overlap syndrome (COPD+obstructive sleep apnoea) before and ~3 months after positive airway pressure (PAP) treatment. Quantitative EEG analyses were performed, and the Delta/Alpha ratio was used as an indicator of EEG activation.

Research paper thumbnail of Increasing Adherence to Obstructive Sleep Apnea Treatment with a Group Social Cognitive Therapy Treatment Intervention: A Randomized Trial

SLEEP, 2000

Objective To examine whether a Social Cognitive Therapy (SCT) intervention increases continuous p... more Objective To examine whether a Social Cognitive Therapy (SCT) intervention increases continuous positive airway pressure (CPAP) use compared to equivalent social interaction (SI) time.

Research paper thumbnail of Diagnostic accuracy of a questionnaire and simple home monitoring device in detecting obstructive sleep apnoea in a Chinese population at high cardiovascular risk

Respirology, 2010

OSA is a common condition associated with cardiovascular (CV) morbidity. It remains underdiagnose... more OSA is a common condition associated with cardiovascular (CV) morbidity. It remains underdiagnosed globally in part due to the limited availability and technical requirements of polysomnography (PSG). The aim of this study was to test the accuracy of two simple methods for diagnosing OSA. Consecutive subjects identified from a community register with high CV risk were invited to complete the Berlin Sleep Questionnaire and undergo simultaneous, home, overnight PSG and ApneaLink device oximetry and nasal pressure recordings. The relative accuracies of the Berlin Questionnaire, oximetry and nasal pressure results in diagnosing PSG-defined moderate-severe OSA were assessed. Of 257 eligible high CV risk subjects enrolled, 190 completed sleep studies and 143 subjects&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; studies were of sufficient quality to include in final analyses. Moderate-severe OSA was confirmed in 43% of subjects. The Berlin Questionnaire had low overall diagnostic accuracy in this population. However, ApneaLink recordings of oximetry and nasal pressure areas had high diagnostic utility with areas under the receiver operating characteristic curves of 0.933 and 0.933, respectively. At optimal diagnostic thresholds, oximetry and nasal pressure measurements had similar sensitivity (84% vs 86%) and specificity (84% vs 85%). Technical failure was lower for oximetry than nasal pressure (5.8% vs 18.9% of tests). In patients with high CV risk overnight single-channel oximetry and nasal pressure measurements may provide high diagnostic accuracy and offer an accessible alternative to full PSG.

Research paper thumbnail of The effects of a single mild dose of morphine on chemoreflexes and breathing in obstructive sleep apnea

Respiratory Physiology & Neurobiology, 2013

The effect of morphine on breathing and ventilatory chemoreflexes in obstructive sleep apnea (OSA... more The effect of morphine on breathing and ventilatory chemoreflexes in obstructive sleep apnea (OSA) is unknown. It has been assumed that acute morphine use may induce deeper respiratory depression in OSA but this has not been investigated. We evaluated awake ventilatory chemoreflexes and overnight polysomnography on 10 mild-moderate OSA patients before and after giving 30 mg oral controlledrelease morphine. Morphine plasma concentrations were analysed. We found a 30-fold range of morphine plasma concentrations with the fixed dose of morphine, and a higher plasma morphine concentration was associated with a higher CO 2 recruitment threshold (VRT) (r = 0.86, p = 0.006) and an improvement in sleep time with Sp O 2 < 90% (T90) (r = −0.87, p = 0.005) compared to the baseline. The improvement in T90 also significantly correlated with the increase of VRT (r = −0.79, r = 0.02). In conclusion, in mild-tomoderate OSA patients, a single common dose of oral morphine may paradoxically improve OSA through modulating chemoreflexes. There is a large inter-individual variability in the responses, which may relate to individual morphine metabolism.

Research paper thumbnail of Sleep-disordered Breathing Before and After Lung Transplantation

The Journal of Heart and Lung Transplantation, 2008

Background: Sleep-disordered breathing (SDB) is common in patients with severe chronic respirator... more Background: Sleep-disordered breathing (SDB) is common in patients with severe chronic respiratory failure, but there are no data describing the prevalence of SDB among patients listed for lung transplantation or the effect of transplantation on SDB. We sought to determine the prevalence and impact of SDB before and after lung transplantation.

Research paper thumbnail of Diagnostic test evaluation of a nasal flow monitor for obstructive sleep apnea detection in sleep apnea research

Behavior Research Methods, 2008

In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea ... more In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea (OSA), 34 patients referred for polysomnography were studied at home for three consecutive nights with the monitor. The mean age of subjects (±SD) was 41.9±10.3 years, and their mean apnea-hypopnea index (AHI) was 31.5±27.2. The difference between the average AHI from three nights at home on the monitor and the polysomnogram (PSG) result was 1.8±17.1. The area under the receiver operating characteristic curve (AUC) for PSG All ? 10 was .96. With a threshold AHI of 18 on the flow monitor, sensitivity was .92, specificity .86, positive predictive value .96, and negative predictive value .75. For detecting severe OSA (AIR ? 30), the AUC was .85. With knowledge of appropriate thresholds and the pretest risk of OSA, the flow monitor can be used to detect or exclude OSA for sleep-related research, as well as to identify severe cases needing priority for further evaluation.

Research paper thumbnail of The Role of Sleepiness, Sleep Disorders, and the Work Environment on Heavy-Vehicle Crashes in 2 Australian States

American Journal of Epidemiology, 2014

Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investiga... more Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investigated the associations of sleepiness, sleep disorders, and work environment (including truck characteristics) with the risk of crashing between 2008 and 2011 in the Australian states of New South Wales and Western Australia. We conducted a case-control study of 530 heavy-vehicle drivers who had recently crashed and 517 heavy-vehicle drivers who had not. Drivers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; crash histories, truck details, driving schedules, payment rates, sleep patterns, and measures of health were collected. Subjects wore a nasal flow monitor for 1 night to assess for obstructive sleep apnea. Driving schedules that included the period between midnight and 5:59 am were associated with increased likelihood of crashing (odds ratio = 3.42, 95% confidence interval: 2.04, 5.74), as were having an empty load (odds ratio = 2.61, 95% confidence interval: 1.72, 3.97) and being a less experienced driver (odds ratio = 3.25, 95% confidence interval: 2.37, 4.46). Not taking regular breaks and the lack of vehicle safety devices were also associated with increased crash risk. Despite the high prevalence of obstructive sleep apnea, it was not associated with the risk of a heavy-vehicle nonfatal, nonsevere crash. Scheduling of driving to avoid midnight-to-dawn driving and the use of more frequent rest breaks are likely to reduce the risk of heavy-vehicle nonfatal, nonsevere crashes by 2-3 times.

Research paper thumbnail of Sleep disorders screening, sleep health awareness, and patient follow-up by community pharmacists in Australia

Patient education and counseling, 2011

Community pharmacies are well placed to deliver education and counseling to improve sleep health.... more Community pharmacies are well placed to deliver education and counseling to improve sleep health. To develop, implement and evaluate a pharmacist led sleep health program. Participating pharmacists (n=23) were trained to screen, counsel and follow up patients at risk of sleep disorders. Patients were screened for specific sleep disorders, counseled, provided written information and/or referred to physicians. Patient outcomes were evaluated by questionnaire at 3 or 12 months post screening. A total of 325 patients were screened, with 142 (44%) patients at risk of one or more sleep disorders. A total of 847 interventions were recorded by pharmacists: verbal counseling (49%), written information (34%), and referrals (16%). A total of 63 patients (of 99 recalling being referred) reported acting on their referral. Positive changes were made with smoking (4%), caffeine intake (10%), alcohol intake (9%) and improved sleep environment (19%). Pharmacists can raise awareness through educating...

Research paper thumbnail of Wang Sleep Med 2011

Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process an... more Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process and is considered a state of recuperation. SWS is reduced in obstructive sleep apnea (OSA) patients, but SWS has not been specifically studied in respiratory failure patients. The aim of this study is to investigate SWS in predominantly hypercapnic respiratory failure patients. Methods: We analyzed sleep and arterial blood gas records of all 97 respiratory failure patients who underwent polysomnography and bilevel non-invasive ventilation (NIV) treatment in our laboratory from 2008 to July 2009. We also analyzed 32 initial diagnostic study data from these 97 patients. Results: The 97 patients had an average age of 58 ± 15 (SD) years. Total sleep time was 320.3 ± 82.8 (SD) min of which 32.9% ± 15.4 (%) was spent in SWS. This high percentage SWS correlated positively with awake arterial CO 2 pressure (PCO 2 ) in both the 97 treatment studies (r = 0.35, p = 0.001) and the 32 initial diagnostic studies (r = 0.40, p = 0.025). The relationship was particularly apparent in patients with obesity hypoventilation syndrome or overlap syndrome. Statistical modelling identified three significant predictor variables for SWS across both diagnostic and NIV nights: PCO 2 , arousal index and female gender. Conclusions: Patients with respiratory failure have a high percentage of EEG assessed SWS which is in part determined by disease specific variables such as hypercapnia as well as by traditional SWS determinants such as sleep fragmentation and gender.

Research paper thumbnail of A comparison of screening methods for sleep disorders in Australian community pharmacies: a randomized controlled trial

PloS one, 2014

Community pharmacies may potentially assist in screening for chronic conditions such as sleep dis... more Community pharmacies may potentially assist in screening for chronic conditions such as sleep disorders, which remain both under-diagnosed and untreated. We aimed to compare a subjective risk-assessment-only questionnaire (RAO) for common sleep disorder screening against the same risk-assessment questionnaire plus a nasal flow monitor as an objective marker of possible underlying obstructive sleep apnea (OSA) (RA+) in a community pharmacy setting. The primary outcome was the number of participants identified in RAO or RA+ group who were likely to have and consequently be diagnosed with OSA. Further outcomes included the number of participants identified as being at risk for, referred for, taking-up referral for, and then diagnosed with OSA, insomnia, and/or restless legs syndrome (RLS) in either group. In a cluster-randomized trial, participants were recruited through 23 community pharmacies. Using validated instruments, 325 (RAO = 152, RA+ = 173) participants were screened for OSA,...

Research paper thumbnail of Obstructive sleep apnoea: does one treatment not fit all?

The Lancet. Respiratory medicine, 2014

Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY revi... more Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY reviewed the papers. KW, BY and RG contributed equally to writing the manuscript.

Research paper thumbnail of Prevalence of patent foramen ovale and its impact on oxygen desaturation in obstructive sleep apnea

International Journal of Cardiology, 2000

BackgroundA possible association between patent foramen ovale (PFO) and obstructive sleep apnea h... more BackgroundA possible association between patent foramen ovale (PFO) and obstructive sleep apnea has been suggested (OSA), whereby right-to-left shunting may exacerbate the severity of nocturnal oxygen desaturation. However, the interaction between these two conditions has not been well characterised.

Research paper thumbnail of Wang Sleep Med 2011

Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process an... more Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process and is considered a state of recuperation. SWS is reduced in obstructive sleep apnea (OSA) patients, but SWS has not been specifically studied in respiratory failure patients. The aim of this study is to investigate SWS in predominantly hypercapnic respiratory failure patients. Methods: We analyzed sleep and arterial blood gas records of all 97 respiratory failure patients who underwent polysomnography and bilevel non-invasive ventilation (NIV) treatment in our laboratory from 2008 to July 2009. We also analyzed 32 initial diagnostic study data from these 97 patients. Results: The 97 patients had an average age of 58 ± 15 (SD) years. Total sleep time was 320.3 ± 82.8 (SD) min of which 32.9% ± 15.4 (%) was spent in SWS. This high percentage SWS correlated positively with awake arterial CO 2 pressure (PCO 2 ) in both the 97 treatment studies (r = 0.35, p = 0.001) and the 32 initial diagnostic studies (r = 0.40, p = 0.025). The relationship was particularly apparent in patients with obesity hypoventilation syndrome or overlap syndrome. Statistical modelling identified three significant predictor variables for SWS across both diagnostic and NIV nights: PCO 2 , arousal index and female gender. Conclusions: Patients with respiratory failure have a high percentage of EEG assessed SWS which is in part determined by disease specific variables such as hypercapnia as well as by traditional SWS determinants such as sleep fragmentation and gender.

Research paper thumbnail of A comparison of screening methods for sleep disorders in Australian community pharmacies: a randomized controlled trial

PloS one, 2014

Community pharmacies may potentially assist in screening for chronic conditions such as sleep dis... more Community pharmacies may potentially assist in screening for chronic conditions such as sleep disorders, which remain both under-diagnosed and untreated. We aimed to compare a subjective risk-assessment-only questionnaire (RAO) for common sleep disorder screening against the same risk-assessment questionnaire plus a nasal flow monitor as an objective marker of possible underlying obstructive sleep apnea (OSA) (RA+) in a community pharmacy setting. The primary outcome was the number of participants identified in RAO or RA+ group who were likely to have and consequently be diagnosed with OSA. Further outcomes included the number of participants identified as being at risk for, referred for, taking-up referral for, and then diagnosed with OSA, insomnia, and/or restless legs syndrome (RLS) in either group. In a cluster-randomized trial, participants were recruited through 23 community pharmacies. Using validated instruments, 325 (RAO = 152, RA+ = 173) participants were screened for OSA,...

Research paper thumbnail of Consolidating innovative practice models: The case for obstructive sleep apnea services in Australian pharmacies

Research in social & administrative pharmacy : RSAP, Jan 27, 2014

Pharmacists in Australia have pioneered an innovative role in providing obstructive sleep apnea (... more Pharmacists in Australia have pioneered an innovative role in providing obstructive sleep apnea (OSA) services in community pharmacies. A professional practice framework is yet to be established for this novel service area. To explore the practices and experiences of Australian pharmacy staff providing OSA services. Semi-structured telephone interviews were conducted using an interview guide to explore a priori areas of interest. Interviews were audio recorded, transcribed verbatim and thematically analyzed using a framework approach. Interviews were completed with 22 practitioners from demographically diverse pharmacies. Key themes emerging from the interviews included motivation for providing the service, current practice frameworks, determinants for sustaining the service and future directions for the profession. Participants reflected on the professional satisfaction they derived from providing the service and being able to contribute to an important public health area. However,...

Research paper thumbnail of Obstructive sleep apnoea: does one treatment not fit all?

The Lancet. Respiratory medicine, 2014

Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY revi... more Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY reviewed the papers. KW, BY and RG contributed equally to writing the manuscript.

Research paper thumbnail of How do pharmacists respond to complaints of acute insomnia? A simulated patient study

International Journal of Clinical Pharmacy, 2011

Objective It is known that many people with insomnia choose to self medicate and present at commu... more Objective It is known that many people with insomnia choose to self medicate and present at community pharmacies, particularly in cases of acute insomnia. The objective of this study is to investigate how community pharmacists respond to complaints of acute insomnia from people who seek self treatment and determine the factors affecting this response. Setting Community pharmacies in New South Wales, Australia. Method A simulated patient study was conducted in 100 randomly selected pharmacies located in Newcastle and Sydney, Australia. A standardized scenario of acute sleep onset insomnia and a scoring system was used in each pharmacy. Main outcome measures Main outcome measures included supply/non supply of an over the counter sleep aid to the simulated patient, and scores for pharmacists for skills in eliciting information prior to supply of medication (Pre Supply Score), counseling about medication (Supply Score), or about sleep (Sleep Score). Results Of the 100 pharmacies, upon simulated patient presentation, 96% supplied a product, the remaining 4% referred to a physician. Non-pharmacological advice was provided in 42%. Pharmacists scored highly on advice provided with supply of a medication (Supply scores/4, 3.1 ± 0.9), but lower on skills in eliciting information prior to supply (Pre-supply score/8, 3.6 ± 1.9) and sleep related counselling (Sleep Score/9, 2.1 ± 1.7). Lower estimated pharmacist age, being in a chain type pharmacy, and having a visible symbol of quality accreditation were found to significantly improve (P \ 0.05 the Sleep Score outcome. Lower estimated pharmacist age as also significantly associated with higher Supply Score (P \ 0.05); whilst both lower estimated age an visible quality assurance signage were associated with higher Pre-Supply scores (P \ 0.05). Conclusion The results of this study suggest that many pharmacists are responding appropriately to complaints of sleeplessness in terms of eliciting insomnia type and counseling about medicines use. However more education for pharmacists would help to further promote good sleep health, and address behaviors including reliance on medicines taking that can progressively worsen insomnia.

Research paper thumbnail of CPAP use, weight change and metabolic outcomes: Data from 3 randomised controlled trials

Obesity Research & Clinical Practice, 2014

Research paper thumbnail of Screening for Sleep Apnoea in Mild Cognitive Impairment: The Utility of the Multivariable Apnoea Prediction Index

Sleep Disorders, 2014

properly cited.

Research paper thumbnail of Comparing the effect of hypercapnia and hypoxia on the electroencephalogram during wakefulness

Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology, 2015

Hypoxia has been postulated as a key mechanism for neurocognitive impairment in sleep-disordered ... more Hypoxia has been postulated as a key mechanism for neurocognitive impairment in sleep-disordered breathing. However, the effect of hypoxia on the electroencephalogram (EEG) is not clear. We examined quantitative EEG recordings from 20 normal volunteers under three 5-min ventilatory control protocols: progressive hypercapnia with iso-hyperoxia (pO2=150mmHg) (Protocol 1), progressive hypercapnia with iso-hypoxia (pO2=50mmHg) (Protocol 2), and progressive hypoxia with a CO2 scrubber in the circuit (Protocol 3). Each protocol started with a 5-min session of breathing room air as baseline. In Protocol 1, compared to its baseline, iso-hyperoxia hypercapnia led to a lower Alpha% and higher Delta/Alpha (D/A) ratio. Similarly, in Protocol 2, the iso-hypoxia hypercapnia induced a higher Delta%, a lower Alpha% and higher D/A ratio. No difference was found in any EEG spectral band including the D/A ratio when Protocols 1 & 2 were compared. In Protocol 3, the Delta%, Alpha% and D/A ratio recorde...

Research paper thumbnail of Hypercapnia is a Key Correlate of EEG Activation and Daytime Sleepiness in Hypercapnic Sleep Disordered Breathing Patients

Journal of Clinical Sleep Medicine, 2000

ABG arterial blood gas AHI apnoea-hypopnoea index BMI body mass index COPD chronic obstructive pu... more ABG arterial blood gas AHI apnoea-hypopnoea index BMI body mass index COPD chronic obstructive pulmonary disease CPAP continuous positive airway pressure D/A ratio Delta/Alpha ratio ECG electrocardiogram EEG electroencephalography ESS Epworth Sleepiness Scle ODI oxygen desaturation index OHS obesity hypoventilation syndrome OSA obstructive sleep apnoea PSG polysomnography PtcCO 2 transcutaneous PCO 2 REM rapid eye movement sleep SDB sleep-disordered breathing SpO 2 oxygen saturation T90 total sleep time with SpO 2 <90% TST total sleep time ABSTRACT Background: The key determinants of daytime drowsiness in sleep-disordered breathing (SDB) are unclear. Hypercapnia has not been examined as a potential contributor due to the lack of reliable measurement during sleep. To overcome this limitation, we studied predominantly on hypercapnic SDB patients to investigate the role of hypercapnia on EEG activation and daytime sleepiness. Methods: We measured overnight polysomnography (PSG), arterial blood gases, and Epworth Sleepiness Scale in 55 severe SDB patients with obesity hypoventilation syndrome or overlap syndrome (COPD+obstructive sleep apnoea) before and ~3 months after positive airway pressure (PAP) treatment. Quantitative EEG analyses were performed, and the Delta/Alpha ratio was used as an indicator of EEG activation.

Research paper thumbnail of Increasing Adherence to Obstructive Sleep Apnea Treatment with a Group Social Cognitive Therapy Treatment Intervention: A Randomized Trial

SLEEP, 2000

Objective To examine whether a Social Cognitive Therapy (SCT) intervention increases continuous p... more Objective To examine whether a Social Cognitive Therapy (SCT) intervention increases continuous positive airway pressure (CPAP) use compared to equivalent social interaction (SI) time.

Research paper thumbnail of Diagnostic accuracy of a questionnaire and simple home monitoring device in detecting obstructive sleep apnoea in a Chinese population at high cardiovascular risk

Respirology, 2010

OSA is a common condition associated with cardiovascular (CV) morbidity. It remains underdiagnose... more OSA is a common condition associated with cardiovascular (CV) morbidity. It remains underdiagnosed globally in part due to the limited availability and technical requirements of polysomnography (PSG). The aim of this study was to test the accuracy of two simple methods for diagnosing OSA. Consecutive subjects identified from a community register with high CV risk were invited to complete the Berlin Sleep Questionnaire and undergo simultaneous, home, overnight PSG and ApneaLink device oximetry and nasal pressure recordings. The relative accuracies of the Berlin Questionnaire, oximetry and nasal pressure results in diagnosing PSG-defined moderate-severe OSA were assessed. Of 257 eligible high CV risk subjects enrolled, 190 completed sleep studies and 143 subjects&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; studies were of sufficient quality to include in final analyses. Moderate-severe OSA was confirmed in 43% of subjects. The Berlin Questionnaire had low overall diagnostic accuracy in this population. However, ApneaLink recordings of oximetry and nasal pressure areas had high diagnostic utility with areas under the receiver operating characteristic curves of 0.933 and 0.933, respectively. At optimal diagnostic thresholds, oximetry and nasal pressure measurements had similar sensitivity (84% vs 86%) and specificity (84% vs 85%). Technical failure was lower for oximetry than nasal pressure (5.8% vs 18.9% of tests). In patients with high CV risk overnight single-channel oximetry and nasal pressure measurements may provide high diagnostic accuracy and offer an accessible alternative to full PSG.

Research paper thumbnail of The effects of a single mild dose of morphine on chemoreflexes and breathing in obstructive sleep apnea

Respiratory Physiology & Neurobiology, 2013

The effect of morphine on breathing and ventilatory chemoreflexes in obstructive sleep apnea (OSA... more The effect of morphine on breathing and ventilatory chemoreflexes in obstructive sleep apnea (OSA) is unknown. It has been assumed that acute morphine use may induce deeper respiratory depression in OSA but this has not been investigated. We evaluated awake ventilatory chemoreflexes and overnight polysomnography on 10 mild-moderate OSA patients before and after giving 30 mg oral controlledrelease morphine. Morphine plasma concentrations were analysed. We found a 30-fold range of morphine plasma concentrations with the fixed dose of morphine, and a higher plasma morphine concentration was associated with a higher CO 2 recruitment threshold (VRT) (r = 0.86, p = 0.006) and an improvement in sleep time with Sp O 2 < 90% (T90) (r = −0.87, p = 0.005) compared to the baseline. The improvement in T90 also significantly correlated with the increase of VRT (r = −0.79, r = 0.02). In conclusion, in mild-tomoderate OSA patients, a single common dose of oral morphine may paradoxically improve OSA through modulating chemoreflexes. There is a large inter-individual variability in the responses, which may relate to individual morphine metabolism.

Research paper thumbnail of Sleep-disordered Breathing Before and After Lung Transplantation

The Journal of Heart and Lung Transplantation, 2008

Background: Sleep-disordered breathing (SDB) is common in patients with severe chronic respirator... more Background: Sleep-disordered breathing (SDB) is common in patients with severe chronic respiratory failure, but there are no data describing the prevalence of SDB among patients listed for lung transplantation or the effect of transplantation on SDB. We sought to determine the prevalence and impact of SDB before and after lung transplantation.

Research paper thumbnail of Diagnostic test evaluation of a nasal flow monitor for obstructive sleep apnea detection in sleep apnea research

Behavior Research Methods, 2008

In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea ... more In this diagnostic test evaluation of a nasal flow monitoring device for obstructive sleep apnea (OSA), 34 patients referred for polysomnography were studied at home for three consecutive nights with the monitor. The mean age of subjects (±SD) was 41.9±10.3 years, and their mean apnea-hypopnea index (AHI) was 31.5±27.2. The difference between the average AHI from three nights at home on the monitor and the polysomnogram (PSG) result was 1.8±17.1. The area under the receiver operating characteristic curve (AUC) for PSG All ? 10 was .96. With a threshold AHI of 18 on the flow monitor, sensitivity was .92, specificity .86, positive predictive value .96, and negative predictive value .75. For detecting severe OSA (AIR ? 30), the AUC was .85. With knowledge of appropriate thresholds and the pretest risk of OSA, the flow monitor can be used to detect or exclude OSA for sleep-related research, as well as to identify severe cases needing priority for further evaluation.

Research paper thumbnail of The Role of Sleepiness, Sleep Disorders, and the Work Environment on Heavy-Vehicle Crashes in 2 Australian States

American Journal of Epidemiology, 2014

Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investiga... more Heavy-vehicle driving involves a challenging work environment and a high crash rate. We investigated the associations of sleepiness, sleep disorders, and work environment (including truck characteristics) with the risk of crashing between 2008 and 2011 in the Australian states of New South Wales and Western Australia. We conducted a case-control study of 530 heavy-vehicle drivers who had recently crashed and 517 heavy-vehicle drivers who had not. Drivers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; crash histories, truck details, driving schedules, payment rates, sleep patterns, and measures of health were collected. Subjects wore a nasal flow monitor for 1 night to assess for obstructive sleep apnea. Driving schedules that included the period between midnight and 5:59 am were associated with increased likelihood of crashing (odds ratio = 3.42, 95% confidence interval: 2.04, 5.74), as were having an empty load (odds ratio = 2.61, 95% confidence interval: 1.72, 3.97) and being a less experienced driver (odds ratio = 3.25, 95% confidence interval: 2.37, 4.46). Not taking regular breaks and the lack of vehicle safety devices were also associated with increased crash risk. Despite the high prevalence of obstructive sleep apnea, it was not associated with the risk of a heavy-vehicle nonfatal, nonsevere crash. Scheduling of driving to avoid midnight-to-dawn driving and the use of more frequent rest breaks are likely to reduce the risk of heavy-vehicle nonfatal, nonsevere crashes by 2-3 times.

Research paper thumbnail of Sleep disorders screening, sleep health awareness, and patient follow-up by community pharmacists in Australia

Patient education and counseling, 2011

Community pharmacies are well placed to deliver education and counseling to improve sleep health.... more Community pharmacies are well placed to deliver education and counseling to improve sleep health. To develop, implement and evaluate a pharmacist led sleep health program. Participating pharmacists (n=23) were trained to screen, counsel and follow up patients at risk of sleep disorders. Patients were screened for specific sleep disorders, counseled, provided written information and/or referred to physicians. Patient outcomes were evaluated by questionnaire at 3 or 12 months post screening. A total of 325 patients were screened, with 142 (44%) patients at risk of one or more sleep disorders. A total of 847 interventions were recorded by pharmacists: verbal counseling (49%), written information (34%), and referrals (16%). A total of 63 patients (of 99 recalling being referred) reported acting on their referral. Positive changes were made with smoking (4%), caffeine intake (10%), alcohol intake (9%) and improved sleep environment (19%). Pharmacists can raise awareness through educating...

Research paper thumbnail of Wang Sleep Med 2011

Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process an... more Background: Slow wave sleep (SWS) has been theorized as reflecting a homeostatic sleep process and is considered a state of recuperation. SWS is reduced in obstructive sleep apnea (OSA) patients, but SWS has not been specifically studied in respiratory failure patients. The aim of this study is to investigate SWS in predominantly hypercapnic respiratory failure patients. Methods: We analyzed sleep and arterial blood gas records of all 97 respiratory failure patients who underwent polysomnography and bilevel non-invasive ventilation (NIV) treatment in our laboratory from 2008 to July 2009. We also analyzed 32 initial diagnostic study data from these 97 patients. Results: The 97 patients had an average age of 58 ± 15 (SD) years. Total sleep time was 320.3 ± 82.8 (SD) min of which 32.9% ± 15.4 (%) was spent in SWS. This high percentage SWS correlated positively with awake arterial CO 2 pressure (PCO 2 ) in both the 97 treatment studies (r = 0.35, p = 0.001) and the 32 initial diagnostic studies (r = 0.40, p = 0.025). The relationship was particularly apparent in patients with obesity hypoventilation syndrome or overlap syndrome. Statistical modelling identified three significant predictor variables for SWS across both diagnostic and NIV nights: PCO 2 , arousal index and female gender. Conclusions: Patients with respiratory failure have a high percentage of EEG assessed SWS which is in part determined by disease specific variables such as hypercapnia as well as by traditional SWS determinants such as sleep fragmentation and gender.

Research paper thumbnail of A comparison of screening methods for sleep disorders in Australian community pharmacies: a randomized controlled trial

PloS one, 2014

Community pharmacies may potentially assist in screening for chronic conditions such as sleep dis... more Community pharmacies may potentially assist in screening for chronic conditions such as sleep disorders, which remain both under-diagnosed and untreated. We aimed to compare a subjective risk-assessment-only questionnaire (RAO) for common sleep disorder screening against the same risk-assessment questionnaire plus a nasal flow monitor as an objective marker of possible underlying obstructive sleep apnea (OSA) (RA+) in a community pharmacy setting. The primary outcome was the number of participants identified in RAO or RA+ group who were likely to have and consequently be diagnosed with OSA. Further outcomes included the number of participants identified as being at risk for, referred for, taking-up referral for, and then diagnosed with OSA, insomnia, and/or restless legs syndrome (RLS) in either group. In a cluster-randomized trial, participants were recruited through 23 community pharmacies. Using validated instruments, 325 (RAO = 152, RA+ = 173) participants were screened for OSA,...

Research paper thumbnail of Obstructive sleep apnoea: does one treatment not fit all?

The Lancet. Respiratory medicine, 2014

Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY revi... more Telephone: +61 2 9515 8196 Author contributions: KW conducted a literature search. KW and BY reviewed the papers. KW, BY and RG contributed equally to writing the manuscript.

Research paper thumbnail of Prevalence of patent foramen ovale and its impact on oxygen desaturation in obstructive sleep apnea

International Journal of Cardiology, 2000

BackgroundA possible association between patent foramen ovale (PFO) and obstructive sleep apnea h... more BackgroundA possible association between patent foramen ovale (PFO) and obstructive sleep apnea has been suggested (OSA), whereby right-to-left shunting may exacerbate the severity of nocturnal oxygen desaturation. However, the interaction between these two conditions has not been well characterised.