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Objectives: Continuous positive airway pressure (CPAP) improves upper airway obstruction in patients with obstructive sleep apnoea (OSA), who often are overweight-obese. Although it is thought that CPAP improves long-term blood pressure control (BP), the impact of acute and short-term CPAP use on the cardiovascular system in obese patients has not been described in detail., Methods: Obese patients (body mass index, BMI > 25 kg/m 2 ) with OSA were studied awake, supine during incremental CPAP titration (4-20 cmH 2 O, +2 cmH 2 O/3 mins). BP was measured continuously with a beat-to-beat BP monitor (Ohmeda 2300, Finapres Medical Systems, Amsterdam/NL), BP variability (BPV) was calculated as the standard deviation of BP at each CPAP level, the 95% confidence interval (95%CI) was calculated and changes in BP and BPV were reported., Results: 15 patients (12 male, 48 ± 10) years, BMI 38.9 ± 5.8 kg/m 2 ) were studied; the baseline BP was 131.0 ± 10.2/85.1 ± 9.1 mmHg. BP and BPV increased linearly with CPAP titration (systolic BP r = 0.960, p < .001; diastolic BP r = 0.961, p < .001; systolic BPV r = 0.662, p = .026; diastolic BPV r = 0.886, p < .001). The systolic BP increased by +17% (+23.15 (7.9, 38.4) mmHg; p = .011) and the diastolic BP by +23% (+18.27 (2.33, 34.21) mmHg; p = .009), when titrating CPAP to 20 cmH 2 O. Systolic BPV increased by +96% (+5.10 (0.67, 9.53) mmHg; p < .001) and was maximal at 14 cmH 2 O, and diastolic BPV by +97% (+3.02 (0.26, 5.78) mmHg; p < .001) at 16 cmH 2 O., Conclusion: Short-term incremental CPAP leads to significant increases in BP and BPV in obese patients with OSA while awake. Careful titration of pressures is required to minimise the risk of nocturnal awakenings while improving BP control.

Effectiveness and side-effect profile data on pharmacotherapy for daytime sleepiness in central hypersomnias are based largely upon randomized controlled trials. Evidence regarding the use of combination therapy is scant. The aim of this study was to examine the effectiveness and occurrence of drug-related side effects of these drugs in routine clinical practice. Adult patients diagnosed with a central hypersomnia during a 54-month period at a tertiary sleep disorders centre were identified retrospectively. Side effects were recorded at every follow-up visit. A total of 126 patients, with 3275 patient-months of drug exposure, were categorized into narcolepsy type 1 (n = 70), narcolepsy type 2 (n = 47) and idiopathic hypersomnia (n = 9). Modafinil was the most common drug used as a first-line treatment (93%) and in combination therapy (70%). Thirty-nine per cent of the patients demonstrated a complete, 25% partial and 36% a poor response to treatment. Combination treatment improved daytime sleepiness in 55% of the patients with residual symptoms despite monotherapy. Sixty per cent of patients reported side effects, and 30% reported treatment-limiting side effects. Drugs had similar side-effect incidence (P = 0.363) and their side-effect profile met those reported in the literature. Twenty-seven per cent of the patients received combination treatment and had fewer side effects compared to monotherapy (29.4% versus 60%, respectively, P = 0.001). Monotherapy appears to achieve satisfactory symptom control in most patients with central hypersomnia, but significant side effects are common. Combination therapy appears to be a useful and safe option in patients with refractory symptoms., (© 2017 European Sleep Research Society.)

Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

The treatment of choice for obstructive sleep apnoea (OSA) is continuous positive airway pressure therapy (CPAP). Since its introduction in clinical practice, CPAP has been used in various clinical conditions with variable and heterogeneous outcomes. In addition to the well-known effects on the upper airway CPAP impacts on intrathoracic pressures, haemodynamics and blood pressure (BP) control. However, short- and long-term effects of CPAP therapy depend on multiple variables which include symptoms, underlying condition, pressure used, treatment acceptance, compliance and usage. CPAP can alter long-term cardiovascular risk in patients with cardiorespiratory conditions. Furthermore, the effect of CPAP on the awake patient differs from the effect on the patients while asleep, and this might contribute to discomfort and removal of the use interface. The purpose of this review is to highlight the physiological impact of CPAP on the cardiorespiratory system, including short-term benefits and long-term outcomes., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Background: In this study we investigated subjective measures of sleepiness and related our findings to dimensions of affect, fatigue, emotion, mood and quality of life based on a hypothetical multidimensional model of sleepiness., Methods: Patients referred to a sleep clinic were assessed regarding their excessive daytime sleepiness (EDS), sleep complaints, routine and symptoms. Age, gender and body mass index (BMI), the Epworth Sleepiness Scale (ESS), the Stanford Sleepiness Scale (SSS), the Samn-Perelli fatigue Scale (SPS), the Global Vigor and Affect Scale (GVS and GAS, respectively), the Hospital Anxiety and Depression Scale (HADS-A and HADS-D, respectively), and the Positive and Negative Affect Schedule (PAS and NAS, respectively) scores were recorded., Results: Fifty patients [25 male, 45.2 (18.7) years] completed the questionnaires. The ESS scores were positively correlated with SSS, SPS, HADS-A, HADS-D and NAS scores and negatively with GVS and GAS scores (P<0.05). The SPS (P<0.001) and HADS-A scores (P=0.002) were independently associated with the ESS scores (R 2 =0.532, adjusted R 2 =0.4794, P<0.001)., Conclusions: A model of sleepiness that assesses dimensions of fatigue and anxiety could explain the symptom of subjective sleepiness better than the isolated use of the ESS., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Background: Obstructive sleep apnoea (OSA) is increasingly common in bariatric patients undergoing sedation during elective surgery. However, it has not been established how significant a contributor it is to peri-operative respiratory complications and mortality. We sought to pre-operatively identify OSA in bariatric patients and record peri-operative complications during and after bariatric surgery., Methods: Data were collected and analysed from June 2014 to March 2017 for 410 bariatric surgery patients referred to the sleep laboratory for pre-operative screening and treatment of OSA. The STOP-Bang questionnaire, Epworth Sleepiness Scale (ESS) and nocturnal pulse oximetry were recorded and treatment was allocated with continuous positive airway pressure (CPAP). Peri-operative complications and mortality were the primary outcome measures for patients receiving CPAP treatment for OSA, with patients who did not require CPAP used as control. The mean follow-up time for all patients was 433 and 732 days for the patients who had undergone bariatric surgery. The two groups were compared with Chi square test and unpaired two-tailed t -test., Results: OSA was present in any form in 70% of the screened patients; 40% of patients involved in the study received CPAP treatment. Patients receiving CPAP treatment [49.5 (11.3) years old, 61% female, 50.3 (8.5) kg/m 2 ] were older, had a lower percentage of females and had a higher body mass index (BMI) than those not receiving CPAP [44.9 (12.0), 81% female, 46.6 (7.7)]. No significant differences were observed between patients on CPAP and those not on CPAP, there was no significant difference in hospital stay or rate of respiratory complications. Out of 53 patients who had undergone bariatric surgery at the cut-off date, only 1 had suffered a respiratory complication., Conclusions: Bariatric patients who are screened pre-operatively for OSA and treated according to guidelines have no increased risk of respiratory complications compared to patients without OSA., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Background: Continuous positive airway pressure (CPAP), the best available treatment for obstructive sleep apnea (OSA), requires long-term compliance to be effective. Behavioral interventions may be used to improve adherence to CPAP. We aimed to investigate whether positive or negative message framing impacts on CPAP compliance in patients with OSA, when compared to standard care., Methods: Consenting patients with confirmed OSA were randomly allocated to receive along with their CPAP either positively or negatively framed messages (Pos; Neg), or standard care (Con). Standardized motivational messages were read out to patients during an initial teaching session and through weekly telephone calls. Patients' compliance data were reviewed 2 and 6 weeks following CPAP initiation., Results: We randomized 112 patients to groups that were matched for age, BMI, and OSA severity. The positively framed group (Pos) showed greater CPAP usage after 2 weeks (total use 53.7±31.4 hours) as compared to the negatively framed and the control group (35.6±27.4 and 40.8±33.5 hours, P<0.05); however, no differences were seen at 6 weeks. There were more dropouts in the control group than in either framed groups (Pos n=5; Neg n=8; Con n=11; P<0.05)., Conclusions: Positively framed messages can improve CPAP adherence in patients with OSA in the short-term; however, strategies for implementing its long-term use need to be developed., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Background: Chronic hypercapnic respiratory failure (HRF) in obesity hypoventilation syndrome (OHS) is commonly treated using non-invasive ventilation (NIV). We hypothesised that treatment of OHS would improve neural respiratory drive index (NRDI) and cardiac function., Methods: Fourteen patients (8 females) with OHS, who were admitted for initiation of domiciliary NIV, were prospectively studied. Patients had (mean ± SD): age (53±10 years), body mass index (BMI) (50.1±10.8 kg/m 2 ), and pCO 2 (7.3±0.9 kPa). NRDI was assessed by surface electromyogram of the parasternal intercostals. Cardiac function was assessed by transthoracic echocardiography (TTE). All measurements were performed at baseline, 6 weeks, and 3 months., Results: NRDI improved on day one following NIV set-up comparing to baseline (484.2±214.8 vs. 316.5±106.5 AU) and this improvement was maintained at 6 weeks (369.1±173.2 AU) and at 3 months (351.2±167.1 AU) (P=0.004). No significant differences were identified in terms of cardiac function between baseline and 3 months [tricuspid annular plane systolic excursion (TAPSE) (24.6±5.8 vs. 23.0±4.0 mm, P=0.317); systolic pulmonary artery (PA) pressures (36.7±15.2 vs. 44.5±23.9 mmHg, P=0.163]., Conclusions: NIV improves NRDI in patients with OHS, while the cardiac function over a three-month period remains unchanged., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Background: Patients with neuromuscular disease (NMD) are at risk of developing sleep-disordered breathing (SDB) with hypercapnic respiratory failure. We hypothesised that a self-administered questionnaire (SiNQ-5 scores) may be useful to assess patients who are established on treatment for NMD with SDB., Methods: Patients attending a tertiary referral centre filled in the SiNQ-5 (range 0-10 points, lower scores indicating fewer symptoms). The questionnaire contains five questions related to breathlessness, sleep and posture. Patients with NMD and treated SDB were compared to NMD without SDB, to sleep apnoea, chronic obstructive pulmonary disease (COPD) and heart failure (HF) patients' scores, as well as a group of patients without SDB. Results were compared using Kruskal-Wallis one-way analysis of variance, with Dunn/Bonferroni post-hoc tests if comparisons were found to be statistically significant., Results: A total of 265 (156 male) patients completed the assessment, 40 had NMD with treated SDB [SiNQ-5 score 3.4 (3.0) points], 11 had NMD without SDB [2.7 (2.9) points], 120 patients had obstructive sleep apnoea (OSA) [4.1 (2.6) points], 16 had COPD [3.9 (3.0) points] and 9 had HF [3.2 (2.8) points], 69 patients had other conditions with no evidence of SDB [3.0 (2.4) points; P=0.077]. Patients with NMD without SDB and those with SDB who were on treatment did not differ in their responses (P=0.417). Question #1 allowed discrimination between patients with NMD with SDB [0.8 (0.8) points] and other disorders without respiratory involvement [0.3 (0.6) points; P=0.024]., Conclusions: The SiNQ-5 scores in neuromuscular patients with SDB who are established on treatment and NMD patients without SDB, as well as in patients with other conditions leading to SDB are similar., Competing Interests: Conflicts of Interest: The authors have no conflicts of interest to declare.

Introduction: Obstructive sleep apnoea is an increasingly prevalent clinical condition with significant impact on individuals and public health. Continuous positive airway pressure therapy is the standard treatment, but adherence is limited and alternative treatments are needed. In this context, non-invasive and invasive methods for the electrical stimulation of upper airway dilator muscles have been demonstrated to be effective in selected patients. Areas covered: This review will cover investigations on the clinical effects, safety, and tolerability of non-invasive and invasive electrical stimulation of the upper airway for the management of obstructive sleep apnoea. Following a search of the relevant literature published on PubMed this review is focused mainly on data obtained from randomized clinical trials and clinical studies. Expert commentary: The available evidence provides a rationale to consider upper airway electrical stimulation as treatment for selected patients with obstructive sleep apnoea, who have poor adherence or experience difficulties with continuous positive airway pressure therapy. Non-invasive stimulation using transcutaneous electrodes and implantable hypoglossal nerve stimulator technologies may provide an alternative to continuous positive airway pressure for the treatment of obstructive sleep apnoea via restoration of neuromuscular tone and improved upper airway patency.

Steier, Joerg, Nic Cade, Ben Walker, John Moxham, and Caroline Jolley. Observational study of neural respiratory drive during sleep at high altitude. High Alt Med Biol. 18:242-248, 2017., Aims: Ventilation at altitude changes due to altered levels of pO 2 , pCO 2 and the effect on blood pH. Nocturnal ventilation is particularly exposed to these changes. We hypothesized that an increasing neural respiratory drive (NRD) is associated with the severity of sleep-disordered breathing at altitude., Methods: Mountaineers were studied at sea level (London, United Kingdom), and at altitude at the Aconcagua (Andes, Argentina). NRD was measured as electromyogram of the diaphragm (EMGdi) overnight by a transesophageal multi-electrode catheter; results were reported for sea level, 3,380 m, 4,370 m, and 5,570 m., Results: Four healthy subjects (3 men, age 31(3)years, body mass index 23.6(0.9)kg/m 2 , neck circumference 37.0(2.7)cm, forced expiratory volume in 1 second 111.8(5.1)%predicted, and forced vital capacity 115.5(6.3)%predicted) were studied. No subject had significant sleep abnormalities at sea level. Time to ascent to 3,380 m was 1 day, to 4,370 m was 5 days, and the total nights at altitude were 21 days. The oxygen desaturation index (4% oxygen desaturation index [ODI] 0.8(0.4), 22.0 (7.2), 61.4 (26.9), 144.9/hour, respectively) and the EMGdi (5.2 (1.9), 12.8 (5.1), 14.1 (3.4), 18.5%, respectively) increased with the development of periodic breathing at altitude, whereas the average SpO 2 declined (97.5 (1.3), 84.8 (0.5), 81.0 (4.1), 68.5%, respectively). The average EMGdi correlated well with the 4%ODI (r = 0.968, p = 0.032)., Conclusion: NRD sleep increases at altitude in relation to the severity of periodic breathing.

Background: Sodium oxybate is licensed in Europe for the treatment of narcolepsy with cataplexy in adults. The aim of this study was to assess the efficacy and safety of sodium oxybate in clinical practice in patients with narcolepsy and cataplexy refractory to other treatments., Materials and Methods: This was a retrospective single centre study including patients with severe narcolepsy with cataplexy refractory to other treatments, who were initiated on sodium oxybate between 2009 and 2015. Patients were allowed to be on other stimulants or/and anti-cataplectic agents. Epworth sleepiness scale (ESS) and weekly cataplexy events were recorded. Side effects (SEs) were recorded at every follow-up visit., Results: 90 patients were prescribed sodium oxybate, with a total of 3116 patient-months of drug exposure. ESS and weekly cataplexy events were significantly reduced by sodium oxybate for all patients (ΔESS = 4.3 ± 4.4 and Δcataplexy = 21.8 ± 18.5 events/week; p < 0.0001, respectively). The required maintenance dose could not be predicted based upon gender, body mass index, or clinical factors. 60% of patients were able to reduce or come off other medications. Half of the patients experienced at least one SE, and 26.6% had to stop treatment due to limiting SEs. Nausea, mood swings and enuresis were the most commonly reported SEs. SEs that led to drug discontinuation, particularly psychosis, were associated with increasing age and were observed early after the initiation of the drug., Conclusions: Sodium oxybate provides a good clinical efficacy and acceptable safety profile in routine clinical practice for the treatment of patients suffering from narcolepsy with cataplexy. A quarter of patients experience SEs requiring withdrawal of the drug with older patients being more vulnerable to the more serious SEs., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Increased arterial stiffness and sympathetic nervous system activity, independent markers of cardiovascular risk, are common in patients with severe obstructive sleep apnoea, who have excessive daytime sleepiness. Among patients with mild-to-moderate obstructive sleep apnoea, however, it remains unknown whether arterial stiffness and/or increased sympathetic nervous system activity correlate with excessive daytime sleepiness., Methods: We measured heart rate variability, as an index of autonomic nervous system activity, and arterial stiffness index, as a marker of vascular damage and cardiovascular risk, in 56 men aged 18 to 75years, with mild-to-moderate obstructive sleep apnoea, and matched into two groups, "sleepy" (Epworth Sleepiness Scale≥10) and "non-sleepy" (Epworth Sleepiness Scale<10)., Results: We found no association of excessive daytime sleepiness with sympathetic nervous system activation (very low frequency power 18,947±11,207ms 2 vs 15,893±8,272ms 2 , p=0.28; low frequency (LH) power 17,753±8,441ms 2 vs 15,414±5,666ms 2 , p=0.26; high frequency (HF) power 7,527±1,979ms 2 vs 8,257±3,416ms 2 , p=0.36; LF/HF ratio 3.04±1.37 vs 2.55±1.01, p=0.15) and mean arterial stiffness index (6.97±0.83 vs 7.26±0.66, p=0.18) in mild-to-moderate obstructive sleep apnoea patients., Conclusions: Symptoms of excessive daytime sleepiness are not associated with sympathetic nervous system activation and arterial stiffness in male subjects with mild-to-moderate obstructive sleep apnoea., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose: Excessive daytime sleepiness is the most common complaint reported in sleep clinics. We hypothesised that utilising modern media to deliver an online Epworth Sleepiness Scale, age- and gender-related differences in subjective daytime sleepiness could be assessed., Methods: Age, gender and online Epworth Sleepiness Scale (range 0-24 points) of 39,448 subjects were recorded between January 2013 and November 2015., Results: A significant trend, for males but not females, was found between age and Epworth score (p < 0.001). Average scores were higher for female subjects in their 1st and 2nd (p = 0.014), 3rd (p < 0.011) and 4th lifetime decade (p = 0.011), whereas male subjects conveyed significantly higher levels of sleepiness in their 7th lifetime decade (p < 0.001). Individual item analysis found differences between gender; females scored significantly higher than males in items 1, 4 and 5, while male subjects had higher scores for items 3, 6, 7 and 8. Lowest levels of sleepiness were reported for item 8 and highest scores for item 5., Conclusions: The use of an online Epworth Sleepiness Scale identifies gender- and age-specific differences and facilitates new pathways in the delivery of chronic care.

Background: The mechanisms underlying sleep-related hypoventilation in patients with coexisting COPD and obstructive sleep apnoea (OSA), an overlap syndrome, are incompletely understood. We compared neural respiratory drive expressed as diaphragm electromyogram (EMG di ) and ventilation during stage 2 sleep in patients with COPD alone and patients with overlap syndrome., Methods: EMG di and airflow were recorded during full polysomnography in 14 healthy subjects, 14 patients with OSA and 39 consecutive patients with COPD. The ratio of tidal volume to EMG di was measured to indirectly assess upper airway resistance., Results: Thirty-five patients with COPD, 12 healthy subjects and 14 patients with OSA completed the study. Of 35 patients with COPD, 19 had COPD alone (FEV 1 38.5%±16.3%) whereas 16 had an overlap syndrome (FEV 1 47.5±16.2%, AHI 20.5±14.1 events/hour). Ventilation (V E ) was lower during stage 2 sleep than wakefulness in both patients with COPD alone (8.6±2.0 to 6.5±1.5 L/min, p<0.001) and those with overlap syndrome (8.3±2.0 to 6.1±1.8 L/min). Neural respiratory drive from wakefulness to sleep decreased significantly for patients with COPD alone (29.5±13.3% to 23.0±8.9% of maximal, p<0.01) but it changed little in those with overlap syndrome. The ratio of tidal volume to EMG di was unchanged from wakefulness to sleep in patients with COPD alone and healthy subjects but was significantly reduced in patients with OSA or overlap syndrome (p<0.05)., Conclusions: Stage 2 sleep-related hypoventilation in COPD alone is due to reduction of neural respiratory drive, but in overlap syndrome it is due to increased upper airway resistance., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Obstructive sleep apnea (OSA) is a common risk factor for cardiovascular disease. Continuous positive airway pressure (CPAP) improves OSA symptoms and blood pressure (BP) control. The effect of CPAP on BP variability (BPV) in patients with and without hypertension treated with autotitrating CPAP (APAP) for 2 weeks was studied. A total of 78 participants (76.9% men, 49% hypertensive, mean body mass index 36.2 [6.9] kg/m 2 , age 49.0 [12.9] years) underwent 2 weeks of APAP therapy. Office BP, BPV (standard deviation of three BP measurements), and pulse rate were measured before and after treatment. Systolic BPV (5.3±4.9 vs 4.2±3.4 mm Hg, P=.047) and pulse rate (78.0±14.5 vs 75.5±15.8 beats per minute, P=.032) decreased after treatment, particularly in hypertensive participants. Mask leak was independently associated with reduced changes in systolic BPV (r=-0.237, P=.048). Short-term APAP treatment reduced BPV and pulse rate, particularly in hypertensive patients with OSA., (©2016 Wiley Periodicals, Inc.)

Objective: It has been debated whether different stages in the human sleep cycle preferentially mediate the consolidation of explicit and implicit memories, or whether all of the stages in succession are necessary for optimal consolidation. Here we investigated whether the selective deprivation of slow wave sleep (SWS) or rapid eye movement (REM) sleep over an entire night would have a specific effect on consolidation in explicit and implicit memory tasks., Method: Participants completed a set of explicit and implicit memory tasks at night, prior to sleep. They had 1 control night of undisturbed sleep and 2 experimental nights, during which either SWS or REM sleep was selectively deprived across the entire night (sleep conditions counterbalanced across participants). Polysomnography recordings quantified precisely the amount of SWS and REM sleep that occurred during each of the sleep conditions, and spindle counts were recorded. In the morning, participants completed the experimental tasks in the same sequence as the night before., Results: SWS deprivation disrupted the consolidation of explicit memories for visuospatial information (ηp2 = .23), and both SWS (ηp2 = .53) and REM sleep (ηp2 = .52) deprivation adversely affected explicit verbal recall. Neither SWS nor REM sleep deprivation affected aspects of short-term or working memory, and did not affect measures of verbal implicit memory. Spindle counts did not correlate significantly with memory performance., Conclusions: These findings demonstrate the importance of measuring the sleep cycles throughout the entire night, and the contribution of both SWS and REM sleep to memory consolidation. (PsycINFO Database Record, ((c) 2016 APA, all rights reserved).)

Objectives: We compared 2 sociocultural cohorts with different duration of exposure to graphic health warning labels (GHWL), to investigate a possible desensitisation to their use. We further studied how a differing awareness and emotional impact of smoking-associated risks could be used to prevent this., Setting: Structured interviews of patients from the general respiratory department were undertaken between 2012 and 2013 in 2 tertiary hospitals in Singapore and London., Participants: 266 participants were studied, 163 Londoners (35% smokers, 54% male, age 52±18 years) and 103 Singaporeans (53% smokers, p=0.003; 78% male, p<0.001; age 58±15 years, p=0.012)., Main Outcomes and Measures: 50 items assessed demographics, smoking history, knowledge and the deterring impact of smoking-associated risks. After showing 10 GHWL, the impact on emotional response, cognitive processing and intended smoking behaviour was recorded., Results: Singaporeans scored lower than the Londoners across all label processing constructs, and this was consistent for the smoking and non-smoking groups. Londoners experienced more 'disgust' and felt GHWL were more effective at preventing initiation of, or quitting, smoking. Singaporeans had a lower awareness of lung cancer (82% vs 96%, p<0.001), despite ranking it as the most deterring consequence of smoking. Overall, 'blindness' was the least known potential risk (28%), despite being ranked as more deterring than 'stroke' and 'oral cancer' in all participants., Conclusions: The length of exposure to GHWL impacts on the effectiveness. However, acknowledging the different levels of awareness and emotional impact of smoking-associated risks within different sociocultural cohorts could be used to maintain their impact., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Introduction: Obstructive sleep apnoea (OSA) is characterised by a loss of neuromuscular tone of the upper airway dilator muscles while asleep. This study investigated the effectiveness of transcutaneous electrical stimulation in patients with OSA., Patients and Methods: This was a randomised, sham-controlled crossover trial using transcutaneous electrical stimulation of the upper airway dilator muscles in patients with confirmed OSA. Patients were randomly assigned to one night of sham stimulation and one night of active treatment. The primary outcome was the 4% oxygen desaturation index, responders were defined as patients with a reduction >25% in the oxygen desaturation index when compared with sham stimulation and/or with an index <5/hour in the active treatment night., Results: In 36 patients (age mean 50.8 (SD 11.2) years, male/female 30/6, body mass index median 29.6 (IQR 26.9-34.9) kg/m(2), Epworth Sleepiness Scale 10.5 (4.6) points, oxygen desaturation index median 25.7 (16.0-49.1)/hour, apnoea-hypopnoea index median 28.1 (19.0-57.0)/hour) the primary outcome measure improved when comparing sham stimulation (median 26.9 (17.5-39.5)/hour) with active treatment (median 19.5 (11.6-40.0)/hour; p=0.026), a modest reduction of the mean by 4.1 (95% CI -0.6 to 8.9)/hour. Secondary outcome parameters of patients' perception indicated that stimulation was well tolerated. Responders (47.2%) were predominantly from the mild-to-moderate OSA category. In this subgroup, the oxygen desaturation index was reduced by 10.0 (95% CI 3.9 to 16.0)/hour (p<0.001) and the apnoea-hypopnoea index was reduced by 9.1 (95% CI 2.0 to 16.2)/hour (p=0.004)., Conclusion: Transcutaneous electrical stimulation of the pharyngeal dilators during a single night in patients with OSA improves upper airway obstruction and is well tolerated., Trial Registration Number: NCT01661712., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Study Objectives: Continuous positive airway pressure (CPAP) is an effective treatment for obstructive sleep apnea (OSA). However, long-term compliance with CPAP is limited. We tested the hypothesis that CPAP levels routinely used during sleep increase neural respiratory drive (NRD) and breathlessness, which may discourage compliance., Methods: This was an observational physiological cohort study in a respiratory physiology and sleep unit, University Hospital. Patients with a body mass index (BMI) > 25 kg/m(2) and confirmed OSA were studied supine and awake on CPAP (4-20 cm H2O, increments of 2 cm H2O/3 min). We measured NRD during awake CPAP titration in obese subjects to quantify the response to the load of the respiratory system and compared it to the CPAP used for nocturnal treatment, with the modified Borg Scale (mBorg) for dyspnea recorded (from 0 to 10 points, with higher numbers indicating more breathlessness)., Results: Fifteen patients (age 48 ± 10 years, 12 male, BMI 38.9 ± 5.8 kg/m(2)) with OSA (AHI 32.2 ± 21.1/h, 95(th) percentile of CPAP 14.1 ± 3.8 cm H2O) were studied and NRD (electromyogram of the parasternal intercostals, EMGpara; EMG of the external oblique, EMGabdomen) was recorded (awake, supine). Awake, EMGpara declined from baseline to 70.2% ± 17.1% when CPAP of 10.7 ± 3.4 cm H2O (P = 0.026) was applied. Further increase in CPAP led to a rise in EMGpara and increased breathlessness (P = 0.02). CPAP compliance (nights used) correlated negatively with mBorg scores (r = -0.738, P = 0.006)., Conclusions: Awake, the respiratory system is maximally offloaded with lower than therapeutic CPAP levels in obese patients with OSA. Levels of NRD observed at effective CPAP levels while asleep are associated with breathlessness which may limit long-term CPAP compliance., (© 2016 Associated Professional Sleep Societies, LLC.)

Objectives: According to National Health Service England (NHSE) specialist respiratory commissioning specification for complex home ventilation, patients with weaning failure should be referred to a specialist centre. However, there are limited data reporting the clinical outcomes from such centres., Setting: Prospective observational cohort study of patients admitted to a UK specialist weaning, rehabilitation and home mechanical ventilation centre between February 2005 and July 2013., Participants: 262 patients admitted with a median age of 64.2 years (IQR 52.6-73.2 years). 59.9% were male., Results: 39.7% of patients had neuromuscular and/or chest wall disease, 21% were postsurgical, 19.5% had chronic obstructive pulmonary disease (COPD), 5.3% had obesity-related respiratory failure and 14.5% had other diagnoses. 64.1% of patients were successfully weaned, with 38.2% weaned fully from ventilation, 24% weaned to nocturnal non-invasive ventilation (NIV), 1.9% weaned to nocturnal NIV with intermittent NIV during the daytime. 21.4% of patients were discharged on long-term tracheostomy ventilation. The obesity-related respiratory failure group were most likely to wean (relative risk (RR) for weaning success=1.48, 95% CI 1.35 to 1.77; p<0.001), but otherwise weaning success rates did not significantly vary by diagnostic group. The median time-to-wean was 19 days (IQR 9-33) and the median duration of stay was 31 days (IQR 16-50), with no difference observed between the groups. Weaning centre mortality was 14.5%, highest in the COPD group (RR=2.15, 95% CI 1.19 to 3.91, p=0.012) and lowest in the neuromuscular and/or chest wall disease group (RR=0.34, 95% CI 0.16 to 0.75, p=0.007). Of all patients discharged alive, survival was 71.7% at 6 months and 61.8% at 12 months postdischarge., Conclusions: Following NHSE guidance, patients with weaning delay and failure should be considered for transfer to a specialist centre where available, which can demonstrate favourable short-term and long-term clinical outcomes., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing frequently associated with obesity. Obese subjects undergoing elective surgical procedures with general anesthesia are potentially at risk if this condition is not identified. Our aim was to assess the prevalence of bariatric patients with undiagnosed OSA following pre-operative assessment and who could benefit from peri-procedural respiratory management., Methods: Patients who were referred for prospective bariatric surgery were screened using the STOP-BANG questionnaire. If patients scored >4 points they underwent a home-based nocturnal pulse oximetry. Severity of OSA was defined by the 4% oxygen desaturation index (ODI) combined with a physician's review. Data were compared using unpaired two-tailed t-test and Chi-square test. Linear regression models were used to assess associations between clinical parameters., Results: Sleep-disordered breathing of any degree was evident in 103 of 141 patients (73%). Thirteen (9%) patients had severe, 19 (13%) moderate, and 34 (24%) mild OSA, 38 (27%) patients had no OSA. 34 (24%) patients were initiated on continuous positive airway pressure (CPAP) prior to the surgical procedure, 15 (11%) were admitted for further respiratory assessment and two of them were given CPAP following inpatient sleep study. Thirteen (9%) patients were advised to use a mandibular advancement device for mild but symptomatic OSA. Out of all patients, 76 (54%) were advised that no treatment was required., Conclusions: OSA is highly prevalent in a cohort of bariatric surgery patients screened with STOP-BANG questionnaires. Almost 3/4 of this cohort have at least some degree of sleep-disordered breathing, and approximately half of them require a plan for the respiratory management perioperatively.

Introduction: Patient-ventilator asynchrony (PVA) can adversely affect the successful initiation of non-invasive home mechanical ventilation (HMV). The aim of this observational study was to quantify the prevalence of PVA during initiation of HMV and to determine the relationship between PVA and nocturnal gas exchange., Method: Type and frequency of PVA were measured by surface parasternal intercostal muscle electromyography, thoracoabdominal plethysmography and mask pressure during initiation of HMV. Severe PVA was defined, as previously, as asynchrony affecting ≥10% of breaths., Results: 28 patients (18 male) were enrolled aged 61±15 years and with a body mass index of 35±9 kg/m(2). Underlying diagnoses were neuromuscular disease with or without chest wall disease (n=6), obesity related chronic respiratory failure (n=12) and COPD (n=10). PVA was observed in all patients with 79% of patients demonstrating severe PVA. Triggering asynchrony was most frequent, observed in 24% (IQR: 11-36%) of breaths, with ineffective efforts accounting for 16% (IQR: 4-24%). PVA types were similar between disease groups, with the exception of auto-triggering, which was higher in patients with COPD (12% (IQR: 6-26%)). There was no correlation observed between PVA and time spent with oxygen saturations ≤90%, mean oxygen saturations or transcutaneous carbon dioxide levels during overnight ventilation., Conclusions: Severe PVA was identified in the majority of patients, irrespective of pathophysiological disease state. This was not associated with ineffective ventilation as evidenced by gas exchange., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Electrical stimulation (ES) of the upper airway (UAW) dilator muscles for patients with obstructive sleep apnoea (OSA) has been used for several decades, but in recent years research in this field has experienced a renaissance; the results of several studies have triggered a steady rise in the interest in this topic. Prospective trials, although still lacking a sham-controlled and randomised approach, have revealed the potential of ES. Hypoglossal nerve stimulation (HNS) leads to a significant reduction in the apnoea-hypopnoea index and the oxygen desaturation index (ODI). There are similar results published from feasibility studies for transcutaneous ES. A limitation of HNS remains the invasive procedure, the costs involved and severe adverse events, while for the non-invasive approach complications are rare and limited. The limiting step for transcutaneous ES is to deliver a sufficient current without causing arousal from sleep. Despite the progress up to date, numerous variables including optimal stimulation settings, different devices and procedures remain to be further defined for the invasive and the non-invasive method. Further studies are required to identify which patients respond to this treatment. ES of the UAW dilator muscles in OSA has the potential to develop into a clinical alternative to continuous positive airway pressure (CPAP) therapy. It could benefit selected patients who fail standard therapy due to poor long-term compliance. It is likely that international societies will need to review and update their existing guidance on the use of ES in OSA.

Study Objectives: It has been hypothesized that arousals after apnea and hypopnea events in patients with obstructive sleep apnea are triggered when neural respiratory drive exceeds a certain level, but this hypothesis is based on esophageal pressure data, which are dependent on flow and lung volume. We aimed to determine whether a fixed threshold of respiratory drive is responsible for arousal at the termination of apnea and hypopnea using a flow independent technique (esophageal diaphragm electromyography, EMGdi) in patients with obstructive sleep apnea., Setting: Sleep center of state Key Laboratory of Respiratory Disease., Patients: Seventeen subjects (two women, mean age 53 ± 11 years) with obstructive sleep apnea/hypopnea syndrome were studied., Methods: We recorded esophageal pressure and EMGdi simultaneously during overnight full polysomnography in all the subjects., Measurements and Results: A total of 709 hypopnea events and 986 apnea events were analyzed. There was wide variation in both esophageal pressure and EMGdi at the end of both apnea and hypopnea events within a subject and stage 2 sleep. The EMGdi at the end of events that terminated with arousal was similar to those which terminated without arousal for both hypopnea events (27.6% ± 13.9%max vs 29.9% ± 15.9%max, P = ns) and apnea events (22.9% ± 11.5%max vs 22.1% ± 12.6%max, P = ns). The Pes at the end of respiratory events terminated with arousal was also similar to those terminated without arousal. There was a small but significant difference in EMGdi at the end of respiratory events between hypopnea and apnea (25.3% ± 14.2%max vs 21.7% ± 13.2%max, P < 0.05]., Conclusions: Our data do not support the concept that there is threshold of neural respiratory drive that is responsible for arousal in patients with obstructive sleep apnea., (© 2015 Associated Professional Sleep Societies, LLC.)

Background: Obstructive sleep apnoea (OSA) is the most common form of sleep-disordered breathing. The standard treatment, continuous positive airway pressure (CPAP), has limited long-term compliance. Alternative treatment options are required and new methods, including hypoglossal nerve stimulation (HNS) and continuous transcutaneous electrical stimulation (CTES), are currently emerging. We report on patients' preference for different treatments of OSA., Methods: We recorded patients' age, gender, body mass index (BMI), Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire with 10 questions (FOSQ10), severity of OSA, and current treatment. We showed pictures of existing [CPAP, mandibular advancement device (MAD)] and emerging treatments (HNS and CTES). We then asked (I) whether participants were interested in further information about HNS/CTES; (II) if they would be willing to try HNS/CTES; and (III) if they were to choose only one of the four listed treatments, which one would they prefer to use every night., Results: One hundred sixty-two patients completed the survey {81 males, mean age 52 [12] years, BMI 34 [7] kg/m(2), ESS 10.2 (6.0) points, FOSQ10 28.5 (8.1) points}. The majority of the respondents (89.5%) had been diagnosed with OSA. A total of 91.3% of the respondents were interested in more information and were willing to try HNS/CTES. Most respondents preferred the potential use of CTES (56.7%), while 21.7% chose HNS, 17.8% CPAP, and 3.8% the MAD. There were no differences in the characteristics of the patients who preferred CTES compared to those who preferred other treatments, but a regression analysis revealed that a low ESS score was an independent predictor of patients choosing CTES (P<0.05)., Conclusions: More than 9 out of 10 of the respondents were interested in trying emerging technologies to treat OSA, most preferring CTES. Less sleepy patients were more likely to choose less invasive treatments. These findings will likely impact on future research and development of therapies for sleep-disordered breathing.

Background: Excessive daytime sleepiness (EDS) is a non-specific but highly prevalent cardinal symptom of sleep disorders. We hypothesized that with modern media and an online pictorial Epworth Sleepiness Scale (ESS) age and gender specific differences of EDS could be identified on a large scale. This could be helpful in the screening of patients with sleep disorders., Patients and Methods: In 8,098 subjects, age and gender were recorded in addition to an online pictorial ESS (range 0-24 points). The cut-off for EDS (ESS >10 points) was chosen in line with the traditional ESS., Results: The prevalence of EDS was slightly higher in male subjects (45% vs. 43%, P=0.033). When age was considered, female subjects tended to be sleepier in their 3(rd) and 4(th) lifetime decade (P=0.01 and P=0.003, respectively), whilst male subjects scored significantly higher in their 7(th) decade (P<0.0001); there was a trend to more daytime symptoms with higher age (P for trend <0.001)., Conclusions: The online pictorial ESS identifies gender differences in EDS and reveals increased levels of sleepiness associated with higher age. The use of modern media facilitates reaching out to the general population to raise awareness of conditions associated with EDS such as sleep apnoea.

Most animal studies using methylphenidate (MP) do not administer it the same way it is administered clinically (orally), but rather by injection, resulting in an altered pharmacokinetic profile (quicker and higher peak concentrations). We evaluated several oral-dosing regimens in rats, including dual-dose drinking, to mimic clinical drug delivery. Using an 8-hour-limited-access-drinking-paradigm, MP solutions were delivered at different doses (20, 30, or 60mg/kg/day; as well as dual-dosages of 4 and 10mg/kg/day, 20 and 30mg/kg/day, or 30 and 60mg/kg/day, in which the low dose was administered in the first hour of drinking followed by 7 h of drinking the high dose). Plasma was assayed for MP levels at many time points. Results showed that an 8-hour limited drinking of a dual-dosage 30/60mg/kg MP solution achieved a pharmacokinetic profile similar to clinically administered doses of MP at the high end of the spectrum (peaking at ~30ng/mL), while the 4/10mg/kg MP dual-dosage produced plasma levels in the range produced by typically prescribed clinical doses of MP (peaking at ~8ng/mL). Treatment with the higher dual-dosage (HD: 30/60mg/kg) resulted in hyperactivity, while the lower (LD: 4/10mg/kg) had no effect. Chronic effects of these dual-dosages were assessed throughout three months of treatment and one month of abstinence, beginning in adolescence. MP dose-dependently decreased body weight, which remained attenuated throughout abstinence. MP decreased food intake during early treatment, suggesting that MP may be an appetite suppressant and may also speed metabolism and/or suppress growth. Chronic HD MP resulted in hyperactivity limited during the dark cycle, decreased exploratory behavior, and increased anxiolytic behavior. Findings suggest that these dual-dosage-drinking-paradigms can be used to examine the effects of clinically relevant pharmacokinetic doses of MP and that chronic treatment with such dosages can result in long-lasting developmental and behavioral changes., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Exercise capacity in chronic obstructive pulmonary disease (COPD) is limited by both breathlessness and leg muscle fatigue. Neural respiratory drive, measured as diaphragm electromyogram (EMGdi) activity expressed as a proportion of maximum (EMGdi%max), quantifies the mechanical load on the respiratory muscles and relates closely to breathlessness. We tested the hypothesis that end-exercise EMGdi%max would be higher in patients stopping because of breathlessness than in those limited by leg fatigue., Methods: EMGdi, ventilation, rate of oxygen consumption (VO2), and ventilatory reserve (ventilation/maximum ventilatory volume ratio [VE/MVV]) were measured continuously in patients with COPD during exhaustive cycle ergometry. EMGdi was measured with a multipair oesophageal catheter passed per-nasally. Differences in physiological variables between groups of patients stopping because of breathlessness, leg fatigue, or both were assessed with one-way ANOVA., Findings: 23 patients were included (median FEV1, 39% of predicted, IQR 30·0-56·8). End-exercise EMGdi%max was significantly higher in patients stopping exercise because of breathlessness (n=12, median EMGdi%max 75·7% [IQR 69·5-77·1]) than in those stopping because of leg fatigue (n=8, 44·1 [39·4-63·3]) or both (n=3, 74·1 [63·6-81·2]) (p=0·02). There were no significant differences between the groups in end-exercise ventilation (breathlessness 25·7 L/min [16·3-32·0] vs leg fatigue 31·5 [20·9-39·6] vs both 22·0 [17·7-35·7]), VO2, (13·4 mL/min per kg [11·6-14·2] vs 12·1 [10·4-14·8] vs 9·4 [9·1-12·4]), or VE/MVV (80·4% [72·6-88·3] vs 57·8 [52·1-92·6] vs 63·9 [34·5-88·9])., Interpretation: These results suggest that patients limited by breathlessness due to ventilatory constraints can be identified as those reaching near-maximum levels of neural respiratory drive during exercise. Measurement of EMGdi%max during exercise could prove useful in identifying patients whose functional performance would be best optimised by improvment in pulmonary mechanics rather than interventions to train peripheral muscle groups., Funding: None., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The aim of this study was to test the hypothesis that neural respiratory drive, measured using diaphragm electromyogram (EMGdi) activity expressed as a percentage of maximum (EMGdi%max), is closely related to breathlessness in chronic obstructive pulmonary disease. We also investigated whether neuroventilatory uncoupling contributes significantly to breathlessness intensity over an awareness of levels of neural respiratory drive alone. EMGdi and ventilation were measured continuously during incremental cycle and treadmill exercise in 12 chronic obstructive pulmonary disease patients (forced expiratory volume in 1 s±sd was 38.7±14.5 % pred). EMGdi was expressed both as EMGdi%max and relative to tidal volume expressed as a percentage of predicted vital capacity to quantify neuroventilatory uncoupling. EMGdi%max was closely related to Borg breathlessness in both cycle (r=0.98, p=0.0001) and treadmill exercise (r=0.94, p=0.005), this relationship being similar to that between neuroventilatory uncoupling and breathlessness (cycling r=0.94, p=0.005; treadmill r=0.91, p=0.01). The relationship between breathlessness and ventilation was poor when expansion of tidal volume became limited. In chronic obstructive pulmonary disease the intensity of exertional breathlessness is closely related to EMGdi%max. These data suggest that breathlessness in chronic obstructive pulmonary disease can be largely explained by an awareness of levels of neural respiratory drive, rather than the degree of neuroventilatory uncoupling. EMGdi%max could provide a useful physiological biomarker for breathlessness in chronic obstructive pulmonary disease., (Copyright ©ERS 2015.)

Purpose of Review: The evidence of a putative causal effect of sleep apnea-induced intermittent hypoxia on the pathogenesis of gestational hypertension and preeclampsia is mounting. The present review presents the evidence of current literature and questions whether an early diagnosis and treatment of obstructive sleep apnea during pregnancy can reduce the risk of preeclampsia., Recent Findings: Although pathophysiological pathways remain to be more clearly defined, recent studies shed light on the association of sleep-disordered breathing, gestational hypertension and preeclampsia. For the first time, a recent prospective study revealed that obstructive sleep apnea increases over the course of pregnancy and that it is common during the third trimester. In this study, age and BMI have been identified as independent predictors of gestational obstructive sleep apnea., Summary: An association between sleep-disordered breathing, gestational hypertension and preeclampsia has been demonstrated. However, there is a lack of evidence on the effect of continuous positive airway pressure treatment during pregnancy on hypertension and preeclampsia. Further studies are required to ascertain whether continuous positive airway pressure can be a useful adjunct treatment for pregnant women at risk of preeclampsia.

Background: Severe obesity causes respiratory morbidity and mortality. The impact of obesity on the mechanics of breathing is not fully understood., Patients and Methods: We undertook a comprehensive observational study of lung volumes and elasticity in nine obese and nine normal weight subjects, seated and supine, during spontaneous breathing. Seated and supine total lung capacity (TLC) and subdivisions were measured by multibreath helium dilution method. Using balloon catheters, oesophageal (Poes) and gastric (Pgas) pressures were recorded. Transpulmonary pressure (PL) was calculated as mouth pressure (Pmouth)-Poes, and complete expiratory PL volume curves were measured., Results: The obese group had a body mass index (BMI) of 46.8 (17.2) kg/m(2), and the normal group had a BMI of 23.2 (1.6) kg/m(2) (p=0.001). Obese and normals were matched for age (p=0.233), gender (p=0.637) and height (p=0.094). The obese were more restricted than the normals (TLC 88.6 (16.9) vs 104.4 (12.3) %predicted, p=0.033; FEV1/FVC 79.6 (7.3) vs 82.5 (4.2) %, p=0.325), had dramatically reduced expiratory reserve volume (ERV 0.4 (0.4) vs 1.7 (0.6) L, p<0.001) and end-tidal functional residual capacity (FRC) was smaller (37.5 (6.9) vs 46.9 (4.6) %TLC, p=0.004) when seated, but was similar when supine (39.4 (7.7) vs 41.5 (4.3) %TLC, p=0.477). Gastric pressures at FRC were significantly elevated in the obese (seated 19.1 (4.7) vs 12.1 (6.2) cm H2O, p=0.015; supine 14.3 (5.7) vs 7.1 (2.6) cm H2O, p=0.003), as were end-expiratory oesophageal pressures at FRC (seated 5.2 (6.9) vs -2.0 (3.5) cm H2O, p=0.013; supine 14.0 (8.0) vs 5.4 (3.1) cm H2O, p=0.008). BMI correlated with end-expiratory gastric (seated R(2)=0.43, supine R(2)=0.66, p<0.01) and oesophageal pressures (seated R(2)=0.51, supine R(2)=0.62, p<0.01)., Conclusions: Obese subjects have markedly increased gastric and oesophageal pressures, both when upright and supine, causing dramatically reduced FRC and ERV, which increases work of breathing., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objectives: There is a lack of evidence regarding the effectiveness of graphic health warning labels (GHWL) in different individuals, including patients with chronic obstructive pulmonary disease (COPD). Investigating knowledge and attitudes may allow better implementation of future public health policies. We hypothesised that differences in the impact of GHWL exist between non-smokers, smokers and patients with COPD, with decreased efficacy in those groups who are longer and more frequently exposed to them., Participants and Setting: 163 participants (54% male, aged 21-80) including 60 non-smokers, 53 smokers and 50 patients with COPD (Gold stage II-IV), attending London respiratory outpatient clinics, participated in case-controlled surveys (50 items)., Outcome Measures: Ten different GHWL were shown and demographics, smoking history, plans to quit, smoking-risk awareness, emotional response, processing and impact of GHWL on behaviour were recorded. Patients were further asked to prioritise the hypothetical treatment or prevention of five specific smoking-related diseases., Results: Smokers, in particular those with COPD, were less susceptible to GHWL than non-smokers; 53.4% of all participants expressed fear when looking at GHWL, non-smokers (71.9%) more so than smokers (39.8%, p<0.001). COPD participants were less aware of the consequences than non-COPD participants (p<0.001), including an awareness of lung cancer (p=0.001). Lung cancer (95%), oral cancer (90.2%), heart disease (84.7%) and stroke (71.2%) were correctly associated with smoking, whereas blindness was least associated (23.9%). However, blindness was prioritised over oral cancer, stroke and in patients with COPD also over heart disease when participants were asked about hypothetical treatment or prevention., Conclusions: GHWL are most effective in non-smokers and a desensitisation effect was observed in smokers and patients with COPD. As a consequence, a tailored and concerted public health approach to use such messages is required and 'blindness' deserves to be mentioned in this context because of an unexpectedly high-deterring impact., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Obstructive sleep apnoea (OSA) is the most common form of sleep-disordered breathing and a known risk factor for cardiovascular disease. We hypothesised that in patients with OSA the characteristics of nocturnal pulse rate (PR) are associated with changes in blood pressure and daytime sleepiness, following commencement of continuous positive airway pressure (CPAP) therapy., Methods: Pulse oximetry data, demographics, daytime sleepiness and blood pressure were recorded at baseline and at one year follow up. Patients with OSA were grouped according to positive and negative changes in the PR (ΔPR) response during the first night of pulse oximetry before commencement of CPAP., Results: A total of 115 patients (58 with OSA and 57 matched subjects without OSA) were identified and included in the analysis. The scale of improvement in daytime sleepiness could be predicted by a negative or positive ΔPR, as recorded in the initial screening pulse oximetry [ΔESS -5.8 (5.1) vs. -0.8 (7.2) points, P<0.05]. A negative correlation was observed between mean nocturnal PR and changes in systolic blood pressure (SBP) after one year of CPAP treatment (r=-0.42, P<0.05)., Conclusions: Mean nocturnal PR prior to CPAP initiation was associated with changes in SBP at one year follow up. A descending nocturnal PR in patients with OSA, prior to CPAP initiation, might help to identify a symptomatic response from long term CPAP treatment.

Objective: To determine the implementation of National Institute for Health and Care Excellence guidance (NICE CG83) for posthospital discharge critical illness follow-up and rehabilitation programmes., Design: Closed-question postal survey., Setting: Adult intensive care units (ICUs) across the UK, identified from national databases of organisations. Specialist-only and private ICUs were not included., Participants: Senior respiratory critical care physiotherapy clinicians., Results: A representative sample of 182 surveys was returned from the 240 distributed (75.8% (95% CI 70.4 to 81.2)). Only 48 organisations (27.3% (95% CI 20.7 to 33.9)) offered a follow-up service 2-3 months following hospital discharge, the majority (n=39, 84.8%) in clinic format. 12 organisations reported posthospital discharge rehabilitation programmes (6.8% (95% CI 3.1 to 10.5)), albeit only 10 of these operated on a regular basis. Lack of funding was reported as the most frequent (n=149/164, 90%) and main barrier (n=99/156, 63.5%) to providing services. Insufficient resources (n=71/164, 43.3%) and lack of priority by the clinical management team (n=66/164, 40.2%) were also highly cited barriers to service delivery., Conclusions: NICE CG83 has been successful in profiling the importance of rehabilitation for survivors of critical illness. However, 4 years following publication of CG83 there has been limited development of this clinical service across the UK. Strategies to support delivery of such quality improvement programmes are urgently required to enhance patient care., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Background: Chronic respiratory failure complicating sleep-disordered breathing in obese patients has important adverse clinical implications in terms of morbidity, mortality and healthcare utilisation. Screening strategies are essential to identify obese patients with chronic respiratory failure., Method: Prospective data were collected from patients with obesity-related sleep-disordered breathing admitted for respiratory assessment at a UK national sleep and ventilation centre. Hypercapnia was defined as an arterial partial pressure of carbon dioxide of >6kPa., Results: 245 obese patients (56±13 years) with a body mass index of 48±12 kg/m(2), forced vital capacity (FVC) of 2.1±1.1 L, daytime oximetry (SpO2) of 91±6% and abnormal overnight oximetry were included in the analysis. Receiver operator curve analysis for the whole group showed that an FVC ≤3 L had a sensitivity of 90% and a specificity of 41% in predicting hypercapnia, and an SpO2 ≤95% had a sensitivity of 83% and a specificity of 63% in predicting hypercapnia. Gender differences were observed and receiver operator curve analysis demonstrated 'cut-offs' for (1) SpO2 of ≤95% for men and ≤93% for women and (2) FVC of ≤3.5 L for men and ≤2.3 L for women, in predicting hypercapnia., Conclusions: The measurement of FVC and clinic SpO2 in obese patients with abnormal overnight limited respiratory studies predicted hypercapnia. This may have clinical utility in stratifying patients attending sleep clinics.

Wrist actigraphy is a valid measure to assess sleep and circadian rhythm abnormalities. It is listed in the diagnostic criteria for sleep disorders where single night polysomnography is insufficient (ICSD-2). However, an optimal recording time remains unclear. We hypothesised that seven days would provide sufficient data for analysis, similar to recordings for 14 days. We analysed three consecutive years of actigraphy data obtained within a tertiary sleep referral centre. Data were recorded continuously for two weeks using an AW4 actiwatch (Cambridge NeuroTechnology, Cambridge, UK; Mini Mitter Co, Sunriver, OR). Parameters, including sleep efficiency (SE), sleep latency (SL), sleep fragmentation index (SFI), total sleep time (TST) and wake after sleep onset (WASO) were analysed using GraphPad Prism (Version 5.02, GraphPad Software Inc, San Diego, CA) and classified into week one, week two and an overall average for the duration of 14 days. In addition, two experienced consultants working in the sleep laboratory compared the results of week one versus week two independently, visually analysing the data for circadian rhythmicity and fragmentation of the pattern, allowing calculation of the intraclass correlation coefficient (ICC), κ. The actigraphies of 239 patients (51.9% male; age 42 (16) years) were analysed. There was no difference in SE, SL, SFI or WASO between week one, week two and 14 days average recording. A small difference was found between TST week one (399.9 minutes, 95% CI 389.9-409.9 minutes) and TST week two (388.7 minutes, 95% CI 378.3-399.1 minutes), but not between TST for 14 days average recording (394.3 minutes, 95% CI 384.7-403.9 minutes) and either week. Independent scorers achieved a good agreement in the rhythmicity of the sleep pattern (ICC κ 0.734, p < 0.001) and a low agreement for the fragmentation of the pattern (ICC κ 0.380, p < 0.001). One week of wrist actigraphy recording provides similar data to two week actigraphies, despite subtle differences between the weeks. One week wrist actigraphy could be recommended as standard compared to longer recordings to maximise efficiency of the clinical service. Further studies are required to validate our results in specific clinical subgroups.

We surveyed the UK distribution of five factors commonly associated with obstructive sleep apnoea (OSA) to produce an overall risk map that could be used to predict relative prevalence estimates. The weighting and mapping of selected risk factors associated with OSA highlighted significant regional variation in predicted prevalence estimates. These data provide the first attempt to systematically map the UK for OSA and identify areas where the condition is likely to be more prevalent. The data show a significant mismatch between areas identified as having a high predicted prevalence estimate and the distribution of existing sleep centres.

Introduction: Sleepiness is one of the cardinal complaints of patients in tertiary referral centres for sleep disorders. It is commonly associated with sleep disorders, but the additional influence of obesity remains unclear. We hypothesised that obesity may be an independent predictor of sleepiness in this population., Patients and Methods: We reviewed 335 patients undergoing overnight polysomnography over a 3 month period (May-July 2011), recording selected sleep parameters in addition to subjective sleepiness as measured by the Epworth Sleepiness Scale (ESS, 0-24 points)., Results: 173 patients (120 male, age 52 (13) years, BMI 33.9 (7.4) kg/m(2)) had obstructive sleep apnoea and 59 of those were established on continuous positive airway pressure (CPAP). 55 patients (38 male, age 56 (14) years, BMI 31.7 (6.7) kg/m(2)) had PLM disorder, with 3 on medical treatment. 155 patients were obese (93 male, age 50 (14) years, BMI 37.3 (6.1) kg/m(2)) and this group was significantly sleepier than the 180 non-obese subjects (107 male, age 42 (15) years, BMI 25.3 (3.0) kg/m(2)). The mean ESS of the obese group was 12.9 (5.5) points, compared to 10.4 (5.7) points for the non-obese patients (p < 0.001). Those with a diagnosis of OSA had an ESS of 12.3 (5.8) versus 10.7 (5.7) points for those without (p = 0.007). Females had an ESS of 12.8 (5.9) compared to 10.7 (5.5) points for male patients (p < 0.001). Regression analysis revealed that obesity (p = 0.007), PLM disorder (p = 0.010) and hypertension (p = 0.032) were independently associated with subjective sleepiness (adjusted R(2) = 0.384, p = 0.02), obesity accounting for 15.7% of the variability in sleepiness., Conclusion: Independent of underlying sleep disorders, obesity contributes significantly to daytime sleepiness. Measures to promote weight loss and close links to a dietician assisted service will be helpful in the specialist setting of a sleep disorders service to improve long-term health outcomes., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Excessive daytime sleepiness is a significant public health problem, with prevalence in the community estimated to be as high as 18%. Sleepiness is caused by abnormal sleep quantity or sleep quality. Amongst others, multiple neurological, psychological, cardiac and pulmonary disorders may contribute. Risk factors for excessive sleepiness include obesity, depression, extremes of age and insufficient sleep. In the clinical setting, two of the most commonly encountered causes are obstructive sleep apnoea and periodic limb movement disorder. There is continuing discussion of the mechanisms by which these disorders cause daytime symptoms, with intermittent nocturnal hypoxia, sleep fragmentation and autonomic dysregulation identified as important factors. The increased prevalence of obstructive sleep apnoea in obese subjects does not fully account for the increased rates of daytime sleepiness in this population and there is evidence to suggest that it is caused by metabolic factors and chronic inflammation in obese individuals. Sleepiness is also more common in those reporting symptoms of depression or anxiety disorders and significantly impacts their quality of life. Clinicians should be aware of factors which put their patients at high risk of daytime sleepiness, as it is a debilitating and potentially dangerous symptom with medico-legal implications. Treatment option should address underlying contributors and promote sleep quantity and sleep quality by ensuring good sleep hygiene. However, stimulant medication may be indicated in some cases to allow for more normal daytime functioning.

Background: Chronic obstructive pulmonary disease (COPD) is associated with impaired exercise tolerance, but it has not been established to what extent cardiac autonomic function impacts on exercise capacity., Objective: To evaluate whether there is an association between airflow limitation and cardiac autonomic function and whether cardiac autonomic function plays a role in exercise intolerance and daily physical activity (PA) in patients with COPD., Methods: Univariate and multivariate analyses were performed to evaluate the association between both 6-minute walking test (6MWT) and PA (steps per day) and pulmonary function, cardiac autonomic function (HR at rest, HRR and heart rate variability, HRV) in patients with COPD., Results: In 154 COPD patients (87 females, mean [SD]: age 62.5 [10.7] years, FEV(1) %predicted (43.0 [19.2]%), mean HR at rest was elevated (86.4 [16.4] beats/min) and HRV was reduced (33.69 [28.96] ms) compared to published control data. There was a significant correlation between FEV(1) and HR at rest (r = -0.32, p < 0.001), between HR at rest and 6MWD (r = -0.26, p = 0.001) and between HR at rest and PA (r = -0.29, p = 0.010). No correlation was found between HRV and 6MWD (r = 0.089, p = 0.262) and PA (r = 0.075, p = 0.322). In multivariate analysis both HR and FEV(1) were independent predictors of exercise capacity in patients with COPD., Conclusions: In patients with COPD the degree of airflow limitation is associated with HR at rest. The degree of airflow limitation and cardiac autonomic function, as quantified by HR at rest, are independently associated with exercise capacity in patients with COPD.

Background: Conventional pulmonary rehabilitation programs improve exercise tolerance but have no effect on pulmonary function in patients with chronic obstructive pulmonary disease (COPD). The role of controlled breathing using respiratory biofeedback during rehabilitation of patients with COPD remains unclear., Objectives: To compare the effects of a conventional 4-week pulmonary rehabilitation program with those of rehabilitation plus controlled breathing interventions., Methods: A randomized controlled trial was performed. Pulmonary function (FEV1), exercise capacity (6-min walking distance, 6 MWD), health-related quality of life (chronic respiratory questionnaire, CRQ) and cardiac autonomic function (rMSSD) were evaluated., Results: Forty COPD patients (mean±SD age 66.1±6.4, FEV1 45.9±17.4% predicted) were randomized to rehabilitation (n=20) or rehabilitation plus controlled breathing (n=20). There were no statistically significant differences between the two groups regarding the change in FEV1 (mean difference -0.8% predicted, 95% CI -4.4 to 2.9% predicted, p=0.33), 6 MWD (mean difference 12.2 m, 95% CI -37.4 to 12.2 m, p=0.16), CRQ (mean difference in total score 0.2, 95% CI -0.1 to 0.4, p=0.11) and rMSSD (mean difference 2.2 ms, 95% CI -20.8 to 25.1 ms, p=0.51)., Conclusions: In patients with COPD undergoing a pulmonary rehabilitation program, controlled breathing using respiratory biofeedback has no effect on exercise capacity, pulmonary function, quality of life or cardiac autonomic function., (Copyright © 2011 S. Karger AG, Basel.)