Compensatory responses to increased mechanical abnormalities in COPD during sleep.

Purpose: To assess whether night-time increases in mechanical loading negatively impact respiratory muscle function in COPD and whether compensatory increases in inspiratory neural drive (IND) are adequate to stabilize ventilatory output and arterial oxygen saturation, especially during sleep when wakefulness drive is withdrawn.

Methods: 21 patients with moderate-to-severe COPD and 20 age-/sex-matched healthy controls (CTRL) participated in a prospective, cross-sectional, one-night study to assess the impact of COPD on serial awake, supine inspiratory capacity (IC) measurements and continuous dynamic respiratory muscle function (esophageal manometry) and IND (diaphragm electromyography, EMGdi) in supine sleep.

Results: Supine inspiratory effort and EMGdi were consistently twice as high in COPD versus CTRL (p < 0.

Deterioration of Nighttime Respiratory Mechanics in COPD: Impact of Bronchodilator Therapy.

Background: COPD is associated with nighttime respiratory symptoms, poor sleep quality, and increased risk of nocturnal death. Overnight deterioration of inspiratory capacity (IC) and FEV have been documented previously. However, the precise nature of this deterioration and mechanisms by which evening bronchodilation may mitigate this occurrence have not been studied.

Comparing a combination of validated questionnaires and level III portable monitor with polysomnography to diagnose and exclude sleep apnea.

Study Objectives: Questionnaires have been validated as screening tools in adult populations at risk for obstructive sleep apnea (OSA). Portable monitors (PM) have gained acceptance for confirmation of OSA in some patients with a high pretest probability of the disorder. We evaluated the combined diagnostic utility of 3 validated questionnaires and a Level III PM in the diagnosis and exclusion of OSA, as compared with in-laboratory polysomnography (PSG) derived apnea hypopnea index (AHI).

Position paper by Canadian dental sleep medicine professionals on the role of different health care professionals in managing obstructive sleep apnea and snoring with oral appliances.

The present Canadian position paper contains recommendations for the management by dentists of sleep-disordered breathing in adults with the use of oral appliances (OAs) as a treatment option for snoring and obstructive sleep apnea (OSA). The recommendations are based on literature reviews and expert panel consensus. OAs offer an effective, first-line treatment option for patients with mild to moderate OSA who prefer an OA to continuous positive airway pressure (CPAP) therapy, or for severe OSA patients who cannot tolerate CPAP, are inappropriate candidates for CPAP or who have failed CPAP treatment attempts.

Validation of the MediByte® type 3 portable monitor compared with polysomnography for screening of obstructive sleep apnea.

Background: Portable monitors are increasingly being used as a diagnostic screening tool for obstructive sleep apnea (OSA), and in-laboratory validation of these devices with polysomnography (PSG) is required.

Objective: To assess the reliability of the MediByte (Braebon Medical Corporation, Canada) type 3 screening device compared with overnight PSG.

Methods: To cover a range of OSA severity, a consecutive series of patients wore the screening device while simultaneously undergoing PSG.

Use of Bioimpedance to Assess Changes in Hemodynamics During Acute Administration of CPAP.

Background: Attempts to investigate the mechanisms by which continuous positive airway pressure (CPAP) therapy improves heart function in patients with obstructive sleep apnea (OSA) have been limited by the lack of non-invasive methods to assess cardiac performance. We used transthoracic electrical bioimpedance (TEB) to assess acute hemodynamic changes including heart rate (HR), stroke volume (SV), cardiac output (CO) and cardiac index (CI) during PAP titration in (1) post-operative cardiac surgery patients, (2) patients with severe OSA, and (3) normal healthy volunteers.

Methods: Post-operative cardiac surgery patients were studied via TEB and pulmonary artery catheter (PAC) during acute titration of positive end-expiratory pressure (PEEP) while mechanically ventilated.

Canadian Sleep Society/Canadian Thoracic Society position paper on the use of portable monitoring for the diagnosis of obstructive sleep apnea/hypopnea in adults.

The present position paper on the use of portable monitoring (PM) as a diagnostic tool for obstructive sleep apnea⁄hypopnea (OSAH) in adults was based on consensus and expert opinion regarding best practice standards from stakeholders across Canada. These recommendations were prepared to guide appropriate clinical use of this new technology and to ensure that quality assurance standards are adhered to. Clinical guidelines for the use of PM for the diagnosis and management of OSAH as an alternative to in-laboratory polysomnography published by the American Academy of Sleep Medicine Portable Monitoring Task Force were used to tailor our recommendations to address the following: indications; methodology including physician involvement, physician and technical staff qualifications, and follow-up requirements; technical considerations; quality assurance; and conflict of interest guidelines.

Evaluation and treatment of sleep complaints: patients' subjective responses.

Background: This study set out to evaluate whether patients' expectations affected their responses to treatment of a sleep disorder.

Methods: Fifty consecutive patients attending a sleep clinic for the first time and who had different diagnoses of sleep disorders were included in this study. The patients completed a set of 6 questionnaires on 7 occasions as they progressed through the process of a sleep clinic referral, assessment and treatment.

Nocturnal sleep, daytime sleepiness, and napping among women with significant emotional/behavioral premenstrual symptoms.

The objective of this study is to examine daytime sleepiness and alertness and nap characteristics among women with significant emotional/behavioral premenstrual symptoms, and to determine their relationship with nocturnal sleep. Participants spent one night during the follicular phase and two nights during the late-luteal phase, one of which occurred after a 40 min opportunity to nap, sleeping in the laboratory. Subjective measures of sleepiness and alertness were completed during the afternoon of each recording.

Circadian rhythms, sleep, and the menstrual cycle.

Women with ovulatory menstrual cycles have a circadian rhythm superimposed on the menstrual-associated rhythm; in turn, menstrual events affect the circadian rhythm. In this paper, we review circadian rhythms in temperature, selected hormone profiles, and sleep-wake behavior in healthy women at different phases of the menstrual cycle. The effects on menstrual cycle rhythmicity of disrupted circadian rhythms, for example, with shiftwork and altered circadian rhythms in women with menstrual-related mood disturbances, are discussed.

The acute impact of continuous positive airway pressure on nasal resistance: a randomized controlled comparison.

Subjective nasal obstruction is common among users of continuous positive airway pressure (CPAP). The aim of this study was to measure the acute effect of CPAP on nasal resistance and nasal symptoms in awake normal subjects. Twenty-four healthy CPAP-naive adults [8 men, 16 women; mean age 30 yr (SD 14)] underwent a randomized controlled crossover study comparing nasal CPAP (8 cmH(2)O) for 6 h on one occasion and the control condition (nasal mask without CPAP) on the other.

The influence of the menstrual cycle on upper airway resistance and breathing during sleep.

Study Objective: Female hormones, specifically progesterone, that peak in the luteal phase may play a significant role in protecting premenopausal women from sleep-disordered breathing. The influence of female hormones on upper airway resistance during sleep was investigated during the follicular and luteal phases of normal menstrual cycles.

Setting: Hospital-based sleep laboratory.

Self-reported sleep across the menstrual cycle in young, healthy women.

Objective: To establish the association between subjective sleep and phase of the menstrual cycle in healthy, young, ovulating women.

Methods: Twenty-six women (mean age: 21 years) who did not suffer from any menstrual-associated disorders, and in whom we had detected ovulation, completed daily questionnaires about their sleep over 1 month.

Results: The women reported a lower sleep quality over the 3 premenstrual days and 4 days during menstruation, compared to the mid-follicular and early/mid luteal phases.

Exercise and sleep.

This paper reviews the literature on the association between exercise and sleep. The epidemiological and experimental evidence for whether or not acute and chronic exercise promote sleep is discussed, as well as moderating factors and agendas for future directions of study. The expectation that exercise will benefit sleep can partly be attributed to traditional hypotheses that sleep serves energy conservation, body restoration or thermoregulatory functions, all of which have guided much of the research in this field.

Partitioning of inhaled ventilation between the nasal and oral routes during sleep in normal subjects.

The oral and nasal contributions to inhaled ventilation were simultaneously quantified during sleep in 10 healthy subjects (5 men, 5 women) aged 43 +/- 5 yr, with normal nasal resistance (mean 2.0 +/- 0.3 cmH(2)O.

Acetaminophen does not affect 24-h body temperature or sleep in the luteal phase of the menstrual cycle.

Body temperature and sleep change in association with increased progesterone in the luteal phase of the menstrual cycle in young women. The mechanism by which progesterone raises body temperature is not known but may involve prostaglandins, inducing a thermoregulatory adjustment similar to that of fever. Prostaglandins also are involved in sleep regulation and potentially could mediate changes in sleep during the menstrual cycle.