Obstructive sleep apnea syndrome: effect of respiratory events and arousal on pulse wave amplitude measured by photoplethysmography in NREM sleep Abstract The objective of the study is to evaluate changes in finger pulse wave amplitude (PWA), as measured by photoplethysmography, and heart rate (HR), related to obstructive respiratory events and associated arousals during sleep. We analyzed 1,431 respiratory events in NREM sleep from 12 patients according to (1) the type of event (apnea, hypopnea, upper airway resistance episode) and (2) the duration of the associated EEG arousal (>10, 3-10, <3 s). Obstructive respiratory events provoked a relative bradycardia and vasodilation followed by HR increase and vasoconstriction. Relative PWA changes were significantly greater than HR changes. These responses differed significantly according to EEG-arousal grades (time×arousal interaction, p<0.0001), with longer arousals producing greater responses, but not to the type of respiratory event (time×event interaction, p = ns). Obstructive respiratory events provoke HR and PWA changes, the magnitude seemingly related to the intensity of central nervous activation, with PWA changes greater than HR. PWA obtained from a simple pulse oxymeter might be a valuable method to evaluate sleep fragmentation in sleep breathing disorders.

More than 10 years after publication, international guidelines remain poorly implemented. To better implement them, we need to develop new strategies adapted to the expectations of patients and health professionals outside hospital settings and to ensure better outpatient follow up in the community. We developed a bilingual education programme including a brochure designed to support an interdisciplinary health care network and measured hospitalisations (H), work absenteeism (WA), emergency visits (EV), asthma medication (AM) and quality of life (QL Juniper) before and 12 months after the intervention. All QL scores improved significantly in comparison with pre-intervention values. Health service use decreased dramatically when comparing the 12 months prior to and after the intervention(H: 35-8%, WA: 39-14%, EV: 88-53%). The final cost/benefit ratio of the programme was 1.96. Interdisciplinary implementation strategy of patient education is cost-effective, improves quality of life for asthmatics, and reduces strain on health services. Such a health care network does not require an expensive infrastructure and is better adapted to the reality and competences of clinical practice.

Background: Evaluation of health-related quality of life (HRQL) in chronic respiratory failure (CRF) is an important issue for evaluating the impact of treatment. Objectives: To elaborate a French version of the Maugeri Foundation Respiratory Failure Questionnaire (MRF-28) disease-specific HRQL questionnaire and determine its validity and reliability in patients with CRF treated by home mechanical ventilation (HMV). Methods: Forward- and back-translation of the MRF-28 questionnaire; the final version was submitted to 81 patients treated with HMV for CRF, simultaneously with the St. George’s Respiratory Questionnaire (SGRQ), the Short Form 36 (SF-36), and the Hospital Anxiety and Depression scale (HAD). Validity was determined by correlation with previously validated HRQL scores and recorded physiological parameters. Reliability was evaluated by assessing internal consistency and test-retest stability of the MRF-28 scores. Results: The French version of the MRF-28 and its subscores (‘daily activity’, ‘cognitive function’, and ‘invalidity’) were highly significantly correlated with subscores of the SGRQ, the SF-36 and the HAD. Both the MRF-28 and the SGRQ were correlated only with age and the 6-min walk test. The MRF-28 showed high test-retest reliability after 2 weeks (r² = 0.80, p < 0.0001) and high internal consistency (Crohnbachs’ α coefficient: 0.91). Conclusion: The French version of the MRF-28 is a valid and reliable disease-specific questionnaire for assessing HRQL in patients with CRF.

Long-term home oxygen therapy (LTOT) improves survival of hypoxic patients with chronic respiratory insufficiency. However, the health-related quality of life (HRQL) of these patients, when LTOT is initiated, is severely impaired. The present study aims to describe the health-related quality of life (HRQL) of patients under LTOT, assessed at home, to identify parameters relevant to HRQL, and to describe changes over a 1-yr period. Seventy-nine patients (aged 68 +/- 11 years, under LTOT for 34 +/- 24 months) underwent pulmonary function testing, measurement of average daily distance walked, SaO2, dyspnoea scores (Borg scale and oxygen-cost diagram), and Hospital Anxiety and Depression scores. After 1 yr, measurements were repeated, and HRQL was measured with the St George Respiratory Questionnaire (SGRQ). Forced expiratory volume in 1 s (FEV1% of predicted) was 36 +/- 19; SaO2 (room air) was 87 +/- 5%, daily distance walked was 1202 +/- 1140 m; 21% suffered from anxiety and 27% from depression. After 1 yr, pulmonary function tests, dyspnoea or prevalence of anxiety or depression were unchanged. Mortality was high (31% 1-yr mortality). Daily distance walked (rho = -0.55, P = 0.01 vs. SGRQ) and number of days spent in hospital (rho = 0.5, P = 0.01 vs. SGRQ) were the parameters with the highest correlation with HRQL scores. Quality of life was poor in these patients, with high rates of emotional disorders. Restoring and maintaining sufficient exercise capacity for everyday life activities through outpatient rehabilitation programmes and support for emotional disturbances should be major goals in the care of these patients.

A 41-yr-old dairy worker, smoker of 40 cigarettes daily, presented with severe gas exchange impairment caused by interstitial lung disease, as shown by transbronchial biopsy. He was exposed chronically to an aerosol of hydrogen peroxide (41 mg/mm3; upper legal limit: 1.5 mg/mm3) which must be incriminated as the etiologic agent, since withdrawal from exposure resulted in improvement, and no other etiology could be identified.