Only a limited number of studies dealing with the epidemiology and therapy of central sleep apnea syndrome (CA) are available. The treatment strategies are poorly defined and not well evaluated. The aim of our present study was to treat selected CA patients with low dose acetazolamide (ACET) for a longer time period than has been done before. Previous studies were performed with high dose ACET provoking severe metabolic acidosis, not for more than 1 wk or only in obstructive apnea patients. Referred patients with suspicion of sleep-related breathing disorders (SRBD) were included in the study if, after a first selection night, their central apnea index (CAI) was > 5 or their apnea-hypopnea index (AHI) > 10 and their obstructive apnea index (OAI) < 5. Of 327 screened patients, 14 (4.3%) fulfilled these criteria. Patients were then treated with ACET (250 mg, 1 h before sleep): Polysomnography was repeated once after one single dose (N2) and twice after 1-mo chronic treatment without (N3) and with (N4) additional ACET administration. After each study night, arterial blood gases and chemical drive were measured. CAI (25.5 +/- 6.8 at N1) already decreased during N2 (13.8 +/- 5.2) and further during N3 (6.6 +/- 2.9) and N4 (6.8 +/- 2.8) p < 0.01). OAI remained unchanged. Total sleep time (TST) and sleep efficiency index (SEI) did not change significantly. The number of arousals decreased from 62 +/- 11 at N1 to 40 +/- 5 at N3 (p = 0.019).(ABSTRACT TRUNCATED AT 250 WORDS)

These results suggest that smaller soft palate volumes at baseline and greater tongue movement anteriorly with stimulation improve the response to upper airway stimulation.

No abstract

Purpose To reduce the environmental impact of the building sector, environmental targets considering the full life cycle of buildings can be supportive. In recent years various benchmarks based on Life Cycle Assessment (LCA) have been developed as part of regulations, labelling systems, sustainability rating tools and research studies. The objective of this paper is to critically analyse 23 existing benchmarking systems focusing on the benchmark methodology but also on the benchmark applications and communication.Methods The critical literature review consists of two parts. In a first part, the choices related to the assessment method, functional equivalent, definition of benchmark values, benchmark scope, benchmark applications and benchmark communication are compared. In the second part, benchmark values are compiled from literature and statistically analysed. Results and discussionThe comparative analysis allows to identify the main approaches and methods used in benchmarking systems. For each evaluation aspect, the strengths and weaknesses of the various approaches are highlighted. The statistical analysis provides insight in the spread of benchmark values. Important variations are found between the literature sources which can be explained by differences in benchmark approach, scope, system boundaries and applications.Conclusions Based on the comparative analysis, recommendations are formulated for the development of LCA benchmarks for the building sector. The results of the statistical analysis furthermore provide reference values which can be used for the validation of future benchmarks. For global warming, the statistical values for the full life cycle impacts (i.e. embodied and operational impacts) range from about 15 up to 35 kg CO2 eq./m².a.