Improved follow-up by peripheral arterial tonometry in CPAP-treated patients with obstructive sleep apnea and persistent excessive daytime sleepiness.

BACKGROUND: OSA-patients with persistent excessive daytime sleepiness (EDS) despite CPAP treatment are challenging in daily clinical life. To rule out residual sleep-disordered breathing (SDB), CPAP device-derived data are used in outpatient setting. In case of no pathological finding, a more intensive work-up with is necessary. 6-channel portable monitoring (6Ch-PM) is frequently used to exclude residual SDB. Peripheral arterial tonometry (PAT), as embodied in the WatchPAT device, represents an alternative technique for detecting SDB based on changes in autonomic tone. We wanted to investigate whether PAT might be a useful tool to improve diagnostic work-up in this specific patient group by better identifying residual SDB due to insufficient CPAP-adjustment. METHODS: Forty-nine OSA patients (39 male, 10 female) with sufficient CPAP treatment according to device-derived data were consecutively recruited. EDS was assessed by Epworth Sleepiness Scale (ESS). All patients underwent home-based CPAP therapy control by 6Ch-PM and portable monitoring using PAT technology on two consecutive nights. A sequence of both types of monitoring was randomized to prevent possible first night effect bias. RESULTS: Twelve out of 49 patients showed persistent EDS according to ESS (ESS > 10 points). 6Ch-PM showed a residually increased AHI under CPAP-treatment in 2 of those 12 subjects (positive predictive value, PPV = 16.7%). PAT-PM revealed 5 patients of those 12 with residual SDB (PPV = 41.7%). CONCLUSION: PAT could detect significantly more residual SDB under CPAP treatment than 6Ch-PM. Diagnostic work-up of CPAP-treated OSA patients with persistent EDS might be optimized, as insufficient pressure level adjustments could be recognized more precisely in time, possibly preventing more resource-consuming procedures, and potentially increased morbidity. CLINICAL TRIAL REGISTRATION: DRKS00007705.

[Lung Health Data of the Study of Health in Pomerania - a Review of Samples, Methods and First Results]. / Pneumologisch relevante Daten aus der "Study of Health in Pomerania" (SHIP) ­ eine Übersicht zu den Kohorten, Methoden und ersten Ergebnissen.

Investigating reasons for differing life expectancy and prevalence of cardiovascular risk factors between old and new states of the Federal Republic of Germany an epidemiological study in Western Pomerania - the population-based project Study of Health in Pomerania (SHIP) - was planned.Prevalence and incidence of common risk factors, subclinical disorders and clinical diseases have been assessed since 1997 in five-year intervals. The third follow up (SHIP-3) was assessed between 2014 and 2016. In addition, an independent representative population sample was investigated between 2008 - 2012 (SHIP-TREND). Recently, the first follow up of this cohort has been started (SHIP-TREND-1). This paper reports the methodological approaches for detecting pneumological relevant morbidities in this population-based study. It aims to offer insights for potential cooperation with interested research groups.

[Portable sleep monitoring in patients with disorders in falling asleep or maintaining sleep]. / Erweiterte ambulante Polygraphie bei Patienten mit Ein- und/oder Durchschlafstörungen.

BACKGROUND: The most common diagnoses in sleep medicine are insomnia, sleep disordered breathing (SDB) and periodic leg movements (PLM). These disorders may coincide. This study examined the role of portable sleep monitoring in the diagnostic process and which sleep medicine diagnoses are additionally found in patients with disorders of initiating and maintaining sleep. METHODS: A total of 217 patients, including 103 men (47.5%) and 114 (52.5%) women aged 52.2 ± 13.6 years with disorders of initiating or maintaining sleep were included in the study. Patients with known SDB were excluded. Patients were investigated using a stepwise diagnostic procedure with clinical interviews, questionnaires, clinical examination and portable sleep recording with electromyography (EMG) of the tibialis anterior muscle to diagnose SDB and PLM. RESULTS: Of the patients 125 (57.6%) were diagnosed with insomnia according to the International Classification of Sleep Disorders (ICSD) and 70 (56%) had no other sleep disorder. Out of the 217 patients SDB was found in 107 (49.3%) patients, PLM in 90 patients (41.5%) and in 78 patients (35.9%) restless legs syndrome (RLS) was diagnosed. Among the 125 patients with insomnia 44 patients had RLS/PLMD and 35 had SDB in addition whereas SDB and RLS/PLMD were found in 33 subjects. All 3 disorders insomnia, RLS/PLMD and SDB were found in 24 subjects. CONCLUSIONS: Out of 217 patients with a complaint of non-restorative sleep only 125 were finally diagnosed with insomnia. As 25.3% of patients showed combinations of sleep disorders, 49.3% with SDB and 41.5% with RLS/PLMD portable monitoring with electromyography of the legs is recommended. The investigation with a portable sleep monitoring system including an EMG of the tibialis muscle is very useful in patients with insomnia in addition to a clinical interview and questionnaires.

Feasibility of noise reduction by a modification in ICU environment.

Noise is a proven cause of wakefulness and qualitative sleep disturbance in critically ill patients. A sound pressure level reduction can improve sleep quality, but there are no studies showing the feasibility of such a noise reduction in the intensive care unit (ICU) setting. Considering all available evidence, we redesigned two ICU rooms with the aim of investigating the physiological and clinical impact of a healing environment, including a noise reduction and day-night variations of sound level. Within an experimental design, we recorded 96 h of sound-pressure levels in standard ICU rooms and the modified ICU rooms. In addition, we performed a sound source observation by human observers. Our results show that we reduced A-weighted equivalent sound pressure levels and maximum sound pressure levels with our architectural interventions. During night-time, the modification led to a significant decrease in 50 dB threshold overruns from 65.5% to 39.9% (door side) and from 50% to 10.5% (window side). Sound peaks of more than 60 decibels were significantly reduced from 62.0% to 26.7% (door side) and 59.3% to 30.3% (window side). Time-series analysis of linear trends revealed a significantly more distinct day-night pattern in the modified rooms with lower sound levels during night-times. Observed sound sources during night revealed four times as many talking events in the standard room compared to the modified room. In summary, we show that it is feasible to reduce sound pressure levels using architectural modifications.

Characterization of the 5'-flanking promoter region of the rat somatostatin receptor subtype 3 gene.

We investigated the 5'-flanking promoter region of the rat somatostatin receptor subtype 3 (rSSTR3). Using a cDNA probe, genomic clones containing the 5'-flanking promoter region of the rSSTR3 gene were isolated. A sequence of 5.4 kb directly upstream from the start codon was analyzed and two introns were found in the 5' untranslated region (UTR) of the cDNA sequence. The transcriptional initiation site was determined by 5' rapid amplification of cDNA ends (RACE), primer extension and RNase protection analysis with cerebellar RNA. Two major transcriptional initiation sites were found at position 1040 (tsp1) and -856 (tsp2) relative to the translational initiation site. Like a number of other promoters of G-protein-coupled receptors, the rSSTR3 gene lacks TATA and CAAT motifs and includes G+C-rich regions. Functional analysis of the promoter region by transfecting rSSTR3 luciferase-reporter gene constructs into rat pituitary GH3 cells and HEK 293 cells indicated that a 107-bp region upstream of tsp2 was sufficient to drive transcription. Furthermore a 562-bp region at position -1304 to -1865 upstream of the ATG start codon exerted a negative regulatory effect on transcriptional activity.

Investigating relative respiratory effort signals during mixed sleep apnea using photoplethysmogram.

Sleep disordered breathing does show different types of events. These are obstructive apnea events, central apnea events and mixed sleep apnea (MSA) which have a central component with a pause in airflow without respiratory effort followed by an obstructive component with respiratory effort. The esophageal pressure (Pes) is the accurate method to assess respiratory effort. The aim of the present study is to investigate whether the features extracted from photo-plethysmogram (PPG) could relate with the changes in Pes during MSA. Therefore, Pes and PPG signals during 65 pre-scored MSA events and 10 s preceding the events were collected from 8 patients. Pulse intervals (PPI), Pulse wave amplitudes (PWA) and wavelet decomposition (Wv) of PPG signals at level 8 (0.15-0.32 Hz) were derived from PPG signals. Results show that significant correlations (r = 0.63, p < 0.01; r = 0.42, p < 0.05; r = 0.8, p < 0.01 for OSA part) were found between reductions in Pes and that in PPG based surrogate respiratory signals PPI, PWA and Wv. Results suggest that PPG based relative respiratory effort signal can be considered as an alternative to Pes as a means of measuring changes in inspiratory effort when scoring OSA and CSA parts of MSA events.

Aza-bis(oxazolines): new chiral ligands for asymmetric catalysis

Aza-bis(oxazolines) are introduced as chiral ligands for asymmetric catalysis combining the advantages of easy availability of bis(oxazolines) and backbone variability of aza-semicorrins. Especially, the title ligands could be attached to a polymeric support, which allowed the development of easily recoverable copper(I)-catalysts for asymmetric cyclopropanation reactions.

Night-to-night variation of the oxygen desaturation index in sleep apnoea syndrome.

The current study investigated the night-to-night variability and diagnostic accuracy of the oxygen desaturation index (ODI), as measured by ambulatory monitoring, in the diagnosis of mild and moderate obstructive sleep apnoea-hypopnoea syndrome. To assess the variability of the ODI, 35 patients were monitored at home during 7 consecutive nights by means of a portable recording device, the MESAM-IV. The ODI variability factor and the influence of age, body mass index (BMI), alcohol, and body position were assessed. Furthermore, the diagnostic accuracy of the MESAM-IV was measured by comparison with polysomnographical outcomes in 18 patients. During home recording, the median ODI was 10.9 (interquartile range: 5.8-16.1) across the patients. Although the reliability of the ODI was adequate, the probability of placing the patient in the wrong severity category (ODI < or =15 or ODI >15) when only one single recording was taken is 14.4%. ODI variability was not significantly influenced by age, BMI, time spent in a supine position, or mild dosages of alcohol. A good correlation was found between the apnoea-hypopnoea index and the ODI. In conclusion, the findings suggest that the diagnostic accuracy of the MESAM-IV is strong, since the oxygen desaturation index is correlated with the apnoea-hypopnoea index. In most obstructive sleep apnoea-hypopnoea syndrome patients, oxygen desaturation index variability is rather small, and screening could be reliably based on single 1-night recordings.