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Background Several studies have analysed adherence to continuous positive airway pressure (CPAP) therapy but little is known on the effects of age and gender. Methods Data from 4281 patients with obstructive sleep apnea (OSA) treated with CPAP (S8, ResMed, Sydney, Australia) were analysed, including apnea–hypopnea index (AHI), mask pressure, leakage, period of use (hours of use/night), and efficiency (days of use/total days). Patterns of use and treatment efficacy were compared between different age groups and genders. Results Average numbers of days used per week (range of the subgroups 5.8±1.6 to 6.3±1.2days/week) and period of use (range 363±88 to 395±120min) increased with age. Residual AHI CPAP (range 4.8±3.4 to 11.1±9.0/h), leakage (range 0.09±0.11 to 0.27±0.32l/s) increased significantly with age. Males had statistically significantly higher average hours of use (377±94 vs. 370±96min), AHI CPAP (6.4±4.9 vs. 5.4±4.5/h), mask pressure (8.8±2.0 vs. 8.4±1.9cm H 2 O), and leakage (0.13±0.16 vs. 0.11±0.15l/s) than females. Conclusion Adherence to therapy is high and therapeutic efficacy is excellent in long-term CPAP users. Adherence is both age- and gender-dependent, but the differences are small and not clinically relevant.

Die derzeitige Standardtherapie zur Behandlung der obstruktiven Schlafapnoe ist die CPAP-Therapie. Um einen Uberblick uber das Nutzungsverhalten der Patienten zu erhalten, wurden in Deutschland flachendeckend Therapiedaten aus dem CPAP-Gerat S8 (Fa. ResMed, Sydney, Australien) ausgelesen und ausgewertet. Folgende Daten wurden retrospektiv von 4281 Patienten (Alter: 58,4±11,2 Jahre; 17,6% w., 82,4% m.) erhoben: Apnoe-Hypopnoe-Index (AHI), mittlerer Maskendruck, Maskendruck 95. Perzentil, mittlere Leckage, Leckage 95. Perzentil, Nutzungsdauer, Nutzungseffizienz (Nutzungstage/Gesamttage). Die Daten der letzten 156,7±25,0 Tage (Spanne: 30–180 Tage) wurden uber eine Datenkarte aus dem CPAP-Gerat ausgelesen. Informationen uber Maskentyp und Therapiedauer wurden ebenfalls ermittelt. Die Therapiedauer betrug 3,5±3,6 Jahre, die maximale Therapiedauer lag bei 15,8 Jahren. Die Patienten nutzten das CPAP-Gerat an 6,4±1,4 Tagen/Woche. Die Anwendungszeit/Nacht betrug 6h 16 min ±1 h 34min. Die Adharenz lag bei den Schwellenwerten 3 h/Nacht, 4 h/Nacht und 5 h/Nacht jeweils bei 97,0%, 91,8% und 79,9%. Der AHI lag bei 6,2±4,8/h, der mittlere Maskendruck bei 8,7±2,0 cmH2O und die mittlere Leckage bei 0,13±0,16 l/s. Das S8 wurde in 71,6% der Falle im CPAP-Modus betrieben und in 28,4% im APAP-Modus. Im untersuchten Patientenkollektiv war die Therapieadharenz sowohl im CPAP- als auch im APAP-Modus hoch und die Therapieeffektivitat in beiden Modi gut.

ApneaLink is a novel single-channel screening device for sleep apnea detection which is based on pressure-transduced measurement of oronasal airflow, summarised as respiratory disturbance index per hour of recording time (RDI(ApneaLink)). We tested ApneaLink's diagnostic performance in a patient population with high prevalence of sleep apnea.ApneaLink was applied simultaneously with in-laboratory polysomnography (PSG) (n = 102, 24 female, age 54.7 years) and sequentially with PSG in the unattended home setting (n = 131, 37 female, age 59.1 years). Predictive values were computed for apnea-defining thresholds of apnea-hypopnea index (AHI)or= 5/h,or=10/h,or=15/h. Night-to-night variability (NNV) was assessed over three consecutive nights (n = 55, 10 female, age 48.9 years).RDI(ApneaLink) correlated well with apnea-hypopnea index on PSG (PSG(AHI)) on simultaneous (r = 0.98, bias -0.7) and unattended home application (r = 0.95, bias -0.6). Predictive values were highest at AHIor= 10/h (in-laboratory: sensitivity 91.1%, specificity 87.5%, LR+ (positive likelihood ratio) 7.4, LR- 0.1; home: sensitivity 80%, specificity 85.5%, LR+5.5, LR- 0.2). NNV was low (V = 0.58 +/- 0.44, range 0-1.69).ApneaLink is an accurate screening tool for sleep apnea in a population with high prevalence of the disorder.

Due to the unattended design screening of sleep-disordered breathing (SDB) has a significant error rate. Possible reasons for the screening failure are off-centered or unfixed sensors. Therefore often another screening is mandatory which is both expensive and impeding for the patient. In order to minimise screening failure it is desirable to develop contactless screening devices. In 7 patients with a total of 477 central apneas we studied the diagnostic accuracy of Sleep-Minder (Biancamed, Dublin, Ireland) that was placed approx. 1m from the patient. Sleep-Minder emitted a very weak radio wave (factor 10-100 less compared to common household devices) and detected thorax and abdomen movement by measuring the Doppler effect. SleepMinder could detect 431 central apneas. This study showed the utility of SleepMinder, a contactless screening device, for detecting central apneas. Thus, SleepMinder can be used as an unattended screening method minimising screening failure.

Background Tacrolimus (TAC) dosing in lung transplantation is traditionally based on blood trough levels (C0). The best sampling strategy for the estimation of total drug exposure (area-under-the-curve [AUC]) has not been determined. Methods Thirty-one 12-hour pharmacokinetic profiles were studied in 15 patients (8 men and 7 women, 42.0 ± 13 years) post-bilateral lung transplantation (7.3 ± 3.7 months; range, 3–18 months). Twelve-hour AUC (AUC 0–12 ) was calculated by trapezoidal rule. Relationships between individual concentration points or abbreviated kinetics (2–4 concentration points) and AUC 0–12 were determined by linear regression analysis ( R 2 ; absolute prediction error [APE]). Results Pharmacokinetic profiles showed high variability, particularly in the absorption phase. AUC was 221 ± 47.2 ng/ml (range, 156–329.3 ng/ml) at C0 10 to 15 ng/ml and was independent of TAC dose ( R 2 = 0.002). C0 was poorly predictive of AUC 0–12 ( R 2 = 0.64; APE, 16.1% ± 10.9%; range, 1.4%–37.8%). The predictive performance for AUC 0–12 was highest with abbreviated kinetics using 4 (C0/C2/C3/C4: R 2 = 0.99; APE, 2.6% ± 2.0%; range, 0.1%–7%) or 3 concentration points (C0/C2/C4: R 2 = 0.98; APE, 2.6% ± 2.1%; range, 0.1%–9.1%). Of the 2-point kinetics C2/C6 ( R 2 = 0.96; APE, 5.3% ± 3.7%; range, 0.1%–12.7%), C2/C4 ( R 2 =0.94, APE 6.7% ± 4.8%; range 0.1%–14.6%) and C0/C4 ( R 2 = 0.94; APE 4.1% ± 2.9%; range, 0.5%–11.4%) performed best. Single point strategies (best was C4: R 2 = 0.94; APE 7.1% ± 5.5%, range, 0.2%–24.1%) all had unacceptably high APE (range > 15%). Conclusion True TAC exposure shows high variability in stable lung transplant patients and is poorly predicted by C0. Abbreviated kinetics covering at least 2 concentration points between 0 and 4 hours post-drug intake are required for an accurate estimation of AUC.

Background: Tacrolimus (TAC) dosing in lung transplantation is traditionally based on blood trough levels (C0). Best sampling strategy for estimation of total drug exposure (area-under-the-curve, AUC) has not been determined. Methods: Thirty-one 12 hour pharmacokinetic profiles were studied in 15 patients (8 men and 7 women, 42.0 13 years) post bilateral lung transplantation (7.3 3.7 months, range 3–18 months). 12 hour AUC (AUC0-12) was calculated by trapezoidal rule. Relationships between individual concentration points or abbreviated kinetics (2–4 concentration points) and AUC0-12 was determined by linear regression analysis (R; absolute prediction error, APE). Results: Pharmacokinetic profiles showed high variability, particularly in the absorption phase. AUC was 221 47.2 ng/ml (range 156 –329.3 ng/ml at C0 10 –15 ng/ml and was independent of TAC dose (R 0.002). C0 was poorly predictive of AUC0-12 (R 0.64, APE 16.1 10.9%, range 1.4 –37.8%). Predictive performance for AUC0-12 was highest with abbreviated kinetics using four (C0/C2/ C3/C4: R 0.99, APE.2.6 2.0%, range 0.1–7%) or three concentration points (C0/C2/C4: R 0.98, APE. 2.6 2.1, range 0.1– 9.1%). Of the 2-point kinetics C2/C6 (R 0.96, 5.3 3.7%, range 0.1–12.7%) and C0/C4 (R2 0.94, APE 4.1 2.9%, range 0.5– 11.4%) performed best. Single point strategies (best was C4: R2 0.94, APE 7.1 5.5%, range 0.2–24.1%, all had unacceptably high APE (range 15%). Conclusion: True TAC exposure shows high variability in stable lung transplant patients and is poorly predicted by C0. Abbreviated kinetics covering at least two concentration points between 0 and 4 hours post drug intake are required for accurate estimation of AUC.