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Cheyne-Stokes respiration (CSR) during sleep is common in patients with severe congestive heart failure (CHF). It induces repetitive oxygen desaturations and impairs sleep [1,2]. Disturbed sleep is likely to cause daytime symptoms and the repetitive oxygen desaturations and arousals increase sympathetic activity as well as right and left ventricular afterload [3] and may thus further impede left ventricular function and exercise tolerance [4][5][6]. Effective treatment for CSR is therefore needed. Nocturnal oxygen by nasal prongs reduces CSR by about 50% and consolidates sleep [1,[6][7][8]. Application of 3% CO 2 prevented CSR by increasing the arterial carbon dioxide tension (Pa,CO 2 ) above the apnoeic threshold [9] but sleep was adversely affected, this being attributed to the tight-fitting face mask used [10]. The hypothesis was tested that CO 2 in conjunction with O 2 given by nasal prongs is efficacious in the treatment of CSR. Plasma catecholamines were measured, to evaluate possible effects on sympathetic activity. Methods Subjects and protocolAll patients with severe heart failure admitted to the department of cardiology were candidates for the study.Patients under the age of 75 yrs were eligible if they met the following criteria: at least one episode of cardiac decompensation, ejection fraction ð35%, stable condition on cardiac medication and evidence of CSR by nocturnal polysomnography. Exclusion criteria were myocardial infarction within 1 yr of entry, significant obstructive lung disease as defined by a forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) <70%, primary valvular heart disease, tibial oedema or evidence of obstructive sleep apnoea (more than five obstructive apnoeas·h -1 ). Plasma catecholamines were evaluated in 15 healthy subjects (age 53.2±5.3 yrs) without significant sleep-disordered breathing. The study was approved by the local ethics committee. Informed written consent was obtained from all subjects.The study was designed as a single-blind, placebo-controlled trial. After an accommodation night where no treatment was applied the patients received air as well as O 2 plus CO 2 in a randomized, cross-over fashion on two consecutive nights. Polysomnography was performed during all three nights. Oxygen was given with a flow rate of 2 L·min -1 by nasal prongs and CO 2 was admixed simultaneously with a flow rate of 0.2-1 L·min -1 . Accordingly, the flow rate of the mixture was 2.2-3 L·min -1 . CO 2 flow rate was regulated depending on the transcutaneous carbon dioxide tension (Ptc,CO 2 ), which was not allowed to increase >7.3 kPa (55 mmHg) and on the occurrence of In conclusion, nocturnal O 2 plus CO 2 improves Cheyne-Stokes respiration in patients with congestive heart failure but has adverse effects on the sequel of CheyneStokes respiration, namely sympathetic activation. Eur Respir J 1998; 12: 414-419.

Endothelin-1 (ET-1), a potent vasoconstrictor, is released mainly by vascular endothelial cells under the influence of hypoxia and other stimuli. ET-1 is related to endothelial dysfunction, as well as arterial and pulmonary hypertension, all of which are thought to be associated with obstructive sleep apnoea (OSA).This study evaluated venous plasma concentrations of ET-1 and noradrenaline and 24-h systemic blood pressure in 29 patients with OSA (age=56.9 1.6 yrs; body mass index=29.5 0.7 kg . m -2 (mean SEM)). Blood samples were taken in the morning, evening and during sleep. In the same way, the patients were assessed during a night of continuous positive airway pressure (CPAP) and after 13.9 1.4 months while still on CPAP. ET-1 levels were compared to those of control subjects, who were selected from in-and outpatients and were matched to patients for age, sex, presence of arterial hypertension and coronary artery disease.ET-1 plasma levels were not elevated in the patients compared to the controls (41.6 2.2 and 44.9 1.3 pg . mL -1 , respectively, p=0.20). The ET-1 concentration did not change significantly, neither during sleep nor in the first night on CPAP therapy, nor under long-term treatment with CPAP. ET-1 neither correlated to the severity of OSA nor to that of systemic hypertension.The results suggest that endothelin-1 does not play a crucial role in the pathophysiology of obstructive sleep apnoea. Endothelins are peptides of 21 amino acids that are produced in a wide variety of cells. Endothelin-1 (ET-1) was isolated from vascular endothelial cells [1], whereas endothelin-2 (ET-2) and endothelin-3 (ET-3) are mainly produced within the kidney and intestine. ET-1 is released under the influence of chemical or physical stimuli, such as hypoxia or shear stress, as well as various receptor operated mechanisms. It is the most potent endogenous vasoconstrictor yet identified and seems to be intimately involved in the pathogenesis of pulmonary hypertension [2,3]. Whether ET-1 production is increased in arterial hypertension remains controversial though [4]. Patients with obstructive sleep apnoea (OSA) exhibit repetitive nocturnal apnoeas and hypopnoeas which result in oxygen desaturations and consecutive arousals. OSA can be successfully treated with continuous positive airway pressure (CPAP). The disease can be associated with pulmonary hypertension even in the absence of daytime hypoxaemia or concomitant lung disease [5,6]. In epidemiological and animal studies an association between systemic hypertension and OSA, independent of obesity, age and sex, was found [7,8]. It is therefore tempting to speculate that in OSA plasma ET-1 levels are elevated due to nocturnal desaturations and give rise to pulmonary as well as arterial hypertension. To further elucidate this hypothesis the authors' studied the influence of CPAP treatment on ET-1 plasma concentration in patients with OSA. Methods Subjects and protocolTwenty-nine consecutive subjects of both sexes that were referred to the authors' sleep labor...

Lacking compliance with liquid intake restrictions is one of the major problems in patients on hemodialysis and causes an increased mortality. In 120 patients on hemodialysis with an average interdialytic weight gain (IWG) exceeding 1.5 kg on at least 2 days during the 4 weeks preceding the intervention, the effect of telemetric body weight measurement (TBWM) on IWG, ultrafiltration rate, and blood pressure was evaluated over a period of 3 months. Patients of the telemetric group (TG) were supplied with automatic scales, which transferred the weight via telemetry on a daily basis. In the case of IWG of more than 0.75 kg/24 h, a telephonic contact was made as required, and in the case of an IWG of more than 1.5 kg, telephonic contacting was obligatory along with the advice of a liquid intake restriction to 0.5 L/day until the next dialysis. The patients of the control group (CG) received standard treatment without telemetric monitoring. We examined specific data of the second interdialytic interval (IDI2) and the average within 1 week. The average difference of IWG between TG and CG was not significant before the start of the study but 0.2 kg (p=0.027) (IDI2)/0.27kg (p=0.001) (WP) at the end of the study, respectively. The average difference in the ultrafiltration rate within 1 week was 19.0 mL/h (p=0.282) (IDI2)/8.2 mL/h (p=0.409) before the start of the study but 28.4 mL/h (p=0.122) (IDI2)/30.9 mL/h (p=0.004) at the end of the study, respectively. Thus, TBWM is a feasible method for optimizing the IWG and reducing the ultrafiltration rate. AbstractLacking compliance with liquid intake restrictions is one of the major problems in patients on hemodialysis and causes an increased mortality. In 120 patients on hemodialysis with an average interdialytic weight gain (IWG) exceeding 1.5 kg on at least 2 days during the 4 weeks preceding the intervention, the effect of telemetric body weight measurement (TBWM) on IWG, ultrafiltration rate, and blood pressure was evaluated over a period of 3 months. Patients of the telemetric group (TG) were supplied with automatic scales, which transferred the weight via telemetry on a daily basis. In the case of IWG of more than 0.75 kg/24 h, a telephonic contact was made as required, and in the case of an IWG of more than 1.5 kg, telephonic contacting was obligatory along with the advice of a liquid intake restriction to 0.5 L/day until the next dialysis. The patients of the control group (CG) received standard treatment without telemetric monitoring. We examined specific data of the second interdialytic interval (IDI2) and the average within 1 week. The average difference of IWG between TG and CG was not significant before the start of the study but 0.2 kg (p = 0.027) (IDI2)/0.27kg (p = 0.001) (WP) at the end of the study, respectively. The average difference in the ultrafiltration rate within 1 week was 19.0 mL/h (p = 0.282) (IDI2)/ 8.2 mL/h (p = 0.409) before the start of the study but 28.4 mL/h (p = 0.122) (IDI2)/30.9 mL/h (p = 0.004) at the end of the study, ...

BackgroundOne of the first investigations concerning extracorporeal treatment of hypercholesterolemia was performed in 1967 by plasma exchange in patients with homozygous or severe heterozygous familial hypercholesterolemia (FH). In the following decades, several specific lipid apheresis systems were developed to efficiently eliminate low-density lipoprotein (LDL) cholesterol and Lp(a) cholesterol in hypercholesterolemic patients. In the early 1980s, the main clinical indication has been homozygous FH including mainly children and pregnant women. In consideration of the current development of lipid-lowering regimens and scientific knowledge of preventing progression of cardiovascular diseases, the spectrum of indications to initiate lipid apheresis was extended due to still insufficient lipid-lowering therapy in some clinical cases. However, a generally accepted indication for lipid apheresis treatment is still under discussion. In Germany, the target-oriented distribution of increasingly limited healthcare resources demand data which support the benefit of established treatment procedures such as lipid apheresis. In recent years, the Federal Joint Committee (G-BA), a paramount decision-making body of the German Healthcare System, issued to reassess the approval of chronic lipid apheresis therapy for regular reimbursement. Therefore, in 2005, an interdisciplinary German Apheresis Working Group has been established by members of both the German societies of nephrology. One of the first goals of this working group was a revision of the indications for lipid apheresis corresponding to current guidelines and recommendations for the treatment of lipid disorders. In addition, recently new pathophysiological perceptions of the impact of lipoproteins on atherogenesis and thrombosis were also considered.Methods and ResultsSince 2005, the working group met on a regular basis to substantiate the first defined goals. The indications for lipid apheresis were critically revised with respect to actual results from clinical investigations, cardiovascular guidelines, and scientific knowledge and were accepted by the members of the apheresis working group.ConclusionsThere is consensus between the medical societies and health insurance funds regarding the need for general accepted guidelines for lipid apheresis. Recommendations for the indications of lipid apheresis were developed, but additionally these results should be confirmed by medical societies to transform them to guidelines. However, due to limited data showing that lipid apheresis has effects on the progression of cardiovascular diseases all members of the apheresis working group support a project for creating a lipid apheresis registry. This apheresis registry has been developed and recently started. The primary goal is to substantiate prospective long-term data on clinical outcome of chronic lipid apheresis treatment and to support additional clinical research activities in this field. In addition, this registry should comply with the actual requests of the Federal Joi...

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In patients with coronary artery disease (CAD) the prevalence of obstructive sleep apnoea (OSA) is found to be about 14-65%. In this study, the influence of OSA in 50 patients with CAD was prospectively compared during a follow-up period of 10 years. In the follow-up period 4 of 25 patients with OSA and 5 of the 25 without OSA died by cardiovascular complications. The proportion survival curve showed no significant difference for patients with CAD and with versus without OSA. The results of this rather small 10-year follow-up study failed to give further evidence for an increased mortality in patients with CAD and OSA.

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