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Objective: The prevalence of exercise-associated hyponatremia (EAH) has mainly been investigated in marathoners and Ironman triathletes. The aim of this study was to investigate the prevalence of EAH in male ultraendurance athletes in other disciplines, such as ultraswimming, ultracycling, and ultramarathon running., Design: Observational field study., Setting: "Marathon Swim" in Lake Zurich, the "Swiss Cycling Marathon," the "Swiss Bike Masters," the "100-km Lauf Biel," and the "Swiss Jura Marathon.", Participants: Fifteen ultraswimmers, 28 ultra-road cyclists, 37 ultra-mountain bikers, 95 ultramarathoners, and 25 mountain ultramarathoners., Main Outcome Measures: Changes in body mass, plasma sodium, urinary specific gravity, and hematocrit were measured. The athletes recorded their intake of fluids., Results: Two swimmers (13%), 3 road cyclists (10.7%), no mountain bikers (0%), 5 ultramarathoners (5%), and 2 mountain ultramarathoners (8%) developed EAH. In the mountain bikers (r = -0.41) and the 100-km ultramarathoners (r = -0.52), fluid intake was significantly and negatively related to race time. In the mountain ultramarathoners, fluid consumption increased during the race., Conclusions: The prevalence of EAH was no higher in ultraendurance athletes compared with existing reports on marathoners and Ironman triathletes. Of the 200 investigated ultraendurance athletes, 12 finishers (6%) developed EAH., (2011 by Lippincott Williams & Wilkins.)

We investigated in 73 male ultraendurance mountain bikers, with (mean and SD) age 39.1 (8.6) years, weight 74.4 (8.3) kg, height 1.78 (0.07) m, and a body mass index of 23.3 (1.9) kg·m⁻², whether variables of anthropometry, training, or prerace experience were associated with race time using bi and multivariate analysis. Our investigation was conducted at the "Swiss Bike Masters," which covers a distance of 120 km and an altitude of 5,000 m. In the bivariate analysis, body mass index (r = 0.29), circumference of upper arm (r = 0.28), sum of upper body skinfolds (r = 0.38), sum of lower body skinfolds (r = 0.25), sum of 8 skinfolds (r = 0.36), percent body fat (r = 0.41), total cycling kilometers per year (r = -0.47), yearly volume in both mountain bike (r = -0.33) and road cycling (r = -0.52), number of training units per week (r = -0.48), distance per unit in road cycling (r = -0.33), average speed during training in road cycling (r = -0.33), and personal best time in the "Swiss Bike Masters"(r = 0.67) were related to race time. In the multiple linear regression analysis, personal best time in the "Swiss Bike Masters" (p = 0.000), total yearly cycling kilometers (p = 0.004), and yearly training kilometers in road cycling (p = 0.017) were related to race time. When the personal best time was the dependent variable in a separate regression model, total yearly cycling kilometers (p = 0.002) remained the single predictor variable. We concluded that finishing a particular mountain bike ultramarathon does not seem to require a special anthropometry but rather a specific skill and experience for this selective kind of race coupled with a high training volume. For practical use, we concluded that successful athletes in a mountain bike ultramarathon, in a special environment and using sophisticated equipment, need prerace experience coupled with high training volume, rather than any special anthropometry.

Background: Cancer diseases and their therapies have negative effects on the quality of life. The aim of this study is to assess the effectiveness of case management in a sample of oncological outpatients with the intent of rehabilitation after cancer treatment. Case management wants to support the complex information needs of the patients in addition to the segmented structure of the health care system. Emphasis is put on support for self-management in order to enhance health - conscious behaviour, learning to deal with the burden of the illness and providing the opportunity for regular contacts with care providers. We present a study protocol to investigate the efficacy of a case management in patients following oncology rehabilitation after cancer treatment., Methods: The trial is a multicentre, two-arm randomised controlled study. Patients are randomised parallel in either 'usual care' plus case management or 'usual care' alone. Patients with all types of cancer can be included in the study, if they have completed the therapy with chemo- and/or radiotherapy/surgery with curative intention and are expected to have a survival time >1 year. To determine the health-related quality of life the general questionnaire FACT G is used. The direct correlation between self-management and perceived self-efficacy is measured with the Jerusalem & Schwarzer questionnaire. Patients satisfaction with the care received is measured using the Patient Assessment of Chronic Illness Care 5 As (PACIC-5A). Data are collected at the beginning of the trial and after 3, 6 and 12 months. The power analysis revealed a sample size of 102 patients. The recruitment of the centres began in 2009. The inclusion of patients began in May 2010., Discussion: Case management has proved to be effective regarding quality of life of patients with chronic diseases. When it comes to oncology, case management is mainly used in cancer treatment, but it is not yet common in the rehabilitation of cancer patients. Case management in oncology rehabilitation is not well-established in Switzerland. A major challenge of the study will therefore probably be the recruitment of the patients due to the physicians' and patients' scarcely existing awareness of this issue. Trial registrationISRCTN41474586

Background: The purpose of this study was to investigate the effect of short-term supplementation of amino acids before and during a 100 km ultra-marathon on variables of skeletal muscle damage and muscle soreness. We hypothesized that the supplementation of amino acids before and during an ultra-marathon would lead to a reduction in the variables of skeletal muscle damage, a decrease in muscle soreness and an improved performance., Methods: Twenty-eight experienced male ultra-runners were divided into two groups, one with amino acid supplementation and the other as a control group. The amino acid group was supplemented a total of 52.5 g of an amino acid concentrate before and during the 100 km ultra-marathon. Pre- and post-race, creatine kinase, urea and myoglobin were determined. At the same time, the athletes were asked for subjective feelings of muscle soreness., Results: Race time was not different between the groups when controlled for personal best time in a 100 km ultra-marathon. The increases in creatine kinase, urea and myoglobin were not different in both groups. Subjective feelings of skeletal muscle soreness were not different between the groups., Conclusions: We concluded that short-term supplementation of amino acids before and during a 100 km ultra-marathon had no effect on variables of skeletal muscle damage and muscle soreness.

Background: Patients understand information about risk better if it is communicated in numerical or visual formats (e.g. graphs) compared to verbal qualifiers only. How frequently different communication formats are used in clinical primary care settings is unknown., Methods: We collected socioeconomic and patient understanding data using questionnaires and audio-recorded consultations about cardiovascular disease risk. The frequencies of the communication formats were calculated and multivariate regression analysis of associations between communication formats, patient and general practitioner characteristics, and patient subjective understanding was performed., Results: In 73% of 70 consultations, verbal qualifiers were used exclusively to communicate cardiovascular risk, compared to numerical (11%) and visual (16%) formats. Female GPs and female patient's gender were significantly associated with a higher use of verbal formats compared to visual formats (p=0.001 and p=0.039, respectively). Patient subjective understanding was significantly higher in visual counseling compared to verbal counseling (p=0.001)., Conclusions: Verbal qualifiers are the most often used communication format, though recommendations favor numerical and visual formats, with visual formats resulting in better understanding than others. Also, gender is associated with the choice of communication format. Barriers against numerical and visual communication formats among GPs and patients should be studied, including gender aspects. Adequate risk communication should be integrated into physicians' education.

The purpose of this study was to investigate in 81 male recreational ultratriathletes (64 finishers and 17 nonfinishers) the relationship of anthropometry, prerace experience, and training with race outcome in a Triple Iron triathlon, using bi and multivariate analyses. In the bivariate analysis, the sum of 8 skinfolds (r = 0.38) and the sum of upper body skinfolds (r = 0.37) were positively related to total race time. None of the anthropometric variables was related to the swim or bike split. Circumference of upper arm (r = 0.42), percent body fat (r = 0.43), the sum of 8 skinfolds (r = 0.47), and the sum of upper body skinfolds (r = 0.45) were positively associated with the time in the run split. None of the training variables was related to total race time or split times. Personal best time in an Ironman triathlon (r = 0.59) and a Triple Iron triathlon (r = 0.82) were positively and highly significantly related to total race time. When all significant variables after bivariate analysis were included in a regression model, personal best time in a Triple Iron triathlon (p < 0.0001) remained the single predictor variable. For practical considerations, athletes with a background as an ultrarunner might have an advantage in successfully finishing a Triple Iron triathlon. However, ultrarunners should also have enough prerace experience in competing in Ironman and Triple Iron triathlons to successfully finish such a race.

Background: Placebos play an important role in clinical trials and several surveys have shown that they are also common in daily practice. Previous research focused primarily on the frequency of placebo use in outpatient care. Our aim was to explore physicians' views on the use of placebos in daily practice, whereby distinction was made between pure placebos (substances with no pharmacological effect, e.g. sugar pills) and impure placebos (substances with pharmacological effect but not on the condition being treated, e.g. antibiotics in viral infections or vitamins)., Methods: We performed semi-structured interviews with a sample of twelve primary care physicians (PCPs). The interview addressed individual definitions of a placebo, attitudes towards placebos and the participants' reasons for prescribing them. The interviews were transcribed and analysed using qualitative content analysis., Results: The definition of a placebo given by the majority of the PCPs in our study was one which actually only describes pure placebos. This definition, combined with the fact that most impure placebos were not regarded as placebos at all, means that most of the participating PCPs were not aware of the extent to which placebos are used in daily practice. The PCPs stated that they use placebos (both pure and impure) mainly in the case of non-severe diseases for which there was often no satisfactory somatic explanation. According to the PCPs, cases like this are often treated by complementary and alternative therapies and these, too, are associated with placebo effects. However, all PCPs felt that the ethical aspects of such treatment were unclear and they were unsure as to how to communicate the use of placebos to their patients. Most of them would appreciate ethical guidelines on how to deal with this issue., Conclusions: Many PCPs seem to be unaware that some of the drugs they prescribe are classified as impure placebos. Perceptions of effectiveness and doubts about the legal and ethical aspects of the use of placebos by PCPs may discourage their application. Dissemination of guidelines and consensus papers may be one approach, but it has to be acknowledged that the topic itself is in conflict with the PCPs' perception of themselves as professional and reliable physicians.

Rationale: Abdominal aortic aneurysms (AAA) are associated with life-threatening complications. The likelihood that an AAA will rupture is influenced by the aneurysm diameter and its expansion rate; reasons for rapid expansion are largely unknown., Objectives: To determine the prevalence of obstructive sleep apnea (OSA) in patients with AAA, and investigate a possible association between OSA and rate of AAA expansion., Methods: A total of 127 patients (11 females), included in an AAA surveillance program, agreed to participate and underwent a sleep study. Annual AAA expansion was determined retrospectively from available ultrasound measurements. OSA was characterized using both oxygen desaturation index (ODI) and apnea-hypopnea index (AHI). Univariate and multivariate analysis was performed to assess the effect of OSA severity on AAA expansion., Measurements and Main Results: Mean age was 67.9 (SD, 6) years. Median interval between the first and last AAA measurements was 18 (range, 2-113) months. An ODI or AHI of greater than 10 was found in 40.5% and 41.5% of the patients, respectively. Patients with an ODI greater than 30 (n = 12) had a significantly faster median yearly AAA expansion rate (2.9; quartiles 2/5.7 mm/y) than patients with an ODI 0-5 (n = 47; 1.2; quartiles 0/3.1 mm/y) or 6-15 (n = 43; 1.3; quartiles 0/2.7 mm/y) (P < 0.05). In multivariate regression analysis, controlling for cardiovascular risk factors and medications, ODI greater than 30 remained an independent risk factor for AAA expansion., Conclusions: In patients with AAA, OSA is highly prevalent. Severe OSA may be a causal factor for faster AAA expansion, but this needs to be proved in a randomized controlled intervention trial.

Background: Loss of body mass during a 24-h run was considered to be a result of dehydration., Aims: We intended to quantify the decrease in body mass as a loss in fat mass or skeletal muscle mass and to quantify the change in hydration status., Methods: Body mass, fat mass, skeletal muscle mass, haematocrit, plasma sodium and urinary specific gravity were measured in 15 ultra-marathoners in a 24-h run., Results: Body mass decreased by 2.2 kg (p = 0.0009) and fat mass decreased by 0.5 kg (p = 0.0084). The decrease in body mass correlated to the decrease in fat mass (r = 0.72, p = 0.0024). Urinary specific gravity increased from 1.012 to 1.022 g/mL (p = 0.0005)., Conclusions: The decrease in body mass and the increase in urinary specific gravity indicate dehydration. The decrease in body mass was correlated to the decrease in fat mass and therefore not only due to dehydration.

We investigated the associations of anthropometry, training, and pre-race experience with race time in 93 recreational male ultra-marathoners (mean age 44.6 years, s = 10.0; body mass 74.0 kg, s = 9.0; height 1.77 m, s = 0.06; body mass index 23.4 kg · m(-2), s = 2.0) in a 100-km ultra-marathon using bivariate and multivariate analysis. In the bivariate analysis, body mass index (r = 0.24), the sum of eight skinfolds (r = 0.55), percent body fat (r = 0.57), weekly running hours (r = -0.29), weekly running kilometres (r = -0.49), running speed during training (r = -0.50), and personal best time in a marathon (r = 0.72) were associated with race time. Results of the multiple regression analysis revealed an independent and negative association of weekly running kilometres and average speed in training with race time, as well as a significant positive association between the sum of eight skinfold thicknesses and race time. There was a significant positive association between 100-km race time and personal best time in a marathon. We conclude that both training and anthropometry were independently associated with race performance. These characteristics remained relevant even when controlling for personal best time in a marathon.

Rationale, Aims and Objectives: To investigate the demand for traditional out-of-hours general practitioner (GP) emergency care in Switzerland including GPs' satisfaction and reasons for encounter (RFE)., Method: During a 2-month period (2009), a questionnaire-based, cross-sectional study was performed in GPs participating in the mandatory out-of-hours service in the city of Zurich, Switzerland. The number and mode of patient contacts were assessed to investigate the demand for GP care in traditional out-of-hours services. GPs and patient characteristics, including RFE according to the International Classification of Primary Care, were noted. Descriptive statistics and non-parametric tests were conducted., Results: Out of the 295 out-of-hours episodes during the study period, 148 (50%) duty periods were documented by a total of 93 GPs (75% men) with a mean (SD) age of 48.0 (6.2) years. The median (interquartile range) number of out-of-hours contacts was 5 (3-8) and the demand for home visits was significantly more common compared with practice and telephone consultations. A total of 112 different RFEs were responsible for the 382 documented patient contacts with fever accounting for the most common complaint (13.9%). Although 80% of GPs agreed to be satisfied overall with their profession as primary care provider, 57.6% among them were dissatisfied with the current out-of-hours service. Inappropriate payment and interference with their daily work in practice were most frequently reported., Conclusions: Our findings indicate that there is still strong patient demand for out-of-hours care with special need for home visits, suggesting that new organizational models such as integrating GPs into emergency care may not be an appropriate approach for all patients. Therefore, the ongoing reorganization of the out-of-hours-service in many health care systems has to be evaluated carefully in order not to miss important patient needs., (© 2010 Blackwell Publishing Ltd.)

Questions Under Study/principles: Research is scarce where most patients are found. One of the main reasons is the difficulty in extracting data from traditionally conducted paper-based medical records. Thus, until now most existing patient records have originated from invoicing-tools. Endeavours to truly reflect a doctor's consultation have been rare. FIRE (Family Medicine ICPC-Research using Electronic Medical Records) is an ambitious project to establish a proper knowledge base in primary care by using the ongoing implementation of EPR (electronic patient records). FIRE will enable many questions on epidemiology and performance within the PC (primary care) setting to be answered., Methods: GPs (general practitioners) throughout Switzerland working with EPR were eligible for participation. Workshops were held to train and standardise ICPC-coding (International Classification of Primary Care), a classification system especially designed for the PC-setting. The recorded data included administrative information on the GP and patient, vital signs, ICPC codes, laboratory analysis and medication. Data exporter software was developed for extracting anonymised data automatically from the EPR onto a database for further statistical analysis., Results: From 1.1.2009 until the beginning of April 2010 24 GPs were successfully recruited providing standardised information on 127,922 consultations in 29,398 patients and 159,956 medical problems according to the ICPC-2 classification., Conclusion: The project proves the feasibility of standardised ongoing collection of research data embedded in routine clinical practice. FIRE provides a unique database for research in PC and highlights the potential of broad implementation of EPR in a PC-setting. Studies resulting from the ongoing project have the potential to assess the quality of care provided by GP's.

We investigated the change in body composition and hydration status in 27 male ultra-runners during a 100 km ultra-run. The athletes drank fluids ad libitum during the run; intake of calories, fluids, and electrolytes during performance were determined. Body mass decreased by 1.9 kg, haematocrit decreased, plasma [Na(+)] remained unchanged, and urinary specific gravity and plasma volume increased. Fluid intake was 0.52 (0.18) L/h and was related to running speed (r = 0.50; p = 0.0081). Δ body mass was associated with total fluid intake during the race (r = 0.49, p = 0.0095). Sodium intake amounted to 425 (478) mg/h and potassium intake to 140 (179) mg/h. Sodium and potassium intake were not related to either postrace concentration or change in plasma concentration. Sodium intake, however, was related to Δ urinary sodium concentration (r = 0.45, p = 0.0227). The increase in plasma volume was significantly and negatively related to both postrace plasma [Na(+)] (r = - 0.42, p = 0.0278) and the postrace potassium-to-sodium ratio in urine (r = - 0.44, p = 0.0218). To conclude, we found no fluid overload in these ultra-runners, the increase in plasma volume was most probably due to a stimulation of the renin-angiotensin-aldosterone system (RAAS) since sodium intake was not related to both the change in plasma [Na(+)] or postrace plasma [Na(+)].

Background: In Switzerland, General Practitioners (GPs) play an important role for out-of-hours emergency care as one service option beside freely accessible and costly emergency departments of hospitals. The aim of this study was to evaluate the services provided and the economic consequences of a Swiss GP out-of-hours service., Methods: GPs participating in the out-of-hours service in the city of Zurich collected data on medical problems (ICPC coding), mode of contact, mode of resource use and services provided (time units; diagnostics; treatments). From a health care insurance perspective, we assessed the association between total costs and its two components (basic costs: charges for time units and emergency surcharge; individual costs: charges for clinical examination, diagnostics and treatment in the discretion of the GP)., Results: 125 GPs collected data on 685 patient contacts. The most prevalent health problems were of respiratory (24%), musculoskeletal (13%) and digestive origin (12%). Home visits (61%) were the most common contact mode, followed by practice (25%) and telephone contacts (14%). 82% of patients could be treated by ambulatory care. In 20% of patients additional technical diagnostics, most often laboratory tests, were used. The mean total costs for one emergency patient contact were €144 (95%-CI: 137-151). The mode of contact was an important determinant of total costs (mean total costs for home visits: €176 [95%-CI: 168-184]; practice contact: €90 [95%-CI: 84-98]; telephone contact: €48 [95%-CI: 40-55]). Basic costs contributed 83% of total costs for home visits and 70% of total costs for practice contacts. Individual mean costs were similarly low for home visits (€30) and practice contacts (€27). Medical problems had no relevant influence on this cost pattern., Conclusions: GPs managed most emergency demand in their out-of-hours service by ambulatory care. They applied little diagnostic testing and basic care. Our findings are of relevance for policy makers even from other countries with different pricing policies. Policy makers should be interested in a reimbursement system promoting out-of-hours care run by GPs as one valuable service option.

The purpose of this study was to investigate the association between selected skin-fold thicknesses and training variables with a half-marathon race time, for both male and female recreational runners, using bi- and multivariate analysis. In 52 men, two skin-fold thicknesses (abdominal and calf) were significantly and positively correlated with race time; whereas in 15 women, five (pectoral, mid-axilla, subscapular, abdominal, and suprailiac) showed positive and significant relations with total race time. In men, the mean weekly running distance, minimum distance run per week, maximum distance run per week, mean weekly hours of running, number of running training sessions per week, and mean speed of the training sessions were significantly and negatively related to total race time, but not in women. Interaction analyses suggested that race time was more strongly associated with anthropometry in women than men. Race time for the women was independently associated with the sum of eight skin-folds; but for the men, only the mean speed during training sessions was independently associated. Skin-fold thicknesses and training variables in these groups were differently related to race time according to their sex.

Background: Smoking is a well-known risk factor for cardiovascular, lung, and many other diseases. Smoking can induce pulmonary arterial hypertension (PAH) in animal models; PAH is common in smokers with COPD and thereby not correlated with the degree of airway obstruction. The impact of tobacco smoke exposure on the development of PAH in humans is not known., Methods: In a case-control study we assessed smoking and secondhand smoke exposure in all patients with PAH and chronic thromboembolic pulmonary hypertension (CTEPH) seen at our pulmonary hypertension clinic from 2002 until July 2008. Data from patients with PAH were compared with CTEPH and healthy control subjects from the Swiss Health Survey 2007., Results: Ninety-one patients with PAH were compared with 64 patients with CTEPH and 18,747 control subjects (women 58, 36, 10,331, respectively). Tobacco smoking was significantly more common in PAH compared with CTEPH and control subjects. This difference could be attributed to men. Patients with PAH also smoked longer and more heavily compared with patients with CTEPH. In addition, secondhand smoke exposure was significantly longer in nonsmokers with PAH compared with control subjects., Conclusion: Our data indicate that tobacco smoke exposure may be a risk factor for men with PAH. Considering smoking as a risk factor for PAH will have implications in counseling patients and especially their hitherto unaffected relatives. Further research on the pathogenetic role of smoking in PAH is warranted.

Background: Peritoneal dialysis (PD) catheter displacement is a major cause of dysfunction. Various catheter forms have been designed to improve outcome. One of them is based on the classical Tenckhoff catheter, but includes a small tungsten cylinder at the distal end to optimize location and to prevent dislocations. ♢, Methods: In this retrospective study, we analyzed the functionality and complication profile of the self-locating catheter implanted at our center from November 2005 to September 2008 in our PD program. ♢, Results: Data from 27 self-locating catheters implanted in 25 patients (12 women) were obtained. Patients were followed for up to 30 months (median observation time: 13 months), resulting in a cumulative study period of 357 PD months. A total of 22 complications were identified, including 1 episode of peritonitis per 52 patient-months, 1 tunnel infection, and 1 exit-site infection. The "functional catheter failure incidence rate" was approximately 0.01 catheters per month on PD (or approximately 1 catheter loss per 100 PD months). The catheter survival was 93% at 1 year. ♢, Conclusions: The "self-locating" PD catheter demonstrates low rates of catheter migration and dislocations, and good catheter survival.

Background: In autosomal dominant polycystic kidney disease (ADPKD), aberrant activation of the mammalian target of rapamycin (mTOR) pathway is associated with progressive kidney enlargement. The drug sirolimus suppresses mTOR signaling., Methods: In this 18-month, open-label, randomized, controlled trial, we sought to determine whether sirolimus halts the growth in kidney volume among patients with ADPKD. We randomly assigned 100 patients between the ages of 18 and 40 years to receive either sirolimus (target dose, 2 mg daily) or standard care. All patients had an estimated creatinine clearance of at least 70 ml per minute. Serial magnetic resonance imaging was performed to measure the volume of polycystic kidneys. The primary outcome was total kidney volume at 18 months on blinded assessment. Secondary outcomes were the glomerular filtration rate and urinary albumin excretion rate at 18 months., Results: At randomization, the median total kidney volume was 907 cm3 (interquartile range, 577 to 1330) in the sirolimus group and 1003 cm3 (interquartile range, 574 to 1422) in the control group. The median increase over the 18-month period was 99 cm3 (interquartile range, 43 to 173) in the sirolimus group and 97 cm3 (interquartile range, 37 to 181) in the control group. At 18 months, the median total kidney volume in the sirolimus group was 102% of that in the control group (95% confidence interval, 99 to 105; P=0.26). The glomerular filtration rate did not differ significantly between the two groups; however, the urinary albumin excretion rate was higher in the sirolimus group., Conclusions: In adults with ADPKD and early chronic kidney disease, 18 months of treatment with sirolimus did not halt polycystic kidney growth. (Funded by Wyeth and others; ClinicalTrials.gov number, NCT00346918.)

Inter- and intra-judge reliabilities of skinfold measures were investigated in a sample of 27 men and 11 women ultramarathon runners. Two physicians had agreement higher than 90% in field measurements before an ultramarathon race.

Background: Insufficient blood pressure control is a frequent problem despite the existence of effective treatment. Insufficient adherence to self-monitoring as well as to therapy is a common reason. Blood pressure self-measurement at home (Home Blood Pressure Measurement, HBPM) has positive effects on treatment adherence and is helpful in achieving the target blood pressure. Only a few studies have investigated whether adherence to HBPM can be improved through simple measures resulting also in better blood pressure control., Objective: Improvement of self-monitoring and improved blood pressure control by using a new colour-coded blood pressure diary., Primary Outcome: Change in systolic and/or diastolic blood pressure 6 months after using the new colour-coded blood pressure diary.Secondary outcome: Adherence to blood pressure self-measurement (number of measurements/entries)., Methods/design: Randomised controlled study., Population: 138 adult patients in primary care with uncontrolled hypertension despite therapy. The control group uses a conventional blood pressure diary; the intervention group uses the new colour-coded blood pressure diary (green, yellow, red according a traffic light system). EXPECTED RESULTS/CONCLUSION: The visual separation and entries in three colour-coded areas reflecting risk (green: blood pressure in the target range 140/>90 mmHg, red: blood pressure in danger zone > 180 mmHg/>110 mmHg) lead to better self-monitoring compared with the conventional (non-colour-coded) blood pressure booklet. The colour-coded, visualised information supports improved perception (awareness and interpretation) of blood pressure and triggers correct behaviour, in the means of improved adherence to the recommended treatment as well as better communication between patients and doctors resulting in improved blood pressure control., Trial Registration: ClinicalTrials.gov ID NCT01013467.

In 16 female nonprofessional Ironman triathletes, body mass, percent body fat, and skeletal muscle mass were determined before and after an Ironman race in order to detect changes. Selected hematological and urinary variables as well as percent total body water were measured in order to quantify a change in hydration status. Body mass, skeletal muscle mass, percent body fat, and percent body water did not change (p > 0.05). Plasma volume increased significantly by 8.1 (13.7) % (p < 0.05). The significant increase in plasma volume, plasma urea concentration, and urinary specific gravity after the race was associated with a significant fall in hematocrit and plasma sodium concentration (p < 0.05). In contrast to studies of male Ironman triathletes, we could not detect a decrease in body mass in female Ironman triathletes. The statistically insignificant loss of 0.6 kg in body mass was smaller than reported in studies of male athletes.

Background: Utility indices are used in cost-effectiveness analyses as a measure of quality of life reflecting the patient's preference for a given health state on a scale anchored at 0 (corresponding to death) to 1 (perfect health). It is uncertain which utility instruments are most suitable for application in patients with the obstructive sleep apnea syndrome (OSA)., Objectives: To compare utility indices obtained in OSA patients by various instruments., Methods: In 66 untreated OSA patients (median Epworth score 12, apnea/hypopnea index, AHI, 57/h), five different utility instruments were employed. In 34 OSA patients, changes in utility after 4 months of continuous positive airway pressure (CPAP) were retrieved from published SF-36 data., Results: In 66 OSA patients, median (quartiles) utility indices were: standard gamble 0.97 (0.89; 0.99); time trade-off 0.94 (0.81; 0.99); EuroQol questionnaire (EQ-5D) 0.92 (0.83; 1.00); Euro-thermometer visual analog scale 0.80 (0.70; 0.90); SF-36 questionnaire (SF-6D) 0.75 (0.69; 0.85; p < 0.05 SF-6D and Euro-thermometer utility vs. other indices). Different utility indices were poorly correlated among each other and with AHI and Epworth scores. SF-6D utility after 4 months of CPAP had changed by 0.04 (0.02; 0.12, p = 0.026)., Conclusions: Utility indices measured by different instruments vary largely and some indices reflect the impaired quality of life in OSA poorly. Interpretation of cost-effectiveness analyses should account for the utility instrument used., (Copyright 2009 S. Karger AG, Basel.)

We investigated in 11 female ultra-runners during a 100 km ultra-run, the association between fluid intake and prevalence of exercise-associated hyponatremia in a cross-sectional study. Athletes drank ad libitum and recorded their fluid intake. They competed at 8.0 (1.0) km/h and finished within 762 (91) min. Fluid intake was 4.1 (1.3) L during the race, equal to 0.3 (0.1) L/h. Body mass decreased by 1.5 kg (p< 0.01); pre race body mass was related to speed in the race (r = -0.78, p< 0.05); and change (Delta) in body mass was not associated with speed in the race. Change in body mass was positively (r = 0.70; p< 0.05), and Delta urinary specific gravity negatively (r = -0.67; p< 0.05), correlated to Delta percent total body water. Changes in body mass were not related to fluid intake during the race. Fluid intake was not correlated to running speed and showed no association with either Delta percent total body water nor Delta [Na] in plasma. Fluid intake showed no relationship with both Delta haematocrit and Delta plasma volume. No exercise-associated hyponatremia occurred. Female ultra- runners consuming fluids ad libitum during the race experienced no fluid overload, and ad libitum drinking protects against exercise-associated hyponatremia. The reported higher incidence of exercise-associated hyponatremia in women is not really a gender effect but due to women being more prone to overdrink.

The aim of the present study was to assess health related characteristics and reasons for participation on the <>, second, to compare these variables with a representative Swiss Health Survey (SHS). Characteristics of the participants were collected cross-sectionally and afterwards compared with results of the SHS. Response rate was 74.6% (n = 206). Compared to the SHS population smoking rate and alcohol consumption were significantly lower and a doctor's visit within the last 12 months more frequent. Considerable differences in health related characteristics exist between our study and the SHS suggesting a self-selection of healthy people. Thus a potential health gain by this kind of medical prevention program is at least questionable.

Aims: Injection drug users are at high risk for chronic hepatitis C virus infection (CHC). Opioid maintenance treatment (OMT) offers a unique opportunity to screen for CHC. This study proposed the hypothesis that a general practitioner (GP) with special interest in addiction medicine can achieve CHC screening rates comparable to specialized centres and aimed to investigate determinants for a successful CHC case finding in a primary care setting., Design and Participants: Retrospective medical record analysis of 387 patients who received opioid maintenance therapy between 1 January 2002 and 31 May 2008 in a general practice in Zurich, Switzerland., Measurements: Successful CHC assessment was defined as performance of hepatitis C virus (HCV) serology with consecutive polymerase chain reaction-based RNA and genotype recordings. The association between screening success and patient characteristics was assessed using multiple logistic regression. findings: Median (interquartile range) age and duration of OMT of the 387 (268 males) patients was 38.5 (33.6-44.5) years and 34 (11.3-68.0) months, respectively. Fourteen patients (3.6%) denied HCV testing and informed consent about screening was missing in 13 patients (3.4%). In 327 of 360 patients (90.8%) with informed consent a successful CHC assessment has been performed. Screening for HCV antibodies was positive in 136 cases (41.6%) and in 86 of them (63.2%) a CHC was present. The duration of OMT was an independent determinant of a successful CHC assessment., Conclusions: In addicted patients a high CHC assessment rate in a primary care setting in Switzerland is feasible and opioid substitution provides an optimal framework.

Background: We initiated a randomized controlled clinical trial to assess the effect of sirolimus on disease progression in patients affected by autosomal dominant polycystic kidney disease (ADPKD). Here we report the preliminary safety results of the first 6 months of treatment., Method: A total of 25 patients were randomized to sirolimus 2 mg/day and 25 patients to no treatment except standard care. Treatment adherence was monitored electronically. At baseline and at Month 6, laboratory parameters were analysed and the urinary protein profile in 24-h urine collections was determined., Results: Both treatment groups were well balanced for age, sex and renal function. In 94.1 +/- 11.4% of the study days, patients in the sirolimus group were exposed to the drug when assuming a therapeutic efficacy duration of 30 h. At Month 6, the mean sirolimus dose and trough level were 1.28 +/- 0.71 mg/day and 3.8 +/- 1.9 microg/l, respectively. Glomerular (albumin, transferrin, IgG) and tubular (retinol-binding protein, alpha(1)-microglobulin) protein excretion remained unchanged. Glomerular filtration rate also did not change significantly. Haematological parameters were similar in both groups, except for a mild reduction of the mean corpuscular volume of erythrocytes in patients receiving sirolimus. Lipid levels were similar in both groups. Adverse events were transient and mild, and no grade 3 or 4 events occurred. The incidence of infections was similar in the sirolimus group (80%) and the standard group (88%). The most common gastrointestinal adverse events were mucositis (72% in the sirolimus group versus 16% in the standard group, P = 0.0001) and diarrhoea (36% in the sirolimus versus 20% in the standard group, P = 0.345)., Conclusion: Treatment of ADPKD patients with sirolimus with a dose of 1-2 mg/day is safe and does not cause proteinuria or impairment of GFR. Treatment adherence was excellent. (ClinicalTrials.gov number, NCT00346918.).

Objective: To assess the change in body composition and hydration status in cyclists in a mountain bike ultra-marathon., Design: Prospective observational field study., Setting: "Swiss Bike Masters" 2008 over 120 km with a total climb of 5000 m in altitude., Participants: Thirty-seven male mountain bikers., Interventions: None., Main Outcome Measures: Prerace and postrace, body mass, percent body fat, skeletal muscle mass, and selected hematologic and urinary parameters were measured to quantify changes in body mass and hydration status. Athletes reported their fluid intake during the race., Results: The athletes lost 1.4 kg in body mass (P < 0.001), equal to 1.9% body mass. Fat mass remained stable and skeletal muscle mass decreased by 0.4 kg (P < 0.05). Prerace fat mass was correlated to total race time (r = 0.37, P < 0.05). The cyclists drank 6.5 (1.8) L of fluids during the race corresponding to 0.7 (0.2) L per hour. A significant inverse relationship was seen between change in body mass and race time when controlled for change in skeletal mass and fluid intake during the race (P > 0.05). Plasma sodium decreased by 0.7% (P < 0.05), plasma volume increased by 1.4%, and plasma urea increased by 40% (P < 0.05). Urinary-specific gravity increased by 0.4% (P < 0.05). The decrease in skeletal muscle mass was associated with the increase in plasma urea (r = -0.34; P < 0.05). Fluid intake was associated with the change in urinary-specific gravity (r = -0.45; P < 0.01)., Conclusions: We conclude that these mountain bike ultra-marathoners suffered a significant decrease in body mass and skeletal muscle mass but no dehydration.

The effects of anthropometry and pre-race experience on race performance were investigated in male nonprofessional ultra-runners performing a multistage run of 1,200 km over 17 days. Of 24 athletes examined pre-race, 14 (58%) dropped out during the race due to overuse injuries of the lower limbs. During the race, body mass, thickness of the calf skin-fold, skeletal muscle mass, and percent body fat decreased significantly, while circumference of the upper arm, thickness of triceps, and abdominal skin-fold as well as Body Mass Index decreased significantly in the finishers. Neither anthropometry nor pre-race experience and training volume nor previously finished races were associated with the race time of the finishers. In future studies of ultra-runners, the influence of psychological (cognitive and emotional) predictors on race outcome should be investigated.

Objective: The objective of this study was to assess predictors of residual shunts after percutaneous patent foramen ovale (PFO) closure with Amplatzer PFO occluder (AGA Medical Corporation, Golden Valley, MN, USA)., Methods: All percutaneous PFO closures, using Amplatzer PFO occluder performed at a tertiary center between May 2002 and August 2006, were reviewed. Follow-up, including saline contrast transesophageal echocardiography, was performed in all patients 6 months after the intervention., Patients: A total of 135 procedures were performed. Mean age of the patients was 51 years. The indication for PFO closure was an ischemic cerebrovascular event in 92%, paradoxical systemic embolism in 4%, and a diving accident in 4%. Recurrent events prior to PFO closure were noted in 34%. A concomitant atrial septal aneurysm was present in 61%., Results: At 6 months follow-up, a residual shunt was detected in 26 patients (19%). Residual shunts were more common in patients with an atrial septal aneurysm (27 vs. 8%, P= .01) and in patients treated with a 35-mm compared with a 25-mm device (39 vs. 15%, P= .01). A concomitant atrial septal aneurysm remained independently associated with residual shunts when controlled for body mass index, gender, age, atrial dimensions, and presence of a Chiari network (odds ratio 4.1, 95% confidence intervals 1.1-15.0)., Conclusion: The presence of atrial septal aneurysms in patients undergoing percutaneous PFO closure with an Amplatzer PFO occluder significantly increases the rate of residual shunts at 6 months follow-up, even if 35-mm devices are used.

A 35-year old man with coldness, paleness, numbness, and pain at Dig. IV of the left hand comes to the consultation. The Allen test is pathological, the angiography shows an occlusion at the length of 4 cm of the Arteria ulnaris beginning at the Hamulus ossis hamati. After therapy with prostaglandin E1, aspirin 100 mg for 10 days and a smoking stop, the symptom disappeared at the re-consultation after 10 days.

Background: Low bone mineral density (BMD) is common in chronic lung diseases and associated with reduced quality of life. Little is known about BMD in pulmonary hypertension (PH)., Methods: Steroid-naïve patients with PH (n=34; 19 idiopathic, 15 chronic thromboembolic) had BMD measured by DXA at the time of diagnostic right heart catheterization. Exercise capacity, quality of life and various parameters related to PH severity and bone metabolism were also assessed. 24 patients with left heart failure (LHF) were similarly assessed as controls., Results: The prevalence of osteopenia was high both in PH (80%) and in controls with LHF (75%). Low BMD was associated with lean body mass, age, lower BMI, impaired exercise capacity and in PH with higher pulmonary vascular resistance. Serum parathyroid hormone (PTH) was elevated and considerably higher in PH than in LHF (above normal, in 55 vs 29%). Secondary hyperparathyroidism was not related to impaired renal function but possibly to low vitamin D status., Conclusions: Osteopenia is common in PH and in chronically ill patients with LHF. Osteopenia is associated with known risk factors but in PH also with disease severity. Preventive measures in an increasingly chronic ill PH population should be considered. Secondary hyperparathyroidism is highly prevalent in PH and might contribute to bone and possibly pulmonary vascular disease. Whether adequate vitamin D substitution could prevent low BMD in PH remains to be determined.

Bloch, Konrad E., Alexander J. Turk, Marco Maggiorini, Thomas Hess, Tobias Merz, Martina M. Bosch, Daniel Barthelmes, Urs Hefti, Jacqueline Pichler, Oliver Senn, and Otto D. Schoch. Effect of ascent protocol on acute mountain sickness and success at Muztagh Ata, 7546 m. High Alt. Med. Biol. 10:25-32, 2009.-Data on acclimatization during expedition-style climbing to > 5000 m are scant. We evaluated the hypothesis that minor differences in ascent protocol influence acute mountain sickness (AMS) symptoms and mountaineering success in climbers to Muztagh Ata (7546 m), Western China. We performed a randomized, controlled trial during a high altitude medical research expedition to Muztagh Ata. Thirty-four healthy mountaineers (mean age 45 yr, 7 women) were randomized to follow one of two protocols, ascending within 15 or 19 days to the summit of Muztagh Ata at 7546 m, respectively. The main outcome measures, AMS symptom scores and the number of proceeding climbers, were assessed daily. Mean +/- SD AMS-C scores of 16 climbers randomized to slow ascent were 0.06 +/- 0.18, 0.26 +/- 0.08, 0.41 +/- 0.45, 0.53 +/- 0.77 at camps I (5533 m), II (6265 m), III (6865 m), and the summit (7546 m), respectively. Corresponding values in 18 climbers randomized to fast ascent were significantly higher: 0.17 +/- 0.23, 0.43 +/- 0.75, 0.49 +/- 0.36, and 0.69 +/- 0.54 (p < 0.008, vs. slow ascent in regression analysis accounting for weather-related protocol deviation). Climbers randomized to slow ascent were able to ascend according to the protocol without AMS for significantly more days than climbers randomized to fast ascent (p = 0.04, Kaplan-Meier analysis). More climbers randomized to slow ascent were successful in reaching the highest camp at 6865 m without AMS (odds ratio 9.5; 95% confidence interval 1.02 to 89). In climbers ascending to very high altitudes, differences of a few days in acclimatization have a significant impact on symptom severity, the prevalence of AMS, and mountaineering success. ClinicalTrials.gov Identifier NCT00603122.

Kidney volume growth is considered the best surrogate marker predicting the decline of renal function in autosomal dominant polycystic kidney disease. To assess the therapeutic benefit of new drugs more rapidly, changes in kidney volume need to be determined over a short time interval. Here we measured renal volume changes by manual segmentation volumetry applied to magnetic resonance imaging scans obtained with an optimized T1-weighted acquisition protocol without gadolinium-based contrast agents. One hundred young patients with autosomal dominant polycystic kidney disease and preserved renal function had a significant increase in total kidney volume by 2.71+/-4.82% in 6 months. Volume measurements were highly reproducible and accurate, as indicated by correlation coefficients of 1.000 for intra-observer and 0.996 for inter-observer agreement, with acceptable within-subject standard deviations. The change in renal volume correlated with baseline total kidney volume in all age subgroups. Total kidney volume positively correlated with male gender, hypertension, albuminuria and a history of macrohematuria but negatively with creatinine clearance. Albuminuria was associated with accelerated volume progression. Our study shows that increases in kidney volume can be reliably measured over a 6 month period in early autosomal dominant polycystic kidney disease using unenhanced magnetic resonance imaging sequences.

Whether nasal congestion promotes obstructive sleep apnea is controversial. Therefore, we performed a randomized placebo-controlled cross-over trial on the effects of topical nasal decongestion in patients with obstructive sleep apnea syndrome (OSA) and nasal congestion. Twelve OSA patients with chronic nasal congestion (mean +/- SD age 49.1 +/- 11.1 years, apnea/hypopnea index 32.6 +/- 24.5/h) were treated with nasal xylometazoline or placebo for 1 week each. At the end of treatment periods, polysomnography including monitoring of nasal conductance by an unobtrusive technique, vigilance by the OSLER test, and symptom scores were assessed. Data from xylometazoline and placebo treatments were compared. Mean nocturnal nasal conductance on xylometazoline was significantly higher than on placebo (8.6 +/- 5.3 versus 6.3 +/- 5.8 mL s(-1)Pa(-1), P < 0.05) but the apnea/hypopnea index was similar (29.3 +/- 32.5/h versus 33.2 +/- 32.8/h, P = NS). However, 30-210 min after application of xylometazoline, at the time of the maximal pharmacologic effect, the apnea/hypopnea index was slightly reduced (27.3 +/- 30.5/h versus 33.2 +/- 33.9/h, P < 0.05). Xylometazoline did not alter sleep quality, sleep resistance time (33.6 +/- 8.8 versus 33.4 +/- 10.1 min, P = NS) and subjective sleepiness (Epworth score 10.5 +/- 3.8 versus 11.8 +/- 4.4, P = NS). The reduced apnea/hypopnea index during maximal nasal decongestion by xylometazoline suggests a pathophysiologic link but the efficacy of nasal decongestion was not sufficient to provide a clinically substantial improvement of OSA.

Background: Individuals with severe deficiency in serum alpha(1)-antitrypsin (AAT) concentrations are at high risk for developing chronic obstructive pulmonary disease (COPD), whereas those carrying the PI*MZ genotype are at slightly increased risk. Testing appropriate subgroups of the population for AAT deficiency (AATD) is therefore an important aspect of COPD prevention and timely treatment. We decided to perform an exhaustive investigation of SERPINA1 gene variants in individuals from the general population with a moderately reduced serum AAT concentration, because such information is currently unavailable., Methods: We determined the Z and S alleles of 1399 individuals enrolled in the Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) with serum AAT concentrations < or = 1.13 g/L and submitted 423 of these samples for complete exon 2-->5 sequencing., Results: We found that 900 of 1399 samples (64%), carried the normal PI*MM genotype, whereas 499 samples (36%) carried at least 1 SERPINA1 deficiency variant. In the subpopulations in which AAT concentrations ranged from > 1.03 to < or = 1.13 and from > 0.93 to < or = 1.03 g/L, individuals with the PI*MM genotype represented the majority (86.5% and 53.8%, respectively). The PI*MS genotype was predominant (54.9%) in the AAT range of 0.83 to 0.93 g/L, whereas PI*MZ represented 76.4% in the AAT range of > 0.73 to < or = 0.83 g/L., Conclusions: This analysis provided a detailed molecular definition of intermediate AATD, which would be helpful in the diagnostic setting.

Background: Severe alpha1-antitrypsin (AAT) deficiency associated with low AAT blood concentrations is an established genetic COPD risk factor. Less is known about the respiratory health impact of variation in AAT serum concentrations in the general population. We cross-sectionally investigated correlates of circulating AAT concentrations and its association with FEV1., Methods: In 5187 adults (2669 females) with high-sensitive c-reactive protein (CRP) levels < or = 10 mg/l from the population-based Swiss SAPALDIA cohort, blood was collected at the time of follow-up examination for measuring serum AAT and CRP., Results: Female gender, hormone intake, systolic blood pressure, age in men and in postmenopausal women, as well as active and passive smoking were positively, whereas alcohol intake and BMI inversely correlated with serum AAT levels, independent of CRP adjustment. We observed an inverse association of AAT with FEV1 in the total study population (p < 0.001), that disappeared after adjustment for CRP (p = 0.28). In addition, the AAT and FEV1 association was modified by gender, menopausal status in women, and smoking., Conclusion: The results of this population-based study reflect a complex interrelationship between tobacco exposure, gender related factors, circulating AAT, systemic inflammatory status and lung function.

Background: Cheyne-Stokes respiration (CSR) frequently occurs in patients with severe heart failure during sleep and may increase mortality. Daytime CSR supposedly poses an even greater risk, but its prevalence and prognostic importance remain elusive. Therefore, we investigated the circadian prevalence of CSR and its influence on survival in patients with heart failure., Methods: In 60 consecutive ambulatory patients (mean age+/-SE, 58.0+/-1.5 years; 6 women) with stable severe heart failure (left ventricular ejection fraction, 26+/-1%; New York Heart Association [NYHA] class, 2.6+/-0.1), the breathing pattern was unobtrusively monitored during 24 h of usual activities with a portable respiratory inductive plethysmograph., Results: During nights, 62% of patients had >or=15 periodic breathing cycles per hour; during days, the corresponding prevalence was 16%. CSR prevailed in 32+/-3% of the night and in 10+/-2% of the day, with peaks at 4:00 am, 2:00 pm, and 6:00 pm. Eighteen patients with CSR during >or=10% of the daytime lived shorter without heart transplantation than 42 patients with <10% of daytime CSR (p<0.05) during 836+/-27 days of follow-up. CSR during >or=10% of the daytime was an independent predictor of mortality (hazard ratio, 3.8; 95% confidence interval, 1.1 to 12.7; p<0.05) when controlling for age, sex, brain natriuretic peptide, left ventricular ejection fraction, and NYHA class., Conclusions: CSR occurs in 62% of patients with severe heart failure at night and in 16% during the day. Since daytime CSR is associated with reduced survival, solely performing sleep studies may not allow to adequately assess prognosis and tailor treatment in patients with severe heart failure.

Background: Understanding the environmental and genetic risk factors of accelerated lung function decline in the general population is a first step in a prevention strategy against the worldwide increasing respiratory pathology of chronic obstructive pulmonary disease (COPD). Deficiency in antioxidative and detoxifying Glutathione S-transferase (GST) gene has been associated with poorer lung function in children, smokers and patients with respiratory diseases. In the present study, we assessed whether low activity variants in GST genes are also associated with accelerated lung function decline in the general adult population., Methods: We examined with multiple regression analysis the association of polymorphisms in GSTM1, GSTT1 and GSTP1 genes with annual decline in FEV1, FVC, and FEF25-75 during 11 years of follow-up in 4686 subjects of the prospective SAPALDIA cohort representative of the Swiss general population. Effect modification by smoking, gender, bronchial hyperresponisveness and age was studied., Results: The associations of GST genotypes with FEV1, FVC, and FEF25-75 were comparable in direction, but most consistent for FEV1. GSTT1 homozygous gene deletion alone or in combination with GSTM1 homozygous gene deletion was associated with excess decline in FEV1 in men, but not women, irrespective of smoking status. The additional mean annual decline in FEV1 in men with GSTT1 and concurrent GSTM1 gene deletion was -8.3 ml/yr (95% confidence interval: -12.6 to -3.9) relative to men without these gene deletions. The GSTT1 effect on the FEV1 decline comparable to the observed difference in FEV1 decline between never and persistent smoking men. Effect modification by gender was statistically significant., Conclusion: Our results suggest that genetic GSTT1 deficiency is a prevalent and strong determinant of accelerated lung function decline in the male general population.

Purpose: Ascent to high altitude is associated with alterations in lung function. The mechanisms of these changes and whether they reflect early stages of high-altitude pulmonary edema (HAPE) has been debated. Therefore, we investigated the time course of pulmonary function in relation to hemodynamics and clinical symptoms in mountaineers ascending rapidly to high altitude., Methods: In 26 unacclimatized subjects we assessed spirometry, single-breath nitrogen washout, diffusing capacity (DLCO), and Doppler echocardiography in Zurich, 490 m, after climbing within 24 h to Monte Rosa, 4559 m, and after one night at 4559 m., Results: Mean (+/- SD) FVC fell from 103 +/- 9% predicted in Zurich to 96 +/- 10% predicted at 4559 m, FEV1/FVC increased from 0.82 +/- 0.06 to 0.84 +/- 0.08, and closing volume increased from 0.35 +/- 0.14 to 0.44 +/- 0.11 L above residual volume (P < 0.05, all changes). On the following day at 4559 m, closing volume remained elevated in 9 of 21 subjects who had a lower DLCO but similar pulmonary artery systolic pressures compared with the remaining 12 subjects (40 +/- 8 vs 43 +/- 7 mm Hg, P = NS). None of the subjects had overt HAPE., Conclusion: We conclude that changes in pulmonary function after rapid ascent to high altitude were consistent with interstitial fluid accumulation, but they were not related to changes in pulmonary artery pressure. Individual lung function responses to high-altitude exposure varied largely and did not predict subsequent HAPE.

Objectives: Treatment of obstructive sleep apnea syndrome (OSA) is often delayed because polysomnography, the recommended standard diagnostic test, is not readily available. We evaluated whether the diagnosis of sleep apnea could be inferred from the response to a treatment trial with nasal continuous positive airway pressure (CPAP)., Design: Study on diagnostic accuracy., Setting: Sleep-disorders clinic of a university hospital., Patients: Seventy-six sleepy snorers consecutively referred for sleep apnea evaluation., Interventions: CPAP treatment trial over 2 weeks as an initial diagnostic test in comparison with polysomnography, and treatment success over > or = 4 months., Measurements and Results: The main outcome was diagnostic accuracy of the CPAP trial. The trial result was positive if the patient had used CPAP for > 2 h per night and wished to continue therapy. This suggested sleep apnea. The trial was evaluated in terms of predicting an obstructive apnea/hypopnea index (AHI) > 10/h during polysomnography performed for validation, and in terms of identifying sleep apnea patients treated successfully over > or = 4 months. Forty-four of 76 patients (58%) had sleep apnea as confirmed by an AHI > 10/h. The CPAP trial predicted sleep apnea with a sensitivity of 80%, a specificity of 97%, and positive and negative predictive values of 97% and 78%, respectively. In 35 of 76 sleep apnea patients (46%) with positive CPAP trial results, polysomnography could have been avoided. These patients were prescribed long-term CPAP therapy. After 4 months, 33 of 35 patients (94%) still used CPAP, and their symptoms remained improved. These patients were identified by the CPAP trial with positive and negative predictive values of 92% and 100%, respectively., Conclusions: In a selected population, a CPAP trial may help to diagnose OSA, to identify patients who benefit from CPAP, and to reduce the need for polysomnography.

Chronic obstructive pulmonary disease (COPD) is a prevalent and preventable disease associated with high morbidity and mortality. Severe and intermediate alpha1-antitrypsin (AAT) deficiency (serum levels <11 and 11-20 micromol.L(-1), respectively) increase the risk of COPD in active smokers. However, little is known about the interaction of severe and intermediate AAT deficiency with modifiable COPD risk factors other than active smoking. In this study, a MEDLINE search was carried out for studies investigating the combined effect of environmental inhalants (occupation and passive smoking) and AAT deficiency in the lung. A total of 18 studies using established methods for the assessment of AAT deficiency were included in this review. Occupational exposures and passive smoking affected lung function decline or prevalence of respiratory symptoms in four out of five studies investigating subjects with severe AAT deficiency, and in eight out of 13 studies with a focus on intermediate AAT deficiency. While study designs mostly prohibited formal assessment of effect modification, an interaction between intermediate AAT deficiency and passive smoking was identified in two studies with children. Additional study limitations included small sample size, poor adjustment for confounding and misclassification of environmental exposure as well as AAT activity. In conclusion, population-based epidemiological studies with associated biobanks are needed to identify gene-environment interactions and population subgroups susceptible to alpha1-antitrypsin deficiency.

Objectives: To evaluate the accuracy of a portable respiratory inductive plethysmograph that allows the monitoring of ventilation without airway instrumentation during exercise in unrestrained subjects., Design: Validation of a novel technique by comparison to a reference standard., Participants: Thirty-one subjects, including 20 healthy volunteers, 6 patients with COPD, and 5 patients with congestive heart failure., Interventions: Participants performed progressive treadmill exercise to exhaustion. Ventilation was monitored by a novel battery-powered, miniaturized, and calibrated respiratory inductive plethysmograph. Inductance sensors encircling the rib cage and abdomen were built into an elastic body garment. A pneumotachograph attached to a mouthpiece served as the reference method., Measurements and Results: Breath-by-breath comparisons between the inductance plethysmograph and pneumotachograph over the course of progressive exercise to exhaustion revealed no significant bias of respiratory cycle time, tidal volume (Vt), and minute ventilation. The corresponding limits of agreement (bias +/- 2 SDs) were +/- 6%, +/-17%, and +/- 17%, respectively, for 2,480 breaths. Comparisons of mean values averaged over 20 breaths revealed improved limits of agreement of +/- 1% for cycle time, and +/- 7% for tidal volume and minute ventilation, respectively, for 124 comparisons. Agreement between methods was similar for patients and healthy subjects. Among the patients, maximal minute ventilation was lower, and breathing was more rapid and shallow than in healthy subjects. Obstructive lung disease was associated with a shorter duty cycle than heart failure., Conclusions: The portable respiratory inductive plethysmograph accurately estimates ventilation during treadmill exercise, and identifies differences in breathing patterns among patients with pulmonary or cardiac diseases and healthy subjects. This unobtrusive monitoring technique is promising for application in ambulatory patients.

Objectives: The purpose of the study was to evaluate a novel, combined sensor for transcutaneous monitoring of arterial oxygen saturation and carbon dioxide tension., Design: The new monitoring technique was compared to established reference methods., Setting: ICU and sleep laboratory of a university hospital., Patients: Eighteen critically ill adult patients with acute respiratory failure or heart failure, and 12 patients with sleep apnea (mean [+/- SD] apnea/hypopnea index, 43 +/- 24 events per hour)., Measurements: Continuous measurements were performed over several hours by the novel heated (temperature, 42 degrees C) earlobe sensor (TOSCA; Linde Medical Sensors; Basel, Switzerland), incorporating electrochemical and optical elements for carbon dioxide measurement (PtcCO2) and pulse oximetry (SpO2), respectively. The data were compared to the results of repeated arterial blood gas analyses in critically ill patients and to simultaneous nocturnal pulse oximetry performed with different devices with earlobe or finger sensors in sleep apnea patients., Results: In critically ill patients, the mean difference and limits of agreement (bias +/- 2 SDs) of transcutaneous PtcCO2 vs arterial PaCO2 were 3 +/- 7 mm Hg; the corresponding values for changes in PtcCO2 vs PaCO2 were 1 +/- 6 mm Hg. The bias +/- 2 SDs for pulse oximetric SpO2 vs arterial oxygen saturation (SaO2) were 1 +/- 4%. In sleep apnea patients, the combined earlobe sensor identified more transient oxygen desaturations, and the rate of change in oxygen saturation during events was greater compared to those with other tested pulse oximeters, indicating a faster response., Conclusions: Due to its ability to accurately assess both ventilation and oxygenation by a single transcutaneous sensor, the described noninvasive monitoring technique is a valuable tool for respiratory monitoring with potential applications in critical care and sleep medicine.

Study Objectives: Transtracheal insufflation of oxygen-enriched air at a high flow rate has been proposed to support ventilation. The purpose of this study was to investigate the physiologic effects of high-flow insufflation unobtrusively with a respiratory inductive plethysmograph in patients with chronic respiratory failure. Using a respiratory inductive plethysmograph also permitted monitoring of end-expiratory lung volume, and respiratory variables could be quantified independently of the tracheal bias flow., Design: Prospective randomized comparison of low-flow vs high-flow transtracheal insufflation., Setting: Pulmonary division of a tertiary teaching hospital., Patients: Fourteen spontaneously breathing outpatients with chronic hypoxemic respiratory failure carrying a transtracheal catheter for long-term oxygen therapy., Interventions and Measurements: Oxygen-enriched air (fraction of inspired oxygen, 0.37) at 15 L/min and oxygen at 1.5 L/min were transtracheally administered for 1 h each. The breathing pattern and the end-expiratory lung volume were monitored by inductive plethysmography along with pulse oximetry and transcutaneous PCO2. Arterial blood gases were also analyzed at the end of the hour of both low-flow and high-flow insufflation., Results: High-flow insufflation decreased the mean (+/- SEM) minute ventilation (Ve) by 20% from 8.37 +/- 0.49 to 6.66 +/- 0.57 L/min, the mean respiratory rate from 19.2 +/- 0.9 to 15.7 +/- 1.0 breaths/min, while mean expiratory time increased from 2.0 +/- 0.1 to 2.8 +/- 0.2 s, and end-expiratory lung volume decreased by 0.55 +/- 0.15 L compared to low-flow oxygen insufflation (p < 0.05 for all comparisons). Mean arterial and transcutaneous PCO2 decreased from 45 +/- 1 to 43 +/- 1 mm Hg and from 54 +/- 2 to 53 +/- 2 mm Hg, respectively (p < 0.05 in both instances), while arterial PaO2 and oxygen saturation did not change., Conclusions: High-flow transtracheal insufflation of oxygen-enriched air assists ventilation by reducing Ve without compromising gas exchange and by reducing end-expiratory lung volume, possibly through the reversal of dynamic hyperinflation.

The purpose of the study was to investigate determinants of acute mountain sickness after rapid ascent to high altitude. A total of 21 climbers were studied ascending from <1,200 m to Capanna Regina Margherita, a hut in the Alps at 4,559 m, within <24 h. During their overnight stay at 4,559 m, breathing patterns and ventilation were recorded by calibrated respiratory inductive plethysmography along with pulse oximetry. In the following morning, acute mountain sickness was assessed. Altogether, 11 mountaineers developed pronounced symptoms of acute mountain sickness (Lake Louise score > or =5) and 10 did not (controls). Compared to controls, subjects with acute mountain sickness had lower nocturnal oxygen saturation (mean+/-SD 59+/-13% versus 73+/-6%), higher minute ventilation (7.94+/-2.35 versus 6.06+/-1.34 L x min(-1)), and greater mean inspiratory flow, a measure of respiratory centre drive (0.29+/-0.09 versus 0.22+/-0.05 L x s(-1)). Periodic respiration was prevalent but not significantly different among the two groups (apnoea/hypopnea index 60.1+/-34.6 versus 47.1+/-42.6 events per h). The data suggest that pronounced nocturnal hypoxemia, which was not related to hypoventilation, may have promoted acute mountain sickness. Periodic breathing seems not to play a predominant role in the pathogenesis of acute mountain sickness.

We evaluated the efficacy of two different continuous positive airway pressure devices with automatic mask pressure adjustment (autoCPAP) in comparison with fixed CPAP in treating obstructive sleep apnea syndrome in 29 patients. The mean (+/- SE) apnea-hypopnea index was 46 +/- 4 per hour and the Epworth score was 14.2 +/- 0.7. Patients were treated over three consecutive 1-month periods with three regimens in random order: an autoCPAP device responding to apnea-hypopnea and snoring, another autoCPAP device responding to snoring and changes in flow contour, and fixed CPAP at the 90th pressure percentile titrated by autoCPAP over 2 weeks. Allowed pressure in the autoCPAP mode was 4 to 15 cm H2O. At the end of each treatment period, symptoms, quality of life, vigilance, and nocturnal breathing disturbances were evaluated. All three treatment modalities improved symptoms, quality-of-life domains, and apnea-hypopnea index significantly and to a similar degree. Mean (+/- SE) maintenance-of-wakefulness time increased by 4.5 +/- 1.8, 6.0 +/- 1.5, and 6.1 +/- 1.4 minutes with DeVilbiss AutoAdjust LT, AutoSet T, and fixed-pressure CPAP, respectively (p<0.001 vs. baseline, p=not significant for comparisons among the three modalities). We conclude that both autoCPAP devices were equally effective as fixed-pressure CPAP in improving major outcomes during short-term therapy of sleep apnea.