A sedentary lifestyle has been shown to have negative effects on morbidity and mortality. In contrast, a large number of prospective cohort studies on the effects of regular physical activity demonstrated positive effects. Therefore, physical training is today an essential part of prevention and therapy in internal medicine. This review is based on literature research in meta-analysis and review papers. Regular physical exercise or training is a significant and evidence-based part of prevention and therapy of diseases such as heart, cardiovascular and lung diseases, diabetes mellitus, renal disease and cancer. Evidence of training effects is mostly high grade. Physical activity or exercise training is indicated in many diseases as medicine--similar as a drug. It is applied after acute treatment as a component of the standard drug therapy. There is a non-linear dose-response effect, psychological aspects and some side-effects need to be considered.In conclusion, physical exercise acts as a highly efficient drug, and should be used in many diseases. Training recommendations refer to the kind, the duration, the intensity, the frequency and the increase of training.

Dear Editor,We read Katherine Margaret Bergs and co-authors’review on non-invasive ventilation (NIV) with greatinterest [1]. The authors focus on NIV in a hospital setting.As an amendment to this review, we would like to drawattention to the fact that NIV has successfully crossed theborder to prehospital use in the past few years. NIV isincreasingly being used for the treatment of severe respi-ratory distress in prehospital settings [2]. This techniquehas even been used successfully in medical emergencies inreally remote places at high altitude in mountain medicine[3, 4]. We think the prehospital use of NIV deservesgrowing interest.

video conferencing system could help address language barriers in the treatment of refugees 859

Drug Prescribing for Patients with Chronic Kidney Disease in General Practice: a Cross-Sectional Study

Fahrner, Anton; Rennhofer, Alexandra; Kalmann, Nicola; Röggla, Georg Author Information

We read Grocott and Johannson's paper on ketamine at high altitude [1] with great interest, as participating in mountain rescue in the Alps quite often requires emergency anaesthesia or analgesia-sedation. The authors report that ketamine at a dose of one quarter to one half of the recommended intravenous dose resulted in sustained apnoea. We would like to draw attention to the fact that other sedating substances have a similar effect. Long-acting and short-acting benzodiazepines impair respiration at high altitude at doses which have no effect on respiration at low altitude [2, 3]. Similar results were found after 50 g alcohol at moderate altitude [4]. These reports provide evidence for impaired function of peripheral chemoreceptors in the carotid bodies under the influence of sedating substances at altitude. From Grocott & Johannsen's report, an impairment of the central chemoreceptors in the medulla seems plausible. To summarise, we agree with the authors' conclusion that anaesthetic agents should be used with extreme caution at high altitude.

Spider Myths and a Case of a Bite by a Yellow Sac SpiderTo the Editor: We enjoyed reading Frithsen's 1 report on the paradox of the number of reported spider bites exceeding the number of Loxosceles spiders in South Carolina.As an amendment, we would like to draw attention to spider myths in Central Europe.A 31-year-old male patient was admitted to our hospital after a bite from a spider that had found shelter in his slipper.His toe showed local edema and erythema, and he reported severe pain comparable to a hornet sting.No generalized symptoms occurred.The patient caught the mediumsized, long-legged, golden and straw-colored spider with pedipalps and multiple dorsal eyes, and brought the living spider with him in a glass.The spider was identified as a yellow sac spider (genus Cheiracanthium, Figure 1).According to review articles, medical textbooks, and medical journal correspondences, yellow sac spiders are considered to be the only potentially dangerous spiders in Central Europe causing dermonecrosis. 2,3This is not supported by a case series of 20 verified bites by Cheiracanthium spiders from the United States and Australia (none with necrosis), nor by a review of the international literature on 39 verified Cheiracanthium bites (which found only one case of mild necrosis in the European species, Cheiracanthium punctorium, nearly 50 years ago). 3,4No verified case of a Cheiracanthium bite in Central Europe has been reported since then in medical literature, but reports of spider sightings have dominated local media in Austria for a year, triggering hundreds of calls to the Vienna poison hotline and prompting the government to issue a plea for calm. 5Spider mythology and spider phobia are clearly phenomena not only of the past. 5Our patient recovered completely within a few days after symptomatic therapy.

All forms of management in medicine involve weighing up: (1) the potential benefits or efficacy of treatment (2) the potential side effects of treatment and (3) the costs or cost-effectiveness of treatment. It is well established that the randomised control trial (RCT) is the gold standard for determining treatment efficacy and it is obvious why RCTs should be subjected to ethical screening. However, RCTs are not the best methodology for every study, particularly as they are so expensive to conduct. Observational studies are particularly valuable for studying side effects and cost-effectiveness of treatment and still have value (albeit of a lesser quality) in assessing treatment efficacy. Most observational clinical studies are not ethically sensitive and, if it is agreed that therefore ethics committee screening is therefore not required for these studies, they can be completed at low cost with minimal need for industry sponsorship. Universal ethics committee requirements for all observational clinical papers would act as an unnecessary barrier to obstruct the publication of useful studies. Paradoxically, the need in many cases to seek industry funding to cover the extra expense for such a requirement would probably make observational studies less ethically sound.