Exercise performance of hemodialysis patients during short-term and prolonged exposure to altitude.

The work capacity of patients on maintenance hemodialysis is impaired even at normal inspiratory oxygen pressure. A further restriction can be expected when these patients are exposed to hypoxia at altitude, since most of the usual compensatory mechanisms required to adjust to this environment are impaired or even missing. We tested the tolerance of hemodialysis patients to hypoxia and measured work capacity, hematological, and cardiovascular parameters at rest and during incremental bicycle ergometry during 3-hour exposure to altitudes of 2,000 m and 3,000 m, and during 2 weeks of exposure to an altitude of 2,000 m and compared these data with prealtitude values or with data evaluated in a control group, respectively. In control tests the patients reached work loads at exercise termination of about 66% of age and sex-matched healthy controls, the reduction correlated well with the degree of anemia. During short-term altitude exposure to 2,000 m peak work performance remained unchanged in comparison to prealtitude tests, whereas at 3,000 m it was reduced by about 12%. During the 2-week stay at 2,000 m peak work loads increased significantly by 17% accompanied by an increase in peak oxygen uptake (+15%), blood lactate, heart rates (+10 min-1), and systolic blood pressure (+20 mmHg), whereas the diastolic pressure was comparable to prealtitude values. In another group of hemodialysis patients studied at low altitude under similar experimental conditions none of these parameters was changed. Our data show that during acute exposure to altitudes up to 2,000 m maximal work of hemodialysis patients is not reduced, but is restricted at altitudes higher than that.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cardiologic diagnosis in general practice]. / Kardiologische Diagnostik in der Praxis.

The cornerstone of cardiological diagnostic evaluation is still the patient's history and physical examination. In the doctor's office non invasive diagnostic procedures are the major means of obtaining the diagnosis necessary for treatment. Aside from ECG and exercise ECG Holter monitoring and echocardiography are the most valuable methods. New possibilities are offered by ST-segment evaluation in Holter monitoring and the combination of doppler and ultrasound techniques, the latter often making invasive studies superfluous. There are special indications for radionuclide imaging. Phonocardiography has been largely replaced by echocardiography.

[Nephrology for general practice--significance of the laboratory]. / Nephrologie für die Praxis--die Bedeutung des Labors.

When anamnesis and clinical findings are suspicious of renal disease, laboratory examinations have to be performed, which are also necessary in evaluating the course of the disease. The first steps are urinalysis, blood sedimentation rate, red and white blood cell count, creatinine, supplemented by urea, electrolytes, acid-base-status, serum-protein with electrophoresis, cholesterol, triglycerides. For special questions beyond this immunological examinations are necessary (i.g. antibodies to basal-membrane, immunocomplexes). Among the renal function tests the concentration test is of some value. The endogenous clearance of creatinine can be determined with sufficient accuracy from the serum creatinine concentration alone by a formula.

[A new antihypertensive agent used in a clinical setting]. / Ein neues Antihypertensivum, angewendet unter Praxisbedingungen.

In a multicenter study with 54 patients with essential and renal hypertension (WHO I to III) the antihypertensive efficacy and safety of guanfacine were evaluated against clonidine in a double blind cross-over design. The treatment period for each drug lasted five weeks. There was a two week's wash-out period with placebo between the application of the respective preparations. During the first two weeks of treatment a daily dose of 3.3 mg guanfacine and 0.5 mg clonidine led to a significant fall in blood pressure from 187/103/138 mm Hg (s/d/m) to 152/86/113 mm Hg and from 186/101/136 mm Hg to 156/91/118 mm Hg respectively. During the following time blood pressure and dosage remained almost unchanged. In contrast to clonidine the guanfacine group showed a smaller fall in blood pressure in upright than in supine position. Both drugs showed a decrease of heart rate by approximately 4 beats per minute. Side effects such as dry mouth and tiredness were more pronounced under treatment with clonidine than with guanfacine (p less than or equal to 0,08). Guanfacine is well tolerated as a potential antihypertensive drug with relatively few side effects of mild nature.