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Biomedical subjects

B Krahenbuhl

Publications and source records attributed to B Krahenbuhl.

At least 19 recordsLinked to original sources
PubMed1993

[Prospective evaluation of specialized consultations in a geriatric university hospital].

In a prospective study carried out over a 3 month period we analysed the views of consultants and residents taking part in 771 consultations to patients admitted to the Geriatric University Hospital of Geneva with the help of visual analogue scales. 27 medical subspecialties were involved. Both consultants and residents agreed that most of the consultations were useful for the elderly patient and for postgraduate teaching and learning. But the residents thought that consultations were more important for the patients' welfare than for the residents' education. Residents showed a tendency to underestimate crucial aspects of geriatric medicine (in particular the autonomy of the elderly patient) in preference to more "classical" medical preoccupations (diagnosis and treatment). Consultants were aware of the specificity of geriatric pathology but restricted their teaching during the intervention to what was requested by the resident.

Aged↗
PubMed1992

Transluminal angioplasty of the aorta, renal and mesenteric arteries in Takayasu arteritis: report of two cases.

Two patients with Takayasu arteritis presented with either severe renovascular hypertension or profound weight loss due to intestinal angina. The leading clinical signs were cured by successful percutaneous transluminal angioplasty (PTA) of the abdominal aorta and renal arteries in one patient and of the superior mesenteric artery and coeliac trunk in the second. These results and a literature review of the topic suggest that PTA should be the first therapeutic approach in symptomatic arterial stenoses due to TA in the inactive stage of the disease.

Adult↗
PubMed1989

Measurement of plasma D-dimer for diagnosis of deep venous thrombosis.

Venography was performed on fifty-six patients suspected of having deep venous thrombosis (DVT) of the legs. The accuracy of the D-dimer measurement in plasma using two latex tests and an enzyme-linked immunosorbent assay (ELISA) was compared with that of usual determination of total fibrin(ogen) degradation products (FDPs) in serum with respect to the presence of DVT. The three D-dimer tests were clearly superior to the FDP assay, but only the ELISA could accurately rule out the diagnosis of DVT with a predictive value of 100% when plasma D-dimer level was less than 200 micrograms/L. However, this test cannot be used for positive diagnosis (false positive rate of 69%). Thus, plasma D-dimer measurement with ELISA allows identification of patients in whom further investigation by means of more specific tests (venography or plethysmography) is indicated in order to establish the diagnosis of DVT. In contrast to this, sensitivity of the two latex tests studied was low (60 and 76%, respectively), which makes them unsuitable for emergency screening. In addition, the potential of D-dimer dosage for diagnosis of DVT in hospitalized patients is hampered by the presence of associated conditions that are responsible for elevated plasma levels in most cases.

Adult↗
PubMed1988

Nicotine induced haemodynamic changes during cigarette smoking and nicotine gum chewing: a placebo controlled study in young healthy volunteers.

Because cigarette smoking is a definite risk for the development of cardiovascular disease and nicotine induced vasoconstriction may be a possible pathogenetic factor the haemodynamic effects of smoking cigarettes with high or low nicotine content were compared with those induced by chewing nicotine gum in a placebo controlled, crossover study in six healthy volunteers. The three stimuli induced similar increases in heart rate (about 20%) and systolic blood pressure (about 7%) and a decrease in digital blood flow. Although the mean haemodynamic changes parallelled the mean plasma nicotine concentration increases, no correlation was found between them when the individual values were considered. It is concluded that the nicotine induced haemodynamic changes probably occur as a result of the (local) release of vasoactive mediators such as adrenaline or noradrenaline after a threshold plasma nicotine concentration has been reached. Such a threshold may explain the large interindividual variability in susceptibility to smoking induced cardiovascular diseases.

Adult↗
PubMed1988

[Subclavian and axillary arteritis in Horton's disease and rhizomelic pseudopolyarthritis. 10 cases].

Ten patients aged from 60 to 73 years presenting with Horton's disease or polymyalgia rheumatica had arteritis of the upper limbs. Asymptomatic abolition of pulse in the upper limbs (1 case) or claudication at rest or exercise (9 cases) and/or Raynaud's phenomenon (5 cases) preceded (4 cases) or accompanied (1 case) the discovery of giant cell arteritis, or complicated the reduction or discontinuation of corticosteroid therapy. Diagnosis rested on the regular association of an inflammatory syndrome with multiple arterial tapered stenoses and/or arterial thrombosis in the post-vertebral subclavian, axillary or brachial arteries and, chiefly, on the demonstration (in 7 cases) of a giant cell granuloma at biopsy of the temporal artery. Corticosteroid therapy (1 mg/kg/24 h in 8 cases and 0.5 mg/kg/24 h in 2 cases) initially combined with anticoagulants in 4 cases resulted in rapid regression of ischaemic and systemic signs in all patients, thus avoiding surgical revascularization of the upper limbs.

Aged↗
PubMed1987

[Involvement of arterial trunks of the upper limbs in giant cell arteritis. Apropos of 7 cases].

On 91 patients with temporal arteritis (TA) and/or polymyalgia rheumatica (PMR), we observed 7 females aged 62 to 73 years with upper extremities ischemia. Arm claudication and/or Raynaud's phenomenon were the initial manifestations of the disease in 2 cases, or appeared simultaneously with other symptoms in 2 cases, or complicated decreasing corticosteroid therapy in 3 cases. A temporal artery biopsy was performed on 6 patients with, in all of them, typical giant cell granulomatous arteritis pathology findings. Angiograms showed, in all cases, multiple bilateral smooth stenosis and/or obliterations of post vertebral subclavian arteries and/or axillary arteries. Symptoms always improved on corticosteroid treatment and no patient needed reconstructive surgery. In conclusion, large arteries involvement, which can occur in TA and/or PMR, affect in our experience most commonly the subclavian and axillary arteries, with female predominance as found in Takayasu's arteries. These disorders should be considered in cases of occlusive disease of the arms in elderly women and the response to steroids is usually adequate to eliminate the need for early surgical intervention. Early recognition of asymptomatic large artery involvement by Doppler evaluation, in all TA and/or PMR patients, and transient anticoagulant therapy might prevent vessels occlusions.

Aged↗
PubMed1986

[Determination of the amputation level by transcutaneous PO2 measurement and distal arterial systolic pressure].

Transcutaneous oxygen partial pressure measurement (TcPO2) using a polarographic probe heating the skin at 44 degrees C provides informations about the capacity of blood to supply skin with oxygen. As oxygen is necessary for tissue survival, TcPO2 could constitute an adequate parameter for the determination of an amputation level. Among 67 amputations performed between 1983 and, 1984, we included in this study 34 patients (35 amputations), in whom TcPO2 was preoperatively measured (24 males, 10 females, mean age 67 years, range 19-86 years). Twenty two were diabetics. Twenty patients suffered from severe ischemia (stage Fontaine 4); 13 patients suffered from chronic diabetic lesions or/and osteomyelitis and two patients suffered from frostbite. The follow-up period lasted until operative wound was healed or a more proximal amputation was undertaken (mean 2.5 months, range 15 days to 10 months). Five operative wounds did not heal, so that a more proximal amputation was undertaken. TcPO2 was below 20 mm Hg in 3 of these 5 patients. TcPO2 was above 20 mm Hg in 24 among 30 patients in whom operative wound healed. When TcPO2 is above 20 mm Hg, the probability of operative wound healing is 92%. When TcPO2 is below 20 mm Hg, the risk of a more proximal amputation is 33%. Distal systolic blood pressure has no predictive value. It is concluded than when TcPO2 is above 20 mm Hg, the probability of healing of operative wound is clinically acceptable. When TcPO2 is below 20 mm Hg, 1 of 3 patients will be reamputated at a more proximal level, but healing does occur in 66% of patients.

Adult↗
PubMed1985

[The venous-arteriolar reflex].

Cutaneous blood flow (Xenon clearance) and transcutaneous pO2 were simultaneously measured on the foot of normal subjects and patients suffering from severe arterial insufficiency of the lower limbs. When the subject is sitting, cutaneous blood flow decreases, as well in normal subjects than in most patients with arterial insufficiency. However, tc pO2 increases in sitting position, probably because local vasoregulation is abolished by local heating. Increase in tc pO2 in sitting position is higher in patients in whom tc pO2 was very low in lying position. In normal subjects, there is a positive correlation between cutaneous blood flow and tc pO2. This correlation do not exist in patients suffering from severe ischemia; it is likely that Xenon clearance actually measures total cutaneous blood flow, while tc pO2 constitutes an index of nutritional circulation. It is also possible that Xenon clearance is modified by changes in partition coefficient in ischemia areas.

Arterial Occlusive Diseases↗
PubMed1984

Pedal blood flow and transcutaneous PO2 in normal subjects and in patients suffering from severe arterial occlusive disease.

Pedal transcutaneous partial pressure of oxygen (tcPO2) has been measured by polarographic method, heating the skin at 44 degrees C. In 50 normal subjects, mean tcPO2 measured 54.5 +/- 7 mmHg. Among 43 patients suffering from chronic ischaemia of lower limbs, mean tcPO2 measured 40.8 +/- 8 mmHg in patients with from claudication and 16.1 +/- 15 mmHg in patients suffering from rest pain and/or gangrene. The variability of repeated tcPO2 measurements, expressed as 1 SD of the mean, was 4.5 mmHg in normal subjects and 2.9 mmHg in patients. The relationships between pedal subcutaneous blood flow measured in xenon-133 clearance method and pedal tcPO2 have been studied in nine normal subjects and in five patients suffering from severe chronic ischaemia of lower limbs (rest pain and/or gangrene). There was a positive correlation between blood flow and tcPO2 in normal subjects (r = 0.77, P less than 0.001). In patients suffering from severe ischaemia, there was no correlation between these two parameters, but measured blood flow was sometimes very high in areas where tcPO2 was low. It is likely that 133Xe clearance method considerably overestimates local blood flow in these patients, because there is considerably less fat in subcutaneous tissue of chronic severely ischaemic areas. Thus, partition coefficient should be determined in each patient. However, tcPO2 may constitute an index of nutritional circulation, while 133Xe clearance actually measures total subcutaneous blood flow.

Adolescent↗
PubMed1984

Peripheral venous pulsatility detected by Doppler method for diagnosis of right heart failure.

This study shows that peripheral venous flow detected by Doppler ultrasound becomes synchronously pulsatile with heart beats as soon as central venous pressure (CVP) is above 7 mm Hg. CVP was above 7 mm Hg in 13 among 46 patients. Clinical signs of right heart failure were detectable in only 7 of these 13 patients (sensitivity 54%), whereas peripheral venous flow was pulsatile in 12 of them (sensitivity 92%). In 4 patients with a normal CVP, peripheral venous flow was also pulsatile; all of them suffered from valvular heart disease with left ventricle ejection fraction below 60% in 3 of them. The detection of a pulsative peripheral venous blood flow constitutes an early sign of right heart failure, more sensitive than clinical evaluation, and probably even more than CVP.

Central Venous Pressure↗