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Biomedical subjects

B Fagrell

Publications and source records attributed to B Fagrell.

At least 91 records · Page 5Linked to original sources
PubMed1984

Antithrombin III in patients with acute deep vein thrombosis during heparin treatment (subcutaneous and intravenous) and during and after treatment with oral coumarins.

The antithrombin III (AT-III) concentration was studied in 98 patients with symptomatic acute deep-vein thrombosis. All patients were initially treated with heparin randomly by subcutaneous injections or by continuous infusions. Then the patients were treated with coumarins during one or six months. The AT-III concentration was estimated daily during heparin treatment and repeatedly during the first year. The mean AT-III concentration decreased progressively 25% during 5 days of heparin treatment regardless of whether heparin was given intravenously or subcutaneously. The mean AT-III concentration during coumarin treatment was higher than after coumarin treatment. Eleven patients developed recurrent thromboembolic episodes during the follow-up period. The mean AT-III concentration in these patients was not lower than in the patients without recurrences.

Adult↗
PubMed1984

Skin capillary abnormalities in patients with Raynaud's phenomenon.

The digital skin microcirculation was studied by vital capillaroscopy in 32 consecutive patients with Raynaud's phenomenon. A detailed classification (stages 0-6) of the capillary abnormalities based upon observations of the capillaries in many different sites of the fingers was used. Associated diseases were searched for by an extensive clinical and immunological investigation. Seventeen (53%) of the patients had distinct structural changes in the capillaries but only 6 of them showed a restricted total digital circulation. Fifteen (88%) of these 17 patients displayed an underlying disease and/or immunological abnormalities. The corresponding figure for patients with mild or no capillary changes was 40% (p less than 0.01). Thus, the presence of marked (greater than or equal to stage 3) skin capillary abnormalities seems to be a good indicator of an associated systemic disease. The majority of patients in this category improved their capillary status during successful treatment of the underlying disease. We conclude that the form of capillaroscopy used in this study is a sensitive method for evaluating disturbances of the skin microcirculation in patients with Raynaud's phenomenon. The method may also contribute to the clinical evaluation of patients with this syndrome by identifying those with an underlying systemic disease.

Adolescent↗
PubMed1984

Vital capillary microscopy for assessment of skin viability and microangiopathy in patients with diabetes mellitus.

Vital capillaroscopy is useful in clinical practice to study the nutritional skin capillaries and for evaluating the risk for skin necrosis in patients with peripheral ischemia. This method is especially valuable in the investigation of patients with diabetes mellitus (DM) in whom the arterial inflow to the foot can be almost normal despite the development of skin necrosis due to impaired nutritional circulation. When the capillary morphology in the feet of asymptomatic diabetic patients was investigated, significantly more areas with widely dilated capillaries were present both in insulin and tablet treated patients compared to controls. By using dynamic capillaroscopy the flow velocity in skin capillaries can be determined under physiological conditions. Fourteen diabetic patients were compared with matched non-diabetic controls. The capillary blood flow during resting conditions was equal in the two groups but a delay in the postocclusive reactive hyperemia response was seen in the diabetic patients. The reason for this may be a vasomotor dysfunction in the precapillary arterioles or an increased blood viscosity. Further studies using dynamic vital capillaroscopy may improve our knowledge of the complex mechanisms responsible for diabetic microangiopathy.

Blood Flow Velocity↗
PubMed1984

A simplified evaluation of vital capillary microscopy for predicting skin viability in patients with severe arterial insufficiency.

In the present study the predictive value of a simplified VCM (Vital Capillary Microscopy) classification in assessing the development of skin necrosis was investigated in 69 patients with severe peripheral arterial obliterative disease (AOD) of the leg. The arterial circulation of the foot was evaluated by systolic blood pressure (SBPt). The structure and blood filling of the skin capillaries of all toes and forefeet were evaluated by an ordinary stereo-microscope at a magnification of 10 to 40 times. A three stage classification was used for evaluating the nutritive skin capillaries: Stage A, B and C. The individual patient was classified according to the worst stage found in the foot. The predictive value for the SBPt measurements with regard to the development of skin necrosis was for the best group (21-30 mmHg) 6%, for the middle group (11-20 mmHg) 58% and for the worst group (0-10 mmHg) 56%. The predictive values for the VCM Stages A, B and C were 5, 16 and 93% respectively. The sensitivity with the borderline between Stage A and B + C was 97% and the specificity 53%. With the borderline between stage A + B and C the sensitivity and specificity became 87% and 95% respectively. It may be concluded that the VCM classification with three stages used in the present study seems to be very useful for predicting the risk of skin necrosis in patients with severe AOD.

Adult↗
PubMed1984

Videophotometric capillaroscopy for evaluating drug effects on skin microcirculation--a double-blind study with nifedipine.

By videophotometric capillaroscopy, blood flow dynamics in the nutritional skin capillaries of man can be quantified. In this double-blind crossover study the acute effect of nifedipine on finger nailfold capillary blood cell velocity (CBV) was investigated in 10 healthy subjects. At the moment of administration of 10 mg nifedipine or placebo sublingually, a transitory but significant increase in heart rate and reduction of digital pulse amplitude (DAPA) were seen. Subsequent measurements of DAPA and heart rate were not significantly different from the baseline ones. CBV however increased after 10 min to a maximum of 49% above baseline values (P less than 0.05) after nifedipine but was unaffected by placebo. The reactive hyperaemia response in the capillaries were unaffected by both placebo and nifedipine. The decrease in DAPA and increase in heart rate upon administration of the drug or placebo are compatible with an increase in sympathetic activity. The subsequent increase in CBV indicates that nifedipine diminishes precapillary vascular tone. However, the drug seems to affect arterio-venous shunt flow to a lesser extent since DAPA did not increase significantly. Videophotometric capillaroscopy is a suitable method for studying the effects of pharmacological compounds on nutritional circulation in human skin.

Adult↗
PubMed1984

Theophylline antagonizes cardiovascular responses to dipyridamole in man without affecting increases in plasma adenosine.

Effects of the vasodilator dipyridamole (Dip) on plasma adenosine levels, heart rate, blood pressure and skin microcirculation were studied in 13 healthy male volunteers. Venous plasma concentrations of adenosine, catecholamines, dipyridamole and theophylline were determined by HPLC. Skin capillary blood cell velocity (CBV) was measured by videophotometric capillaroscopy in the finger nailfold. The adenosine uptake inhibitor Dip (approximately 1-3 microM in plasma) increased plasma adenosine from 0.15 +/- 0.03 to 0.29 +/- 0.03 microM (p less than 0.01) and heart rate (HR) by 13 +/- 2 beats/min (p less than 0.01) and reduced diastolic blood pressure by 6 +/- 2 mmHg (p less than 0.05). Dip did not significantly affect the skin circulation since basal CBV, digital pulse amplitude (DAPA), skin temperature and post-occlusive reactive hyperemia were unchanged. Plasma catecholamine levels were also unaffected. The adenosine receptor antagonist theophylline (45-55 microM in plasma) did not influence basal plasma catecholamine or adenosine levels, HR, blood pressure or skin microcirculation. Following theophylline Dip caused similar elevations of plasma adenosine but no changes in HR or blood pressures. Our results support the hypotheses that Dip dilates blood vessels in man by elevating endogenous adenosine and that theophylline acts as an adenosine antagonist. Under basal conditions, the skin microcirculation appears to be regulated mainly by factors other than adenosine.

Adenosine↗
PubMed1983

Synchronous assessment of human skin microcirculation by laser Doppler flowmetry and dynamic capillaroscopy.

Synchronous assessments of microcirculatory flow in human skin have been made by the techniques of laser Doppler flowmetry and dynamic capillaroscopy in adjacent areas of the same nailfold. Microvascular flow was studied at rest, following release of arterial occlusion and during application of venous occlusion in seven normal subjects. Despite broad comparability in the pattern of responses recorded by the two techniques certain significant differences were observed. Vasomotor activity of a similar frequency (4 to 9 cycles per min) was recorded by both techniques, but the activity was asynchronous. The amplitude of the cyclical change in the mean resting flow value recorded by dynamic capillaroscopy was considerably greater than that recorded by laser Doppler (X +/- SD, 25.3 +/- 7.0% mean rest flow; 11.4 +/- 4.9% mean rest flow, p less than 0.01). The time to peak flow following release of a 60 s arterial occlusion was significantly longer as assessed by dynamic capillaroscopy (5.7 +/- 1.6 s: 3.3 +/- 1.0 s. p less than 0.02). In response to a venous congestion pressure of 50 mm Hg, capillary flow rate fell to 24 +/- 6% of the resting flow value as assessed by dynamic capillaroscopy over the first 30 s of occlusion. Laser Doppler flowmetry also recorded a fall in microcirculatory flow to 59 +/- 21% of resting flow value during this period, but this reduction was significantly less than that recorded by dynamic capillaroscopy (p less than 0.05). These discrepancies are interpreted as evidence that laser Doppler flowmetry records blood flow in vessels in addition to the superficial, nutritional capillaries.

Adult↗
PubMed1983

The influence of venous and arterial occlusion on capillary blood flow and transcutaneous oxygen tension in fingers.

We have previously reported a lack of correlation between the reactions of finger skin capillary blood cell velocity (CBV) and transcutaneous oxygen tension (pTcO2) to different hydrostatic pressures. In the present study the influence of different venous and arterial pressures on nailfold CBV and pTcO2 of the dorsum of the middle phalanx was investigated. In six subjects venous occlusion (50 mm Hg) was performed with the hand at heart level and 40 cm above heart level. At heart level venous occlusion caused a marked reduction in CBV from 0.59 to 0.02 mm/s (p less than 0.01) while pTcO2 was not significantly affected. When the hand was raised 40 cm above heart level CBV remained unchanged but pTcO2 fell from 58.8 to 41.8 mm Hg (p less than 0.001). Venous occlusion in this position caused a decrease in CBV and a further decrease in pTcO2. In another 5 subjects arterial occlusions of varying duration (0.5, 1, 2, 6, 15 min) were performed at the finger base. As judged by the CBV, reactive hyperemia (RH) was always present when duration of occlusion was one minute or more. Post-occlusive pTcO2 was significantly increased compared to baseline pTcO2 (p less than 0.05) only after the 15 min occlusion. Thus, there is a marked difference in the responses of CBV and pTcO2 to variations in venous and arterial pressures. The lack of response of pTcO2 to manoeuvers that result in autoregulatory adjustment of CBV probably reflects the local heating of the probe which causes maximal vasodilation in the underlying skin.

Adult↗
PubMed1982

Subcutaneous administration of heparin. A randomised comparison with intravenous administration of heparin to patients with deep-vein thrombosis.

One-hundred and forty-one patients with clinical signs of acute deep venous thrombosis (DVT) in the legs were randomly allocated to receive heparin either as two daily subcutaneous injections (s.c.) or as continuous intravenous infusion (i.v.). The thrombi extended into the popliteal or femoral veins in 83% of the patients. Verification of diagnosis and evaluation of therapy was performed by phlebography, plethysmography and thermography. The results showed that heparin administered s.c. twice daily was as efficient as continuous i.v. infusion in preventing extension of the thrombus. In two patients the s.c. administration was stopped due to local haematomas at the injection sites. Retroperitoneal or intramuscular bleedings occurred in four patients, two in each group. Two major, non-fatal pulmonary emboli occurred, one in each group.

Adult↗
PubMed1982

The response of blood flow velocity in finger nailfold capillaries to contralateral cooling.

The present study was performed in order to determine the effect of contralateral cooling on capillary blood flow velocity (CBV) in human nailfold capillaries during rest and postocclusive reactive hyperemia. The following reactions were found: Mean resting CBV (2 min) was slightly (19%) but not significantly (p greater than 0.05) decreased by cooling of the contralateral hand. However, immediately after the hand was submerged in the cold water (15 +/- 1 degree C) there was a short (3-10 S) but marked decrease of CBV. In 3 of 7 subjects CBV stopped completely for 5-10 S. No change of the skin temperature was seen during the contralateral cooling procedure. There was an increase in periodic and intermittent flow fluctuations of CBV during contralateral cooling, which was not noticed in the digital pulse amplitude (DAPA), indicating a reflex-mediated vasoconstriction at the microcirculatory level. The peak CBV during postocclusive reactive hyperemia (PRH) response was not influenced by contralateral cooling (1.01 +/- 0.57 mm/s before and 0.98 +/- 0.4 mm/s after cooling). However, because of the decrease in mean resting CBV during contralateral cooling, the percent increase in CBV during PRH increased from 66% to 104% by the cooling procedure (p greater than 0.05).

Adult↗
PubMed1982

The influence of hydrostatic pressure and contralateral cooling on capillary blood cell velocity and transcutaneous oxygen tension in fingers.

Measurement of transcutaneous oxygen tension (pTcO2) has become a rather widely used technique. The relation of pTcO2 to skin microcirculatory parameters is, however, unclear. Capillary blood cell velocity (CBV) was compared with transcutaneous oxygen tension (pTcO2) of the finger in seven volunteers on change of hydrostatic pressure and contralateral cooling. On increase in hydrostatic pressure and also with contralateral cooling CBV decreased, while pTcO2 remained unchanged. This finding can be explained by a heat-induced local vasodilation under the pTcO2 probe in spite of a general increase in vasomotor tone. During decreasing perfusion pressure CBV was unchanged, while pTcO2 fell. This shows that with reduction in driving pressure skin pO2 is lowered. Teh absence of a decrease in CBV under these circumstances may be explained by a closure of the arteriovenous shunts, with diversion of blood into the superficial nutritional capillaries. It is suggested that CBV is related to changes in skin vasomotor tone. The pTcO2 findings indicate that the skin vasculature under the isothermally heated (44 degrees C) sensor is dilated and does not respond to vasoconstrictor stimuli.

Adult↗
PubMed1981

Digital pulse volume in the evaluation of haemodynamic effects of cardiac pacing.

Some artificially paced patients experience symptoms referrable to competition between spontaneous and pacemaker-induced heart activity. Haemodynamic studies are necessary to establish a relationship. Non-invasive techniques are desirable. Because of the considerable variations in haemodynamic variables from one beat to another it seems necessary to do beat-to-beat analysis. In the present study a comparison has been made between digital arterial pulse amplitude (DAPA) and central haemodynamic parameters in six patients at different pacing modes. A good correlation was found between DAPA and arterial pulse pressure (r = 0.83-0.99). The mean difference in cardiac output between atrio-ventricular pacing and ventricular pacing with atrial activation in early systole was 1.11 /min (P less than 0.01). A mean increase of 70% in DAPA was found at optimal PR-time as compared to simultaneous atrial and ventricular activation; wide individual variations were, however, seen. The results presented indicate that peripheral pulse volume registrations may be helpful in evaluating the consequences of atrial contractions for haemodynamic variables and to find those paced who may benefit from atrial or bifocal heart stimulation.

Aged↗