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R Jelnes

Publications and source records attributed to R Jelnes.

At least 37 records · Page 2Linked to original sources

Microvascular circulatory changes in the lower extremities after reconstructive vascular surgery for intermittent claudication.

We have studied the circulatory changes in the lower extremities after reconstructive vascular surgery in ten patients with intermittent claudication. The following examinations were carried out 3 days before, 3 days, and 28 days after the operation: measurement of ankle systolic blood pressure, calf plethysmography, resting calf muscle blood flow and resting subcutaneous foot blood flow. The vasoconstrictor response (veno-arteriolar reflex) was also assessed. On the night before the operation and on the 28th night after aorto-bifemoral bypass surgery, subcutaneous adipose tissue blood flow in the forefoot was measured during sleep. The ankle systolic blood pressure and the ankle index rose significantly. The former increased from 57 +/- 16.4 mmHg to 93 +/- 24.0 mmHg (mean +/- S.E.M.) and was still elevated on the 28th postoperative day. The total limb blood flow, the muscle blood flow and the blood flow in the subcutaneous tissue of the forefoot during daytime were unchanged. In contrast, the blood flow in the forefoot during sleep increased significantly from 3.5 +/- 1.63 ml x (min x 100 g)-1 to 5.2 +/- 2.14 ml x (min x 100 g)-1 (mean +/- S.E.M.) on the 28th night. The vasoconstrictor response was potentiated, and increased from 27% before the operation to 45% on the third postoperative day. This change was maintained 28 days postoperatively. In conclusion the increase in arterial blood pressure was only reflected in the vasoconstrictor response which had returned to normal by the third postoperative day and nocturnal blood flow in the subcutaneous adipose tissue which did likewise.

Aged↗

The cause of ischaemic nocturnal rest pain.

Adipose tissue blood flow in the forefoot was measured simultaneously with mean systemic arterial blood pressure over 24 hours in 8 patients (15 feet) with different degrees of arterial insufficiency. Mean systemic arterial pressure decreased by 19 +/- 9% during sleep, irrespective of symptomatology. In two limbs, with a normal peripheral circulation, blood flow decreased by 8 +/- 7%. In five limbs with arterial insufficiency, but no rest pain, blood flow decreased by 16 +/- 8% and in eight limbs with ischaemic nocturnal rest pain blood flow was reduced by 32 +/- 12% during sleep. It is concluded that nocturnal hypotension is a major factor in the production of nocturnal ischaemic rest pain.

Aged↗

The regulation of subcutaneous adipose tissue blood flow in the ischaemic forefoot during 24 hours. Studies using the 133-xenon wash-out technique continuously over 24 hours.

A method for continuous measurement of subcutaneous adipose tissue blood flow in the forefoot during 24 hours (SBF) is described. The method is based on the radioisotope wash-out principle using 133-Xenon. A portable semiconductor detector is placed just above a local depot of 1-2 microCi 133-Xenon in 0.1 ml isotonic saline injected into the subcutaneous adipose tissue in the forefoot. The detector is connected to a memory unit allowing for storage of data. Due to the short distance, the recorded elimination rate constant must be corrected for combined convection and diffusion of the radioactive indicator. Characteristic 24-hour blood flow patterns were unveiled in patients with normal peripheral circulation and in patients having ischaemic nocturnal rest pain. In normals SBF doubled from day to night. This is ascribed to the local veno-arteriolar sympathetic axon reflex, which induces arteriolar vasoconstriction when the transmural pressure of the veins exceeds approximately 25 mmHg. In patients having ischaemic rest pains SBF was reduced by 37% on the average from day to night. This was caused by nocturnal hypotension, which is reflected proportionally in the foot. As the resistance vessels most probably are fully dilatated in feet with rest pain, the blood pressure drop during sleep causes the perfusion pressure and thus blood flow to come below a certain critical limit. There was a pronounced correlation between the reduction of systemic mean arterial blood pressure and SBF. The patients complaining of intermittent claudication, but no rest pains showed a variety of changes in SBF compatible with the continuous spectrum of the peripheral arteriosclerotic disease. After reconstructive vascular surgery, the 24-hour blood flow pattern normalized although the ankle/arm systolic blood pressure index did not come within normal range. SBF during day-time activities decreased by up to 50% postoperatively. This is caused by the reappearance of the local, sympathetic, veno-arteriolar vasoconstrictor response. During sleep SBF increased by 71%. The term postreconstructive hyperaemia seems improper, at least in a long-term context, normalization of preoperative ischaemia is a more correct notation. The coefficient of variation of nocturnal SBF was calculated to 10%. The method thus seems apt as a monitor in medical therapy for occlusive arterial disease. Changes of lambda has, however, to be considered in each study.

Adipose Tissue↗

[Pneumothorax].

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Denmark↗

Tissue/blood partition coefficients for xenon in various adipose tissue depots in man.

Tissue/blood partition coefficients (lambda) for xenon were calculated for subcutaneous adipose tissue from the abdominal wall and the thigh, and for the perirenal adipose tissue after chemical analysis of the tissues for lipid, water and protein content. The lambda in the perirenal tissue was found to correlate linearly to the relative body weight (RBW) in per cent with the regression equation lambda = 0.045 . RBW + 0.99. The subcutaneous lambda on the abdomen correlated linearly to the local skinfold thickness (SFT) with the equation lambda = 0.22 SFT + 2.99. Similarly lambda on the thigh correlated to SFT with the equation lambda = 0.20 . SFT + 4.63. It is concluded that the previously accepted lambda value of 10 is generally too high in perirenal as well as in subcutaneous tissue. Thus, by application of the present regression equations, it is possible to obtain more exact estimates of the adipose tissue blood flow measured with the 133Xe wash-out method.

Adipose Tissue↗

A pitfall in the measurement of arterial blood pressure in the ischaemic limb during elevation.

In order to evaluate if elevation of the ischaemic limb above heart level is an alternative to the conventionally applied method with external counterpressure for estimation of skin perfusion pressure, femoral and popliteal artery pressures were measured directly in eight patients with occlusion of the superficial femoral artery. The measurements were done in the horizontal position and during elevation of the calf above heart level. During elevation relative blood flow, measured by arterio-venous oxygen saturation differences, decreased compared with the horizontal position. In contrast the popliteal arterial pressure decreased only by 20% of the value expected from the degree of elevation of the calf above the level of the heart. Thus, it could be calculated that calf vascular resistance increased two- to three-fold on average during elevation. Four patients were reexamined with the venous pressure kept at 10 mmHg during elevation. In these patients, the increase in vascular resistance was significantly less compared with the situation in which venous pressure was 0 mmHg during elevation. The arterial pressure still did not decrease. It is concluded that perfusion pressure in the ischaemic lower extremity cannot be determined non-invasively by elevation of the extremity, probably due to collapse of segments of the vascular bed increasing the vascular resistance considerably.

Arteriosclerosis↗

Pleurodesis in spontaneous pneumothorax by means of tetracycline. Follow-up evaluation of a method.

The validity of previous recommendation of early thoracoscopy and tetracycline pleurodesis in the management of spontaneous pneumothorax without thoracoscopically visualized true cyst was assessed under non-trial, normal hospital conditions. Among 46 patients treated during a year, seven underwent immediate thoracotomy following finding of large cysts. Of the remaining 39 patients, 11 had recurrence of pneumothorax after a median of 11 (range 2-64) weeks. Repeat thoracoscopy then showed large cyst or bullous emphysema in seven cases. Tetracycline pleurodesis was again performed in the others. In continued observation for at least 2 years there were no further recurrences. The importance of meticulous thoracoscopy is stressed. The demonstrated diagnostic errors do not detract from the value of tetracycline pleurodesis when spontaneous pneumothorax is caused by rupture of only tiny blebs on the surface of an otherwise healthy lung. The procedure is fast, simple and efficacious.

Adolescent↗

A pitfall in the evaluation of medical therapy for occlusive arterial disease using the xenon wash-out technique.

In a double-blind cross-over trial an oral thromboxane synthetase inhibitor (TSI) or placebo was given to 15 patients with severe foot ischaemia. After TSI therapy, rest pain remitted in nine out of 14 legs, while remission during placebo was seen in three out of 11 legs (NS). The ankle and toe systolic blood pressures remained constant during both study periods. Nocturnal adipose tissue blood flow in the forefoot was measured by the xenon wash-out method. A significant increase of the nocturnal perfusion rate constant during TSI therapy was found. A slight oedema developed during TSI therapy. This causes a change of the composition of the tissue under study and thus of lambda-xenon. The perfusion rate in the present study thus merely illustrates the latter and not a true increase in blood flow.

Adipose Tissue↗

Subcutaneous adipose tissue blood flow in the forefoot during 24 hours. Labeling pattern and reproducibility.

Wash-out of 133xenon from a local depot in the subcutaneous adipose tissue in the forefoot was measured continuously during 24 hours on subsequent recordings in 51 feet (normal circulation: 10, intermittent claudication: 22 and ischaemic nocturnal rest pain: 19) with a mean time interval of 26 days (range: 3-90 days). The patients were studied under two different conditions. Firstly, during the day in the erect position, awake (sitting, standing and quiet walking) and secondly, during night hours in the supine position, asleep. The coefficient of variation of nocturnal adipose tissue blood flow was calculated to 10%, and for the ratio of blood flow from day to night to 5%. The method is thus considered apt as a monitor in the treatment of peripheral vascular disease, for example, surgery and medical therapy. As predominant source of error is the formation of oedema.

Adipose Tissue↗

Why do patients with severe arterial insufficiency get pain during sleep?

Simultaneous measurement during 24 h of mean arterial blood pressure (MABP) and forefoot subcutaneous adipose tissue blood flow (SBF) was undertaken in eight patients (15 feet) with different degrees of arterial insufficiency. The recordings were undertaken with the patients in the supine position only. The MABP decreased by 19 +/- 9% from awake to asleep independently of symptomatology. In two limbs with normal circulation, SBF decreased by 8 +/- 7%. In five limbs with arterial insufficiency but no rest pain SBF decreased by 16 +/- 8%, and in eight limbs with ischaemic nocturnal rest pain, SBF was reduced by 32 +/- 12% during sleep. It is concluded that nocturnal hypotension is the major aethiological factor for the symptom ischaemic nocturnal rest pain.

Adipose Tissue↗

Fate in intermittent claudication: outcome and risk factors.

The fate of 257 consecutive patients (100 women) aged 36-85 years (mean 65) first seen with intermittent claudication in 1977 was analysed after a mean of 6.5 (SD 0.5) years. When first seen none of the patients complained of rest pain or had ulcers or gangrenous lesions on the feet. At follow up 113 of the patients (44%) had died. Causes of death were no different from those in the general population. Mortality was twice that of the general population matched for age and sex. Mortality among the men was twice that among the women. In men under 60 mortality was four times that expected. The rate of clinical progression of the arteriosclerotic disease (that is, rest pain or gangrene) of the worst affected leg was 7.5% in the first year after referral. Thereafter the rate was 2.2% a year. An ankle systolic blood pressure below 70 mm Hg, a toe systolic blood pressure below 40 mm Hg, or an ankle/arm pressure index below 50% were individually significantly associated with progression of the arteriosclerotic disease. These findings show the importance of peripheral blood pressure measurements in the management of patients with intermittent claudication due to arteriosclerotic disease.

Adult↗

Twenty-four hour blood flow in the forefoot after reconstructive vascular surgery.

Local blood flow in the forefoot (SBF) was measured continuously during 24 hours by 133xenon clearance technique in 10 patients prior to and at least 1 year after successful reconstructive vascular surgery for severe arterial insufficiency (mean: 18 months, range: 12-36). A group of 10 patients with normal peripheral circulation served as a control group. In spite of a considerable increase of the ankle/arm systolic blood pressure index--preoperative: 0.30 +/- 0.12, postoperative: 0.78 +/- 0.28 (mean +/- 1 SD)--the SBF decreased by 50% (p less than 0.001) following reconstructive vascular surgery during day activities. During sleep, however, SBF increased by 80% (p less than 0.001). The relative changes in SBF from day to night at the postoperative examination did not differ from that of the control group, i.e., the normal 24-hour blood flow pattern had been obtained. These changes in SBF are explained by the reappearance of peripheral vasoregulatory mechanisms. Postreconstructive hyperemia was evaluated by the same technique. The changes in SBF following surgery in the positions supine, awake and supine, asleep were found to be insignificant (0.80 less than p less than 0.90). It is concluded that the long-term postreconstructive hyperemia merely is a reflection of the normal 24-hour blood flow pattern.

Adult↗

The effects of acebutolol and metoprolol on walking distances and distal blood pressure in hypertensive patients with intermittent claudication.

The effects of acebutolol (with intrinsic sympathomimetic activity (ISA] and metoprolol (without ISA) on arm blood pressure, ankle systolic blood pressure, claudication distances (CD) and maximal walking distances (MWD) were compared in patients with essential hypertension and intermittent claudication. Fourteen patients participated in a long-term, open, randomized cross-over study. After randomization the patients received either acebutolol, 200 mg b.i.d., or metoprolol, 100 mg b.i.d. After eight weeks the drugs were shifted and after another eight weeks they were withdrawn. Arm and ankle blood pressure, CD and MWD were determined before randomization and after 4, 8, 12 and 16 weeks, and again 4-6 weeks after withdrawal of the drugs. The arm blood pressure was reduced by 20/13 mmHg after acebutolol and by 22/21 mmHg after metoprolol. In spite of a significant decrease in arm blood pressure there were no significant changes in ankle blood pressure, CD or MWD after the two drugs. After withdrawal of the drugs and after the arm blood pressure had returned to the control value no significant changes were seen in CD, MWD or ankle blood pressure. It is concluded that beta-blockers have no deleterious effect on CD, MWD or ankle blood pressure in patients with hypertension and intermittent claudication. No effect of ISA was demonstrated.

Acebutolol↗

Improvement of subcutaneous nutritional blood flow in the forefoot by hydroxyethylrutosides in patients with arterial insufficiency: case studies.

Four patients with bilateral arterial insufficiency were treated with i.v. hydroxyethylrutoside for three days (1.5 grs twice a day). All patients experienced relief of symptoms. By continuous registration of subcutaneous nutritional blood flow in the forefoot (by 133Xenon clearance technique) a significant increase in nutritional blood flow of 33% on the average during the second and third hour after medication could be demonstrated. The drug seems to be of use in treating subacute occlusions and thrombosis of arteries in the lower extremity.

Aged↗

Reconstructive vascular surgery below the knee.

In a series of 38 consecutive patients with advanced peripheral vascular disease (i.e. rest pain) reconstructive vascular surgery was performed with the distal anastomosis below the knee. Ankle/arm pressure index (AAI) was 0.28 (0.11-0.47) preoperatively; accumulated graft patency rate was 0.47 (SD = 0.08) after one year, after three years 0.22 (SD = 0.08). At follow-up (June 83) 34 patients were still alive, 11 patients with patent grafts and an AAI of 0.87 (0.74-1.01). During the study 19 patients required amputation. Seven patients had an occluded graft, but had avoided amputation. Although the prognosis in regard to graft patency is poor, we still suggest that distal vascular surgery should be considered prior to primary amputation.

Adult↗