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Biomedical subjects

U Albrechtsson

Publications and source records attributed to U Albrechtsson.

At least 19 recordsLinked to original sources

Surgical treatment versus thrombolysis in acute arterial occlusion: a randomised controlled study.

Thrombolytic treatment has been tried in various forms for acute limb ischaemia with varying degrees of success but is also often accompanied by bleeding problems. The present investigation compares the effect of surgical thrombectomy (TE) and thrombolysis (TL) using recombinant tissue plasminogen activator (rt-PA). Twenty patients with a need for intervention owing to ischaemia lasting more than 24 h but less than 14 days were included. Patients randomised to TE were operated under epidural anaesthesia and patients in the TL group received 30 mg rt-PA during a 3 h period through a catheter placed into the thrombus and advanced as lysis was achieved. Thrombectomy resulted in an immediate restitution of blood flow in six out of nine cases, in three cases a bypass procedure was performed, and one of these failed with a resultant amputation. Thrombolysis gave a good primary result in six cases which lasted in four of them. Three had a subsequent percutaneous transluminal angioplasty. Partial lysis was seen in two cases and a further two failed. Five went to surgery with three bypass and two fogarty procedures being necessary. There was no hospital mortality and there were no bleeding complications due to the rt-PA treatment in this series. In 19 out of 20 patients the circulation was re-established. Appropriate handling of acute ischaemic conditions implies the use of both thrombolysis and appropriate surgical procedures, including distal bypass grafts.

Acute Disease

A case of right coronary artery occlusion, caused by blunt chest trauma and treated with acute coronary artery bypass surgery.

A 37-year-old man sustained occlusion of the right coronary artery after a bicycle accident with blunt chest trauma over the left scapula. Acute coronary angiography was performed because of chest pain and ST-segment elevation. Despite surgically successful acute revascularization the patient developed a transmural inferior wall infarction. Coronary artery occlusion after blunt chest trauma is rare, especially occlusion of the right coronary artery. When it occurs, the impact is usually frontal (car accidents), and not dorsal as in this case. Coronary artery bypass surgery has been reported in a few cases but to the best of our knowledge this is the first report of bypass surgery at the stage of acute transmural ischaemia.

Adult

Iodixanol--a new nonionic dimer--in aortofemoral angiography.

In 26 patients iodixanol, a new nonionic dimer, isotonic to blood in all concentrations, was used as contrast medium in aortofemoral angiography. Half of the patients received contrast medium in a concentration of 270 mg I/ml and the other half 320 mg I/ml. The aim of the trial was to evaluate the safety and tolerability of iodixanol and the radiographic efficacy of the two concentrations. The degree of discomfort, adverse events, changes in serum chemistry parameters, and diagnostic information were assessed. There were no changes or trends of clinical importance in serum chemistry parameters. The side effects were mild and consisted mostly of some sensation of warmth of short duration. No other adverse events were seen. The overall radiographic efficacy did not show any significant difference between the two concentrations. This indicates that iodixanol is safe and well tolerated when used in adult femoral angiography.

Adult

Patency after iliac and femoro-popliteal angioplasty. Difference between angiographic and clinical results.

Twenty-five patients with clinical relapse after previous successful angioplasty of iliac or femoro-popliteal arteries were evaluated with repeat angiography. The angiographic patency was 80% despite the clinical symptoms. The discrepancy between the angiographic appearance and the clinical findings was explained by the progress of the general arteriosclerotic vascular disease. Such progression is more important regarding late prognosis than the result of the angioplasty per se.

Aged

Digital luminescence radiography using a chest phantom. Comparison between radiographs displayed on monitor and hard-copy.

Ninety-eight digital radiographs of a chest phantom with simulated tumors in the mediastinum and left lung and a pneumothorax-simulation in the right hemithorax were compared with the corresponding examinations saved on optical disk and viewed on a 1,000-line monitor. The examinations were reviewed by 7 radiologists with different experience, and receiver operating characteristic (ROC) curves were constructed. There was no significant difference between the hard-copy and the monitor results. A significant interobserver difference was seen only with the low attenuating 6 mm "tumor" and then only between the observer with the highest and the one with the lowest scores.

Humans

Lung mechanics and gas exchange during exercise in pulmonary sarcoidosis.

To clarify how lung function at exercise is affected in sarcoidosis, and to analyze how exercise studies compare to testing measurements, 63 patients with pulmonary sarcoidosis were examined with lung mechanics and arterial blood gases during exercise. These findings were compared with simultaneously obtained, but previously reported results of the static lung pressure/volume curve and the lung resistance/static lung pressure curve. While mechanical variables at maximal exercise were as sensitive as those determined by measuring the PstL/V and RL/PstL curves, mechanics during spontaneous breathing at rest was less sensitive. The derangement of mechanics was more evident than that of arterial blood gases. No measurement at rest was a good predictor of working capacity or of arterial PaO2. A comprehensive exercise examination may be an alternative to resting investigations, which are either more elaborate or less sensitive.

Adult

Lung mechanics and gas exchange in steroid treated pulmonary sarcoidosis. A seven year follow-up.

Fifteen patients with pulmonary sarcoidosis, representing the functionally most severely affected quartile of referred patients, were prescribed steroids during one year. During this period and after 7 years on average, measurements were made of lung volumes, the static elastic pressure/volume (PstL/V) curve and lung resistance (RL). Lung mechanics and arterial blood gases were studied at exercise. Within months static compliance (CstL) and the arterial partial pressure of oxygen improved along with radiography. A modest positive trend continued throughout the follow-up. The vital capacity followed CstL changes closer than did the total lung capacity, which remained low. Though CstL improved, transpulmonary pressure at maximal inspiration increased and the upper part of the PstL/V curve became flatter. RL remained moderately increased. The course of the physiologic findings may be explained by fairly stable parenchymal and peribronchial fibrosis after cessation of active inflammation, and by regress of reflex inhibition of inspiration. Thus most subjects showed modest improvement during and after treatment. The initial study of lung function provided important prognostic information. The study does not allow conclusive evidence with respect to long term benefit of treatment, but encourages continued use of steroids under the guidance of function tests.

Adult

Efficacy of inverted digital luminescence radiography in evaluating chest neoplasms.

Inverted (positive) digital chest radiographs of patients with lung tumors were compared with commonly used (negative) digital images, consisting of one simulated normal and one contrast enhanced image. The first part of the material consisted of 80 patients of whom 40 had tumors and 40 were normal. Five radiologists with different experience reviewed the examinations. From their answers, ROC curves were constructed. The second part of the material consisted of 100 chest phantom examinations with a simulated tumor in the mediastinum (45 examinations) and/or the left lung (46 examinations). In 31 exposures there was no abnormality. These were reviewed by 3 observers and performed as an ROC study as well. There was no statistical difference between the different types of images or between the observers in the 2 studies.

Adult

Digital luminescence radiography in interstitial lung disease. A receiver operating characteristics (ROC) analysis.

The subtle changes often found in interstitial lung disease can be difficult to evaluate at conventional radiography. In order to define the information obtained with digital radiography, it is particularly important to find out to what extent interstitial lung disease can be observed with this technique. Ninety-one patients, 56 with interstitial lung disease and 35 with normal lungs, were examined both with a digital system and with conventional film-screen technique. The examinations were reviewed independently by 4 radiologists with different experience and receiver operating characteristics (ROC) curves were constructed. The 2 systems were equal in diagnostic performance with no statistic difference between the conventional radiographs, the 2 digital images reviewed together or the 2 digital images reviewed separately. There was a significant difference between the 2 observers with the highest and the one with the lowest score only in the review of digital unsharp mask images, but otherwise no differences statistically. A lower number of false negatives and a higher number of false positives were seen with the digital unsharp mask image, producing a higher sensitivity and lower specificity.

Adult

Comparison of iopromide versus iohexol in aortobifemoral arteriography. A Swedish multi-center study of 446 patients.

A double-blind randomized, clinical trial was conducted in 9 hospitals comparing the use of non-ionic contrast media (CM) iopromide 300 (Ultravist) and iohexol 300 (Omnipaque) during peripheral arteriography in a total of 446 patients. After premedication with morphine-scopolamine each patient was given two consecutive injections of 50 ml CM at a rate of 12 ml/s above the aortic bifurcation. Both CM were well tolerated. There were no differences between the two substances as far as general tolerance, pulse rate, blood pressure, sensation of heat or pain after CM injection were concerned.

Adult

Improved ECG interpretation using synthesized VCG for the diagnosis of inferior myocardial infarction.

Electrocardiographic (ECG) criteria for the diagnosis of inferior myocardial infarction (IMI) have high specificity but low sensitivity. Vectorcardiographic IMI criteria attain higher sensitivity without sacrificing specificity. One approach to improving ECG interpretation is to synthesize VCG loops from the 12-lead ECG. The performance of synthesized VCG (SVCG) was assessed, using the Frank VCG criterion of Starr et al. ECGs and SVCGs from 351 normal subjects and 65 patients with IMI verified by myocardial scintigraphy or angiocardiography were studied. The sensitivity was 14 percentage points higher for SVCG than for ECG (72% vs. 58%).

Adult

Vectorcardiogram more sensitive than 12-lead ECG in the detection of inferior myocardial infarction.

The vectorcardiogram (VCG) is commonly stated to be more sensitive than the 12-lead electrocardiogram (ECG) for the diagnosis of inferior myocardial infarction. However, a recent study indicated that VCG is not superior to ECG for this diagnosis. The purpose of this study was to compare the performance of VCG and ECG criteria and to indicate possible explanations for the disagreement between earlier studies. Accordingly, we studied 65 patients with inferior myocardial infarction verified by left ventriculography or 201-TI myocardial scintigraphy and 351 normal subjects. Sensitivity was 69% (45/65) and 43% (28/65) for the VCG and ECG criteria, respectively. This difference was highly significant (P less than 0.001). Among the normal subjects there were only three with false positive ECG. We conclude that both VCG and ECG criteria for the diagnosis of inferior myocardial infarction are highly specific and that VCG criteria have greater sensitivity than ECG criteria.

Adult

ST changes in relation to heart rate during bicycle exercise in patients with coronary artery disease.

Exercise test on cycle ergometer and coronary angiography were performed on 190 patients with chest pain. Volunteers with a normal thallium scintigraphy (n = 47) served as controls. The load started at 20 W and increased at a rate of 10 W min-1 until exhaustion or symptoms. Conventional 12-lead ECGs were recorded by means of computer before, during and after exercise. Minimum ST amplitude 60 ms after the STJ point (ST60) at end of work with a cut-off level of -1.10 mm had a sensitivity of 69% (52/75) and a specificity of 89% (37/42) when individuals with a normal resting ECG were considered. ST80 and sum of ST60 in left ventricular leads had slightly lower values of sensitivity and specificity. Changes in ST60 during exercise discriminated less well between the groups. Final heart rate during exercise (less than 148 min-1) had a sensitivity of 88% (53/60) and a specificity of 89% (42/47). The change in heart rate during exercise (less than 66 min-1) had a sensitivity of 50/60 (only patients without beta-blockers were considered). The best discrimination was obtained by defining a test score (TS) according to the linear equation TS = 2.95-0.23 x HRE-0.301 X ST60 where a positive value indicates a positive test and a negative value a negative test. Sensitivity and specificity were 21/23 (91%) and 40/42 (95%), respectively. The test score was also calculated in those patients having significant coronary disease and an abnormal resting ECG (no bundle branch block, no beta-blockers) and this yielded a sensitivity of 30/34.

Adult

Accuracy of digital radiography using stimulable phosphor for diagnosis of pneumothorax.

To evaluate the efficacy of digitized radiography in diagnosing pneumothorax 78 patients were examined with both the conventional film-screen technique and digital radiography. Of these 78 examinations 40 were normal and in 38 a pneumothorax was found. Four observers with different experience reviewed the films. In an ROC analysis no significant differences were found between the two systems. Between the observers, however, there were slight differences, one of them showing significantly lower specificity.

Humans

Increased rate of left predominance associated with adult valvular aortic stenosis.

The anatomy of the coronary arteries was outlined angiographically in 2,190 adult patients in order to determine the proportion of left predominance. Of 253 patients with valvular aortic stenosis 14.3 per cent were found to have left predominance, while the frequency of left predominance in the rest of the patients (1937) was 8.5 per cent. Furthermore, this rate increases with the severity (gradient greater than 50 mmHg) of the aortic stenosis in the absence of aortic valve incompetence. These findings support the current concept of a relationship between adult aortic stenosis and congenital valvular malformation.

Angiography

Diagnosis of pulmonary embolism based upon alveolar dead space analysis.

Pulmonary embolism (PE) leads to an abnormal alveolar deadspace that is expired in synchrony with gas from normally perfused alveoli. This feature of PE separates it from pulmonary diseases affecting the airways, which are characterized by nonsynchronous emptying of compartments with an uneven ventilation/perfusion relationship. An analysis of the single breath test (SBT) for CO2, SBT-CO2, focusing on the late tidal expirate, was made in order to evaluate the feasibility to use the SBT-CO2 for the diagnosis of PE. The test was evaluated in 38 patients with suspected PE where pulmonary angiography showed that nine had PE and 29 did not. It was also tested in a reference population consisting of patients with normal lung function, obstructive lung disease and interstitial lung disease. Previously suggested gas exchange measurements for the diagnosis of PE, ie, the physiologic deadspace fraction, VDphys/VT, and the arterial-to-end-tidal CO2 gradient, P(a-E')CO2, were also evaluated in the groups. SBT-CO2 achieved a nearly complete separation between the patients with PE and those without. The other measurements, however, showed a substantial overlap between patients with PE and those with obstructive or interstitial lung disease. The SBT-CO2 is simple and potentially widely available and warrants further study as a routine technique for the diagnosis of PE.

Angiography

Lung mechanics and their relationship to lung volumes in pulmonary sarcoidosis.

Pulmonary sarcoidosis was studied with respect to lung mechanical properties and to the influence of these on lung volumes. Sixty-six patients, with histological support for the diagnosis of sarcoidosis, and radiological signs of pulmonary involvement, i.e., stage II or III, were studied. The static pressure/volume (P/V) curves showed that the static elastic recoil pressure (PelL) tended to be increased at a given percentage of predicted total lung capacity (TLC). Reduction of static lung compliance (CstL) was a typical finding. At maximal inspiration PelL was abnormally low in 20 subjects, including in the main those with recent onset of the disease and older patients. The possibility of a greater inflammatory activity at the site of mechanical receptors in the lungs and airways of these patients is proposed. Pulmonary resistance, measured at a given PelL, was usually increased signifying bronchial involvement. TLC, residual volume (RV) and functional residual capacity (FRC) were lower in current smokers and ex-smokers than in lifelong nonsmokers. This may be due to synergistic effects of the inflammatory processes caused by smoking and sarcoidosis. A reduced vital capacity (VC) mainly reflected a low CstL but also obstruction with increased RV. Forced expiratory volume in one second (FEV1) reflected lung stiffness and obstruction equally. Lung mechanics revealed functional abnormalities which were not obvious from the standard tests, particularly in patients with respiratory symptoms.

Adult