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At least 505 records · Page 28Linked to original sources
PubMed1990

Interobserver variability in the interpretation of contrast venography, technetium-99m red blood cell venography and impedance plethysmography for deep vein thrombosis.

Contrast venography (CV) is the standard technique for diagnosing deep vein thrombosis (DVT). Newer noninvasive tests have also proven efficacious. However, there is a lack of data on the level of agreement among observers in their interpretation of the results of the various tests. After agreeing on well-defined criteria, three experienced observers assessed, blindly, the results of tests performed over a 4-month period on 117 patients who were suspected clinically of having had a first episode of DVT. The kappa statistic was used to measure the level of agreement beyond chance for CV (69 patients), red blood cell venography (RBCV) (82 patients) and impedance plethysmography (76 patients). The results of CV were assigned to normal, abnormal or inadequate categories, and those of RBCV and IPG to normal, equivocal or abnormal categories. The kappa values for CV, RBCV and IPG ranged from 0.53 to 0.56, 0.42 to 0.56 and 0.90 to 0.91 respectively. Values greater than 0.75 represented excellent agreement beyond chance and those between 0.40 and 0.75 represented fair to good agreement. Excellent kappa values were obtained for IPG because interpretation of the results of this method is entirely objective. Although the values for CV and RBCV showed good to fair agreement, there was a greater degree of observer variation, despite the well-defined criteria, indicating the subjectivity of interpretation of these test results. It is concluded that the kappa statistic can be used to measure observer variation of the results of tests for diagnosing DVT and may serve as a quality control tool for studies in which more than one person interprets the results.

Contrast Media↗
PubMed1990

[Assessment of fluid balance and several hemodynamic parameters in lung surgery using the method of impedance plethysmography].

The hemodynamic effects of different modes of controlled ventilation (CV) were studied by means of impedance plethysmography in 52 anesthetized patients during surgery on the lungs, trachea, and bronchi. To adapt this investigation technique to the conditions of the operating room, a specially designed device was applied for extracorporeal measurement of electric resistance of the blood flow. It was found that impaired transcapillary exchange of fluid in the lungs and its accumulation in the interstitial spaces were secondary to the operated lung collapse irrespective of the composition of the inhaled gas mixture used for the controlled ventilation of the contralateral lung. A differential approach to the ventilation of the dependent and independent lungs using the conventional and high-frequency CV modifications allows for an optimal compensation for the damaged transcapillary exchange of fluids in the lungs, is most physiological, sparing, and organ-saving.

Body Fluids↗
PubMed1990

[Study of venous inflow and outflow using mercury gauge venous occlusion plethysmography during pregnancy].

Changes due to hormone activity and caval compression by the uterus were noted in venous hemodynamics of the lower limbs during pregnancy. The purpose of the study was to search for a possible incidence of these modifications on venous inflow ant outflow during mercury strain gauge plethysmography (fig. 1). A total of 183 subjects were distributed into 4 groups: (table I) nonpregnant women of childbearing age (controls = C) and women of the first (G1), second (G2) and third (G3) trimesters of gestation. Women with a history of phlebitis or pronounced varicosis were excluded. The figures for venous filling (table II, III et IV) (delta V) were 3.2 (C), 3.1 (G1), 2.64 (G2) and 2.04 (G3). There was a significant (P less than 0.001) reduction in G3 (and left-sided G2) delta V compared to that of controls. Maximum venous outflow (MVO) was 125.3 (G1), 123.7 (G2) and 123.5 (G3), showing no significant difference with controls (125.1). It is concluded that no significant change in MVO occurred during pregnancy, whereas there was a decrease in delta approximately greater than V during the third trimester. These results suggest that the latter parameter should not be considered as a criterion for diagnosis of phlebitis in the pregnant woman.

Adolescent↗
PubMedDate not supplied

["Determination of venous hemodynamics". Contribution of air plethysmography].

Plethysmographic techniques based on the variation of a parameter linked to venous stasis, have permitted an approach to venous hemodynamics. The use of a new technique of air-plethysmography, which cold be quantified in volume variation, and permitting to study the progression of the venous stasis from a static as well as a dynamic standpoint, enable us to better assess the overall venous function. The first results obtained in healthy patients, are presented and the advantages of this new technique are discussed.

Humans↗
PubMed1990

[Comparison of plethysmography findings before and following varicose vein surgery].

In the chronic venous insufficiency on the basis of a primary varicosis the occlusion plethysmography of the veins is a suitable remedy in the positioning trial before and after a combined phlebectomy to determine the capacity of the venous part of the circulation on the lower extremity. In altogether 160 patients the functional capacity of the venous valves with the initial inclination to swelling St as well as the capacity of the venous vascular system on the calf and the ankle were established by the determination of the maximal venous capacity Vmax. It could be proved that particularly in stage III of the chronic venous insufficiency the haemodynamically most effective efficacy can be achieved by an operation of the varices.

Female↗
PubMed1989

[Evaluation of biological equivalency of Sustonit (Polfa) and Sustac by plethysmography].

Bioequivalence of Sustonit tablets (2.6 and 6.5 mg) produced at WZF Polfa and Sustac tablets (2.6 and 6.5 mg) made by Krka (Yugoslavia) and WZF Polfa (Poland) was studied by means of the digital plethysmography. All the three drugs with the nitroglycerin content of 2.6 mg were found to be biologically equivalent. On the other hand, Sustonit (WZF Polfa) and Sustac (Krka) tablets with 6.5 mg nitroglycerin proved to possess better bioavailability than Sustac (6.5 mg) tablets produced previously at WZF Polfa.

Adult↗
PubMed1989

An evaluation of impedance plethysmography and 125I-fibrinogen leg scanning in patients following hip surgery.

Venous thromboembolism is a common post-operative complication in patients following hip surgery. 125I-fibrinogen leg scanning and impedance plethysmography (IPG), are often used in the detection of venous thrombi in such patients. Information on the sensitivity and specificity of these non-invasive tests for the diagnosis of venous thrombosis following hip surgery is relevant for both patient management and for choosing the appropriate outcome measure for clinical trials evaluating new prophylactic regimens. We determined the sensitivity and specificity of the IPG alone, the 125I-fibrinogen leg scan alone, as well as the combined use of the two tests from a retrospective analysis of 685 hip surgery patients who participated in clinical trials of anti-thrombotic prophylaxis. These patients were followed prospectively with non-invasive tests. Bilateral venography was attempted either when one or both screening tests became positive or on day 10-14 post-operatively if both screening tests remained negative. Adequate venography was obtained in 1,010 (73.7%) legs and thrombi were identified in 198 (19.6%) legs. The sensitivities of the IPG and leg scanning were 12.9% and 44.6% respectively; the corresponding specificities were 98.1% and 95.0%. The sensitivity of a positive result on one or both screening tests was 49.6% with a specificity of 93.9%. Therefore, leg scanning and IPG, even in combination, are not sufficiently accurate to be recommended as the only strategy for the diagnosis of venous thrombosis following hip surgery. Venography should be considered in all patients undergoing surveillance testing either when one or both of the screening tests become positive or on day 10-14 if the screening tests remain negative.

Fibrinogen↗
PubMedDate not supplied

[Varitest plethysmography].

Varitest plethysmography is a non-invasive diagnostic method of venous insufficiency based on the study of the emptying of leg veins by flexion movements and their subsequent filling. The Varitest records the curves and measurements of these two stages. The physiological bases of the test and its technique are presented. Our experience, following the first few cases, enabled us to identify three main groups of patients:--Patients presenting chronic symptoms, in whom the clinical examination was negative or not obvious;--Patients presenting a problem of differential diagnosis with a deep/superficial or mixed chronic venous insufficiency. It also enabled us to specify the results of the treatments. According to our results, Varitest is a simple, easy to reproduce method, presenting a sensitivity and specificity with regard to the clinical symptoms and the Doppler, of approximately 80%. Its negative aspects are the poor collaboration of the patients or their inability to be available in order to study acute venous thromboses.

Humans↗
PubMed1989

[Evaluation of airway resistance determined by whole-body plethysmography].

Methods of estimation of the airway resistance by flow-pressure curve obtained in whole-body plethysmography are investigated. The analysis of the physical processes controlling the flow-limitation during expiration shows that these methods are useful only for healthy subjects for the estimation of the airway resistance. The way for estimation of the airway resistance by flow-pressure curve is proposed.

Airway Resistance↗
PubMed1989

Correlation between macrovascular disease as assessed by bioimpedance plethysmography and various parameters used to assess diabetic "control".

Blood flow in a segment of the leg was determined by bioimpedance plethysmography in 47 diabetic patients and in 19 normal volunteers. The blood flow through the limb, expressed as stroke volume/m2 (SV/m2), was not significantly different in the two populations. SV/m2 showed significant negative correlation with the presence of peripheral vascular disease, fasting serum cholesterol concentration, glycosylated hemoglobin (HbA1c) concentration, and the duration of diabetes. The presence or absence of retinopathy (27.7% of cases) or nephropathy (4.3% of cases) did not show strong association with the SV/m2. Neither the duration of the hypertension nor the systolic or diastolic blood pressure correlated significantly with blood flow in the extremity. These data suggest that only some of the parameters used to assess "control" of diabetic patients can be useful predictors of macrovascular as well as microvascular disease in diabetic patients.

Adult↗
PubMedDate not supplied

[The application of informatics to mercury gauge plethysmography].

In this study, the authors present a computerized mercury-gauge plethysmography device. The electrical signals collected by the plethysmograph are sent to the computer where they are analyzed by a specially devised interpretation program. The graphs are flashed on the screen, the parameters are automatically and instantly calculated, and a printed-out medical report may be obtained at the end of the test. The various characteristics of the material and the program are presented.

Data Display↗
PubMed1989

[Bronchial provocation in children: a comparison between the polyfrequent oscillation method and body plethysmography].

With the aid of the forced oscillation technique (FOT), parameters of the mechanics of respiration are measured with a minimum requirement of patient cooperation. This means that this technique is particularly suitable for use in children. The resistance (Rrs) established with the FOT correlates well with the airway resistance (Raw) measured with whole-body plethysmography (BP) (2, 4). So far, the blind resistance (Xrs) also simultaneously measurable with FOT, has received but little attention. The objective of this investigation was, in children, to compare all the resistances measurable with FOT with the parameters of BP during bronchial provocations with carbachol.

Adolescent↗
PubMedDate not supplied

[Tetrapolar modification of integral body impedance plethysmography].

A decrease in the amplifying ratio of inlet high-frequency amplifiers makes it possible to use PPG2-02 apparatus for tetrapolar modification of integral body impedance plethysmography (IBIP) without the currently used accessory device - divider. In 15 subjects impedance was measured using PPG-01 apparatus in the modification of M. I. Tischenko (intended for bipolar IBIP) or PPG2-02 apparatus. A direct close correlation (r = 0.982) has been established between impedance value, as measured by PPG2-02 apparatus and calculated according to linear regression equation, and impedance value, as measured by PPG2-02 apparatus. Mean deviation of the impedance value measured by PPG2-02 apparatus from that measured by PPG-01 apparatus was 2.8% and did not exceed 6%. The impedance value measured may be used for the determination of the cardiac output and extracellular fluid volume according to M. I. Tishchenko's formulas.

Humans↗
PubMed1989

Impedance plethysmography. A noninvasive screening method to detect deep-vein thrombosis.

Impedance plethysmography (IPG) is a useful noninvasive detection of proximal segment thrombosis. Seven hundred patients treated with total hip arthroplasty were examined preoperatively and several times postoperatively using this technique. Twenty-one abnormal IPG results were obtained, and venography confirmed that 12 of these patients had proximal segment thrombi and five had evidence of calf thrombi. Four venograms were completely clear, demonstrating a false-positive rate of 1.3% (including calf thrombi). Six patients with normal IPG results had calf thrombi. All positive venograms indicating a thrombus in the proximal venous segment were indicated with a positive IPG result, giving a sensitivity of 100%. The standardization of the procedure involving constant leg elevation has assisted in the accuracy of this screening system.

Hip Prosthesis↗
PubMed1989

Management of clinically suspected acute venous thrombosis in outpatients with serial impedance plethysmography in a community hospital setting.

The reported high sensitivity and specificity of impedance plethysmography (IPG) in the diagnosis of proximal vein thrombosis were evaluated in a prospective cohort follow-up study, in which IPG was performed three times over a period of seven days in 243 consecutive outpatients with clinically suspected deep venous thrombosis (DVT). The test was abnormal in 112 patients (46%). The positive predictive value of an abnormal IPG for venography-proved DVT was 90%. One hundred thirty-one patients (54%) with repeatedly normal tests were considered not to have DVT, and anticoagulants were withheld. During six months of follow-up, completed in all patients with repeatedly normal IPG, no patient died of venous thromboembolism and no patient returned with clinically suspected pulmonary embolism. One patient (0.8%) returned after two months with recurrent leg symptoms, and venous thrombosis was documented (95% confidence limits, 0.02% to 4.21%). Another patient, who was nonsymptomatic, had an abnormal IPG at the three-month follow-up visit, and venography revealed venous thrombosis. Patients sent by general practitioners to a community hospital, with clinically suspected acute DVT, can be effectively managed by serial IPG alone.

Ambulatory Care↗
PubMed1985

The study of mechanical properties of rats lungs by whole body plethysmography.

A simple technic for studying the pulmonary mechanics of rats by whole body plethysmography is presented. The parameters measured were: Tidal Volume (TV); Respiratory Frequency (RF); Transpulmonary Basal Pressure (TBP); Dynamic Compliance (Cdyn); Functional Residual Capacity (FRC); Transpulmonary Pressure/Volume curve (TP/V); Forced Expiratory Volume of 1/4 second (FEV 1/4); Expiratory Reserve Volume (ERV); Inspiratory Capacity (IC); Inspiratory Reserve Volume (IRV); Forced Vital Capacity (FVC); Residual Volume (RV); Forced Expiratory Mean Flow between 100-50% (FEMF 100-50), 50-25% (FEMF 50-25) and 25-0% (FEMF 25-0) of the FVC, and Total Lung Capacity (TLC). In order to verify the accuracy of the technic, common male adult Wistar rats, in which pulmonary obstructive disease is normally expected, were first submitted to these functional tests and then to pathological examination. According to the intensity of the morphological pulmonary lesion, the rats were divided in two groups: with and without suppurative pneumopathy. The analysis of the pulmonary function data showed significant decrease of the FEV 1/4 and FEMF 50-25 and increase of the FRC and RV in the groups with pulmonary suppuration. Thus, a discriminant function could be established to characterize the two groups with 100% efficiency. It was concluded that these pulmonary function tests are a valuable and reliable tool to detect lung diseases in rats.

Animals↗
PubMed1986

Non-invasive measurement of skin blood flow: comparison between plethysmography, laser-Doppler flowmeter and heat thermal clearance method.

A comparison was made between (a) a new probe measuring heat thermal (HTC), (b) plethysmography and (c) a Laser-Doppler (LDF) technique during changes in skin blood flow (SkBF) on six subjects, each participating in a single experiment. Increase of SkBF was induced by heating the body skin with an electric cover. Heat thermal clearance correlated well with the forearm blood flow (FBF) (r = 0.69-0.97) and with LDF measurements (r = 0.86-0.92) in each experiment, Laser-Doppler flowmeter also correlated well with FBF (r = 0.73-0.97). However, the relationship between HTC, LDF and FBF varied from one experiment to another. Values for HTC and for LDF at zero FBF, extrapolated from the regression relationships, ranged from 6.438 to 10.919 k, and from -0.37 to +0.17 volt respectively. The value for HTC at zero LDF extrapolated from the regression relationships ranged from 4.109 to 12.413 k. Values for HTC and LDF when blood flow to the arm was mechanically occluded ranged from 5.17 to 10.71 k and from 0.07 to 0.24 volt respectively. Thus HTC, LDF and FBF measurement of SkBF appear to produce the same response pattern during reflex cutaneous vasodilatation. Each of these three methods measured SkBF in different skin areas and at different depths in the skin, which might also explain the variability in their relationship.

Adult↗