PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “PLETHYSMOGRAPHY”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1997

Changes in subcutaneous interstitial fluid pressure, tissue oxygenation, and skin red cell flux during venous congestion plethysmography in men.

OBJECTIVE: Venous congestion plethysmography enables noninvasive assessment of microvascular filtration capacity (Kf) in limbs. However, increases in fluid filtration might alter the balance of Starling forces: for example, progressive increases in interstitial fluid pressure (Pi) would reduce net fluid flux, thus underestimating Kf. Furthermore, elevation of cuff pressure to values close to diastolic blood pressure, as used in the protocol, may be itself impair tissue perfusion with unknown effects on the microvascular parameters investigated. METHODS: Pi was measured in healthy volunteers (n = 14) with a modified "Wick in needle" technique during small (8 mm Hg) cumulative increases in venous pressure (0-95 mm Hg). Changes in the hemoglobin (Hb) concentration, oxygenated hemoglobin (HbO2) concentration and oxidized cytochrome aa3 concentration were assessed in the calf using noninvasive near-infrared spectroscopy. Skin red blood cell flux close to the strain gauge was evaluated by laser Doppler fluxmetry. RESULTS: Pi at control was -0.89 +/- 0.8 mm Hg and during elevation of venous pressure remained constant until a cuff pressure of 30 mm Hg was reached. It rose thereafter to 1.57 +/- 1.3 mm Hg (mean +/- SD). Skin red cell flux was significantly reduced when cuff pressure exceeded 30 mm Hg and following cuff deflation, evidence of reactive hyperemia was obtained. Hb concentration increased significantly as a result of venous pressure elevation. No change in either HbO2 or cytochrome aa3 concentration was observed as long as cuff pressure remained under diastolic blood pressure. CONCLUSIONS: The small increase in Pi together with an absence of impaired tissue oxygenation during the venous congestion plethysmography protocol described by Gamble et al. supports the contention that this protocol enables accurate assessment of filtration capacity.

Adult↗
PubMed1993

Limitations of impedance plethysmography in the diagnosis of clinically suspected deep-vein thrombosis.

OBJECTIVE: To re-evaluate the accuracy of impedance plethysmography (IPG) for the detection of proximal deep-vein thrombosis (DVT). PATIENTS: A total of 384 of 390 consecutive outpatients referred with their first episode of clinically suspected deep-vein thrombosis. SETTING: University-based tertiary care medical center associated with a cancer clinic. DESIGN: A retrospective analysis of a cohort of patients whose data were recorded and stored prospectively on a computerized data base over a 22-month period. MEASUREMENTS: Patients were evaluated by a physician and underwent IPG testing. Patients with abnormal IPG tests and those with normal IPG results in whom there was a high clinical suspicion of DVT or in whom follow-up IPG testing was not feasible were referred for venography. Venography and IPG results were interpreted by a panel of independent observers. Two models of the IPG instrument were used (Codman 200 and Electrodiagnostic Instruments 800). RESULTS: Venography (or compression ultrasound) was done in 57 patients with an abnormal IPG test and in 85 patients with normal IPG results. Impedance plethysmography was abnormal in only 37 of 56 patients with confirmed proximal-vein thrombosis (sensitivity, 66%; 95% Cl, 52% to 78%). Of the 57 patients with an abnormal IPG result, 37 had DVT (positive predictive value, 65%). The sensitivity for the detection of proximal DVT did not differ between the IPG 200 and 800 instruments (sensitivity, 63% and 71%, respectively; P > 0.2). Of the 19 proximal-vein thrombi not detected by IPG, 12 (63%) were occlusive and 11 (58%) involved at least the popliteal and superficial femoral veins. CONCLUSIONS: At our center, IPG has a far lower sensitivity for proximal-vein thrombosis than has been previously reported for symptomatic outpatients. The reason for this low sensitivity is unclear. Our findings indicate that centers using IPG as the initial diagnostic test for suspected DVT should be aware of this potential problem and should consider re-evaluating the sensitivity of their IPG machines by performing venography in a cohort of their patients with normal test results.

Female↗
PubMed2005

Reproducibility of duplex ultrasonography and air plethysmography used for the evaluation of chronic venous insufficiency.

OBJECTIVE: The purpose of this study was to determine the reproducibility of measurements on duplex ultrasonography (DU) and air plethysmography (APG) in subjects with post-thrombotic syndrome. METHODS: Duplex ultrasonography and APG were used to measure indices of lower limb venous reflux in 15 limbs with a history of deep vein thrombosis and evidence of venous insufficiency as diagnosed by ultrasonography. Three limbs were in class 0; 4 were in classes 1 to 3; and 8 were in classes 4 to 6, according to clinical, etiologic, anatomic, and pathophysiologic clinical classification. Duplex ultrasonography was performed 3 times on the same day, and venous diameter, area, peak reflux velocity, reflux flow volume, and reflux duration measurements were obtained. Air plethysmography was performed on 2 days, 7 to 10 days apart, with 1 measurement on the first day and 2 measurements on the second day. Values obtained from APG included outflow fraction, venous filling index, ejection fraction, and residual volume fraction. The measurements were performed by a vascular technologist blinded to the previous test results. One-way analysis of variance, the Student paired t test, and Bland-Altman plots were used to examine the statistical differences of the DU and APG parameters for all measurements. RESULTS: The mean coefficient of variation for within-subject measurements of all DU and APG parameters measured was less than 10%. Bland-Altman plots showed that there were no apparent trends with increasing values over a wide range for any of the DU parameters, nor were there any for the APG parameters. CONCLUSIONS: Under ideal conditions, when measured by a highly trained technologist, both DU and APG showed satisfactory reproducibility.

Adult↗
PubMed1975

Immediate assessment of vascular operations using segmental plethysmography.

Segmental plethysmography was used as a monitoring device during 156 direct vessel operations on the abdominal aorta and lower extremity vessels. Patency of distal vessels was assessed continuously and noninvasively before and during wound closure. A pulsatile response at wound closure was indicative of immediate and lasting patency in 94 per cent of extremities monitored. Plethysmographic detection of acute intraoperative occlusive phenomena allowed correction of such problems during the same procedure. The "chronic nonpulsatile" plethysmographic response, although not indicative of accidental occlusions in the majority of cases, portended a poor result, primarily on the basis of insufficient collateralization around pre-existing distal occlusive disease. Patients with such responses should be considered for additional efforts at revascularization. Segmental plethysmography is a reliable and objective method of immediate assessment of vascular patency and for prediction of long-term results.

Humans↗
PubMed1975

The clinical significance of biphasic venous emptying curves from the lower limb in venous occlusion plethysmography.

The utilization of venous occlusion plethysmography in the routine diagnosis of acute venous thrombosis in the leg has disclosed a previously unreported type of biphasic venous emptying curve that has proved to be of special diagnostic significance. The examinations were undertaken with a Dohn plethysmograph for segmental application of the calf. The emptying curves in question had an initial phase at the ordinary rapid rate, changing distinctly within 1.5 sec into a definitely slower phase of venous emptying. Biphasic emptying curves were found to be characteristic of patients with isolated, high venous obstruction, mostly acute thromboses, but more or less intact veins in peripheral parts of the leg. The same type of pathological emptying curves could be provoked by external compression of the femoral vein or Valsalva's manoeuvre, providing experimental evidence of the underlying mechanism. The venous emptying course might be similarly influenced also by varicose veins, pregnancy, and right heart failure. The diagnostic experience of biphasic emptying curves in clinical practice indicates, that this particular way of interpreting venous occlusion plethysmography is a valuable complement to phlebography in the detection of proximal venous obstructions in the lower limb, whether due to iliac thrombosis or elusive intrapelvic tumours.

Acute Disease↗
PubMed1999

[A comparative study of finger plethysmography and aortic pressure for monitoring the effect of external counterpulsation].

Invasive pressure detecting and monitoring of aortic root was conducted in 20 volunteers so as to study the effect of Enhanced External Counterpulsation (EECP) on aortic pressure and finger plethysmography. The results demonstrated that the changes of aortic diastolic pressure linearly related to the counterpusation's bladder pressure, and the aortic augmentation increased to the top of 168.56 mmHg with a D/S ratio of 2.75(amplitude ratio of diastolic waveform and systolic waveform, D/S ratio) following the bladder pressure of 0.45 Kg/cm2. With the increase of bladder pressure, the dp/dt of aortic augmentation elevated gradually, but a down-regulating trend was seen in systolic waveform. During EECP, the starting time of plethysmographic augmentation had a mean delay of 108.20 +/- 25.70 ms comparing with that of aortic augmentation. The duration between the starting time of aortic systolic waveform and that of finger plethysmogram was arround 96.69 +/- 38.70 ms. When the bladder pressure changed, no significant difference was observed among them. The D/S ratio of finger plethysmographic waveform changed in concord with that of aortic pressure with the promotion of bladder pressure. Therefore, a relationship between aortic D/S ratio (Y) and plethysmographic D/S ratio (x) was constructed by the linear regression analysis: Y = 0.376 + 0.457X. It can be concluded that EECP has significant effects on aortic D/S ratio, aortic peak augmentation and its dp/dt value. Finger plethysmography, to date, still plays important roles in monitoring and controlling EECP work safely and effectively.

Adolescent↗
PubMed1992

Comparison of descending phlebography with quantitative photoplethysmography, air plethysmography, and duplex quantitative valve closure time in assessing deep venous reflux.

To assess the role of noninvasive tests--quantitative photoplethysmography, air plethysmography, and quantitative duplex scanning, we compared a group of normal (group N, eight limbs) volunteers to patients with severe chronic venous insufficiency who were stratified according to the degree of reflux seen on the current "gold standard," descending phlebography. Group M (10 limbs) had mild (grades 0 to 2) reflux, and group S (10 limbs) had severe (grades 3 to 4) reflux as determined by phlebography. Quantitative photoplethysmography could identify normal from abnormal limbs but could not distinguish the severity of reflux. Air plethysmography was used to calculate venous filling index, ejection fraction, and residual volume fraction. Ejection fraction was the same in all groups. Venous filling index could not significantly distinguish the degree of reflux (group M vs group S) but increased as reflux increased. Residual volume fraction was considerably higher in group S. Quantitative duplex valve closure time was measured in the superficial femoral and popliteal veins, with the values added together in each limb to give a total valve closure time (TVCT). A TVCT value greater than or equal to 4 seconds correlated best with severe phlebographic reflux, with a sensitivity of 90%, a specificity of 94%, and an accuracy of 93%. This value was confirmed as the best test for venous reflux by receiver operating characteristic curve analysis. Thus in the evaluation of patients with severe chronic venous insufficiency who are candidates for phlebography and surgery, quantitative duplex measurement of TVCT gives the best noninvasive assessment of the severity of deep venous reflux.

Adult↗
PubMed1992

[A comparative study in children of 3 anesthetic techniques using plethysmography, pulse oximetry and the level of postoperative pain].

This study compares three techniques of anesthesia on the ground of the course of plethysmography, pulse oximetry and evaluation of postoperative pain in 75 pediatric patients divided into 3 groups. Results show that combined anesthesia, intravenous and regional anesthesia, has a less desaturation incidence, a better development of plethysmography and a positive reply to postoperative pain.

Anesthesia↗
PubMed2004

[Comparison of four techniques for the measurement of lung volumes and airway resistances by plethysmography].

OBJECTIVE: To search influence of measurement technique of thoracic gas volume(Vgt) and airway resistance(Raw) by plethysmography on results. MATERIALS AND METHODS: 20 healthy subjects, aged 22.75 + 0.40 years were studied. Vgt and Raw were measured by series of gentle panting manoeuvres (GPM) or calm respiration (CR) before and after closure of a shutter valve. So, four methods were compared : method 1 (M1) CR before ahd after, method 2 (M2): CR before and GPM after, method 3 (M3) GPM before and CR after, and method 4 (M4): GPM before and after the closure of the shutter valve. Five tests were maked with each method. RESULTS: There is no significant inter-tests variability with each method. Raw(cm H2O/L/s) measured by M1 and M2 were so elevated if compared to M3 and M4 (M1 : 2.65 + 0.102; M2: 2.47 + 0.171; M3: 1.21 + 0.080; M4: 1.30 + 0.102 ; p < 0.05). There is also a significant variability intermethods in Vgt I): (M1: 3.53 + 0.188; M2 : 3.60 + 0.203; M3 : 3.91 + 0.262; M4: 3.84 + 0.247; p < 0.05). CONCLUSION: The plethysmography measurement method must be considered in the interpretation of Vgt and Raw values.

Adult↗
PubMed2005

Comparative analysis of the bronchodilator response measured by impulse oscillometry (IOS), spirometry and body plethysmography in asthmatic children.

BACKGROUND: Asthma is common among young children. The assessment of respiratory resistance by the impulse oscillometry system (IOS), based on the superimposition of respiratory flow by short-time impulses, requires no patient active collaboration. AIM: We evaluated the baseline repeatability and bronchodilator response of IOS indices in preschool children, their correlation with spirometry and whole body plethysmography, and differences between atopic and nonatopic children. PATIENTS AND METHODS: Thirty-three asthmatic children (3-6 yrs.) underwent IOS measurement (R5rs, R20rs and X5rs) by triplicate at the baseline, after placebo and after salbutamol inhalation. Spirometry (FEV1) and whole body plethysmography (sRaw) were made at the baseline and after salbutamol. Baseline within-test (coefficient of variation: CV%) and between-test repeatability (baseline-placebo) were addressed. Bronchodilator response was evaluated by the SD index (change in multiples of the between-test repeatability). RESULTS: Baseline repeatability for R5rs was 4.1%. Its values decreased by 2SD after salbutamol inhalation, and correlated with FEV1 and sRaw at both, baseline (r=-0.51 and r=0.49) and post-salbutamol (r=-0.63 and r=0.54). A trend towards correlation between salbutamol-induced changes in R5rs and in sRaw (r=0.33) was observed. Atopic and non-atopic children showed no differences in lung function. CONCLUSION: IOS was well accepted by young asthmatic children and provided reproducible and sensitive indices of lung function. Resistance values obtained by IOS at low frequency (R5rs) were reproducible and correlated with spirometry and plethysmographic values.

Airway Resistance↗
PubMed1991

[Site resolution study of venous outflow velocity and capacity by imaging plethysmography systems].

Two imaging systems designed for plethysmography purposes are used to investigate venous capacity as well as maximum venous outflow. A series of pictures of the extremity are taken during a subsystolic blood obstruction. As a result, capacity as well as maximum outflow can be plotted as locally resolved profiles alongside the axis of the extremity. The advantage of the new method compared to conventional plethysmography is discussed.

Humans↗
PubMed1991

Combined technetium radioisotope penile plethysmography and xenon washout: a technique for evaluating corpora cavernosal inflow and outflow during early tumescence.

Combined technetium radioisotope penile plethysmography and xenon washout is a new technique that measures both corporal arterial inflow and venous sinusoidal outflow during early tumescence in patients with erectile dysfunction. Fourteen patients were studied using 99mTc-RBCs to measure inflow and 133Xe or 127Xe in saline to measure outflow. Tumescence was induced by injecting papaverine intracorporally. Peak corporal rates corrected for outflow (r = 0.88) and uncorrected for outflow (r = 0.91) and change in volume over 2 min centered around peak flow [corrected] (r = 0.96) all correlated with angiography. Outflow measurements did not correlate with intracorporal resistance. Thus, outflow rates alone could not be used to predict venous sinusoidal competence. Normal inflow rate is greater than 20 ml/min; probable normal 12-20; indeterminate inflow 7-12; and abnormal inflow less than 7 ml/min. Technetium-99m radioisotope penile plethysmography and xenon washout can be performed together and both provide a method for simultaneously evaluating the relationship between corporal inflow and outflow rates in patients with erectile dysfunction.

Adult↗
PubMed1990

Non-invasive and simultaneous cardiovascular measurements using plethysmography techniques.

New non-invasive multifunctional methods have been proposed for the simultaneous measurements of more than two cardiovascular hemodynamic parameters such as peripheral and central blood flow, arterial and venous pressure, peripheral flow resistance, arterial and venous elasticity, hematocrit, blood oxygenation, etc. A proper combination of one or two of the recently developed sphygmomanometries called the 'volume oscillometric method' and the 'volume compensation method' with photoelectric plethysmography, and blood flowmetry with electrical admittance plethysmography provides successful measurement of these cardiovascular parameters. This paper discusses the measurement principles, including methodologies, and evaluates the accuracy and practicability of each method. Preliminary descriptions of newly designed instruments based on these methods together with a few examples of measured data are also presented. The results obtained show that the proposed non-invasive and simultaneous physiological measurements appear promising for use not only in basic research laboratories, but also in clinical practice including health screening and testing.

Adult↗
PubMed1990

[Non-invasive diagnosis of phlebothrombosis of the limbs. Prospective evaluation of mercury gauge plethysmography associated with ultrasonic Doppler].

Associated ultrasonic Doppler study (D) and plethysmography (P) were evaluated as compared to phlebography in diagnosis of venous thrombosis of the lower limbs (TVP). Probes (5 and 7.5 MHz respectively) were used in D for examination of proximal and calf veins. Plethysmography using a mercury ring gauge (Perivein, ETNA) was considered pathologic if filling volume was less than 1.5 vol% and/or emptying volume less than 40 ml/min/100 ml. One hundred and four patients hospitalized in an internal medicine department for suspected deep venous thrombosis were studied, including 97 for whom phlebography interpretation was unmistakable: 11 calf vein, 28 collector trunk and 42 total limb involvement TVP. In these localizations, D sensitivity was respectively 55, 72 and 100% (mean 85.5%) and that of P 63.5, 68 and 88% (mean 77.7%); association of D or P improved sensitivity: 82, 82 and 100% (mean 91.5%). Specificity was 86.6% for D, a poor 62.5% for P and 93.5% for associated D and P. The results are comparable to those in the literature but disappointing for diagnosis of isolated calf vein TVP. False-negatives in both D and P were due to strong collateral circulation or limited thrombus extension.

Adolescent↗
PubMed1990

A method for the elimination of artefacts in electric field plethysmography of the lung.

The reliability of electric plethysmography for respiration monitoring is reduced by artefacts caused by the cardiac activity, by motions, electromagnetic cross-talk and others. For artefact suppression, a constant-current field-plethysmography technique is discussed which uses the voltage of an auxiliary electrode in addition to the conventional four-electrode arrangement. By means of a differential amplifier, a respiration signal is produced which is almost entirely free from heart artefacts, while the intensity of additional artefacts is suppressed. In principle, the technique can also be used for the separate determination of the ventilation intensity of the two lungs.

Electric Conductivity↗
PubMed1990

Comparison of platelet scintigraphy, impedance plethysmography gray scale and color flow duplex ultrasound and venography for the diagnosis of venous thrombosis.

The several techniques available for the diagnosis of venous thrombosis have not been directly compared in the same patient population. Thus color and gray scale duplex ultrasound (U), impedance plethysmography (IPG), 3-4 hr platelet imaging (PS) were compared to venography (V), in 104 consecutive patients (in hospital and out). PS and V were read by two, and IPG and U by one, blinded reader. Comparisons were made for the calf (CA), popliteal (Pop) and femoral (Fem) vessels. Reproducibility of V and PS was 84 and 87%. (table; see text) We conclude that PS, while having a very high specificity, has an unacceptably low sensitivity. However, while both impedance plethysmography and color flow ultrasound have excellent and similar diagnostic accuracy in the femoral, these techniques have either a low sensitivity or low technical success rate in the calf or popliteal veins.

Blood Platelets↗
PubMed1990

[The value of occlusion plethysmography and stress venous pressure in functional diagnosis following leg vein thrombosis].

In 52 patients with condition after thrombosis of the deep leg veins before discharge from hospital the venous capacity and the venous outflow were measured on the two legs by means of occlusion plethysmography of the veins as well as the percental decrease of the venous pressure during action of the leg muscles by means of phlebodynamometry. The results have been compared with the phlebography. 10 patients again had a venous system without pathologic findings, in 12 patients unchangedly was a complete and in 30 ones in incomplete occlusion. By means of the measuring of the venous pressure still existing obstacles of the outflow of the pelvic and femoral region could be separated from the lower leg and their degree of severity, too, could be quantified. The venous capacity and the venous outflow allowed with sufficient security to delimit the values of the healthy leg from those of the postthrombotic one, whereas a localization of the height and a further quantification of the postthrombotic condition failed. Improved technology of the devices as well as the establishment of venous capacity and venous outflow in one measuring process increase the value of the venous occlusion plethysmography clearly as a non-invasive method which can be carried out by a function-assistant.

Adult↗