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At least 217 records · Page 12Linked to original sources
PubMed1989

Radioisotope penile plethysmography: a technique for evaluating corpora cavernosal blood flow during early tumescence.

Radioisotope penile plethysmography is a nuclear medicine technique which assists in the evaluation of patients with erectile dysfunction. This technique attempts to noninvasively quantitate penile corpora cavernosal blood flow during early penile tumescence using technetium-99m-labeled red blood cells. Penile images and counts were acquired in a steady-state blood-pool phase prior to and after the administration of intracorporal papaverine. Penile counts, images, and time-activity curves were computer analyzed in order to determine peak corporal flow and volume changes. Peak corporal flow rates were compared to arterial integrity (determined by angiography) and venosinusoidal corporal leak (determined by cavernosometry). Peak corporal flow correlated well with arterial integrity (r = 0.91) but did not correlate with venosinusoidal leak parameters (r = 0.01). This report focuses on the methodology and the assumptions which form the foundation of this technique. The strong correlation of peak corporal flow and angiography suggests that radioisotope penile plethysmography could prove useful in the evaluation of arterial inflow disorders in patients with erectile dysfunction.

Adult↗
PubMed1988

[Reproducibility of venous occlusion plethysmography. Value of a computerized system of calculation].

The manual interpretation of identical occlusive venous plethysmography curves by different technicians is subject to a wide variation. The object of this study is to verify this state of affairs and to propose an automatic calculation of the different parameters usually used: the percentage volume increase (delta V), the time taken to half empty (t V/2) and the maximal venous outflow (MVO). We compared the variations, due to the operators, in the measurement of the parameters characterising identical curves obtained by occlusive venous plethysmography. Sixty curves from 30 patients, were photocopied and each was measured independently by four different operators. The results were compared with the measurements obtained automatically from a micro-computer connected to the plethysmograph. The measurements of the percentage volume increase and the time taken to half empty differed among the operators and the computer by less than 2%. However, the maximal venous outflow was subject to very large variations amongst the operators (up to 60%). This uncertainty is due to the operators choice of the point on the curve where the tangent is measured. The micro-computer, by fixing this point at 0.3 second after releasing the cuff allows a standardisation of this parameter.

Humans↗
PubMed1988

Comparison of the dose-response curves obtained by forced oscillation and plethysmography during carbachol inhalation.

We compared the cumulative dose-response curves obtained during carbachol inhalation by simultaneous measurements of airway specific conductance (sGaw) and respiratory conductance, in 23 subjects with or without bronchial hyperresponsiveness. The sGaw was measured by a body plethysmograph, whilst the random noise forced oscillation technique (FOT) was used to determine respiratory conductance. The sGaw was compared to respiratory conductance extrapolated to zero frequency (Grs0). Bronchial sensitivity was assessed by the threshold dose of carbachol (TD) that induced a decrease in sGaw and Grs0 of twice the baseline coefficient of variation. Bronchial responsiveness was assessed by the slopes (S) of the individual dose-response curves. The TD and S values obtained by FOT and by plethysmography were closely correlated (p less than 0.001). The carbachol doses inducing a 50% reduction in sGaw were equivalent to those causing a 42% reduction in Grs0 (r = 0.90; p less than 0.001). During bronchial challenge testing, FOT provides comparable information in terms of bronchial sensitivity and responsiveness to that supplied by plethysmography.

Adult↗
PubMed1988

[Body plethysmography studies in patients with obstructed nasal respiration before and following corrective surgery of the nasal septum].

The nasal resistance of 28 patients with nasal septum deviation was measured before and after septum correction according to Cottle by means of body plethysmography. Clinical state according to clinical state history and body plethysmography results before and after surgery are compared by means of a standardised measuring unit. There was statistical significance for improvement of nasal ventilation after surgery in all three parameters. An analysis of the discrepancy between history, clinical state and rhinomanometry was made. History and rhinomanometry correlated closely. They seemed to be the most important parameters to determine nasal complaints. 30 volunteers with normal breathing function of the nose were examined. The normal resistance values of both nasal cavities are 0.31 kPa/l/sec. before and 0.28 kPa/l/sec after shrinkage of the nasal mucosa. The normal values of the nasal airflow of the entire nose were compared with the measurements of the patient group.

Adolescent↗
PubMed1988

Face mask application for calibration of respiratory inductive plethysmography in lambs.

Respiratory inductive plethysmography is a non-invasive method of assessing breathing patterns that requires an airway connection for calibration. In previous studies an endotracheal tube was used to establish this connection. We employed a single position graphic calibration technique for gain calculation using a conical face mask in place of the endotracheal tube, thus eliminating the need for sedation and topical anaesthesia. Thirteen studies were completed on seven lambs. Validation of gains was performed by comparing volumes obtained simultaneously by respiratory inductive plethysmography and integrated pneumotachography. Total study time ranged between 5 and 10 min for each calibration procedure. Our results suggest that the conical mask can be used to perform accurate and time-efficient calibration of the respiratory inductive plethysmograph in the spontaneously breathing non-sedated lamb and eliminates the need for endotracheal intubation.

Animals↗
PubMedDate not supplied

[The value of postural plethysmography in the study of venous physiology and in the evaluation of vasotonic agents].

Venous physiology is generally neglected and badly studied. Knowledge of it is nevertheless essential in pathological cases such as venous incompetence and its treatment. It is this which is principally responsible for cardio-vascular adaptation after positional changes. Mercury gauge venous occlusion plethysmography has contributed certain progress. Postural mercury gauge plethysmography without venous occlusion answers the chief physiological preoccupations. No artefact impedes the physiology. The positional adaptation is tested. A DV/DP diagram is established and compared in normal subjects and patients with venous incompetence. A complementary procedure for a microcirculatory study is proposed: the measurement of cutaneous flux using laser Doppler or photoplethysmography and a study of the permeability of the capillary walls using fluorescein videodensitometry. This veritable testing stand of the venous system can serve as reference for procedures of therapeutic tests for all medication for venous tropism (vasotonics, vasodilators of venous location) or in studies on spatial medicine.

Humans↗
PubMedDate not supplied

[Effect of "anti-thrombosis" stockings on the venous hemodynamics of the lower extremities. Study using mercury gauge plethysmography].

Study by plethysmography with mercury gauge. The authors have analyzed the effects of "anti-thrombosis" stockings on venous hemodynamics of 18 lower extremities, by plethysmography with mercury gauge (Periflow J.S.I.). With this method, they delineate the limits of efficacy of the use of only elastic stockings as prophylactic treatment of the thrombo-embolic disease in immobilized patients.

Clothing↗
PubMed1987

Venous plethysmography values in patients with spinal cord injury.

To determine whether venous hemodynamics differ fundamentally between patients with spinal cord injury (SCI) and the abled-bodied population, quantitation of lower extremity venous plethysmography values was performed in 14 SCI patients and ten able-bodied subjects. The control group had an average maximum venous outflow (MVO) of 59.3 +/- 2.75 mL/min/100mL of tissue, mean +/- SE, and an average venous capacitance (VC) of 3.2 +/- 0.13mL/100mL. In contrast, the SCI patients had an average MVO of 32.5 +/- 2.57mL/min/100mL and an average VC of 2.3 +/- 0.17mL/100mL. The differences between the two groups were statistically significant, suggesting that the standard venous function index of plethysmography values used in the general population may not be applicable to the SCI population and that, therefore, a new standard for SCI patients derived from a larger data base should be sought.

Adolescent↗
PubMed1987

Assessment of venous muscle pump function by ambulatory calf volume strain gauge plethysmography after surgical treatment of varicose veins: a prospective study of 21 patients.

A prospective study of the improvement in leg muscle pump function after radical surgery was performed for treatment of varicose veins. Venous muscle pump function was assessed in 21 patients with primary varicose veins by means of ambulatory strain gauge plethysmography immediately before surgery and 3 months and 60 months after surgical treatment of varicose veins. The physiologic documentation of the operative efficacy was provided by the mean venous reflux, which was reduced by 54% (p less than 0.001), and the mean expelled volume, which was increased by 58% (p less than 0.001). Initially, all patients had improved venous muscle pump function. This improvement was still present 60 months after surgery. At clinical assessment 3 months after surgery, it was noted that 90% of the patients were without residual varicose veins (p less than 0.01). Sixty months after surgery, 71% of the patients were without apparent varicose veins (p less than 0.05). Subjective symptoms had virtually disappeared 3 months after surgery (p less than 0.001) but were found to a variable extent in 80% of the patients at the 60-month control follow-up. It is concluded that ambulatory strain gauge plethysmography may quantitate the effect of surgery in patients with venous valvular incompetence; in addition to measurements of refilling time, it is able to measure the muscle-pump-generated expelled volume because of in-place electrical calibration.

Adult↗
PubMedDate not supplied

Value of venous occlusion plethysmography to study venoactive medication in men.

Venous occlusion plethysmography is a useful tool to investigate the effect of a vaso-active medication on the venous circulation in man. However, room temperature can be very critical when small changes have to be detected. Therefore several authors induce a preconstriction of the veins for example with norepinephrine. When the conditions of the experiment are carefully controlled and a very sensitive plethysmograph is used, a significant effect on forearm veins can be shown even after small doses of nitrates and a high room temperature; matching with placebo is critically needed. It is likely that by lowering room temperature the response would be exaggerated. Taking these restrictions in mind, venous occlusion plethysmography can be a very valuable, non-invasive tool to study the effect of vaso-active treatment on the veins in men.

Heart Failure↗
PubMed1985

[Thromboembolic disease in pneumology. Value of mercury-gauge plethysmography with venous occlusion].

Mercury gauge plethysmography with venous occlusion (PJC) is an atraumatic procedure for the diagnosis of deep venous thrombosis (TVP) of the lower limbs: 103 patients were studied both by plethysmography and phlebography (the reference examination). 54 were hospitalised for a suspicion of pulmonary emboli (EP), 21 for clinical phlebitis and finally 28 subjects had the studies as part of a systematic work-up. 60 cases of TVP of the lower limbs were discovered: 47 were recent, 34 were proximal and 13 sural. The clinical examination failed to reveal these in 36% of cases; the phlebographic and PJC results were concordant for 75% of cases: PJC seemed particularly to be the technique of high sensibility for the early diagnosis of proximal TVP but of a lesser interest for the early diagnosis of peripheral TVP (sensibility 69%). This examination makes an important contribution: for the early diagnosis of hidden proximal TVP; for the diagnosis of EP in its deceptive forms where the presence of a peripheral embolic focus constitutes one weighing factor towards the diagnosis of peripheral thrombo-embolic disease (MIE); for the control of anti-coagulant therapy in the clinic where the local inflammatory process and the biology controlling the consumption of heparin are jointly observed and the study of venous drainage allows an appropriate decision to be made as to the cessation of anticoagulant therapy and minimises the risk of recurrence or avoiding postphlebitis disease by a prolonged treatment.

Anticoagulants↗
PubMedDate not supplied

Critical evaluation of venous occlusion plethysmography in the diagnosis of occlusive arterial diseases in the lower limbs.

In this paper, the value of venous occlusion plethysmography in the differentiation between normal and abnormal is discussed. Data are obtained with an ECG triggered plethysmograph allowing an automatic and also a fast recording of the different parameters of the reactive hyperemia. A group of 74 proven "normal" limbs and of 93 proven "abnormal" limbs was studied. No difference in resting blood flow was seen; however, several parameters derived from reactive hyperemia were significantly different; curves obtained after arrest of the circulation during 3 minutes yielded the best results. Discriminant analysis showed that peak blood flow was the best individual performing parameter; using four variables of the reactive hyperemia curve, an overall performance of 84.9% was obtained with specificity of 93% and sensitivity of 76%. The place of plethysmography in the definition of vascular changes is discussed.

Arterial Occlusive Diseases↗
PubMedDate not supplied

[Proof of the effectiveness of compression by nuclear medicine, plethysmography and venous pressure measurement].

1) In a lying down position a) immediately and under rapid compression, one observes a reduction in muscle flow as well as a reduction of the perfusion of the foot and of the systolic pressure of the big toe. After disinfiltration of the leg by compression, the muscular flow more than doubles (clearance with Xenon 133). b) a reduction in the venous blood volume of the limb by about 1/3. c) an increase in the venous circulation speed by about 1.5 times (tracer in a vein of the back of the foot). The degree of change is depending from the pressure of the compressive bandage (in a lying down position, between 20 mmHg and a maximum of 40 mmHg). 2) while walking a) shortening of the pathological refluxes in the veins of the lower limbs (directional Doppler). b) improvement of the pump output (increase inthe volume of blood pumped upwards), and a variable influence of the peripheral venous pressure (simultaneous methods of plethysmography of the foot and the venous pressure). c) reduction of edema, improvement of the disturbed lymphatic flow (plethysmography, lymphotropic tracers with radioactive marking).

Arteries↗
PubMedDate not supplied

Venous occlusion plethysmography for the detection of venous thrombosis.

Venous occlusion plethysmography (VOP) was originally developed to study the physiology of the arterial circulation in the extremities. Improvements in plethysmographic instruments have now made bedside evaluation of peripheral hemodynamics feasible. In recent years, VOP has been employed for the detection of deep vein thrombosis. Combined analysis of the venous volume increase and the subsequent venous outflow in 3 sec, and measured by impedance plethysmography, has produced a 95% correlation with venography in detecting thrombosis of the popliteal, femoral, and iliac veins in 390 limbs. The method is inadequate for detection of isolated calf thrombi.

Blood Circulation↗
PubMed1979

[Systolic time intervals measurement by electrical plethysmography (author's transl)].

The determination of left systolic time intervals by electrical impedance plethysmography, using precordial pick-up electrodes, gives as good results as classical method using phonocardiogramm and carotid pulse trace. Moreover the measurement of right systolic time intervals is possible with this method. Another advantage of this technic is that it only requires affixing four electrocardiographic electrodes to the thorax and is usable during relatively long periods of time. The value of the basal thoracic impedance provides also a mean of following intrathoracic fluid changes and an early detection of pulmonary oedema, pleural effusion or hemorrage into the chest. So, cardiac impedance plethysmography appears as a good tool for cardiac monitoring.

Cardiography, Impedance↗
PubMed1980

[Measurement of cardiac output by electrical impedance plethysmography during respiration and in apnea].

The measurement of cardiac output by electrical impedance plethysmography (non-invasive technique) may be disturbed by a certain number of factors, including respiration. The authors sought to demonstrate that this factor could be eliminated during measurement calculations. By this method, in 18 adult subjects with coronary artery disease, 50 measurements during respiration and 50 measurements in apnoea (paired measurements) of stroke volume and of cardiac output were performed. Stroke volume was calculated using Kubicek's formula: SV = P(L2/Zo2) (dz/dt min)t Results were as follows: highly significant correlation between values for stroke volume obtained during respiration and in apnoea (r ;.9767; n=50; P < 0.001); highly significant correlation between values for cardiac output obtained under the same conditions (r = 0.9744; n=50; P < 0.001). The authors conclude that with the limits of certain technical conditions of measurement, respiration does not disturb measurements of stroke volume and of cardiac output by electrical impedance plethysmography.

Adult↗
PubMedDate not supplied

[Evaluation of venotropic drugs by venous gas plethysmography. A study of procyanidolic oligomers (author's transl)].

Venous tone in the lower limbs can be measured by venous occlusion gas plethysmography before and after giving venotropic drugs. Four groups, each of which included ten patients with widespread varicose veins, were given different medications. Each patient was studied by plethysmography during the first five hours following drug ingestion. In untreated controls, venous tone decreased during rest. A reference drug was uneffective. Increase in venous tone induced by 150 mg of procyanidolic oligomers was comparable to that which followed ingestion of a high dose of hamamelis-hydrastis mixture.

Benzopyrans↗
PubMed1984

[Strain-gauge plethysmography in the evaluation of the evolution of deep vein thrombosis of the legs].

Previous research has shown that MVO (Maximum Venous Outflow), VR (Venous Reflux), VE (Venous Emptying) and the respiratory waves recording are useful in differentiating occlusion and recanalization in postphlebitic syndrome. In the present work strain-gauge plethysmography was employed to quantitate the venous function after deep venous thrombosis of the legs. The studies were performed in a vascular laboratory with controlled temperature (23 to 25 C); records were obtained by a plethysmograph Parks mod. 270 connected to a Hewlett-Packard multi-channel mod. 7700. 17 patients (12 males, 5 females), mean age 55 years (range 24-75) that presented femoropopliteal thrombophlebitis documented by phlebography at the admission to the hospital were examined. MVO with and without superficial veins occlusion was measured by a mercury in silastic strain-gauge placed circumferentially about the calf. A pneumatic cuff thigh was inflated to 60 mm Hg. VE was measured in patients lying in inclined bed with the lower extremities 100 cm below the heart level compressing the calf with a pneumatic cuff 10 times for 5 seconds; the strain-gauge was placed on the foot level. VR after Valsalva's maneuver and the respiratory waves were recorded by a strain-gauge positioned at the maximum girth about the calf in patients lying on inclinated bed with the lower extremities 50 cm below the heart level. The result are here indicated: (Table: see text) There was differences in the evolution of venous function after deep venous thrombosis of the legs for each patient. Strain-gauge plethysmography may become evaluable non invasive technique in the evaluation of deep venous thrombosis evolution in the legs. The therapeutic assessment of postphlebitic syndrome.

Adult↗