Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Supination”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 505 records · Page 28Linked to original sources
PubMed1991

Volumetric response of right ventricle during progressive supine exercise in men.

Right ventricular (RV) adaptation to supine exercise has been studied in 10 young male volunteers by 81mKr electrocardiogram (ECG)-gated radionuclide ventriculography. During progressive supine exercise, the ejection fraction gradually increased from a mean value of 46% at rest up to 60% at a maximal exercise level. End-diastolic volume however remained unchanged at a low exercise level and even slightly decreased at a higher exercise level. Little or no change in end-diastolic volume and an increase in ejection fraction produced a significant decrease in end-systolic volume and a net increase in stroke volume. These results indicate that the Frank-Starling mechanism does not contribute to the increase in right ventricular stroke volume during progressive supine exercise, but the increase in right ventricular stroke volume rather seems related to an increased contractility, presumably mediated by an increased sympathetic activity.

Adult↗
PubMed1979

Plasma volume and electrolyte shifts with heavy exercise in sitting and supine positions.

Plasma volume (PV) and electrolyte shifts were measured before and for 60 min after a continuous peak oxygen uptake (VO2 peak) test in four men (26-45 yr) on a bicycle ergometer. Mean (+/-SE) sitting VO2peak (3.16 +/- 0.32 1/min) was the same as supine VO2peak (3.13 +/- 0.33 1/min). In recovery (R + 1.5 min), mean PV had decreased by 477 ml (-16.1%, P less than 0.05) in the sitting and by 548 ml (-17.6%, P less than 0.05) in the supine positions, whereas total osmolality increased progressively with its peak at R + 3.5 min. The percentage losses of protein, total Ca2+, and ionized Cai2+ were about half as great as the percentage loss in PV, indicating a selective retention of these constituents. Calculated osmolality (sigma Na+, K+, Cl-, Cai2+) returned to control levels within 1.5 min after sitting exercise but required about 15 min after supine exercise. These small increases in protein concentration were not likely to significantly aid restitution of plasma volume and the ions were probably in equilibrium across the capillary membrane. So a change in hydrostatic and/or systemic blood pressures most likely provided the force for restitution of plasma volume.

Adult↗
PubMed1976

Comparison of spontaneous and positive-pressure breathing in supine normal subjects.

Distribution of ventilation (V) and perfusion (Q) was studied with 133Xe in eight supine, normal subjects comparing spontaneous breathing (SB) and intermittent positive-pressure breathing (IPPB). Tidal volume, inspiratory flow, and breathing frequency measured during SB were closely matched during automatically triggered IPPB. V and Q in the lung bases (adjacent to the diaphragm) were decreased relative to other regions during SB and further diminished by IPPB at similar volumes. During IPPB, basilar V and Q improved when tidal volume was increased; however; spontaneous hyperinflation resulted in significantly higher basilar V and Q than large tidal volumes delivered by IPPB. Thus, changes in lung volumes and gas exchange in the supine posture are attributable to impaired V and Q in the bases but not in dependent (posterior) regions. IPPB further reduces basilar V and Q, possibly due to loss of interdependence resulting from diminished respiratory muscle contraction. These findings may explain atelectasis during prolonged IPPB in supine patients. Although large tidal volumes improve basilar V during IPPB, spontaneous deep breaths are more effective and may prevent atelectasis better than IPPB at similar tidal volumes.

Humans↗
PubMed1978

Plasma volume changes with movement to supine and standing positions.

The chronology of hemoconcentration and hemodilution associated with changes in posture, and the reliability of venous hematocrit (Hct), hemoglobin (Hb), and plasma proteins (PP) as indicators in evaluating changes in plasma volume were determined in seven male subjects. Red cell mass was also measured by the CO method at the termination of the erect and supine positions. Movement to and from supine and erect positions produced consistent, rapid, and progressive changes in Hct, Hb, and PP. Thirty-five minutes in a supine position resulted in a 440-ml expansion of plasma volume. Resumption of the standing position resulted in an increase of 10.3 and 10.8% for Hct and Hb, respectively, and an increase in PP of 20.8%. A fluid efflux of 593 ml reduced blood and plasma volume by 9.5 and 16.2%, respectively. Red cell mass was unaffected by changes in posture. The significance of these postures on the reported alterations in plasma volumes consequent to the imposition of stresses on man are discussed.

Adult↗
PubMed1979

Measurement of lung volumes from supine portable chest radiographs.

Lung volumes in supine nonambulatory patients are physiological parameters often difficult to measure with current techniques (plethysmograph, gas dilution). Existing radiographic methods for measuring lung volumes require standard upright chest radiographs. Accordingly, in 31 normal supine adults, we determined helium-dilution functional residual and total lung capacities and measured planimetric lung field areas (LFA) from corresponding portable anteroposterior and lateral radiographs. Low radiation dose methods, which delivered less than 10% of that from standard portable X-ray technique, were utilized. Correlation between lung volume and radiographic LFA was highly significant (r = 0.96, SEE = 10.6%). Multiple-step regressions using height and chest diameter correction factors reduced variance, but weight and radiographic magnification factors did not. In 17 additional subjects studied for validation, the regression equations accurately predicted radiographic lung volume. Thus, this technique can provide accurate and rapid measurement of lung volume in studies involving supine patients.

Adult↗
PubMed1981

Nonlinear increases in diffusing capacity during exercise by seated and supine subjects.

To study the effects of exercise on pulmonary diffusing capacity, we measured the lungs' diffusing capacity for carbon monoxide (DLCO) during exhalation from 30 to 45% exhaled vital capacity in eight healthy subjects at rest and during exercise while both sitting and supine. We found that DLCO at these lung volumes in resting subjects was 26.3 +/- 3.2% (mean +/- SE) higher in the supine than in the sitting position (P less than 0.001). We also found that, in both positions, DLCO at these lung volumes increased significantly (P less than 0.001) with increasing exercise and approached similar values at maximal exercise. The pattern of increase in DLCO with an increase in oxygen consumption in both positions was curvilinear in that the rate of increase in DLCO during mild exercise was greater than the rate of increase in DLCO during heavy exercise (P = 0.02). Furthermore, in the supine position during exercise, it appeared that DLCO reached a physiological maximum.

Adult↗
PubMed1983

Dynamics of cardiac output and systolic time intervals in supine and upright exercise.

Transient and steady-state responses of stroke volume (SV), heart rate (HR), cardiac output (Q), left ventricular ejection time (LVET), preejection period (PEP), and the ratio of LVET to PEP during bicycle exercises of 50 and 100 W were studied in four healthy male subjects in supine and upright postures. A computer-based system in which impedance cardiography was incorporated served to determine the above parameters on a 10-s interval basis. SV remained almost unchanged in response to exercises in a supine posture, whereas it increased significantly in an upright posture, although the individual differences among subjects were found to be large. The half-response times of variables to a step work load were determined. An approximate accordance was observed among the response times for HR, Q, and LVET/PEP. There was an inverse relationship between LVET and HR, the slope of which was found to be steeper in the supine posture than in the upright posture, reflecting the difference between the SV responses in both postures. LVET fell shortly after the cessation of exercise despite the decreasing HR. Inasmuch as the paradoxical reduction of LVET was also found in the case where SV remained unchanged in response to exercise, no changes in SV can be the cause thereof. Thus, a transient increase in ejection rate, which is due to either the increased myocardial contractility or decreased peripheral vascular resistance, may be responsible for the phenomenon.

Adult↗
PubMed1988

Thoracoabdominal restriction in supine men: CT and lung function measurements.

Thoracoabdominal restriction was brought on by means of a corset, and the subsequent effects on thoracic dimensions and lung tissue were studied by computerized tomography (CT) and by various lung function tests in supine healthy volunteers (mean age 30 yr). Restriction caused reductions in total lung capacity (helium equilibration) from mean 6.84 to 4.80 liters, in functional residual capacity (FRC) from 2.65 to 2.08 liters, and in vital capacity from 5.16 to 3.45 liters. Closing capacity (single-breath N2 washout) fell from 2.42 to 1.88 liters, thus matching the reduction in FRC. The static pressure-lung volume curve was shifted to the right by 1.5 cmH2O at 50% of total lung capacity. However, no change in the slope of the curve was observed. The diaphragm was moved cranially by 1.2 cm, and the thoracic cross-sectional area was reduced by a mean 32 cm2 at a level just above the diaphragm. No changes in the lung tissue were seen on CT scanning. Gas exchange, as assessed by multiple inert gas elimination technique and arterial blood gas analysis, was unaffected by restriction. It is concluded that in supine subjects, thoracoabdominal restriction that reduces FRC by 0.6 liter is not accompanied by atelectasis (normal CT scan). In this respect the result differs from that found in anesthetized supine subjects who show the same fall in FRC and atelectasis in dependent lung regions.

Abdomen↗
PubMed1982

Hemodynamic differences between supine and upright exercise in patients with congestive heart failure.

Although the differences in hemodynamic responses to supine and upright exercise have been studied in normal subjects and in patients with angina pectoris, no such comparison has been made in patients with congestive heart failure. Many investigators measure exercise hemodynamics in heart failure patients to assess the effect of vasodilator and inotropic drugs. Both modes of exercise have been used and have often yielded differing results. We compared the hemodynamic response to supine and upright exercise in 14 patients with stable, New York Heart Association class III chronic heart failure. During upright exercise, peak heart rate was higher (124 +/- 15 vs 115 +/- 18 beats/min, p less than 0.025) and peak mean arterial pressure was lower (102 +/- 15 vs 95 +/- 17 mm Hg, p less than 0.25), yielding similar double products. Although the peak left ventricular filling pressure was slightly lower during upright exercise (40 +/- 7 vs 35 +/- 10 mm Hg, p less than 0.05), the maximum cardiac and stroke indexes were not significantly different (3.6 +/- 0.8 vs 3.4 +/- 0.8 l/min/m2 and 30 +/- 8 vs 30 +/- 6 ml/m2, upright vs supine exercise). In contrast to these relatively similar hemodynamic responses, exercise capacity was significantly greater during upright exercise (peak work load 336 +/- 84 vs 293 +/- 73 kpm/min, p less than 0.1; maximum oxygen consumption 12.1 +/- 2.4 vs 9.8 +/- 1.9 ml/min/kg, p less than 0.001). We conclude that either exercise method may be used to assess the hemodynamic effects of drugs, but that exercise capacity should be measured in the upright position.

Aged↗
PubMed1990

Left lower lobe ventilation is reduced in patients with cardiomegaly in the supine but not the prone position.

To determine the effect of the heart on regional ventilation, Krypton-81m (81mKr) tomographic (SPECT) ventilation scans were recorded in seven patients with cardiomegaly and four normal subjects in the supine and prone positions. All patients had a cardiothoracic ratio of greater than 0.50 and clear lung fields radiographically. Using standard gamma camera tomographic reconstruction techniques, images of transaxial slices were obtained during a 360 degree rotation around the thorax of the subject breathing the radioactive gas 81mKr. The transaxial images, acquired over 10 min were aligned in each posture at the level of the cardiac apex, mid-heart, and aortic arch and were matched in relation to a radioactive marker on the chest wall and to anatomic landmarks. A horizontal line (gravity independent and parallel to the couch) was drawn on the transaxial section through the dorsal regions of the right and left lung. Counts per resolution element (12 to 15 mm) were plotted along this line and the ratios of the peak values in right and left lung compared. These ratios represent differences in regional ventilation per unit lung volume. In controls the mean left-to-right (L/R) peak count ratio varied from 0.91 to 1.00 at the three levels (range: 0.76 to 1.04); there were no significant differences between supine and prone. In patients with cardiomegaly the mean (+/- SEM) L/R peak count ratio at cardiac apex, mid-heart, and aortic arch was 0.46 (+/- 0.08), 0.55 (+/- 0.07), and 0.89 (+/- 0.08) when supine and 1.04 (+/- 0.07), 1.05 (+/- 0.05), and 1.08 (+/- 0.07) when prone, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

A comparison of triceps skinfold and upper arm circumference measurements taken in standard and supine positions.

Because hospitalized patients are often unable to assume the upright position recommended for anthropometric measurements, the effect of patient position on accuracy of triceps skinfold and arm circumference measurements was investigated. Three measurements of triceps skinfold and arm circumference were taken on the right arm of 74 patients by trained technicians with extensive experience in anthropometric evaluation using a Lange caliper and Inser-tape. Measurements were repeated in the supine position 5 hours later on the same day by the same observer. Mean triceps skinfold, arm circumference, and calculated arm muscle circumference values obtained in the upright position correlated highly with those obtained in the supine position. Differences were less than one measurement unit and not significant when compared using parametric (Student t-test) and non parametric (Wilcoxon Matched-Pairs Signed-Ranks Test) statistically analysis. This study indicates that triceps skinfold and arm circumference can be measured accurately, reproducibly, and comparably in the supine position when the patient is unable to assume the recommended upright stance.

Adult↗
PubMed1991

A comparative study between a new, 50-degree right-semidecubital scanning and usual supine scanning of thallium-201 myocardial tomography for evaluation of coronary artery disease.

Images of thallium-201 cardiac tomography in the 50-degree right-lateral-semidecubital vs. usual supine positions were compared after a single dose of the isotope in 225 patients with or suspected of coronary artery diseases. Compared with the supine position method, the semidecubital position method enabled 25% shortening of the orbital radius (20.0 +/- 0.9 cm to 15.3 +/- 0.6 cm, n = 174, p less than 0.05), higher posteroinferior wall counts in both exercise and 3-hour-delayed images by up to 18%, better image sharpness and contrast, less motion artifact, more marked redistribution in the ischemic walls, and significantly higher specificity (57% vs. 78%, p less than 0.05) and accuracy (63% vs. 79%, p less than 0.05) for inferior wall lesions. The results indicate that the thallium cardiac scan is significantly affected by patient position during scanning, i.e., artifactual inferior wall defects due to photon attenuation in the supine position method. The semidecubital position method is recommended to minimize this artifact. The method is simple, easy to perform, well tolerated, feasible in any 1-headed tomography system, inexpensive, and free of running costs.

Angina Pectoris↗
PubMed1979

The effect on dosimetry of changing from the lithotomy to the supine position in treating uterine cancer with the Cathetron and external radiotherapy.

Uterine carcinoma can be treated by combined external and intracavitary irradiation. With an afterloading technique intracavitary irradiation is given with the patients in the lithotomy position. External irradiation is given with the patient in the supine position. A lead shield is used with the external fields to cover the tissues which are close to the intracavitary sources and receive high doses. The positions of the intracavitary sources seen on radiographs taken when the patient is in the lithotomy position are transferred to films taken with the patient in the supine position. From the latter the position and profile of the shield are calculated. It is shown that a reliable transfer of the positions of the sources and determination of the necessary shielding cannot be achieved in this way. It is therefore concluded that both intracavitary and external irradiation should be carried out with the patient in the supine position.

Cobalt Radioisotopes↗
PubMed1986

Decrease in blood pressure and increase in total peripheral vascular resistance in supine resting subjects with normotension or essential hypertension.

Hemodynamic changes in the supine resting position were investigated in 70 male subjects, consisting of 15 healthy volunteers with normotension (blood pressure of 113 +/- 7/70 +/- 5 mmHg, M +/- SD), 25 patients with borderline essential hypertension (143 +/- 12/90 +/- 6 mmHg) and 30 patients with established essential hypertension (166 +/- 13/108 +/- 6 mmHg). The supine position reduced blood pressure, heart rate, stroke volume and cardiac output (p less than 0.001), but increased total peripheral vascular resistance (p less than 0.001). The decrease in systolic blood pressure (p less than 0.01), stroke volume (p less than 0.05) and cardiac output (p less than 0.05), and the increase in total peripheral vascular resistance (p less than 0.01) were significantly greater in the borderline and established essential hypertensive groups than in the normotensive group. The results demonstrated that the decrease in blood pressure was due to a reduction in both heart rate and stroke volume, and that the decrease in stroke volume and increase in total peripheral vascular resistance seen in the supine position were greater in the hypertensive groups than in the normotensive group. These hyperresponses may contribute to the development and persistence of high blood pressure in patients with essential hypertension.

Adult↗
PubMed2004

[Spirometric values of obese and non-obese subjects on orthostatic, sitting and supine positions].

BACKGROUND: It is possible that obesity could lead to pulmonary restriction with decreasing lung volumes. However, controversies about this restriction and its etiology still exist. Thus, the purpose of this report was to evaluate the effects of body weigh excess on spirometry, on three different body positions, evaluated by Body Mass Index (BMI), percentage of fatness and the ratio of abdominal girth to hip breadth (AG/HB). METHODS: Forty-six sedentary volunteers, with ages between 20 and 40 years, were studied and distributed on five groups, based on BMI. Skin fold thickness and ratio of abdominal girth to hip breadth (AG/HB) of the volunteers were measured. FVC, FEV1 and ratio of FEV1 to FVC were measured on three different body positions--sitting, supine and orthostatic positions. RESULTS: Comparing the values measured and predicted between the groups, no difference was detected. Comparing body positions, the supine position shows lower values than sitting and orthostatic positions (p<0.05). Associations between CVF, VEF1 e VEF1/CVF values and BMI, percentage of fatness and ratio of AG/HB were not found. CONCLUSIONS: Spirometric values from obese people are into normality range and decrease on the supine position.

Adult↗
PubMed1980

Adequacy of lower limb venous opacification:comparison of supine and upright phlebography.

A direct comparison of 50 normal supine and 50 normal upright phlebograms revealed a superiority of the supine technique in the opacification of the soleal and gastrocnemius sinusoids (90% vs. 72% and 74% vs. 26%, respectively). Of greater importance in relation to life-threatening thromboemboli, the supine method provided diagnostic studies of the pelvic veins more frequently than the upright technique (96% vs. 76%).

Diagnostic Errors↗
PubMed1984

Evaluation of history and simple supine cystometry as a preoperative test in stress urinary incontinence.

In a follow-up study the accuracy of a simple preoperative screening including history, Bonney 's test and supine cystometry was evaluated in patients with stress urinary incontinence. Based upon preoperative history alone, the patients were divided into two different groups, pure stress incontinence, and mixed stress and urge incontinence. All patients accepted had a normal supine cystometry at the preoperative work-up. The results of the operation were good in pure stress incontinence. In patients with mixed stress and urge incontinence the results were unsatisfactory and most of them presented a variety of urodynamic abnormalities postoperatively. Thus, in patients with pure stress incontinence, acceptance for surgery may be based upon a careful history, a simple supine cystometry and Bonney 's test, but in patients with mixed stress and urge incontinence a comprehensive clinical and urodynamic evaluation is mandatory. It seems that combination of detrusor instability and a history of pronounced urgency preoperatively calls for other therapeutic alternatives than operation.

Adult↗
PubMed1989

[Effect of changing position from supine to standing upright on the circulation of young men and women].

This study investigated the effect of changing position from supine to standing upright on the circulation of young men and women. Healthy men and women ranging from age of 18 to 24 were examined. Two minutes before standing, the baseline heart rate and blood pressure were measured. Heart rate and blood pressure were recorded immediately and at every minute for 10 minutes after standing upright. Differences in heart rate and blood pressure between supine and standing upright position were evaluated. The results were summarized as follows: 1. Heart rate increased significantly immediately and at every minute for 10 minutes after standing upright. 2. Systolic blood pressure increased significantly immediately and at every minute for 4 minutes after standing upright. 3. Diastolic and mean blood pressure increased significantly immediately and at every minute for 10 minutes after standing upright. 4. Pulse pressure immediately and at every minute for 10 minutes after standing upright was significantly narrower than that of supine position. 5. There was no significant difference of heart rate between men and women after standing upright. 6. Systolic and diastolic blood pressure of men after standing upright was significantly greater than those of women. From these results, it may be concluded that heart rate, systolic, diastolic and mean blood pressure and pulse pressure increase after standing upright, and systolic and diastolic blood pressure in men is greater than those of women after standing upright.

Adult↗