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 307 records · Page 17Linked to original sources
PubMed2003

Supine body position is an important factor influencing postprandial ambulatory blood pressure.

BACKGROUND: Although body position is known to be an important factor influencing the results of ambulatory blood pressure monitoring (ABPM), even very recent studies assessing postprandial blood pressure (BP) have not taken into account the possibility that the examined subjects were lying down after a meal. We addressed this issue by analysing diurnal BP profiles together with subject's reports on supine rest periods and meal consumption during ABPM. MATERIAL/METHODS: The ABPM results of 109 non-medicated subjects were analysed (age 40+/-12 years, daytime BP 132/84+/-15/11 mmHg). BP and heart rate (HR) changes were assessed on the basis of 2-hour means. RESULTS: Subjects who lay down within 2 hours after a meal showed significantly greater decreases in systolic and diastolic BP and HR than individuals who did not: -10+/-10 vs. 1+/-10 mmHg, -11+/-10 vs. -3+/-7 mmHg, and -7+/-9 vs. 0+/-11 beats/min, respectively. The BP decrease was greater when the duration of supine rest was longer. There were no significant differences between BP/HR changes during those periods when the subjects lay down within 2 hours after the meal and BP/HR changes during those periods when supine rest was not preceded by a meal. The mean changes for the latter group were -9+/-10 mmHg, -11+/-8 mmHg, and -9+/-9 beats/min. for SBP, DBP, and HR, respectively. CONCLUSIONS: Our results indicate that supine body position is an important factor, which may influence postprandial BP investigated by ABPM. Body position should always be taken into consideration when ABPM results are analysed.

Adult↗
PubMed2002

[A vertical vibration model of human body in supine position].

Objective. To establish the models of head, abdomen, and chest of supine human body respectively under vertical vibration. Method. The mechanical impedance of 12 healthy volunteers aged 24-56 was measured under vertical white noise stimulus in the frequency range of 2-35 Hz. To explain these findings, the model of head was proposed, the models of abdomen and chest were computed by way of an optimization procedure. Result. The models of abdomen and chest are three-degree-of-freedom and the head is rigid. Conclusion. The mechanical impedance of the supine human body is linear and sole. The established models of head, abdomen and chest of supine human body when subjected to vertical vibration are useful for calculating and evaluating the comfort of supine human body under whole-body vibration.

Abdomen↗
PubMed2003

[Thoracic epidural pressure and peripheral venous pressure in the lower extremity during supine hypotensive syndrome].

BACKGROUND: After induction of spinal anesthesia, thoracic epidural pressure and left saphenous venous pressure were monitored and recorded during supine hypotensive syndrome in 8 pregnant patients who underwent elective cesarean section. METHODS: A 22 G venous catheter was inserted into the left saphena, and an epidural catheter for 18 G needles was positioned 5 cm cephalad in the epidural space through a Tuohy needle at the T 11-12 intervertebral space. Each catheter was connected to a pressure transducer, and recording was started in a supine position immediately after induction of spinal anesthesia with 0.5% isobaric bupivacaine at the L 3-4 intervertebral space. RESULTS: In all patients, epidural pressure and peripheral venous pressure synchronously increased as soon as they began to recover from hypotension and tachycardia regardless of uterine displacement to the left. CONCLUSIONS: The synchronous increase in both pressures was late after the hypotension probably because sympathetic block with spinal anesthesia inhibited vasoconstriction of the lower extremity, a factor to compensate for supine hypotensive syndrome. Only collateral flow via epidural venous plexus emptying into azygos system could not compensate for decreased venous return to the right atrium from obstructed inferior vena cava, and differences in the degree of compression of the inferior vena cava by gravid uterus would affect the recovery from supine hypotension.

Adult↗
PubMed2004

[Orthostatic hypotension and supine hypertension in pure autonomic failure].

Orthostatic hypotension is associated with significant morbidity and mortality in elderly patients. In orthostatic hypotension caused by central and peripheral nervous system disorders (neurogenic orthostatic hypotension), the release of catecholamine in the standing posture is insufficient to compensate adequately for decreased venous return to the heart. Primary autonomic failure exhibits, often, supine hypertension, that can be worsened by pressor agents, such as midodrine, used to prevent syncope episodes. Salt-retaining steroid fludrocortisone, also, used to treat orthostatic hypotension, increases blood pressure both in supine and in standing position. We describe 3 patients with neurogenic orthostatic hypotension caused by pure autonomic failure. They complained of several syncope episodes. On examination, orthostatic hypotension and supine hypertension were detected in the absence of pharmacological therapy. All the patients presented hypertensive organ disease. Fludrocortisone acetate was started in one patient, and short-acting vasopressor agents during the day and dihydropyridine-calcium antagonist during the night in the other two. During the follow-up a transient ischemic attack occurred in the patient treated with fludrocortisone. When fludrocortisone was titrated down and short-acting antihypertensive drugs were started, the patient did not complain of any symptoms. Supine hypertension is part of pure autonomic failure, and short-acting antihypertensive agents should be associated with vasopressor agents to prevent hypertensive target organ disease.

Aged↗
PubMed2006

Clinical comparison of automatic, noninvasive measurements of blood pressure in the forearm and upper arm with the patient supine or with the head of the bed raised 45 degrees: a follow-up study.

BACKGROUND: Noninvasive measurement of blood pressure in the forearm is used when the upper arm is inaccessible and/or when available blood pressure cuffs do not fit a patient's arm. Evidence supporting this practice is limited. OBJECTIVE: To compare noninvasive measurements of blood pressure in the forearm and upper arm of medical-surgical inpatients positioned supine and with the head of the bed raised 45 degrees . METHODS: Cuff size was selected on the basis of forearm and upper arm circumference and manufacturers' recommendations. With a Welch Allyn Vital Signs 420 Series monitor, blood pressures were measured in the forearm and then in the upper arm of 221 supine patients with their arms resting at their sides. Patients were repositioned with the head of the bed elevated 45 degrees and after 2 minutes, blood pressures were measured in the upper arm and then the forearm. Starting position was alternated on subsequent subjects. RESULTS: Paired t tests revealed significant differences between systolic and diastolic blood pressures measured in the upper arm and forearm with patients supine and with the head of the bed elevated 45 degrees . The Bland-Altman procedure revealed that the distances between the mean values and the limits of agreement were from 15 to 33 mm Hg for individual subjects. CONCLUSIONS: Noninvasive measurements of blood pressure in the forearm and upper arm cannot be interchanged in medical-surgical patients who are supine or in patients with the head of the bed elevated 45 degrees .

Adolescent↗
PubMed2006

Effects of compression tights on calf muscle oxygenation and venous pooling during quiet resting in supine and standing positions.

AIM: We applied near-infrared spectroscopy (NIRS) to evaluate in resting conditions the effects of compression tights (CT) on calf muscle oxygenation and venous pooling compared with Lycra(R) elastic tights (ET) and shorts (no compression) according to the body posture (supine vs standing). METHODS: Twelve sportsmen regularly involved in endurance training volunteered to this study. Their average age, height and weight (+/-SD) were 26.5+/-2.6 years, 177+/-6 cm and 70.1+/-4 kg, respectively. Tissue oxygenation index (TOI), deoxyhemoglobin (HHb), and blood pooling (Hbtot) of the right gastrocnemius medialis were continuously monitored at 2 Hz using a NIRS device (NIRO-300, Hamamatsu Photonics, Japan). A home made transducer was used to measure applied pressure at the interface between skin and clothing over the calf area. Subjects were asked to realize a supine-standing protocol (5 min for each position) by wearing CT, ET or shorts in a counterbalanced order on the same day. RESULTS: HHb and Hbtot concentration changes were significantly lower whereas TOI was significantly higher by wearing CT compared with shorts and ET (P<0.001) as did supine compared to upright postures. The mean pressures applied over the calf were 5.6 and 23.2 mmHg during supine and 5 and 24.1 mmHg during standing for ET and CT, respectively. Pressures were significantly different among clothing according to the following rank order: CT>ET>shorts (P<0.001). CONCLUSIONS: CT compared to ET have positive effects on calf muscle oxygenation and venous pooling in quiet resting positions.

Adult↗
PubMed1989

Prone versus supine thallium myocardial SPECT: a method to decrease artifactual inferior wall defects.

Artifactual inferior wall defects as a result of diaphragmatic attenuation of activity are a frequent source of error in thallium myocardial single photon emission computed tomography (SPECT) studies. Thirty-four patients and 11 clinically normal volunteers were studied prospectively to see if specificity of inferior wall defects for right coronary artery disease could be improved by scanning patients prone versus supine. All individuals were scanned both prone and supine, in random order, following symptom limited treadmill exercise. Images were acquired at 3 degrees steps, 25 sec per frame, in a 180 degrees elliptical orbit always beginning in the 45 degrees right anterior oblique position relative to the patient. Polar maps generated from the short axis slices were used to calculate the average regional activity. The prone studies showed consistently higher inferior wall activity compared to the supine studies on both the exercise (182 +/- 22 vs. 160 +/- 23, p less than or equal to 0.001) and 4-hr delay studies (183 +/- 20 vs. 175 +/- 21, p less than or equal to 0.001). Prone imaging resulted in a significantly higher specificity for RCA disease compared to supine imaging (90% vs. 66%, p less than 0.05) with an improvement in accuracy from 71% to 82%. Sensitivity, specificity, and accuracy for left anterior descending and left circumflex artery disease were not significantly affected by patient position during imaging. All patients having SPECT thallium myocardial perfusion studies should be imaged prone to minimize artifactual inferior wall defects and improve accuracy.

Adult↗
PubMed1993

Prone or supine body position and sleep characteristics in infants.

OBJECTIVE: To evaluate the potential relation between body position and sleep characteristics in normal infants. PATIENTS: Two groups of 3-month-old healthy infants were evaluated: 40 infants who usually slept supine, and 40 who usually slept prone. The two groups were matched for gender, gestational age, postnatal age, birth weight, and total recording time. RECORDING TECHNIQUES: The 80 infants were studied polygraphically during one night in the pediatric sleep laboratory. They were allowed to fall asleep in their usual sleep position, and every 3 hours were gently turned from prone to supine, or from supine to prone. RESULTS: In each group, 6 infants were excluded from the analysis, because they woke up after having been turned over. In both groups, no significant difference was seen between the prone and the supine body positions for the following variables: number of sleep state changes; number of gross body movements; percent of rapid eye movement sleep; saturation with oxygen, arterial blood levels; number and duration of acid esophageal reflux; rectal temperature; mean respiratory rates; water evaporation rates from the forehead skin; and number or duration of central or of obstructive apneas. In both groups of infants, prone body position was associated with a significant increase in sleep duration (+16%) and in non-rapid eye movement sleep (+25%) and a significant decrease in number of arousals (-40%) and in their duration (-43%). CONCLUSIONS: No explanation has been found for the sleep-promoting effect of prone body positioning. The finding could be of interest to the study of infants' sleep quality, as well as to the potential relation between body positions and sudden death during sleep.

Female↗
PubMed1998

Oculomotor response to linear acceleration as induced by counter-rotation in supine subjects.

BACKGROUND: Horizontal nystagmus occurs in response to sinusoidal linear accelerations directed along an upright subject's Y (interaural) axis, and is proposed to be mediated by an utricular otolith mechanism. HYPOTHESIS: The otolith organs, composed of the utricles and saccules, provide a unique set of signals for any linear acceleration in 3-dimensional space. A supine subject under alternate changing directions of linear acceleration as induced by counter-rotation will receive alternate stimulation along the Y as well as the Z (dorsoventral) axis. We hypothesized that alternate horizontal and vertical nystagmus would be elicited as a result of the changing direction of linear acceleration. METHODS: A group of eight subjects in the supine position were exposed to counter-rotation at 0.16, 0.25, and 0.33 Hz. Vertical and horizontal eye movements were recorded simultaneously using the El-Mar eye and head tracking system. RESULTS: Horizontal nystagmus was observed in all supine subjects. The direction of the slow phase of nystagmus changed with directional changes in linear acceleration. Reversals in the direction of eye movements lagged behind the reversals in the direction of the acceleration. However, only two subjects exhibited alternating horizontal and vertical nystagmus as a result of changing axis of linear acceleration, from "along the Y axis" to "along the Z axis." CONCLUSION: We propose that the nystagmus induced in the supine subject was provoked by linear acceleration and largely an otolith-mediated reflex. The lack of vertical response could be due to the relative paucity of vestibular afferents information along the dorsoventral axis.

Acceleration↗
PubMed1987

Postprandial changes in supine and erect heart rate, systemic blood pressure and plasma noradrenaline and renin activity in normal subjects.

The haemodynamic effects of a standard meal were assessed in a balanced cross-over study in eight normal fasting subjects, investigated under conditions applicable to many drug tests. Both the supine and erect diastolic blood pressure were reduced on average by 10 mmHg over the 4 h following the meal. The supine systolic pressure was increased on average by 2 mmHg, a difference of no biological relevance. Erect systolic blood pressure was not affected by eating. Supine heart rate was slightly but significantly increased, but the erect heart rate did not change. Postprandial plasma renin activity was increased. Venous plasma noradrenaline levels in the supine position were not affected by eating and after standing erect, and immobile for 5 min they were only slightly and not-significantly increased. A food-induced vasodepressor response combined with baroreceptor resetting is considered to have occurred in this population. The changes had a gradual onset, reaching their maximum about 2 h after eating and they were still evident after 3 h. Eating should be considered as an important potential source of bias in cardiovascular studies.

Adult↗
PubMed1982

Normal values of functional residual capacity in the sitting and supine positions.

The measurement of functional residual capacity (FRC) has assumed new importance in the diagnosis of acute respiratory failure. However few reference values exist for FRC in supine positions for both sexes. We measured the FRC in 100 healthy subjects with the helium dilution closed circuit method in the sitting and supine positions. There were 50 women aged 20 to 63 years and 50 men aged 22 to 65 years. Fifty five subjects were smokers (25 women and 30 men) but no significant differences were found between FRC of smokers and nonsmokers. The FRC always decreased when the subject changed from the sitting to supine position. In this study, the correlation coefficients between FRC and height were statistically significant for both sexes, the influence of age and weight on FRC being negligible. Our results provide useful reference values for FRC in the supine position.

Adult↗
PubMedDate not supplied

Diagnostic accuracy of gated Tc-99m sestamibi stress myocardial perfusion SPECT with combined supine and prone acquisitions to detect coronary artery disease in obese and nonobese patients.

BACKGROUND: The diagnostic value of gated myocardial perfusion single-photon emission computed tomography (MPS) with combined supine and prone acquisitions to detect coronary artery disease (CAD) in obese and nonobese patients has not been defined. METHODS AND RESULTS: We studied 1511 patients without prior myocardial infarction or coronary revascularization who either had coronary angiography within 3 months of MPS (n = 785) or had a low pretest likelihood of CAD (n = 726). All patients underwent rest thallium 201/gated exercise or adenosine stress technetium 99m sestamibi MPS in both the supine and prone positions. According to body mass index (BMI), patients were categorized as normal weight (BMI of 18.5-24.9 kg/m2), overweight (BMI of 25.0-29.9 kg/m2), or obese (BMI > or = 30.0 kg/m2). There were no significant differences in stress, fixed, or ischemic defects among patients in different weight categories. The sensitivity of MPS was 85%, 86%, and 89% for detecting patients with 50% or greater coronary stenosis and 89%, 91%, and 92% for detecting those with 70% or greater coronary stenosis in the normal-weight, overweight, and obese groups, respectively. Normalcy rates were nearly identical among the 3 weight groups (99%, 98%, and 99%, respectively). Multivariate logistic regression analysis further confirmed that BMI was a nonsignificant predictor for the detection of CAD. In a subset of 290 patients, automated quantitative MPS analysis confirmed that combined supine and prone MPS increased specificity (86%) in identifying CAD, without a significant reduction in sensitivity (83% for > or = 50% stenosis and 88% for > or = 70% stenosis). CONCLUSION: The findings of this study suggest that MPS performed with gating and combined supine and prone acquisitions without attenuation correction had a similar diagnostic accuracy for the detection of CAD in normal-weight, overweight, and obese patients.

Aged↗
PubMed1996

Effects of alprazolam and lorazepam on catecholaminergic and cardiovascular activity during supine rest, mental load and orthostatic challenge.

Effects of oral alprazolam (0.5 and 1 mg) and lorazepam (2 mg) on sympathetic adrenomedullary activity and sedation were studied during supine rest, mental load (Color Word Test, CWT) and active standing (OCT), in 12 male volunteers in a randomized double-blind placebo-controlled cross-over design. Compared to placebo, alprazolam significantly increased subjective sedation, reduced plasma adrenaline and noradrenaline concentrations and mean blood pressure (MBP) during supine rest, and attenuated plasma adrenaline responses during the CWT and the OCT; these effects during the CWT and OCT appeared to be dose-dependent. In comparison with lorazepam (2 mg), alprazolam (1 mg) showed reduced MBP levels during supine rest, whereas lorazepam showed a higher heart rate level during supine rest, a reduced plasma noradrenaline response to the OCT and a performance deterioration to the CWT. There were no differences between alprazolam (1 mg) and lorazepam regarding subjective sedation. Although the benzodiazepines were similar regarding their increase of sedation, alprazolam and lorazepam induced differential effects on sympathetic adrenomedullary activity during rest and stress, whereby suppression of adrenomedullary activity may be specific for alprazolam.

Adult↗
PubMed2000

Cardiovascular responses to upright and supine exercise in humans after 6 weeks of head-down tilt (-6 degrees).

Seven healthy men performed steady-state dynamic leg exercise at 50 W in supine and upright postures, before (control) and repeatedly after 42 days of strict head-down tilt (HDT) (-6 degrees) bedrest. Steady-state heart rate (fc), mean arterial blood pressure, cardiac output (Qc), and stroke volume (SV) were recorded. The following data changed significantly from control values. The fc was elevated in both postures at least until 12 days, but not at 32 days after bedrest. Immediately after HDT, SV and Qc were decreased by 25 (SEM 3)% and 19 (SEM 3)% in supine, and by 33 (SEM 5)% and 20 (SEM 3)% in upright postures, respectively. Within 2 days there was a partial recovery of SV in the upright but not in the supine posture. The SV and Qc during supine exercise remained significantly decreased for at least a month. Submaximal oxygen uptake did not change after HDT. We concluded that the cardiovascular response to exercise after prolonged bedrest was impaired for so long that it suggested that structural cardiac changes had developed during the HDT period.

Bed Rest↗
PubMed1982

Effects of nitroglycerin on supine and upright exercise in mitral stenosis.

Resting, supine, and upright exercise hemodynamics were studied in 11 patients with pure or predominant mitral stenosis before and after 0.4 mg sublingual nitroglycerin. Resting mean pulmonary wedge pressure was reduced from 27 +/- 1.6 to 21 +/- 1.6 mm Hg (p less than 0.001), while mean cardiac index (2.98 +/- 0.40 vs 2.68 +/- 0.30 cc/min/m2; NS) and mean heart rate (82 +/- 4.4 vs 87 +/- 6.7 bpm; NS) were unchanged after nitroglycerin. Resting mean left ventricular end-diastolic pressure dropped from 11 +/- 1.7 to 8 +/- 1.1 mm Hg (p less than 0.02) after nitroglycerin, while stroke index (37 +/- 5.1 vs 32 +/- 3.8 mm Hg; NS) was unchanged. Left ventricular systolic pressure fell from 122 +/- 6.0 to 111 +/- 3.1 mm HG (p less than 0.001) after nitroglycerin. At peak supine exercise similar qualitative changes were observed. Mean pulmonary wedge pressure was lower after nitroglycerin (43 +/- 2.3 vs 36 +/- 2.1 mm Hg; p less than 0.02), while cardiac index (3.62 +/- 0.39 vs 3.4 +/- 0.26 cc/min/m2; NS) and heart rate (116 +/- 7.1 vs 113 +/- 4.6 bpm; NS) were not different. Left ventricular end-diastolic pressure (13 +/- 1.4 vs 10 +/- 1.3; NS) was slightly but not significantly reduced by nitroglycerin. Left ventricular stroke index (34 +/- 3.4 vs 31 +/- 2.2 mm Hg; NS) was unchanged by nitroglycerin. Left ventricular systolic pressure (137 +/- 7.3 vs 127 +/- 6.1 mm Hg; p less than 0.02) was reduced 10 mm Hg at peak supine exercise after nitroglycerin. During upright exercise, peak heart rate (160 +/- 8.1 vs 160 +/- 8.0 bpm; NS) and peak systolic blood pressure (117 +/- 5.7 vs 112 +/- 2.8 mm Hg; NS) were not changed with nitroglycerin. Exercise duration was improved after nitroglycerin (5.02 +/- 0.62 vs 5.66 +/- 0.65 minutes; p less than 0.02). Thus sublingual nitroglycerin lowers mean pulmonary wedge pressure to reduce pulmonary congestive symptoms, improves supine exercise hemodynamics, and may enhance treadmill exercise duration in some patients with pure or predominant mitral stenosis.

Adolescent↗
PubMed1985

Effects of upright and supine position on cardiac rest and exercise response in aortic regurgitation.

The effects of upright and supine position on cardiac response to exercise were assessed by radionuclide ventriculography in 15 patients with moderate to severe aortic regurgitation (AR) and in 10 control subjects. In patients with AR, heart rate was higher during upright exercise, but systolic and diastolic blood pressure and left ventricular (LV) output were similar during both forms of exercise. LV stroke volume and end-diastolic volume were not altered during supine exercise. LV end-systolic volume increased and ejection fraction decreased during supine exercise, but both were unchanged during upright exercise. Of 15 patients, 5 in the upright and 12 in the supine position had an abnormal LV ejection fraction response to exercise (p less than 0.01). Right ventricular ejection fraction increased and regurgitant index decreased with both forms of exercise and was not significantly different between the 2 positions. Thus, posture is important in determining LV response to exercise in patients with moderate to severe AR.

Adult↗
PubMed1982

Post-stress development and healing of supine-restraint induced stomach lesions in the rat.

In Experiment 1, rats were subjected to 3 hr of supine restraint and sacrificed either immediately, 30, 60, 90, 120 or 180 min following restraint. Rats sacrificed 90 min after restraint revealed significantly more stomach lesions as compared to other treatment conditions. The healing rate for supine-restraint ulcers was observed in Experiment 2 and comparisons with conventional restraint procedures, as reported in other publications, would suggest a slower healing rate for lesions induced with supine restraint. Experiment 3 indicated that cimetidine significantly accelerated the rate of healing for supine-restraint lesions.

Animals↗
PubMed1981

Cranio-caudal distribution of inspired gas and perfusion in supine man.

We measured the cranio-caudal distribution (A/B) of slowly inspired gas (VI) and of perfusion (Q) at different lung volumes in 8 supine subjects. When supine closing capacity (CC) exceeded supine FRC, A/B of VI was greater than unity and decreased at higher lung volumes (VL). When CC less than FRC, A/B of VI less than or equal to 1.0 and showed no VL dependence. When abdominal girth/height ratio (Ag/Ht) exceeded 0.50, supine CC was greater than upright CC and A/B of VI was greater. In contrast, A/B of Q greater than 1.0 at all VL and was not related to (FRC--CC). The results suggest that cranio-caudal distribution of inspired gas is influenced by airway closure in the dependent paradiaphragmatic lung regions and that the latter is enhanced in the presence of abdominal obesity. Perfusion distribution is preferential to lung apices, relatively volume independent, and not influenced by airway closure.

Adult↗