Hemodynamic effects of eating and prolonged supine position in healthy subjects studied under clinical-pharmacological test conditions

We tested the hypothesis that decreasing nasal air volume (i.e., increasing nasal turbinate blood volume) improves nasal air conditioning. We performed a randomized, two-way crossover study on the conditioning capacity of the nose in six healthy subjects in the supine and upright position. Cold, dry air (CDA) was delivered to the nose via a nasal mask, and the temperature and humidity of air were measured before it entered and after it exited the nasal cavity. The total water gradient (TWG) across the nose was calculated and represents the nasal conditioning capacity. Nasal volume decreased significantly from baseline without changing the mucosal temperature when subjects were placed in the supine position ( P < 0.01). TWG in supine position was significantly lower than that in upright position ( P < 0.001). In the supine position, nasal mucosal temperature after CDA exposure was significantly lower than that in upright position ( P < 0.01). Our data show that placing subjects in the supine position decreased the ability of the nose to condition CDA compared with the upright position, in contrast to our hypothesis.

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Effects of Shoulder Abduction in Opposite Directions on EMG Activity in the Abdominal Muscles during Single Leg Raising in the Supine Position on the Foam Roller in Healthy Subjects

The Journal of Korean Physical Therapy ◽

10.18857/jkpt.2015.27.4.270 ◽

2015 ◽

Vol 27 (4) ◽

pp. 270-274 ◽

Cited By ~ 2

Author(s):

Sung-Joon Yun ◽

Moon-Hwan Kim

Keyword(s):

Supine Position ◽

Healthy Subjects ◽

Emg Activity ◽

Shoulder Abduction ◽

Abdominal Muscles

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Hemodynamic effects of oxygen at 1 and 2 Ata pressure in healthy subjects

Journal of Applied Physiology ◽

10.1152/jappl.1972.32.2.223 ◽

1972 ◽

Vol 32 (2) ◽

pp. 223-226 ◽

Cited By ~ 36

Author(s):

A. C. Kenmure ◽

W. R. Murdoch ◽

I. Hutton ◽

A. J. Cameron

Keyword(s):

Healthy Subjects ◽

Hemodynamic Effects

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Influence of posture on left ventricular long- and short-axis shortening

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01041.2001 ◽

2002 ◽

Vol 283 (4) ◽

pp. H1302-H1306 ◽

Cited By ~ 15

Author(s):

Patrik Sundblad ◽

Bengt Wranne

Keyword(s):

Supine Position ◽

Healthy Subjects ◽

Mitral Annulus ◽

Left Ventricular ◽

Upright Position ◽

Lateral Part ◽

Short Axis ◽

Spherical Form ◽

End Diastolic Volume ◽

Axis Length

End-diastolic volume and left ventricular stroke volume are increased in the supine compared with upright position, but the contribution of long-axis (LAS) and short-axis shortening (SAS) to these changes with change in posture has not been established. We examined long- and short-axis motion and dimensions with echocardiography in 10 healthy subjects in the upright and supine position. Long-axis length at end diastole was almost identical, whereas the diastolic short-axis diameter was increased in the supine position. At end systole, there was a decreased long-axis length and increased short-axis length in the supine vs. upright position. Both LAS and SAS were enhanced in supine vs. upright positions [LAS: 9.3 ± 2.2 vs. 15.1 ± 3.1 mm ( P < 0.001); SAS: 12.7 ± 3.2 vs. 16.3 ± 2.8 mm ( P < 0.001)], presumably via Starling mechanisms. LAS increased more in the lateral part of the mitral annulus than in the septal part [7.7 ± 2.6 vs. 4.0 ± 2.8 mm ( P < 0.006)], which implies that the more spherical form, in the supine position, induces more stretch at the lateral free wall than in the ventricular septum. These findings support the notion that Starling mechanisms affect systolic LAS.

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Bioelectrical impedance variation in healthy subjects during 12 h in the supine position

Clinical Nutrition ◽

10.1054/clnu.2002.0616 ◽

2003 ◽

Vol 22 (2) ◽

pp. 153-157 ◽

Cited By ~ 26

Author(s):

F SLINDE

Keyword(s):

Supine Position ◽

Healthy Subjects ◽

Bioelectrical Impedance ◽

Impedance Variation

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Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects

Clinical Pharmacology & Therapeutics ◽

10.1038/clpt.2009.186 ◽

2009 ◽

Vol 87 (1) ◽

pp. 87-92 ◽

Cited By ~ 6

Author(s):

D Schmidl ◽

E Polska ◽

B Kiss ◽

S Sacu ◽

G Garhofer ◽

...

Keyword(s):

Healthy Subjects ◽

Hemodynamic Effects

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Dynamics of esophageal bolus transport in healthy subjects studied using multiple intraluminal impedancometry

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1997.273.4.g958 ◽

1997 ◽

Vol 273 (4) ◽

pp. G958-G964 ◽

Cited By ~ 23

Author(s):

H. N. Nguyen ◽

J. Silny ◽

D. Albers ◽

E. Roeb ◽

C. Gartung ◽

...

Keyword(s):

Temporal Resolution ◽

Healthy Subjects ◽

Upright Position ◽

Bolus Transit ◽

Test Conditions ◽

Impedance Technique ◽

Bolus Viscosity ◽

Liquid Bolus ◽

Bolus Propulsion ◽

Different Parts

The dynamics of a bolus transport through the esophagus are largely unexplored. To study this physiological process, we applied multiple intraluminal impedancometry in 10 healthy subjects. Three different protocols were used: 1) liquid bolus administered with subject supine, 2) liquid bolus with subject upright, or 3) semisolid bolus with subject supine. Transit of different parts of a bolus (bolus head, body, and tail) was analyzed at different anatomic segments, namely the pharynx and the proximal, middle, and distal thirds of the esophagus. A characteristic pattern of bolus transport was seen in all subjects. Impedance changes related to air were observed preceding the bolus head. The bolus head propelled significantly faster than did the bolus body and tail. Pharyngeal bolus transit was significantly faster than esophageal bolus transit. Within the esophagus, bolus propulsion velocity gradually decreased. Bolus transport was significantly accelerated in the upright position and delayed with increase of bolus viscosity. In conclusion, the dynamics of a bolus transport from the pharynx into the stomach are complex. It varies within both different anatomic segments and different parts of the bolus and depends on bolus characteristics and test conditions. The spatial and temporal resolution of a bolus transport can be obtained by the impedance technique.

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Leg pain in neuropathic postural tachycardia syndrome is associated with altered muscle membrane properties

Clinical Autonomic Research ◽

10.1007/s10286-021-00830-5 ◽

2021 ◽

Author(s):

Belén Rodriguez ◽

Karin Jost ◽

Lotte Hardbo Larsen ◽

Hatice Tankisi ◽

Werner J. Z’Graggen

Keyword(s):

Supine Position ◽

Healthy Subjects ◽

Body Position ◽

Lower Leg ◽

Membrane Properties ◽

Leg Pain ◽

Muscle Membrane ◽

Postural Tachycardia Syndrome ◽

Postural Tachycardia ◽

Muscle Excitability

Abstract Purpose In neuropathic postural tachycardia syndrome, peripheral sympathetic dysfunction leads to excessive venous blood pooling during orthostasis. Up to 84% of patients report leg pain and weakness in the upright position. To explore possible pathophysiological processes underlying these symptoms, the present study examined muscle excitability depending on body position in patients with neuropathic postural tachycardia syndrome and healthy subjects. Methods In ten patients with neuropathic postural tachycardia syndrome and ten healthy subjects, muscle excitability measurements were performed repeatedly: in the supine position, during 10 min of head-up tilt and during 6 min thereafter. Additionally, lower leg circumference was measured and subjective leg pain levels were assessed. Results In patients with neuropathic postural tachycardia syndrome, muscle excitability was increased in the supine position, decreased progressively during tilt, continued to decrease after being returned to the supine position, and did not completely recover to baseline values after 6 min of supine rest. The reduction in muscle excitability during tilt was paralleled by an increase in lower leg circumference as well as leg pain levels. No such changes were observed in healthy subjects. Conclusions This study provides evidence for the occurrence of orthostatic changes in muscle excitability in patients with neuropathic postural tachycardia syndrome and that these may be associated with inadequate perfusion of the lower extremities. Insufficient perfusion as a consequence of blood stasis may cause misery perfusion of the muscles, which could explain the occurrence of orthostatic leg pain in neuropathic postural tachycardia syndrome.

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