scholarly journals A Technique of Forced Expiratory Noise Time Evaluation Provides Distinguishing Human Pulmonary Ventilation Dynamics During Long-Term Head-Down and Head-Up Tilt Bed Rest Tests Simulating Micro and Lunar Gravity

2018 ◽  
Vol 9 ◽  
Author(s):  
Veronika V. Malaeva ◽  
Vladimir I. Korenbaum ◽  
Irina A. Pochekutova ◽  
Anatoly E. Kostiv ◽  
Svetlana N. Shin ◽  
...  
Keyword(s):  
Pulmonary Ventilation ◽  
Bed Rest ◽  
Lunar Gravity ◽  
Head Up Tilt ◽  
Time Evaluation

No effect of artificial gravity on lung function with exercise training during head-down bed rest

2015 ◽  
pp. 1-7
Author(s):  
Longxiang Su ◽  
Yinghua Guo ◽  
Yajuan Wang ◽  
Delong Wang ◽  
Changting Liu
Keyword(s):  
Lung Function ◽  
Pulse Rate ◽  
Vital Capacity ◽  
Pulmonary Ventilation ◽  
Bed Rest ◽  
Forced Expiratory Volume ◽  
Observation Time ◽  
Artificial Gravity ◽  
Postural Changes ◽  
Expiratory Flow

AbstractTo explore the effectiveness of microgravity simulated by head-down bed rest (HDBR) and artificial gravity (AG) with exercise on lung function. Twenty-four volunteers were randomly divided into control and exercise countermeasure (CM) groups for 96 h of 6° HDBR. Comparisons of pulse rate, pulse oxygen saturation (SpO2) and lung function were made between these two groups at 0, 24, 48, 72, 96 h. Compared with the sitting position, inspiratory capacity and respiratory reserve volume were significantly higher than before HDBR (0° position) (P< 0.05). Vital capacity, expiratory reserve volume, forced vital capacity, forced expiratory volume in 1 s, forced inspiratory vital capacity, forced inspiratory volume in 1 s, forced expiratory flow at 25, 50 and 75%, maximal mid-expiratory flow and peak expiratory flow were all significantly lower than those before HDBR (P< 0.05). Neither control nor CM groups showed significant differences in the pulse rate, SpO2, pulmonary volume and pulmonary ventilation function over the HDBR observation time. Postural changes can lead to variation in lung volume and ventilation function, but a HDBR model induced no changes in pulmonary function and therefore should not be used to study AG CMs.

scholarly journals Long-term bedrest study and astronaut training

2016 ◽  
Author(s):  
Edwin Mulder ◽  
Alexandra Noppe ◽  
Ulrich Limper
Keyword(s):  
Bed Rest ◽  
Dual Purpose ◽  
Planetary Environments ◽  
Exercise Regimen ◽  
Long Duration ◽  
Astronaut Training ◽  
Health Support ◽  
Art Research ◽  
Induced Changes

In the context of space physiology, research is being conducted to understand the physiological effects from radiation, hypogravity, spaceflight and planetary environments. The goal is to identify new methods to address the unique challenges in medical treatment, human factors, and behavioral health support on future exploration missions. As crew size is small and time is limited during actual missions, space agencies resort to addressing the effects of space travel in analog environments that have features similar to those of spaceflight. Head-down tilt bed rest (HDBR), for instance, is one of the established terrestrial models used to simulate some of the physiological changes experienced during spaceflight under weightless conditions and is therefore considered a valuable testbed to prepare for future long-duration exploration missions. HDBR studies are performed in extremely-well controlled laboratory settings, offering the possibility to test the effects of – what is in essence - physical inactivity and fluid shift. However, HDBR studies have a dual purpose, as they are also invaluable for the development, testing and validation of countermeasures aimed at mitigating microgravity-induced changes to the human body. With respect to the latter, the consensus is that short-term bed rest studies (< 14 days) serve foremost as a first screening of potential promising countermeasures, particularly for the cardiovascular system. Screening of preventative procedures and protocols for the muscular system requires at least mid-term (14 -28 days), whereas studies aiming to validate countermeasures for bone require long-term HDBR studies, in the order of 60-90 days. Hitherto the preferred countermeasure during spaceflight has been physical exercise. The presentation will therefore provide a short overview of the current onboard exercise regimen and will, in light of this, outline the scientific background and aims of the ongoing 60-day HDBR study at the :envihab (from the words ‘Environment’ and ‘Habitat’), the DLR Institute of Aerospace Medicine’s state-of-the-art research facility.

scholarly journals Indices of Increased Decompression Stress Following Long-Term Bed Rest

2018 ◽  
Vol 9 ◽  
Author(s):  
Mikael Gennser ◽  
S. L. Blogg ◽  
Ola Eiken ◽  
Igor B. Mekjavic
Keyword(s):  
Bed Rest ◽  
Decompression Stress

Successful Treatment of Experimental Neonatal Respiratory Failure Using Extracorporeal Membrane Lung Assist

1986 ◽  
Vol 9 (6) ◽  
pp. 427-432 ◽  
Author(s):  
R. Fumagalli ◽  
T. Kolobow ◽  
P. Arosio ◽  
V. Chen ◽  
D.K. Buckhold ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Pulmonary Ventilation ◽  
Blood Gases ◽  
Blood Gas ◽  
Arterial Blood Gases ◽  
Arterial Blood Gas ◽  
Membrane Lung ◽  
Arterial Blood ◽  
Long Term Survivors

A total of 44 preterm fetal lambs at great risk of developing respiratory failure were delivered by Cesarean section, and were then managed on conventional mechanical pulmonary ventilation. Fifteen animals initially fared well, and 14 of these were long term survivors. Twenty-nine other lambs showed a progressive deterioration in arterial blood gases within 30 minutes of delivery, of which 10 lambs were continued on mechanical pulmonary ventilation (20% survival), while the remaining 19 lambs were placed on an extracorporeal membrane lung respiratory assist (79% survival). Extracorporeal membrane lung bypass rapidly corrected arterial blood gas values, and permitted the use of high levels of CPAP instead of the continuation of mechanical pulmonary ventilation at high peak airway pressures. Improvement in lung function was gradual, and predictable. Early institution of extracorporeal respiratory assist using a membrane artificial lung rapidly corrected arterial blood gas values and significantly improved on neonate survival.

Changes in leg vein filling and emptying characteristics and leg volumes during long-term head-down bed rest

1997 ◽  
Vol 82 (6) ◽  
pp. 1726-1733 ◽  
Author(s):  
Francis Louisy ◽  
Philippe Schroiff ◽  
Antonio Güell
Keyword(s):  
Bed Rest ◽  
Venous Occlusion ◽  
Arterial Flow ◽  
Flow Index ◽  
Venous Compliance ◽  
Physiological Factors ◽  
Control Value ◽  
Flow Changes ◽  
Mercury Strain Gauge

Louisy, Francis, Philippe Schroiff, and Antonio Güell.Changes in leg vein filling and emptying characteristics and leg volumes during long-term head-down bed rest. J. Appl. Physiol. 82(6): 1726–1733, 1997.—Leg venous hemodynamics [venous distensibility index (VDI), arterial flow index (AFI), half-emptying time (T1/2)], and leg volumes (LV) were assessed by mercury strain-gauge plethysmography with venous occlusion and volometry, respectively, in seven men before, during, and after 42 days of 6° head-down bed rest. Results showed a high increase in VDI up to day 26 of bed rest (+50% vs. control at day 26, P < 0.05), which tended to subside thereafter (+20% increase vs. control value at day 41, P < 0.05). VDI changes were associated with parallel changes in T1/2 (+54% vs. control at day 26 of bed rest, P < 0.05, and +25% vs. control at day 41, P < 0.05) and with a decrease in AFI (−49% at day 41 vs. control, P < 0.05). LV continuously decreased throughout bed rest (−13% vs. control at day 41, P < 0.05) but was correlated with VDI only during the first month of bed rest. These results show that during long-term 6° head-down bed rest alterations of leg venous compliance are associated with impairment of venous emptying capacities and arterial flow. Changes in skeletal muscle mass and fluid shifts may account for venous changes during the first month of bed rest but, subsequently, other physiological factors, to be determined, may also be involved in leg venous hemodynamic alterations.

Skeletal Muscle Mass Regulation in Critical Illness

2014 ◽  
Author(s):  
Zudin Puthucheary ◽  
Hugh Montgomery ◽  
Nicholas Hart ◽  
Stephen Harridge
Keyword(s):  
Skeletal Muscle ◽  
Critical Illness ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Bed Rest ◽  
Protein Homeostasis ◽  
Highly Sensitive ◽  
And Function ◽  
Inadequate Nutrition

Muscle is a dynamic, plastic, and malleable tissue that is highly sensitive to mechanical and metabolic signals. Muscle mass is regulated by protein homeostasis, with protein being continually turned over, reflecting a balance between synthesis and breakdown. This chapter discusses the effect of critical illness on skeletal muscle mass, protein homeostasis, and the intracellular signalling driving anabolism and catabolism. The focus will be on the unique challenges to which the skeletal muscle are exposed, such as inflammation, sepsis, sedation, and inadequate nutrition, which, in combination with the disuse signals of immobilization and bed rest, engender dramatic changes in muscle structure and function. The mechanisms regulating muscle loss during critical illness are being unravelled, but many questions remain unanswered. Detailed understanding of these mechanisms will help drive strategies to minimize or prevent intensive care-acquired muscle weakness and the long-term consequences experienced by ICU survivors.

scholarly journals Recompensation of Decompensated Hepatitis B Cirrhosis: Current Status and Challenges

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Hong Zhao ◽  
Qi Wang ◽  
Changling Luo ◽  
Ligai Liu ◽  
Wen Xie
Keyword(s):  
Hepatocellular Carcinoma ◽  
Chronic Hepatitis ◽  
Hepatitis B ◽  
Antiviral Treatment ◽  
Research Data ◽  
Current Status ◽  
Evaluation Time ◽  
Long Term Prognosis ◽  
Time Evaluation

Liver-function decompensation or hepatocellular carcinoma (HCC) gradually appears after chronic hepatitis B progresses to cirrhosis. Effective antiviral treatment can significantly improve the long-term prognosis of decompensated patients, and some patients present recompensation of decompensated hepatitis B cirrhosis. At present, there are limited research data on the recompensation of decompensated hepatitis B cirrhosis. There is still controversy regarding the evaluation time, evaluation indicators, influencing factors, and long-term prognosis of recompensation.

Changes in standing body sway of pregnant women after long-term bed rest

2015 ◽  
Vol 36 (4) ◽  
pp. 479-482
Author(s):  
Y Shibayama ◽  
T. Kuwata ◽  
J. Yamaguchi ◽  
M. Matsumoto ◽  
M. Watanabe ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Bed Rest ◽  
Body Sway
Sign in / Sign up

Export Citation Format

Share Document