What question did this study set out to answer?

To determine the effects of 8- to 14-day spaceflight missions on arterial baroreflex function, autonomic regulation, and orthostatic tolerance.

October 1, 1994Journal of Applied Physiology

Spaceflight alters autonomic regulation of arterial pressure in humans

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Why the study?

Does spaceflight of 8-14 days alter autonomic regulation of arterial pressure and orthostatic tolerance in astronauts?

Population

16 astronauts

Comparison

Spaceflight (shuttle missions lasting 8-14 days) vs Preflight baseline measurements

Design

Cohort

Follow-up

8-14 days of spaceflight plus several days after landing

Authors

JFJanice M. Fritsch-YelleNational Space Biomedical Research Institute JCJohn B. CharlesHome Office MJM. M. JonesBaylor College of Medicine

Discussion

Member takes

Implication

May warrant postflight orthostatic monitoring in astronauts; leaves open mechanisms and countermeasures for longer missions.

Key Points

To determine the effects of 8- to 14-day spaceflight missions on arterial baroreflex function, autonomic regulation, and orthostatic tolerance.
Evaluated 16 astronauts before flight and on landing day following space shuttle missions lasting 8 to 14 days.
Measured R-R interval power spectra, antecubital vein plasma catecholamine levels, carotid baroreceptor-cardiac reflex responses, and hemodynamic responses to Valsalva maneuvers.
Orthostatic tolerance decreased after landing, accompanied by significant increases in plasma norepinephrine, epinephrine, and 0.05-to-0.15-Hz R-R interval spectral power.
The slope, operational range, and operational point of the carotid baroreceptor-cardiac reflex decreased, alongside altered responses to Valsalva maneuvers that persisted for several days postflight.

Structured PICO

Does spaceflight of 8-14 days alter autonomic regulation of arterial pressure and orthostatic tolerance in astronauts?

Population

16 astronauts

Intervention

Spaceflight (shuttle missions lasting 8-14 days)

Comparator

Preflight baseline measurements

Outcome

Changes in orthostatic tolerance, R-R interval power spectra, antecubital vein plasma catecholamine levels, carotid baroreceptor-cardiac reflex responses, and responses to Valsalva maneuverssurrogate

Spaceflight lasting 8-14 days reduces parasympathetic and increases sympathetic influences on arterial pressure control, leading to decreased orthostatic tolerance.

Cite This Study

Fritsch-Yelle et al. (1994) studied this question.

synapsesocial.com/papers/6a6fd4d42fdcb5703edb4f92 https://doi.org/10.1152/jappl.1994.77.4.1776

View Full Paper

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Spaceflight alters autonomic regulation of arterial pressure in humans

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Spaceflight alters autonomic regulation of arterial pressure in humans

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider