Beat-to-beat agreement of noninvasive tonometric and intra-radial arterial blood pressure during microgravity and hypergravity generated by parabolic flights.

BACKGROUND

Accurate measurement of beat-to-beat arterial blood pressure is essential for understanding the cardiovascular adaptation to weightlessness; however, the intra-arterial standard of beat-to-beat blood pressure measurement has never been used during space flight because of its invasive nature.

OBJECTIVES

The aim of the present study was to compare noninvasive radial artery tonometry blood pressure measurement with intra-radial pressure measurement during microgravity and hypergravity generated by parabolic flights.

METHODS

Two study participants, equipped with an intra-radial pressure line on the left arm and a Colin CBM-7000 (Colin Corp., Komaki City, Japan) beat-to-beat pressure measurement apparatus on the right arm, were studied in a supine position, during parabolic flights on board of the Airbus A300 OG of the Centre National d'Etudes Spatiales. The mean and standard deviations of the beat-to-beat difference between tonometric and intra-radial blood pressure were calculated for systolic and diastolic arterial pressure in the three gravity conditions (1g, 0 g and 1.8 g) experienced during parabolic flight.

RESULTS

The Colin CBM-7000 met the specifications required by the Association for the Advancement of Medical Instrumentation in the 0 g environment. Gravity, however, significantly affected the difference between tonometric and intra-arterial blood pressure, possibly owing to the effect of gravity on the apparent weight of the device and the corresponding calibration factor.

CONCLUSION

We conclude that the Colin CBM-7000 can be used with confidence during space flight.