Continuous Non-Invasive Blood Pressure Monitoring at High Altitude

Continuous non-invasive blood pressure monitoring at high altitude

Trapp M.1,7, Miggitsch E.-M.1,7, Velik R.2, Habenbacher W.3, Rohrer P.M.1,7, Schwaberger G.4, Wieser O.5, Domej W.6,7, Egger J.W.1

1 Research unit of behavioural medicine, health psychology and empirical psychosomatics, Medical University of Graz, AUSTRIA

2 Institute of Computer Technology, Vienna, AUSTRIA

3 CNSystems, Graz, AUSTRIA

4 Institute of Physiology,Medical University of Graz, AUSTRIA

5 University of Heidelberg, GERMANY

6University Clinic of Internal Medicine, Medical University of Graz, AUSTRIA

7 ARGE Alpinmedizin, Graz

The effects of hypobaric hypoxia depend both on the actual elevation and on the rate of ascent[1]. In high altitudes, we can notice an increase in sympathetic tone. Therefore, studies demonstrate alterations of heart rate and blood pressure due to the decrease of partial pressure of O2[1]. Guger et al. (2004) described that the ascent in a cable car is associated with a rise in heart rate and a decrease of heart rate variability (HRV)[2]. Beside HRV, also blood pressure (BP) and blood pressure variability (BPV) are important parameters to describe the cardiovascular reaction due to exposure to high altitudes[1].

In the “Dachsteinstudy 2008”, the Medical University of Graz and the interdisciplinary ARGE Alpinmedizin investigated the dynamic effect of hypobarichypoxia on cardiovascular parameters like heart rate and blood pressure.

In order to monitor and record the blood pressure during the ascent of a cable car from the Dachstein base station (1700 m above sea level) to the top station (Hunerkogel, 2700 m above sea level), the measuring system CNAP™ Monitor 500 was utilized. TheCNAP™ Monitor 500 offered various benefits that resulted in a high quality of collected data. Among others, benefits are:high-fidelity blood pressure waveform, real time systolic, diastolic and mean blood pressure, real time pulse rate, 2 hours internal battery, reusable CNAPTM double finger cuff, integrated thermal printer(trend, snapshot, alarm, report). Thus blood pressure could be measured continuously during the ascent of the cable car with a measuring range sys:40 - 250 mmHg (5.3 - 33.3 kPa), dia: 30 - 210 mmHg (4 - 28 kPa) and mean: 35 - 230 mmHg.

The results of the “Dachsteinstudy” will emphasize the importance of throwing a light on dynamic changes of blood pressure in order to describe short term effects of stimuli like the hypobaric hypoxia.

1.Hainsworth R, Drinkhill MJ, Rivera-Chira M: The autonomic nervous system at high altitude. Clin Auton Res 2007;17:13-19.

2.Guger C, Domej W, Lindner G, Pfurtscheller K, Pfurtscheller G, Edlinger G: Effects of a fast cable car ascent to an altitude of 2700 meters on EEG and ECG. Neurosci Lett. 2005;377:53-58.