orthostatic intolerance
Conditions
Interventions
Group 1: Performance of the following centrifuge profile:
- 20 min. baseline measurements lying on the centrifuge without rotation
- 10 min. baseline measurements lying on the centrifuge at +1Gz (foot
Sponsors
DLR - Institut für Luft- und Raumfahrtmedizin
Eligibility
Sex/Gender
Male
Age
18 Years to 50 Years
Inclusion criteria
Inclusion criteria: • Healthy male participants aged between 18 and 50 years old with a Body Mass Index (BMI) of 18-26 kg/m2 and a height of 170-210 cm • Successful completion of screening examination • physically fit (VO2max at least 35 ml/kg/min) and experience with +Gz (if possible) • Ability to comprehend and consent to the risks associated with the study to provide informed consent • In the position to participate in the complete study.
Exclusion criteria
Exclusion criteria: • Drug or alcohol abuse (regular consumption of 20-30 g alcohol/day) • Regular smokers • Current muscle or joint disease • Allergies to ultrasound gel or its ingredients • Diabetes mellitus • Herniated disc • Use of psychotropic drugs and any other drugs that may affect the study experiments • Heart disease or a cardiac pacemaker • Abnormal blood pressure (above 140/90 mmHg or below 90/60 mmHg) • Severe orthostatic intolerance or impaired neurovestibular function • Kidney disease (deviations from normal values of creatinine in plasma; Creatinine normal value < 1.20 mg/dL) • Thyroid dysfunction (deviations from normal values for TSH in plasma; normal values TSH 0,27 – 4,20 mU/l) (a laboratory examination carried out only in case of suspicion of dysfunction) • Anemia (Hb lower the normal value; standard value Hb men: from 13.5 to 17.5 g/dL) • History of epileptic seizures • Chronic back pain
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Reduction in blood pressure at the end of the centrifuge protocol is lower when subjects are cooled compared with the uncooled subjects. | — |
Secondary
| Measure | Time frame |
|---|---|
| - +Gz exposure time - changes of cardiovascular parameters (ECG, heart rate, Oxygen Saturation), Philips Intellivue X2 - changes in hemodynamics (cardiac Output, stroke volume), calculated with Beatscope, measurement of continous blood pressure with Finometer - changes in physical Performance, measured by VO2max (spiroergometry), baseline during medical Screening, post measurements after centrifugation - changes in cognitive Performance, cognifit test battery, pre and post centrifugation - changes in different stress parameters (catecholoamine Levels, hematocrit, plasma osmolality), blood sample pre and post centrifugation - changes in peripheral vasoconstriction: measurement of skin perfusion by laser doppler (4-channel laser Doppler, Moor Instruments), iontophoresis for local application of nitroprusside and phentolamine on the intact skin (VMSLDF2 and MIC2, Moor Instruments); measurements are taken continuously during centrifugation - Volume changes in the lower leg, measured via plethysmography, pre and post centrifugation - changes in haemoglobin concentration in the lower leg muscle, measured via NIRS (NIRO-200, Hamamatsu), continously during centrifugation | — |
Countries
Germany
Contacts
Public ContactAlexandra Noppe
DLR - Institut für Luft- und Raumfahrtmedizin
Outcome results
None listed