A Device for Sampling Arterialized Earlobe Blood in Austere Environments

Russomano T, Evetts SN, Castro J, dos Santos MA, Gavillon J, Azevedo DFG, Whittle J, Coats E, Ernsting J. A device for sampling arterialized earlobe blood in austere environments. Aviat Space Environ Med 2006; 77:453–455.



Introduction: There is currently no effective method of measuring arterial blood gas tensions in austere environments such as in space or at high altitude. An alternative to direct arterial measurement is the sampling of arterialized earlobe blood, an accurate technique that has been in use in clinical medicine and physiology for more than 50 yr. We, therefore, developed an earlobe arterialized blood (EAB) collector for practical use in extreme environments. Methods: The results from the EAB collector were compared with simultaneous samples of blood drawn from the radial artery. Six healthy subjects breathed a gas mixture of 12.8% O₂ in N₂ during 15 min of 8° head-down tilt. The blood samples were analyzed immediately. Results: The mean differences in Po₂ between arterialized earlobe and radial artery samples were 0.25 ± 1.25 mmHg for Po₂ and 1.0 ± 0.75 mmHg for Pco₂; neither difference was significant. There was no difference between the pH values obtained by the two techniques. Conclusion: This study suggests that arterialized blood sampled from the earlobe using the EAB collector may provide sufficiently accurate measurements of the Po₂, Pco₂ and pH of arterial blood for clinical or research use in extreme environments.