A device for sampling arterialized earlobe blood in austere environments.
BACKGROUND
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 degree 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.


CONCLUSIONS
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.
Russomano
Thais
T
Microgravity Laboratory/PUCRS, Porto Alegre, Brazil. trussomano@hotmail.com
Evetts
Simon N
SN
Castro
Joao
J
Dos Santos
Marlise A
MA
Gavillon
Jorge
J
Azevedo
Dario F G
DF
Whittle
John
J
Coats
Edward
E
Ernsting
John
J