[Capillary blood gas test usefulness to evaluate gas exchange with 21% and 100% of oxygen inspired fractions in subjects with stable cardiopulmonary disease at 2,240 meters above sea level].
OBJECTIVE
Capillary blood gas test has had ample use in the infantile population. In the adult population, the information is limited and controversial. The agreement between capillary-arterial gases seems to parallel the pH and the carbon dioxide pressure in different studied populations. In order to know the degree of agreement between these gases, we evaluate them at breathing room air and at 100% of oxygen fractions at 2,240 meters above sea level.


METHODS
We obtained capillary-arterial blood gases simultaneously from subjects with stable cardiopulmonary disease in both conditions of inspired oxygen. Demographic, hemodynamic, diagnostic, and laboratory variables were gathered.


METHODS
agreement was analyzed with the intraclass correlation coefficient and the Bland-Altman procedure.


RESULTS
We studied 101 subjects, 48 men and 53 women, whose respective ages were 55 +/- 16 and 56 +/- 16. Mean systemic arterial pressure was 94.96 +/- 10.57 mmHg. Hemoglobin was 15.94 +/- 2.48 g/dl. The agreement between the variables with the inspired oxygen fractions, 21%, 100%, and the mean difference in parenthesis was respectively: potential hydrogen, 0.94 (0.0091), 0.94 (0.0039); oxygen pressure, 0.90 (2.94), 0.84 (74.99); carbon dioxide pressure, 0.97 (0.079), 0.97 (0.179); bicarbonate, 0.93 (-0.067), 0,96 (0.262); total dissolved carbon dioxide, 0.94 (-0.142), 0.93 (0.161); base excess: 0.94, (-0.125), 0.92 (0.235); oxygen saturation, 0.98 (0.764), 0.97(0.202).


CONCLUSIONS
Capillary blood gas test could be a useful alternative to the arterial one, nevertheless, it is limited by its low agreement with the oxygen pressure in both oxygen inspired fractions.
Santos-Martínez
Luis-Efrén
LE
Departamento de Cardioneumología, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, México D.F., México. sanlui@cardiologia.org.mx
Martínez-Guerra
María Luisa
ML
Duran
Aída
A
Rodríguez
Francisca
F
Gotés
José
J
Roquet
Ivonne
I
López
Luis Antonio
LA
Pulido
Alicia
A
Lupi
Eulo
E
Bautista
Edgar
E
Pulido
Tomás
T
Sandoval
Julio
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000531:Altitude; D001784:Blood Gas Analysis; D002196:Capillaries; D005260:Female; D006331:Heart Diseases / Q000097:blood* / Q000378:metabolism; D006801:Humans; D008171:Lung Diseases / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage* / Q000378:metabolism*; D011659:Pulmonary Gas Exchange; D055815:Young Adult
D010100:Oxygen