[Normal ventilatory response to hypoxia and hypercapnia at an altitude of 2240 meters].
OBJECTIVE
To evaluate the ventilatory response to hypoxia and hypercapnia in healthy residents of Mexico City at 2240 m above sea level.


METHODS
15 healthy subjects, 10 women and 5 men, were studied (mean age 38; range 26-76). All completed one or two tests of ventilatory response to hypoxia and hypercapnia as described by Rebuck-Campbell and Read, respectively. The results were analyzed by linear regression using the minute ventilation as the dependent variable and SaO2 (hypoxia) or PCO2 (hypercapnia) as the independent variables.


RESULTS
Seven subjects had very low or no response to hypoxia. The mean hypoxia slope was 0.7 +/- 0.6 L/min/% (+/- SD) and the hypercapnia slope was 3.0 +/- 1.4 L/min/mmHg. The intercepts were 176 +/- 278 for SaO2 and 3.0 +/- 7 for PCO2.


CONCLUSIONS
A low respiratory response to hypoxia was found in Mexico City Healthy residents. The response to hypercapnia was similar in slope to other studies but had an intercept shifted to lower values. The Mexico City residents showed a behavior typical of patients with chronic hypoxemia or of dwellers at high altitudes.
Vázquez-García
J C
JC
Departamento de Fisiología Respiratoria, Instituto Nacional de Enfermedades Respiratorias, INER, México DF.
Arellano-Vega
S L
SL
Regalado-Pineda
J
J
Pérez-Padilla
J R
JR
D000328:Adult; D000368:Aged; D000531:Altitude; D002245:Carbon Dioxide / Q000378:metabolism*; D005260:Female; D006801:Humans; D006935:Hypercapnia / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D008800:Mexico; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D010313:Partial Pressure; D012119:Respiration
D002245:Carbon Dioxide; D010100:Oxygen
Respuesta ventilatoria normal a hipoxia e hipercapnia a una altitud de 2240 metros.