A study of bronchial sensitivity and bronchial reactivity using Astograph and transcutaneous oxygen tension in asthmatic chilaren The problems of simultaneous measurement

Abstract

Bronchial sensitivity and reactivity in 60 patients with bronchial asthma was measured using the Astograph and simultaneous transcutaneous oxygen tension [PtcO₂].
In spite of increasing respiratory resistance, there were some cases in which PtcO₂ did not show remarkable decrease.
The PtcO₂ percentage was defined as (basal value of PtcO₂ - bottom value of PtcO₂) / (basal value of PtcO₂).
The correlation between PtcO₂% and the basal value of PtcO₂ was relatively high (r=0.42, n=58, p<0.005).
The correlation between PtcO₂% and V50/Ht or V25/Ht was also relatively high (r=0.41, n=45, p<0.01, r=0.49, n=45, p<0.001, respectively).
In some cases of small airway obstruction or low basal value of PtcO₂, the PtcO₂% was smaller.
The patients of over 70% in FEV_1.0/VCP were in accord with that of over 70 mmHg in the basal value of PtcO₂.
The results suggest the recommended basal value of PtcO₂ to measure bronchial sensitivity and reactivity may be over 70 mmHg.