ABSTRACT
OBJECTIVES: The presence of chronic low oxygen delivery to the tissues (blood flow X Hb concentration X arterovenous oxygen content difference) in patients with chronic lung disease (CLD) leads to a aggravated dyspnea. Therefore, total oxygen delivery to the tissues is a reverse correlation with severity of dyspnea. So far, the treatment of patients with CLD has been limited to only the increase of ventilation and perfusion capacity. However, this study focused on the capacity of oxygen delivery to the tissues in patients with CLD. We measured blood oxygen parameters as one of the extended approaches. METHOD: Simultaneous arterial and venous blood samples from 15 patients with CLD at rest were evaluated for 2.3-DPG, CO-Hb (Carboxy-monohe-moglobin), Met-Hb (methomoglobin), ABGA (Arterial blood gas analysis), VBGA (Venous blood gas analysis) and Hb (Hemoglobin). Smokers and patients with other disease were excluded from the study in order to avoid the factors (2.3-DPG, CO-Hb etc.) which can shift the oxygen dissociation curve. There were 12 men and 3 women, ranging in age from 40 to 75 years. The disease onset varied from 3 years to more than 30 years. RESULTS: 1) As total oxygen delivery to the tissues decreased, Ao2(Arterial oxygen partial pressure) and A-VCb (Arteriovenous oxygen content difference) decreased, while 2.3-DPG increased. Total oxygen delivary to the tissues showed a significant correlation with more A-V and 2.3-DPG than AO2. 2) AO2 had a correlation with A-VO2 but AO2 did not clearly reflect A-VO2. 3) 2.3-DPG activity depended on more A-VO2 than AO2. 4) As A-VO2 decreased, there was more significant relationship among 2.3-DPG, A-VO2 and tissue oxygen delivery. 5) A-VO2 showed a significant reverse correlation with 2.3-DPG as well as Met-Hb % + CO-Hb %. 6) ACO2 (arterial carbon dioxide partial pressure) showed a correlation with 2.3-DPG as well as A-VO2. 7) Arterial PH did not correlate with 2.3-DPG as well as A-V. CONCLUSION: 1) AO2 in patient with CLD correlated with A-VO2 but AO2 did not clearly reflect A-V. 2) Total oxygen delivery (severity of dyspnea) showed a significant correlation with more A-VO2 and 2.3-DPG than AO2. 3) 2.3-DPG activity depended on more A-VO2 than AO2. 4) 2.3-DPG activity had a reverse correlation with A-V in spite that 2.3-DPG shifts the oxygen dissociation curve to the right, because 2.3-DPG shift is secondary change associated with the low oxygen delivery to the tissues, More extensive k prospective investigations are needed to clearly define correlation among A-VO2, 2.3-DPG and prognosis of patients with CLD.