The measurement of exhaled carbon monoxide and arterial carboxyhemoglobin concentrations in middle-aged and elderly patients with copd

Introduction: Arterial blood carboxyhemoglobin concentrations and exhaled carbon monoxide concentrations have been suggested to be inflammatory markers. Arterial carboxyhemoglobin concentrations can be measured from blood gas samples and concentrations of carboxyhemoglo-bin can be measured from carbon monoxide in exhaled air. We studied the relationship between arterial carboxyhemoglobin and exhaled carbon monoxide concentrations and disease severity. We evaluated whether arterial carboxyhemoglobin is useful for monitoring disease activity in patients with chronic obstructive pulmonary disease. Materials and Methods: Fifty-seven middle aged or elderly patients who were admitted to the outpatient clinic were included in the study. Patients were stable for chronic obstructive pulmonary disease and all participants were ex-smokers. The carboxyhemoglobin concentrations were measured and arterial and venous carboxyhemoglobin concentration differences were calculated. Exhaled carbon monoxide concentrations in both control subjects and patients were measured. Results: There were 13 controls and 44 patients with chronic obstructive pulmonary disease. There were no significant differences in age and smoking history (pack/year) between groups. The arterial blood carboxyhemoglobin concentrations in patients with chronic obstructive pulmonary disease were higher than those in control subjects (p<0.001). There was a significant correlation between carboxyhemoglobin concentrations in arterial blood and exhaled carbon monoxide concentrations (p<0.001; r:0.71). Arterial carboxyhemoglobin was inversely correlated with force expiratory volume in one second (p<0.001; r:-0.74). Venous blood carboxyhemoglobin concentrations were higher in the chronic obstructive pulmonary disease group than in the controls (p<0.05). exhaled carbon monoxide levels of patients were significantly higher than controls (p<0.001). Conclusion: Arterial carboxyhemoglobin is useful for monitoring disease activity in patients with chronic obstructive pulmonary disease.