Abstract
Introduction: The treatment of hypercapnic chronic obstructive pulmonary disease (COPD) patients with concomitant sleep-disordered breathing (SDB) starts with continuous positive airway pressure (CPAP-therapy) under the control of the hypercapnia level in order to correct therapeutic optionsin the case of hypercapnia worsening.
Aim: To evaluate the possibility of capnometry in efficacy and safety control of CPAP-therapy in COPD patients with SDB and hypercapnia.
Methods: 10 hypercapnic COPD patients combined with obstructive sleep apnea (8 persons) or obesity hypoventilation syndrome (2 persons) received CPAP-therapy. Capnometry before and after 10 treatment nights was performed. Expired CO2 fraction (FECO2) and end-tidal CO2 fraction (FETCO2) were evaluated. The minimal clinically important difference (MCID) for FETCO2 was calculated. Data are presented as mean±SD.
Results: After CPAP-therapy we observeda statistically significant CO2 level reductionin the exhaled air: FECO2 decreased from (4.46±0.39)% to (3.71±0.46)%, FETCO2 from (6.40±0.62)% to (5.63±0.73)%, p<0.01, which means lower the degree of hypercapnia in patients. The therapy was sufficiently safe,without CO2 accumulation. The MCID for FETCO2 by the way of the standard error of measurement calculation is 0.31%, which incidentally coincides with other concept that half of the baseline standard deviation is a measure of MCID.
Conclusions:Capnometryas a simple procedure may be a useful additional tool to control efficacy and safety of CPAP-therapy in COPD patients with SDB and hypercapnia. The minimal clinically important difference for FETCO2 is 0.31%.
- © 2014 ERS