[The capnography parameters in healthy adults and patients with psychogenic dyspnea]

A comparison is made the end-tidal fractional concentration of carbon dioxide (FetCO2) and breathing frequency (f) obtained by capnography between 106 healthy persons (H-group) and 30 persons with a psychogenic dyspnea (P-group). The structure of a respiratory cycle was estimated by parameter R(CO2). It was calculated by relation of time of an exhalation to time of all respiratory cycle. Degree of "breath arrhythmia" was estimated by means of parameter CVR(CO2). It was the coefficient of variation (CV) for R(CO2) recorded during the 5-min capnography. The groups was differed for all parameters (p < 0.01), except for R(CO)2 (structures of a respiratory cycle). FetCO2 at H-group was 5.24 +/- 0.36%, at P-group 4.07 +/- 0.47. The breathing frequency at H-group was 14.3 +/- 3.7 br/min, at P-group 17.9 +/- 4.5 and CVR(CO2) at H-group was 8.9 +/- 2.7%, at P-group 12.7 +/- 3.1. We conclude that the most informative indicator of a psychogenic dyspnea is the complex of parameters taking into account all three characteristics of a pattern of breath: decrease FetCO2, increase f, and rhythm of breath.