عنوان مقاله [English]
Background & Purpose: The aim of this study was investigation of the effect of exercise intensity on accuracy of arterial CO2 pressure estimation from end tidal CO2 pressure. Methodology: Ten subjects were selected as samples. At first, the maximum oxygen consumption (VO2max) of each subject was obtained by performing progressive exercise protocol. Then, each subject performed three protocols with intensities of 30%, 50% and 70% of his own VO2max and duration of each exercise was 12-minute. Blood samples were taken during the rest, exercise and recovery periods, and data on respiratory gases were also collected. Results: Correlation coefficient between PaCO2 and PaCO2pre and p value in exercise with intensities of 30%, 50% and 70% of VO2max were r = 0.807, p = 0.001; r = 0.822, p = 0.001 and r = 0.552, p = 0.003 respectively. The percentage of estimation error was higher in the intensity of 70% of VO2max than intensities of 30% and 50% of VO2max. Conclusion: Based on the findings of this study, it seems that the accuracy of prediction of arterial CO2 pressure from end tidal CO2 pressure is lower in high intensities exercise than low intensities exercise.