Using the oxygen-cost diagram in ramp-slope selection for dyspneic patients

Intern Med. 2010;49(14):1325-32. doi: 10.2169/internalmedicine.49.3094. Epub 2010 Jul 15.


Background: Maximal incremental exercise testing should be completed within 8-12 minutes. The ramp-slope influences the exercise duration. Oxygen-cost diagram (OCD) is a scoring scale for the capability of daily activity performed and therefore can be used to estimate the ramp-slope.

Methods: The OCD-algorithm and the reported-algorithm were used prospectively in random order for selecting optimal ramp-slope: Ramp-slope(OCD)=Score(OCD)xweight in kg/40 for men and weight/50 for women and Ramp-slope(reported)=(Predicted V(O2peak)-V(O2unloaded))/100. Fifty-three dyspneic patients and 16 normal controls were enrolled to perform a ramp-pattern exercise. Fourteen patients not reaching maximum exercise levels were excluded. The exercise capacity, exercise time, and success rate of loaded exercise between 8 and 12 minutes were measured.

Results: Comparing the reported-algorithm to the OCD-algorithm in normal controls, the only difference was that the ramp-slope was higher in males; in patients, the ramp-slope was higher in males, the exercise time shorter and the success rate lower (8.6+/-3.3 vs. 9.4+/-2.1 min, 61.5% vs. 84.6%, both p<0.05); in obese patients, the ramp-slope was lower and the exercise time longer.

Conclusion: OCD score can predict the ramp-slope selection for exercise testing in normal controls and dyspneic patients. This may be affected by gender and body weight when using the reported-algorithm for dyspneic patients.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Algorithms
  • Dyspnea / diagnosis*
  • Dyspnea / physiopathology*
  • Exercise Test / methods*
  • Exercise Test / standards
  • Female
  • Humans
  • Male
  • Middle Aged
  • Obesity / diagnosis
  • Obesity / physiopathology
  • Oxygen Consumption / physiology*
  • Prospective Studies