Fig. 2
![Fig. 2](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13741-022-00279-8/MediaObjects/13741_2022_279_Fig2_HTML.png)
Fitted model variables — nomograph. These are COPD, chronic obstructive pulmonary disease. CRI, chronic renal impairment. VO2 max, maximal oxygen consumption at maximal exercise capacity. BMI, body mass index. VE/VCO2 — ventilatory equivalent for carbon dioxide; VE/VCO2 values in this diagram refers to VE/VCO2 taken at anaerobic threshold (AT VE/VCO2). Rob/Lap, robotic-assisted or laparoscopic-assisted surgery. DM, diabetes mellitus. NIDDM, non-insulin-dependent DM. IDDM, insulin-dependent DM. Pri, primary. WHO PS, World Health Organisation point score. TIA, transient ischaemic attack. CPET, cardiopulmonary exercise testing. AT, anaerobic threshold