Fig. 1

Correlations (Spearman’s rank correlation) and comparison of the analyzed parameters: hypoxanthine (HYP), xanthine (XA), uric acid (UA), lactate (LA), β-hydroxybutyrate (β-HB), blood pH, between the studied groups as follows: preoperative oral carbohydrate group and preoperative standard fasting group (p < 0.05). ↑ higher concentration/higher parameter value compared to the second study group; ↓ lower concentration/lower parameter value compared to the second study group; - negative correlation (red line); - positive correlation (green line); (Created with BioRender.com)