Fig. 2

The prognostic utility of bladder urinary oxygen tension in the early detection of acute kidney injury over 24 h in Gram-negative sepsis in non-anesthetised sheep. A The time course of changes in renal medullary tissue PO₂ and bladder urinary PO₂ and urine flow over 24 h of sepsis. Urine flow is presented as absolute values corrected for kilogram of body weight. B Scatterplot of the relationship between medullary tissue and urinary PO₂ (different symbols represent individual sheep). The line of best fit, determined by ordinary least-product regression analysis, had an X intercept of 2.4 mmHg (95% confidence interval: 0.3–4.5) and a slope of 1.02 (95% confidence interval: 0.95–1.09) (P < 0.001). C Changes in renal medullary tissue and bladder urinary PO₂ and D plasma creatinine and urinary neutrophil gelatinase-associated lipocalin (NGAL) over 24 h of Gram-negative sepsis-induced acute kidney injury. *P < 0.05 indicates significant differences from pre-morbid baseline (Time 0). Figures modified from [16, 17]