Relationship between renal function in the chronic phase and acute stage renal oxygen saturation.

(a, b) Box-and-whisker plots show serum BUN and 24 h creatinine clearance for the control (5 mice) group and the mild (14 mice) and severe (13 mice) AKI groups. Each box in the plot represents the 25th and 75th quartiles, with the line inside each box indicating the median, and the whiskers, the maximum and minimum serum BUN and 24 h creatinine clearance. There is a statistically significant difference (P = 0.016 and 0.042, respectively) between the mild and severe AKI groups at day 28, using the non-parametric Mann-Whitney U test. (c, d) Scatterplots show the correlation between renal oxygen saturation at 24 h and kidney function at day 28, with this correlation being significant for both serum BUN (r = -0.736, Pr = 0.405, P = 0.036). *p < 0.050.