Intraoperative renal near-infrared spectroscopy indicates developing acute kidney injury in infants undergoing cardiac surgery with cardiopulmonary bypass: a case–control study

Table 4 Intra- and postoperative renal near-infrared spectroscopy scores of infants with versus without acute kidney injury ^a

	AKI	No AKI	P -value
Renal NIRS <65% intraoperative (min%)	598 (86 to 2,532)	154 (0 to 2,997)	0.01*
Renal NIRS <65% 12 hr p.o. (min%)	694 (0 to 11,534)	26 (0 to 3,124)	0.02*
Renal NIRS <65% 24 hr p.o. (min%)	3,747 (0 to 22,590)	267 (1 to 9,417)	0.007*
Renal NIRS <65% 48 hr p.o. (min%)	1,113 (0 to 21,740)	150 (0 to 8,153)	0.04*
Renal NIRS ∆25% intraoperative (min%)	131 (0 to 1,200)	0 (0 to 2,263)	0.001*
Renal NIRS ∆25% 12 hr p.o. (min%)	4 (0 to 7,091)	0 (0 to 1,772)	0.04*
Renal NIRS ∆25% 24 hr p.o. (min%)	214 (0 to 13,267)	4 (0 to 312)	0.02*
Renal NIRS ∆25% 48 hr p.o. (min%)	25 (0 to 6,935)	0 (0 to 3,518)	0.1

^aThe renal near-infrared spectroscopy (NIRS) decrease below the baseline of 65% and the decrease of 25% below the individualized preoperative renal NIRS intraoperatively and 12, 24 and 48 hours postoperatively are expressed as median and range. AKI, Acute kidney injury; p.o., Postoperatively. *P < 0.05 indicates statistically significant values.