	Creatinine	eGFR	Na⁺	K⁺	Cl⁻
Operating time (minutes)	R = −0.1219	R = 0.0073	R = 0.0291	R = −0.0477	R = 0.0115
Operating time (minutes)	P = 0.352937	P = 0.959453	P = 0.808349	P = 0.678809	P = 0.924169
0.9% NS (litres)	R = −0.0727	R = 0.1446	R = −0.0842	R = −0.0237	R = 0.0093
0.9% NS (litres)	P = 0.581345	P = 0.311355	P = 0.486137	P = 0.849006	P = 0.938644
BMI	R = −0.0296	R = −0.1715	R = −0.0855	R = −0.1247	R = −0.2136
BMI	P = 0.824424	P = 0.233006	P = 0.480943	P = 0.302879	P = 0.074515
ASA	R = −0.0936	R = 0.2199	R = 0.1354	R = 0.0422	R = −0.0193
ASA	P = 0.475924	P = 0.121018	P = 0.260232	P = 0.726768	P = 0.875033
IV fluids (ml)	R = −0.0759	R = −0.0381	R = 0.1439	R = 0.0424	R = 0.0488
IV fluids (ml)	P = 0.565656	P = 0.834465	P = 0.231212	P = 0.728013	P = 0.686111