Table 2. Results of laboratorial exams before the surgery described in medical records.

Variables	With POAF (n=20)	Without POAF (n=85)	p value*
Magnesium, mEq/L	1.8 (0.2)	1.7 (0.2)	0.913
Sodium, mEq/L	137.7 (3.8)	139.1 (3.1)	0.099
Potassium, mEq/L	4.32 (0.5)	4.3 (0.4)	0.914
Calcium, mg/dL	1.2 (0.1)	1.3 (0.6)	0.351
CRP, mg/dL	12.9 (19.7)	9.0 (13.5)	0.129
Creatinine, mg/dL	1.4 (1.4)	1.6 (1.9)	0.645
Urea, mg/dL	44.9 (30.4)	44.0 (24.3)	0.819

*Mann-Whitney test. Results presented in means (standard deviation).

POAF: postoperative atrial fibrillation; CRP: C-reactive protein.