Analysis of Risk Factors for Sternal Wound Infection After Off-Pump Coronary Artery Bypass Grafting

Figures & data

Figure 1 Flow chart.

Table 1 The Comparison of the Risk Factors for Sternal Wound Infection Between the Two Groups of Patients [M (P25, P75)], n(%)]

Item	Observation Group (n=32)	Control Group (n=433)	t/x^2	P
Age (year-old)	66.2 (60.2, 70.2)	58.7 (50.2, 69.6)	3.725	0.002
Gender (male/female)	20/12	262/171	0.05	0.824
Body mass index (kg/m2)	26.78 (22.28, 30.56)	20.34 (17.21, 23.56)	2.357	0.032
The history of hypertension	11 (34%)	102 (24%)	1.896	0.169
The history of diabetes mellitus	13 (41%)	98 (23%)	5.308	0.021
The history of COPD	9 (28%)	84 (19%)	1.418	0.234
The smoking history	12 (38%)	202 (47%)	1.005	0.316
Triglyceride (mmol/l)	6.34 (5.66, 7.20)	4.57 (4.07, 5.27)	1.409	0.158
Operation time (h)	6.13 (5.08, 8.37)	4.24 (3.16, 5.32)	10.362	0.000
Tracheal intubation time (h)	30.81 (21.24, 55.60)	27.31 (20.26, 41.67)	3.882	0.002
Time of stay in CCU (d)	8.13 (5.05, 11.21)	5.24 (3.24, 7.32)	6.632	0.018
Amount of bleeding (mL)	622.24 (500.24, 754.22)	598.14 (503.24, 698.21)	0.904	0.403
Blood transfusion (blood plasma)>800mL	18 (56%)	127 (29%)	10.063	0.002
Blood transfusion (erythrocyte suspension)>6u	11 (34%)	75 (17%)	5.749	0.016
Secondary thoracotomy	4 (13%)	17 (4%)		0.048*
Postoperative pulmonary infection	15 (47%)	142 (33%)	2.642	0.104
Postoperative hypoxemia	13 (41%)	139 (32%)	1.145	0.285

Note: *Fisher’s exact probability method.

Table 2 The Logistic Regression Analysis of the Risk Factors for Sternal Wound Infection in the Two Groups of Patients

Variate	b	SE	Waldx^2	P	OR	95% CI
Age	0.025	0.457	1.946	0.445	1.025	0.968–1.072
BMI > 28 kg/m^2	0.730	0.248	10.074	0.000	2.290	1.380–3.705
The history of diabetes mellitus	1.264	0.332	14.320	0.000	3.440	1.844–6.780
Operation time >6h	1.315	0.241	4.811	0.002	3.096	1.186–6.338
Tracheal in tubation time >30h	0.792	0.203	12.163	0.001	2.235	1.065–3.882
Time of stay in CCU >8d	0.782	0.195	2.438	0.031	1.198	0.912–2.694
Blood transfusion (blood plasma) >800mL	0.875	0.217	3.482	0.002	3.072	2.409–6.081
Blood transfusion (erythrocyte suspension) >6u	1.404	0.392	7.946	0.012	2.784	2.698–5.682
Secondary thoracotomy	2.164	1.508	4.131	0.040	21.680	1.182–280.056