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Table 1 Characteristics and preoperative, intraoperative, and postoperative data for patients with and without surgical site infections (SSIs).

From: Intraoperative PaO2 is not related to the development of surgical site infections after major cardiac surgery

Characteristics Patients
Without SSI
(n = 970)
Patients
With SSI
(n = 54)
Univariate OR
(95% CI)
P value Adjusted OR
(95% CI)b
P value
Preoperative value       
Age, mean (SD), years 68.2 ± 10,1 69.07 ± 10,9 1.009 (0.981 to 1.03) 0.54   
Sex, male/female 591 (60.9)/379 (39.1) 37 (68.5)/17 (31.5) 1.396 (0.77 to 2.51) 0.26   
Underlying conditions, No. (%)       
   Diabetes mellitus 285 (29.4) 16 (29.6) 1.01 (0.55 to 1.84) 0.97   
   Hypertension 427 (44) 27 (50) 1.27 (0.73 to 2.28) 0.39   
   Chronic renal failure 50 (5.2) 2 (3.7) 0.70 (0.16 to 2.98) 0.64   
   Chronic obstructive pulmonary disease 202 (20.8) 18 (33.3) 1.90 (1.05 to 3.41) 0.03   
   Peripheral vascular diseasea 74 (7.6) 2 (3.7)   0.28   
Additional drugs, No (%)       
   β-blockersa 435 (44.9) 21 (38.9) 1.28 (0.72 to2.27) 0.39   
   Statin 373 (38.5) 23 (42.6) 0.84 (0.48 to 1.47) 0.55 1.29(0.71 to2.33) 0.39
   Corticosteroids 19 (2.0) 1 (1.9) 0.94 (0.12 to 7.19) 0.95   
Intraoperative values       
Antibiotic prophylaxis, No. (%)       
   Cefazolin 938 (96.7) 46 (85.2) 0.19 (0.008 to 0.44) 0.001 4.90(2.07 to11.61) 0.0001
   Teicoplanin 32 (3.3) 8 (14.8)   0.001   
Surgical procedure, No. (%)       
   Valve 490 (50.5) 31 (57.4) 1.33 (0.76 to2.32) 0.32   
   CABG 296 (30.5) 14 (25.9) 0.8 (0.42 to 1.49) 0.47   
   Valvular + CABG 184 (19.0) 9 (16.7) 0.85 (0.41 to 1.78) 0.67   
Total CPB time, mean (SD), min 92.8 ± 38.2 96.3 ± 35.7 1.002 (0.99 to 1.009) 0.502 1.001(0.99 to1.009) 0.77
Aortic cross-clamp time, mean (SD), mina 66.7 ± 29.04 69.5 ± 26.6 1.003 (0.99 to 1.01) 0.48   
Glucose, mean (SD), mg/dLa 180.2 ± 51.4 178.5 ± 48.5 0.99 (0.98 to 1.001) 0.07 1.00(0.99 to1.01) 0.95
PaO2, mean (SD), mm Hga 148.4 ± 38.4 150.1 ± 34.2 1.001 (0.99 to 1.008) 0.74   
Hematocric during CPB, mean (SD), (%) 26.5 ± 4.4 25.8 ± 3.7   0.25   
Postoperative       
Duration of mechanical ventilation, mean (SD), days 51.4 ± 200.7 44.5 ± 146.3   0.805   
Glucose, mean, mg/dL 1-h ICU admission 166.2 ± 47.5 159.6 ± 52.4 1.001 (0.99 to 1.008) 0.32 0.99(0.98 to1.01) 0.19
   8-h ICU post-admissiona 169.1 ± 63.02 156.30 ± 40.8 0.996 (0.98 to 1.003) 0.14   
Core temperature, ICU admission, mean,°C 36.1 ± 0.7 36.1 ± 0.6 1.152 (0.78 to 1.696) 0.47 1,13(0.74 to1.71) 0.56
PaO2, mean (SD), mm Hg 1-h ICU post-admission 134.8 ± 41.3 136.5 ± 39.5   0.77 1.00(0.99 to1.01) 0.29
   8-h ICU post-admission 130.1 ± 37.5 124.4 ± 34.02   0.27 0.99(0.98 to1.00) 0.22
Leukocyte, ICU admission, mean (SD),mm3 10934.5 ± 3826.5 11316.4 ± 3611.01 1.000 (1.000 to1.000) 0.47   
Hematocric, ICU admission, mean (SD), (%) 30.3 ± 4.7 31.5 ± 4.0 1.06 (0.99 to 1.12) 0.06   
Units red-cell transfusion, mean (SD) 2.02 ± 2.8 2.2 ± 2.5 1,027 (0.94 to 1.121) 0.54   
Mediastinal bleeding, mean (SD), mm3 828.9 ± 554.3 709.9 ± 92.5 1.000 (0.99 to 1.000) 0.03   
Complications, No. (%)       
   Cardiac 72 (7.4) 6 (11.1) 1.5 (0.64 to 3.75) 0.32   
   Respiratory failure 89 (9.2) 3 (5.7) 0.59 (0.18 to 1.93) 0.38   
   Stroke 20 (2.1) 2 (3.7) 1.82 (0.41 to 8.0) 0.42   
   Acute renal failure 61 (6.3) 8 (14.8) 2.63 (1.17 to 5.88) 0.01   
Length of stay, mean (SD), days       
   Preoperativea 10.4 ± 9.8 12.1 ± 8.8 1.01 (0.99 to1.03) 0.209   
   In the ICU stay after surgerya 4.4 ± 9.4 4.1 ± 6.6 0.99 (0.96 to 1.03) 0.81   
   Postoperativea 13.8 ± 17.9 35.6 ± 19.5 1.03 (1.02 to1.04) 0.0001   
   In the hospital 24.2 ± 20.2 47.8 ± 20.3 1.03 (1.01 to 1.04) 0.0001 1.01(1.008 to1.02) 0.0001
Mortality, No. (%)c       
   In-hospital 76 (7.8) 7 (13.0)   0.17   
   30 days 72 (7.4) 4 (7.4) 0.99 (0.35 to2.85) 0.99   
   90 days 73 (7.5) 6 (11.1) 1.53 (0.63 to 3.70) 0.34   
  1. Abbreviations: SD, standard deviation; SSIs, surgical site infections; PaO2, partial pressure of oxygen; CI, confidence interval; ICU, intensive care unit; OR, odds ratio; CABG, coronary artery bypass graft; CPB, cardiopulmonary bypass.