Analysis of Characteristics and Risk Factors of Surgical Site Infection after Coronary Artery Bypass Graft

Mi Hye Kim; Jae Sim Jeong; Sung Ho Choi

doi:10.14192/kjhaicp.2016.21.2.57

Original Article

Korean J Healthc Assoc Infect Control Prev 2016;21(2):57-64.

Published online: 19 December 2016

DOI: https://doi.org/10.14192/kjhaicp.2016.21.2.57

Analysis of Characteristics and Risk Factors of Surgical Site Infection after Coronary Artery Bypass Graft

Mi Hye Kim^1,², Jae Sim Jeong^2,³, Sung Ho Choi⁴

¹Department of Nursing, Asan Medical Center, Seoul, Korea

²Department of Clinical Nursing, University of Ulsan Graduate School of Industrial Technology, Ulsan, Korea

³Department of Nursing, University of Ulsan College of Medicine, Ulsan, Korea

⁴Department of Cardiacthoracic Surgery, University of Ulsan College of Medicine Asan Medical Center, Seoul, Korea

Correspondence to: Jae Sim Jeong, Department of Nursing, University of Ulsan College of Medicine, Daehak-ro, Nam-gu, Ulsan 44610, Korea Tel: 052-259-1298, Fax: 052-259-1236 E-mail: jsejongicp@ulsan.ac.kr

Received 19 October 2016 Accepted 5 December 2016

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background

The purpose of this study was to examine surgical site infection (SSI) characteristics and risk factors in patients undergoing coronary artery bypass graft (CABG) surgery.

Methods

A retrospective observational study was conducted, involving patients undergoing CABG surgery at a tertiary care hospital in Seoul, between January 2010 and December 2013. This study adopted the SSI definition proposed by the Centers for Disease Control and Prevention and only infections at the sternotomy site were included. Multivariate risk analysis was performed to identify independent risk factors for CABG SSI.

Results

Out of 998 CABG patients, 3.9% (39) cases of SSI were identified. In multivariate analysis, diabetes mellitus (OR=2.016, 95% CI=0.994-4.089), increased body mass index (BMI) (OR=4.555, 95% CI=1.748-11.871), red blood cell (RBC) transfusion (OR=1.106, 95% CI=1.021-1.197), and undergoing cardio-pulmonary bypass surgery (OR=2.790, 95% CI=1.239-6.286) were significantly associated with CABG SSI.

Conclusion

Diabetes mellitus, increased BMI, RBC transfusion, and undergoing cardio-pulmonary bypass surgery are independent risk factors for CABG SSI.

Go to :

Keywords: Coronary artery bypass, Risk factors, Surgical wound infection

Table 1.

Characteristics of surgical site infections after coronary artery bypass graft

Characteristics	N (%)
Type of surgical site infection
Superficial	4 (10.3)
Deep incisional	9 (23.1)
Mediastinitis	26 (66.7)
Duration from operation to SSI (day)
≤5	1 (2.6)
6-10	4 (10.3)
11-20	10 (25.6)
21-30	14 (35.9)
31-60	8 (20.5)
≥60^*	2 (5.1)
Mean±SD (median)	31.0±43.9 (23)
Causative organisms
Coagulase negative staphylococci	22 (56.4)
Methicillin-resistant Staphylococcus. aureus	7 (18.0)
Acinetobacter baumannii	4 (10.3)
Candida albicans	3 (7.7)
Corynebacterium spp.	2 (5.1)
Enterococcus faecalis	1 (2.6)

^* The duration of two surgical site infection cases were 75 and 285 days.

Table 2.

Univariate analysis of risk factors associated with surgical site infection (SSI)

Variables		Total	N (%), Mean±SD		P-value	Odds ratio	95% CI
Variables		Total	SSI (n=39)	No SSI (n=959)	P-value	Odds ratio	95% CI
Gender
	Male	766 (76.8)	31 (79.5)	735 (96.0)		1
	Female	232 (23.2)	8 (20.5)	224 (23.4)	.680	0.847	0.384-1.869
Age (years)		64.2±9.2	65.8±9.7	64.2±9.2	.275	1.020	0.984-1.058
Current smoking
	No	446 (44.7)	12 (30.8)	434 (45.3)		1
	Yes	552 (55.3)	27 (69.2)	525 (54.7)	0.079	1.860	0.931-3.715
Diabetes mellitus
	No	530 (53.1)	13 (33.3)	517 (53.9)		1
	Yes	468 (46.9)	26 (66.7)	442 (46.1)	.014	2.339	1.188-4.607
Alcohol drinking
	No	561 (56.2)	22 (56.4)	539 (56.2)		1
	Yes	437 (43.8)	17 (43.6)	420 (43.8)	.980	1.008	0.529-1.923
Hypertension
	No	384 (38.5)	15 (38.5)	369 (38.5)		1
	Yes	614 (61.5)	24 (61.5)	590 (61.5)	.998	0.999	0.517-1.930
Body Mass Index
	≤24.9	603 (60.4)	20 (51.3)	583 (60.8)		1
	25.0-29.9	348 (38.5)	13 (33.3)	335 (34.9)	.734	1.131	0.556-2.303
	≥30.0	47 (4.7)	6 (15.4)	41 (4.3)	.003	4.266	1.624-11.205
ASA class score
	1	5 (0.5)	1 (2.5)	4 (0.4)		1
	2	323 (32.4)	9 (23.1)	314 (32.7)	.077	0.127	0.013-1.245
	3	624 (62.5)	26 (66.7)	598 (62.4)	.116	0.167	0.018-1.551
	4	46 (4.6)	3 (7.7)	43 (4.5)	.314	0.279	0.023-3.347
Total bilirubin (preoperative) (mg/dl)
	≤0.2	31 (3.1)	1 (2.6)	30 (3.1)		1
	0.2-1.2	915 (91.7)	36 (92.3)	879 (91.7)	.842	1.229	0.163-9.263
	≥1.3	52 (5.2)	2 (5.1)	50 (5.2)	.884	1.200	0.104-13.806
White blood cell (preoperative) (×10³/μl)
	＜5.0	152 (15.2)	4 (10.3)	148 (15.4)		1
	5.0-10.0	773 (77.5)	29 (74.3)	744 (77.6)	.498	1.442	0.500-4.163
	≥10.0	73 (7.3)	6 (15.4)	67 (7.0)	.070	3.313	0.905-12.129
Preoperative length of stay (day)		6.2±7.2	6.3±4.8	6.1±7.3	.822	1.004	0.968-1.042
Duration of operation (min)		241.5±61.5	237.9±73.0	241.5±61.0	.713	0.999	0.994-1.004
Emergency operation
	No	935 (93.7)	38 (97.4)	897 (93.5)		1
	Yes	63 (6.3)	1 (2.6)	62 (6.5)	.345	2.627	0.355-19.450
IMA (internal mammary artery)
	No	18 (1.8)	0.0	18 (2.0)		1
	Single	916 (91.8)	34 (87.1)	882 (91.8)	.291	1.684	0.640-4.431
	Bilateral	64 (6.4)	5 (12.9)	59 (6.2)	.104	0.446	0.168-1.182
CPB (cardio-pulmonary bypass)
	No	959 (96.0)	30 (77.0)	929 (76.9)		1
	Yes	39 (3.9)	9 (23.0)	30 (3.1)	.007	2.933	1.349-6.373
Postoperative bleeding control
	No	943 (94.5)	36 (92.3)	907 (94.6)		1
	Yes	55 (5.5)	3 (7.7)	52 (5.4)	.545	1.461	0.205-2.308
RBC transfusion in operating room (pint)
	No	456 (45.7)	14 (35.9)	442 (46.1)		1
	1-2	350 (35.0)	13 (33.3)	337 (35.1)	.615	1.218	0.565-2.625
	3-4	160 (16.0)	9 (23.1)	151 (15.7)	.148	1.882	0.798-4.436
	≥5	32 (3.2)	3 (7.7)	29 (3.0)	.075	3.266	0.888-12.012
RBC transfusion in ICU (pint)
	No	511 (51.2)	150 (38.5)	361 (37.6)		1
	1-2	471 (47.2)	17 (43.6)	454 (47.3)	.901	0.436	0.138-1.376
	3-4	105 (10.5)	3 (7.7)	102 (10.6)	.591	0.393	0.126-1.222
	＞5	46 (4.6)	4 (10.3)	42 (4.4)	.157	0.309	0.066-1.440
Total transfusion amount (pint)		2.7±3.5	2.7±1.1	2.4±0.9	.008	1.109	1.027-1.198

Abbreviations: CI, confidence interval; ASA, American Society of Anesthesiologist; RBC, red blood cell; ICU, intensive care unit.

Table 3.

Multivariate analysis of risk factors for surgical site infections after coronary artery bypass graft

Variables	P-value	Odds ratio	95% CI
Current smoking	0.052	2.016	0.994-4.089
Diabetes mellitus	0.037	2.080	1.043-4.145
Body Mass Index =30 kg/m^*	0.002	4.555	1.748-11.871
RBC transfusion amount^†	0.013	1.106	1.021-1.197
Use of cardio-pulmonary bypass	0.013	2.790	1.239-6.286

^* Reference ＜30 kg/m;

^† By 1 unit increments.

Abbreviation: CI, confidence interval.

REFERENCES

1. Simmons BP. CDC guideline for prevention of surgical wound infections. AORN J. 1983; 37:556–576.

2. Ahn YJ, Sohng KY. Factors related to surgical site infections in patients undergoing general surgery. J Korean Acad Fundam Nurs. 2005; 12:113–120.

3. Leavitt BJ, Sheppard L, Maloney C, Clough RA, Braxton JH, Charlesworth DC, et al. Effect of diabetes and associated conditions on long-term survival after coronary artery bypass graft surgery. Circulation. 2004; 110 11 Suppl 1:II41–II44.

4. Oh HS. In: The epidemiology of post-operative wound infection and it's effects on the hospital stay and the cost of hospitalization [Master's thesis]. Seoul: Seoul National University; 1993.

5. Park ES, Kim JM. Surveillance of surgical wound infection among patients from the department of general surgery. Korean J Infect Dis. 1995; 27:37–43.

6. Cruse PJ, Foord R. The epidemiology of wound infection. A 10-year prospective study of 62,939 wounds. Surg Clin North Am. 1980; 60:27–40.

7. Choi JB, Lee MK, Jeong ET. Long-term survival after coronary artery bypass surgery. Korean J Thorac Cardiovasc Surg. 2005; 38:139–145.

8. Baek JH, Jung TE, Lee DH, Lee JH, Kim JH. Analysis of risk factors and effect of vancomycin for sternal infection after coronary artery bypass graft. Korean J Thorac Cardiovasc Surg. 2010; 43:381–386.

9. Olsen MA, Lock-Buckley P, Hopkins D, Polish LB, Sundt TM, Fraser VJ. The risk factors for deep and superficial chest surgical-site infections after coronary artery bypass graft surgery are different. J Thorac Cardiovasc Surg. 2002; 124:136–145.

10. Potapov EV, Loebe M, Anker S, Stein J, Bondy S, Nasseri BA, et al. Impact of body mass index on outcome in patients after coronary artery bypass grafting with and without valve surgery. Eur Heart J. 2003; 24:1933–1941.

11. Hassan M, Smith JM, Engel AM. Predictors and outcomes of sternal wound complications in patients after coronary artery bypass graft surgery. Am Surg. 2006; 72:515–520.

12. Jonkers D, Elenbaas T, Terporten P, Nieman F, Stobberingh E. Prevalence of 90-days postoperative wound infections after cardiac surgery. Eur J Cardiothorac Surg. 2003; 23:97–102.

13. Acuff TE, Landreneau RJ, Griffith BP, Mack MJ. Minimally invasive coronary artery bypass grafting. Ann Thorac Surg. 1996; 61:135–137.

14. Toumpoulis IK, Anagnostopoulos CE, Derose JJ Jr, Swistel DG. The impact of deep sternal wound infection on long-term survival after coronary artery bypass grafting. Chest. 2005; 127:464–471.

15. Barner HB, Standeven JW, Reese J. Twelve-year experience with internal mammary artery for coronary artery bypass. J Thorac Cardiovasc Surg. 1985; 90:668–675.

16. Chang W, Park HG, Kim H, Youm W. Analysis of risk factors in poststernotomy sternal wound infection and mediastinitis after open-heart surgery. Korean J Thorac Cardiovasc Surg. 2003; 36:583–589.

17. Yu JH, Lim SP, Lee SK, Kim YH, Kim SW, Kang SK, et al. Clinial analysis of surgical management for descending necrotizing mediastinitis. Korean J Thorac Cardiovasc Surg. 2008; 41:463–468.

18. Redmond AC, Keenan AM. Understanding statistics. Putting p-values into perspective. J Am Podiatr Med Assoc. 2002; 92:297–305.

19. Centers for Disease Control and Prevention. National Healthcare Safety Network (NHSN) Overview: SSI - surgical site infection p. 40-43.. [Updated on January 2014]. http://www.cdc.gov/nhsn/PDFs/pscManual/validation/pcsManual-2014-valid.pdf.

20. Korean Center for Disease Control and Prevention. A study on the Korean Surgical Site Infection Surveillance System. [Updated on January 2015]. http://konis.cdc.go.kr/konis/sub/reports_ssi.htm.

21. Borger MA, Rao V, Weisel RD, Ivanov J, Cohen G, Scully HE, et al. Deep sternal wound infection: risk factors and outcomes. Ann Thorac Surg. 1998; 65:1050–1056.

22. Smyth ET, Emmerson AM. Surgical site infection surveillance. J Hosp Infect. 2000; 45:173–184.

23. Keech A, Zambahari R, Ritchie G, Thongtang V, White H, Carruthers A, et al. Hypercholesterolaemia as a risk factor for coronary heart disease in the Asia-Pacific region: the ASPAC study (Abstract). Atherosclerosis. 2000; 151:83.

24. Milano CA, Kesler K, Archibald N, Sexton DJ, Jones RH. Mediastinitis after coronary artery bypass graft surgery. Risk factors and long-term survival. Circulation. 1995; 92:2245–2251.

Go to :