An audit of risk factors for wound infection in patients undergoing coronary artery bypass grafting or valve replacement.
OBJECTIVE
To investigate the epidemiology of surgical site infection in cardiac surgery patients operated on in 2006.


METHODS
Retrospective study of a case-control sample.


METHODS
Cardiac surgery unit of a university teaching hospital in Hong Kong.


METHODS
Cardiac surgery patients with surgical site infection were matched by procedure type, sex, and year of surgery with non-infected patients.


METHODS
Identification of risk factors for surgical site infection.


RESULTS
The infected and non-infected cardiac surgery patients did not differ in age, sex, or smoking history; however, patients with surgical site infection were significantly heavier (mean body mass index, 26.6 vs 23.9 kg/m2, P < 0.046). Almost 41% of the subjects had a history of diabetes mellitus, there being a significantly greater proportion among infected than non-infected patients (53.1% vs 28.1%, P < 0.042). All 37 of the patients without a diagnosis of diabetes had normal (ie < 8 mmol/L) preoperative glucose levels, but 99% of them yielded evidence of subsequent glycaemic dysfunction during or after surgery. Overall, 50% of the patients had a blood transfusion during the operation, with infected patients significantly more likely to have been transfused than the non-infected ones (65.6% vs 34.4%, P < 0.008).


CONCLUSIONS
There appears to be a relationship between surgical site infection in cardiac surgery patients and pre-existing (diagnosed and covert) diabetes mellitus and blood transfusion. Future studies should consider these factors in relation to surgical site infections, both in the wider surgical population and from a risk-minimisation perspective.
Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong. wendyb@surgery.cuhk.edu.hk
Wendy F
WF
Bower
Catherine S K
CS
Cheung
Raymond W M
RW
Lai
Malcolm J
MJ
Underwood
C Andrew
CA
van Hasselt
D000328:Adult; D000368:Aged; D001803:Blood Transfusion / Q000706:statistics & numerical data; D015992:Body Mass Index; D016022:Case-Control Studies; D001026:Coronary Artery Bypass; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000453:epidemiology*