Last month (November 2008 Whatís New in the Patient Safety World ďPreventing Surgical Site Infections: New ResourcesĒ) we noted some of the evidence-based recommendations for preventing surgical site infections (SSIís). A couple of the recommendations that have been based on less rigorous evidence, smoking cessation and avoidance of hyperglycemia, have just received more backing in studies just published.
Lindstrom and colleagues (Lindstrom 2008) reported the results of a randomized controlled trial on the impact of smoking cessation begun within 4 weeks of elective surgery on surgical complication rates. The found almost a 50% reduction in total complication rate for patients in the intervention (smoking cessation) arm. The study, however, was limited by its small size (they had difficulty recruiting patients who might be randomized to the smoking cessation arm). Looking at just SSIís, though fewer wound infections occurred in the intervention group, the numbers were far too small to meet statistical significance. Nevertheless, the study is important in lending weight to smoking cessation preoperatively. Whereas most prior studies that showed a benefit on postoperative complications began smoking cessation 6-8 weeks prior to surgery, this study demonstrates that there is a benefit even when smoking cessation is begun as late as 4 weeks prior to elective surgery.
Ramos and colleagues (Ramos 2008) published a study strengthening the correlation between perioperative hyperglycemia and postoperative infections (including SSIís), independent of preoperative blood glucose level or diabetic status. Using data from a risk-adjusted outcomes database from the National Surgical Quality Improvement Project, they showed that for each 40 mg/dl increase in serum glucose the risk of postoperative infection rose 30%. Postoperative hyperglycemia also had a significant adverse effect on length of stay. Caution: this was not a randomized controlled trial to show that treatment to avoid perioperative hyperglycemia results in fewer SSIís or better outcomes but it further strengthens the association between hyperglycemia and postoperative infections.
Together, these two studies strengthen the evidence for those two interventions in the guidelines for preventing SSIís that we talked about last month.
Ramos M, Khalpey Z, Lipsitz S, Steinberg J, Panizales MT, Zinner M, Rogers SO. Relationship of Perioperative Hyperglycemia and Postoperative Infections in Patients Who Undergo General and Vascular Surgery. Ann Surg 2008; 248(4):585-591
Lindstrom D, Azodi OS, Wladis A, Tonnesen H, Linder S, Nasell H, Ponzer S, Adami J. Effects of a Perioperative Smoking Cessation Intervention on Postoperative Complications: A Randomized Trial. Annals of Surgery. 2008; 248(5):739-745 http://www.annalsofsurgery.com/pt/re/annos/abstract.00000658-200811000-00008.htm;jsessionid=J2LL93fxpLQhQMXlrBMyG85SWpcX3xy1s3LPbxj5bF6S49HWfGhQ!976670012!181195629!8091!-1