Clinical Review

UPDATE: INFECTIOUS DISEASE

OBG Manag. 2010 June;22(6):36-46

References

1. Antiviral drugs for influenza. The Medical Letter. 2009;51(1325):89-92.

2. Wenzel RP, Edmond MB. Preparing for 2009 H1N1 influenza. N Engl J Med. 2009;361(20):1991-1993.

3. Perez-Padilla R, Rosa-Zambori D, deLeon SP, et al. Pneumonia and respiratory failure from swine-origin influenza A (H1N1) in Mexico. N Engl J Med. 2009;361(7):680-689.

4. H1N1 vaccine for prevention of pandemic influenza. The Medical Letter. 2009;51(1322):77-78.

5. Chapman S, Duff P. Frequency of glove perforations and subsequent blood contact in association with selected obstetric surgical procedures. Am J Obstet Gynecol. 1993;168(5):1354-1357.

6. Lancaster C, Duff P. Single versus double-gloving for obstetric and gynecologic procedures. Am J Obstet Gynecol. 2007;196(5):e36-e37.

7. Smaill F, Hofmeyr GJ. Antibiotic prophylaxis for cesarean section. Cochrane Database of Systematic Reviews. 2002;(3):CD000933.-doi:10/1002/14651858.

8. Prophylactic antibiotics in labor and delivery. ACOG Practice Bulletin No. 47. American College of Obstetricians and Gynecologists. Obstet Gynecol. 2003;102(4):875-882.

9. Sullivan SA, Smith T, Chang F, Hulsey T, Vandorsten JP, Soper D. Administration of cefazolin prior to skin incision is superior to cefazolin at cord clamping in preventing postcesarean infectious morbidity: a randomized controlled trial. Am J Obstet Gynecol. 2007;196(5):455.e1-e5.

10. Costantine MM, Rahman M, Ghulmiyah L, et al. Timing of perioperative antibiotics for cesarean delivery: a metaanalysis. Am J Obstet Gynecol. 2008;199(3):301.e1-e6.

11. Tita ATN, Hauth JC, Grimes A, Owen J, Stamm AM, Andrews WW. Decreasing incidence of postcesarean endometritis with extended-spectrum antibiotic prophylaxis. Obstet Gynecol. 2008;111(1):51-56.

12. Tita AT, Owen J, Stamm AM, Grimes A, Hauth JC, Andrews WW. Impact of extended-spectrum antibiotic prophylaxis on incidence of postcesarean surgical wound infection. Am J Obstet Gynecol. 2008;199(3):303.e1-e3.

13. Burke JF. The effective period of preventive antibiotic action in experimental incisions and dermal lesions. Surgery. 1961;50:161-168.

14. Gordon HR, Phelps D, Blanchard K. Prophylactic cesarean section antibiotics: maternal and neonatal morbidity before and after cord clamping. Obstet Gynecol. 1979;53(2):151-156.

15. Cunningham FG, Leveno KJ, DePalma RT, Roark M, Rosenfeld CR. Perioperative antimicrobials for cesarean delivery: before or after cord clamping? Obstet Gynecol. 1983;62(2):151-154.

16. Kaimal AJ, Zlatnik MG, Chang YW, et al. Effect of a change in policy regarding the timing of prophylactic antibiotics on the rate of postcesarean delivery surgical-site infections. Am J Obstet Gynecol. 2008;199(3):310.e1-e5.

17. Tita AT, Rouse DJ, Blackwell S, Saade GR, Spong CY, Andrews WW. Emerging concepts in antibiotic prophylaxis for cesarean delivery: a systemic review. Obstet Gynecol. 2009;113(3):675-682.

18. Chaiyakunapruk N, Veerstra DI, Lipsky BA, Saint S. Chlorhexidine compared with povidone-iodine solution for vascular catheter-site care: a meta-analysis. Ann Intern Med. 2002;136(11):792-801.

19. Culligan PJ, Kubik K, Murphy M, Blackwell L, Snyder J. A randomized trial that compared povidone iodine and chlorhexidine as antiseptics for vaginal hysterectomy. Am J Obstet Gynecol. 2005;192(2):422-425.

Sullivan and colleagues were the first authors to successfully challenge this dictum.⁹ In a well-designed investigation, they demonstrated that preoperative administration of antibiotics significantly reduces the frequency of endometritis (RR, 0.22) but not wound infection, and does not increase the need for neonatal sepsis evaluation. Kaimel and coworkers later confirmed these findings,¹⁶ and this study by Owen and associates offers additional proof of the effectiveness and safety of preoperative antibiotic administration.

I offer only one addendum to the conclusions presented by Owen and colleagues. Two recent investigations from the University of Alabama conclusively demonstrate that, by extending the spectrum of antibiotic coverage by combining azithromycin and cefazolin, we can further reduce postcesarean endometritis and wound infection.^11,17 Accordingly, at our center, we now administer both intravenous (IV) azithromycin (500 mg over 1 hour) and IV cefazolin (1 g) approximately 30 to 60 minutes before the start of surgery.

WHAT THIS EVIDENCE MEANS FOR PRACTICE

Antibiotic prophylaxis reduces the rates of postcesarean endometritis and wound infection, and preoperative administration is superior to administration after cord clamping. Preoperative administration is also safe for the neonate.

Administer IV azithromycin (500 mg over 1 hour) and IV cefazolin (1 g) approximately 30 to 60 minutes before the start of surgery.

Chlorhexidine solutions are superior to povidone-iodine for surgical-site antisepsis

Darouiche RO, Wall MJ, Itani KMF, et al. Chlorhexidine-alcohol versus povidone-iodine for surgical-site antisepsis. N Engl J Med. 2010;362(1):18–26.

This report is an excellent complement to the two studies discussed above, which focused on systemic antibiotic prophylaxis for the prevention of postcesarean infection. Here, Darouiche and colleagues conducted a randomized, prospective, unblinded, multi-center comparison of two skin preparations to prevent surgical-site infection:

2% chlorhexidine gluconate and 70% isopropyl alcohol (409 patients)
10% povidone-iodine solution (440 patients).

Participants underwent a variety of abdominal and nonabdominal (thoracic, gynecologic, and urologic) procedures. All patients received systemic antibiotic prophylaxis within 1 hour before the start of surgery.

The primary outcome measure was the occurrence of any surgical-site infection up to 30 days after surgery. This rate was lower among patients who received chlorhexidine-alcohol skin preparations than among those who received povidone-iodine (9.5% vs. 16.1%; P = .004).

Secondary endpoints were specific types of infection:

superficial incisional infection (skin and subcutaneous tissue): lower among patients receiving chlorhexidine-alcohol (4.2% vs. 8.6%; P = .008)
deep incisional infection (involving fascia and muscle): lower among patients receiving chlorhexidine-alcohol (1% vs. 3%; P = .05)
organ-space infection (any organ or space other than the body wall): no significant difference between women treated with chlorhexidine-alcohol and those treated with povidone-iodine.

Seventeen patients would need to be treated with chlorhexidine-alcohol to prevent one surgical-site infection.

Chlorhexidine has a solid track record

The 41% reduction in the rate of surgical-site infection with chlorhexidine-alcohol (RR, 0.59; 95% CI, 0.41–0.85) is consistent with a 49% reduction in the risk of vascular catheter-related bacteremia using the same formulation.¹⁸ The findings are also consistent with a recent report showing that chlorhexidine was more effective than iodine-containing solutions in reducing bacterial concentration in the operative field in women undergoing vaginal hysterectomy.¹⁹

Darouiche and coworkers suggest that chlorhexidine is more effective because it has a more rapid onset of action and greater and more persistent antibacterial activity despite exposure to body fluids. Quite appropriately, they indicate that the solution used in their study is flammable, but they observed no adverse effects in a large sample of patients undergoing a variety of procedures.

WHAT THIS EVIDENCE MEANS FOR PRACTICE

I strongly recommend that chlorhexidine be used for all surgical skin preparation in obstetric and gynecologic patients. this intervention, along with consistent use of systemic antibiotic prophylaxis, should be highly effective in reducing the risk of superficial and deep abdominal wound infection.