The infection control department of a hospital noticed a marked increase in the rates of post-operative sternal wound infections in surgical patients admitted to the hospital for coronary artery bypass graft (CABG) surgery. The increased infection rates were accompanied by increased readmissions and prolonged lengths of stay. Two patients had to have their sternum removed because of infection; two others died. One cardiac surgeon and his team were identified as having higher infection rates than others, even though they used the same operating room (OR) suites and facilities.
An infection control practitioner conducted "environmental rounds" within the OR suite to observe the surgical team during the entire CABG surgical procedure. She found that the team was very "sloppy"—members of the team wore loose hair and jewelry (earrings, necklaces); several also wore regular sandals into the OR. The infection control practitioner noted also that several team members did not re-scrub when moving from working on the saphenous graft in the patient's leg back to the patient's open chest.
This case involves an outbreak of sternal wound infections that may be attributable to poor environmental infection control practices. Deep sternal wound infections occur in less than 1%-2% of sternotomies during non-outbreak periods and are associated with increased morbidity, mortality, and costs in patients undergoing cardiac surgery.(1,2) If caused by medical errors, these infections are considered preventable adverse events requiring intervention to prevent harm to future patients.
Infection control programs perform surveillance to benchmark infection rates against past rates at a single institution or from other medical centers, such as those available through the National Nosocomial Infection Surveillance (NNIS) program at the Centers for Disease Control and Prevention (CDC).(3) Increased rates of infection, as seen in this case, should trigger an investigation to identify which modifiable factors are associated with infection. Interventions are then implemented to decrease the risk of infection in future patients. In this case, a high rate of sternal wound infections appropriately catalyzed an investigation by the infection control team.
Root cause analysis, on the other hand, investigates sentinel events—serious adverse events that may occur in only a single patient—to determine what risk factors can be modified to prevent future patients from suffering similar harm.(4) While infection control surveillance and root cause analysis both attempt to identify ameliorable factors predisposing to adverse events, they differ in what triggers an investigation. The two methods should be considered complementary: surveillance can detect problems that don't rise to the level of "sentinel events" in individual patients, and root cause analysis can identify system-level problems in the delivery of health care.
Attention has recently highlighted the need to improve the safety of patients undergoing medical care.(5) The central role of infection control within the broader arena of patient safety was recently recognized with the recent inclusion of infection control standards within the National Patient Safety Goals of the Joint Commission on Accreditation of Healthcare Organizations (JCAHO).(6,7) Beginning in 2004, these goals now include adherence to the CDC's hand hygiene guidelines and surveillance for cases of permanent loss of function or mortality due to healthcare-associated infection.(8)
The CDC's hand hygiene guidelines emphasize the critical importance of hand hygiene in the prevention of healthcare-associated infections.(9) An inverse relationship has been demonstrated between proper hand hygiene by health care workers and healthcare-associated infections in patients. Alcohol-based hand rubs are even more effective in reducing hand bacterial counts than hand washing with soap and water, and may promote adherence by reducing the time it takes for providers to clean their hands.
In this case, multiple breaks in procedure by operating room personnel were noted. The CDC guidelines recommend removing jewelry (or, in the case of necklaces, covering with surgical gowns), covering head and facial hair, using surgical masks, avoiding long or artificial nails, and covering the feet.(10) The rationale for most of these recommendations is that the use of precautions to prevent shedding of bacteria from health care workers "seems prudent."(10) Although research supporting these recommendations is limited and few studies examine patient outcomes, the existing data are suggestive. Bacteria shed from the skin or hair of surgical staff have caused outbreaks of surgical site infections (11), and fewer bacteria are shed if a mask and surgical hat are used.(12) Rings and artificial nails result in higher levels of persistent hand colonization with pathogenic bacteria after hand disinfection compared with unadorned hands (13,14), and artificial nails have been implicated in outbreaks among postoperative cardiovascular patients.(15) Shoe coverings have not been shown to prevent surgical site infections, but are recommended to protect staff from patient body fluids in accordance with Occupational Safety and Health Administration Regulations.(10,16) No available recommendations or studies address rescrubbing when moving between surgical sites in cardiac operations.
Changing the behavior of health care workers is challenging. For example, although hand hygiene by health care workers is known to decrease serious hospital-acquired patient infections (17), adherence to this important intervention typically hovers around 40%.(18) This may be due to the many barriers to proper hand hygiene on both the individual and organizational level, including lack of accessibility to hand hygiene agents and high workload.(18)
Behavioral theory can be used to explain some of the difficulties in changing human behavior. The PRECEDE model (19) suggests that successful behavioral interventions for adults should include predisposing, enabling, and reinforcing factors. The acronym PRECEDE stands for "Predisposing, Reinforcing, Enabling, Causes in, Educational Diagnosis and Evaluation."(20) Changing health care worker behavior—for instance, improving the infection control practices of operating room staff—can be framed using this model. First, staff must believe that restraining loose hair and jewelry will decrease the risk of surgical site infections (predisposing factors). Next, barriers such as lack of comfortable head coverings and simple forgetfulness need to be addressed (enabling factors). Finally, staff needs to receive positive feedback when their adoption of infection control interventions leads to lower infection rates (reinforcing factors).
It may be difficult to effect changes when definitive studies have not been performed. However, reasonable arguments based on supportive data in the literature (and optimally from local experience) may be enough to prompt health care workers to change behavior. It may be particularly difficult to change behavior where there is no supporting data, the potential for harm is perceived as small, or the burden of complying is perceived as large. Forbidding coffee consumption by physicians in the intensive care unit may be an example of such situations.
A variety of interventions to improve health care worker behavior have been tried. Consistent with the PRECEDE model, multifaceted interventions are the most successful.(21) A reasonable approach for this case may include an initial session with the operating room teams and the surgery leadership to provide information about their current infection rate and data supporting the importance of adequate infection control practices. This could be followed by unscheduled audits to check adherence to good infection control practices, and by feedback on both the improvement in performance as well as any change in the sternal wound infection rate. Emphasis should be placed on practices likely to protect both patients and staff: in this case, adequate hair covering, foot protection, and jewelry removal. This model may not only be useful for improving infection control, but, if adapted thoughtfully, might serve as a useful model for the implementation of other patient safety interventions.(7)
- Infection control will increasingly be viewed as vital to patient safety.
- Root cause analysis and benchmarking should be considered complementary approaches.
- While definitive studies have not been performed for many aspects of surgical infection control, data suggest that the currently available recommendations will limit surgical site infections.
- Changing health care worker behavior is a challenging endeavor that requires a comprehensive approach for success.
Darren R. Linkin, MD Hospital Epidemiologist, Philadelphia Veterans Administration Medical Center Faculty-Fellow, Center for Clinical Epidemiology and Biostatistics Post-doctoral Fellow, Division of Infectious Diseases University of Pennsylvania School of Medicine
Ebbing Lautenbach, MD, MPH, MSCE Assistant Professor of Medicine and Epidemiology, Division of Infectious Diseases Associate Hospital Epidemiologist, Hospital of the University of Pennsylvania Senior Scholar, Center for Clinical Epidemiology and Biostatistics University of Pennsylvania School of Medicine
1. Kohli M, Yuan L, Escobar M, et al. A risk index for sternal surgical wound infection after cardiovascular surgery. Infect Control Hosp Epidemiol. 2003;24:17-25.[ go to PubMed ]
2. Fry DE. The economic costs of surgical site infection. Surg Infect (Larchmt). 2002;3:S37-43.[ go to PubMed ]
3. National Nosocomial Infections Surveillance System. National Nosocomial Infections Surveillance (NNIS) System Report, data summary from January 1992 to June 2002, issued August 2002. Am J Infect Control. 2002;30:458-75.[ go to PubMed ]
4. Shojania KG, Duncan BW, McDonald KM, Wachter RM, eds. Making health care safer: a critical analysis of patient safety practices. Rockville, MD: Agency for Healthcare Research and Quality; 2001: AHRQ publication 01-E058. Evidence report/technology assessment. no. 43. Available at: [ go to related site ]. Accessed January 13, 2004.
5. Kohn LT, Corrigan J, Donaldson MS, eds. To err is human: building a safer health system. Washington, D.C.: National Academy Press; 2000.
6. Burke JP. Patient safety: infection control - a problem for patient safety. N Engl J Med. 2003;348:651-6.[ go to PubMed ]
7. Gerberding JL. Hospital-onset infections: a patient safety issue. Ann Intern Med. 2002;137:665-70.[ go to PubMed ]
8. Joint Commission on Accreditation of Healthcare Organizations Web site. 2004 National patient safety goals. Available at: [ go to related site ]. Accessed January 13, 2003.
9. Boyce JM, Pittet D, Healthcare Infection Control Practices Advisory Committee, HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force. Guideline for hand hygiene in health-care settings. Recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force. Society for Healthcare Epidemiology of America/Association for Professionals in Infection Control/Infectious Diseases Society of America. MMWR Recomm Rep. 2002;51:1-45, quiz CE1-4.[ go to PubMed ]
10. Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for prevention of surgical site infection, 1999. Hospital Infection Control Practices Advisory Committee. Infect Control Hosp Epidemiol. 1999;20:250-78, quiz 279-80.[ go to PubMed ]
11. Mastro TD, Farley TA, Elliott JA, et al. An outbreak of surgical-wound infections due to group A streptococcus carried on the scalp. N Engl J Med. 1990;323:968-72.[ go to PubMed ]
12. Hubble MJ, Weale AE, Perez JV, Bowker KE, MacGowan AP, Bannister GC. Clothing in laminar-flow operating theatres. J Hosp Infect. 1996;32:1-7.[ go to PubMed ]
13. McNeil SA, Foster CL, Hedderwick SA, Kauffman CA. Effect of hand cleansing with antimicrobial soap or alcohol-based gel on microbial colonization of artificial fingernails worn by health care workers. Clin Infect Dis. 2001;32:367-72.[ go to PubMed ]
14. Trick WE, Vernon MO, Hayes RA, et al. Impact of ring wearing on hand contamination and comparison of hand hygiene agents in a hospital. Clin Infect Dis. 2003;36:1383-90.[ go to PubMed ]
15. Passaro DJ, Waring L, Armstrong R, et al. Postoperative Serratia marcescens wound infections traced to an out-of-hospital source. J Infect Dis. 1997;175:992-5.[ go to PubMed ]
16. U.S. Department of Labor, Occupational Safety and Health Administration Web site. Bloodborne pathogens Regulation-1910.1030. Available at: [ go to related site ]. Accessed January 13, 2004.
17. Larson E. Skin hygiene and infection prevention: more of the same or different approaches? Clin Infect Dis. 1999;29:1287-94.[ go to PubMed ]
18. Pittet D. Improving adherence to hand hygiene practice: a multidisciplinary approach. Emerg Infect Dis. 2001;7:234-40.[ go to PubMed ]
19. Green LW, ed. Health education planning: a diagnostic approach. Palo Alto, CA: Mayfield Publishing Company; 1980.
20. University of South Florida Community and Family Health Web site. The PRECEDE/PROCEED model. Available at: [ go to related site ]. Accessed January 28, 2004.
21. Greco PJ, Eisenberg JM. Changing physicians' practices. N Engl J Med. 1993;329:1271-3.[ go to PubMed ]