Does Sterile or Nonsterile Technique Make a Difference in Wounds Healing by Secondary Intention?

Carol Lawson, RN, BSN; Lynn Juliano, RN, BSN; and Catherine R. Ratliff, PhD, GNP, CWOCN, CS

I n the spring of 1998, nursing staff on two surgical units at a major medical center noticed inconsistencies in the care of open surgical wounds. Some nurses used sterile while others employed a clean dressing change technique. Because the nursing staff felt that existing wound care literature did not support the selection of one technique over another, they wanted to establish their own consistent guidelines based on infection rates and costs. Surgical site infections for wounds healing by secondary intention for more than 5,000 patients during the previous 15 months on the two surgical units showed a 1.2% wound infection rate. Because the surgical site infection rate was low, the nursing staff wanted to know if the infection rate would remain low if everyone practiced clean technique in order to provide a more consistent cost-effective practice.

Literature Review

The clean-versus-sterile technique debate has been waged among clinicians for years with no consensus of opinion. The terms "sterile" and "clean" have many different meanings among healthcare providers.1,2 Sterile technique involves methods to reduce exposure to micro-organisms, including hand washing, and using a sterile field, instruments, gloves, and sterile dressing. Sterile dressing change may be defined as the replacement of the wound dressing using sterile technique and supplies. Clean technique involves employing methods to reduce the overall number of micro-organisms. Clean technique involves hand washing, preparing a clean field, and using clean gloves and instruments. Clean dressing change may be defined as the replacement of the wound dressing using clean technique and supplies. When considering which technique to use, the major concern is reducing the infection risk to the patient. Universal precautions should be the most essential component regardless of the technique used.

In 1993, Stotts et al3 surveyed members of the Wound Ostomy Continence Nurses Society regarding wound care practices. Of the 240 members who returned the surveys, 51% reported using sterile technique and 43% reported using nonsterile technique. However, these percentages varied widely when type of wound and setting were taken into consideration. Sterile technique was performed more frequently in the acute care facilities. Also, with the exception of immunosuppression, risk factors such as impaired perfusion were not deemed sufficient to warrant the use of sterile technique.

Wounds healing by secondary intention require dressings to provide a moist environment, debride necrotic tissue, absorb exudate, and protect the wound from trauma and contamination. In preparing patients for hospital discharge, respondents reported that 90% of patients with open wounds were taught to perform nonsterile technique regardless of the method used during hospitalizations. Consistency between what patients and caregivers are taught and actual practice during hospitalization is important in reinforcing home care instructions.

In 1997, the Nursing Consortium for Research and Practice4 surveyed 743 staff nurses from five healthcare agencies in San Francisco, Calif. regarding glove use. Sixty-one percent of respondents (n = 427) indicated that their choice of sterile or nonsterile gloves varied. Sterile gloves were chosen more often than nonsterile gloves for packing wounds and for dressing purulent wounds, tunneling wounds, and exposed orthopedic wounds. Clean gloves were generally used for dressing changes over intact surgical wounds and pressure ulcers. Acute care nurses indicated they were likely to use sterile gloves about 80% of the time (n = 544). Technique choices among staff nurses were based on the educational level of the provider and perception of the infection risk to the patient. A scientific foundation for wound care practice choices was not evident.

Despite the lack of specific evidenced-based research to support this practice, nurses are traditionally taught to use sterile techniques when caring for surgical wounds. Recent studies examining the effect of bacterial bioburden on healing suggest that clean technique may not have a substantial effect on the rate of healing or increase the rate of infection.5 Specifically, in a controlled clinical pilot study involving 30 patients undergoing gastrointestinal surgery, Stotts et al5 compared clean to sterile dressing change techniques. The principle variables for this study were cost and wound healing rate; secondary variables addressed wound infection, wound perfusion, nutrition, and immunologic status. Subjects were randomly assigned to clean and sterile wound dressing changes three times per day and monitored for 3 to 9 days. Wound healing rates did not vary between the clean and sterile groups, but the cost associated with dressing changes using clean technique was significantly less than the costs of using sterile technique (P
Two studies examined contamination of boxes containing nonsterile gloves. Sadowski et al6 obtained cultures from glove boxes (n = 32) in patients' rooms to investigate the infection risk of using nonsterile gloves in 13 burn patients. Although cultures of the wound exudate of 11 of 13 patients (85%) showed evidence of Staphylococcus aureus, the patients and not the gloves proved to be the sources of contamination. Rossoff et al7 looked at 29 boxes of nonsterile gloves from patient rooms and also found contamination of the gloves but with a low bacterial bioburden. The clean glove boxes in this study were located directly outside the hospital rooms.

Purpose and Methodology

The purpose of this study was to determine differences in infection rates and costs of using sterile versus clean dressing change technique in the management of open surgical wounds.

A nonexperimental, longitudinal study design was used to monitor the infection rates and supply usage on two acute care surgical units at a major medical center for 3 months before and 3 months after implementation of nonsterile wound care for all patients with open surgical wounds. The two acute care units in the study comprise patients from the services of digestive health, trauma, transplant, general surgery, and urology. The sample included all hospitalized adult patients with one or more open surgical wounds healing by secondary intention who were receiving dressing changes three times per day with normal saline. The study was approved by the hospital's institutional review board.

Infection control tracks all hospital-acquired infections, including surgical site infections, through the documentation of culture results. This practice was not changed during the study period. Quarterly unit data of these rates are provided to the managers of the units for monitoring purposes. Managers also receive monthly cost reports of supply usage for their units for budgetary monitoring purposes. Before starting the second 3-month phase of the study, all registered nurses working on the two units were instructed in the clean wound care procedure (see Table 1). The nurses typically rotate between the two units based on clinical need. Descriptive statistics were used to describe the infection rates and supply costs for the study period.


Three months before the change in wound care procedures, nine surgical site infections were recorded in 1,070 admissions to the two surgical units (rate .84%). During the next 3 months, following the change in procedures, eight surgical site infections were detected out of 963 admissions to the two units for a rate of .83%. The difference in wound infection rates 3 months before and after the change in protocol was not statistically significant.

Following a change in wound care procedures, when the need for sterile supplies was eliminated (staff no longer used sterile gloves, scissors, or bowls) the surgical units' supply budget decreased by $380. For the two acute care nursing units involved in the study, this could mean saving approximately $1,520 per year. Additionally, two nurses timed the two different dressings techniques and determined that approximately 10 minutes is needed to perform nonsterile wound care; whereas, sterile wound care takes approximately 13 minutes to complete. This means almost 10 minutes (three wound changes times 3 minutes) of a nurse's day could be spent carrying out other responsibilities.


This study has several limitations. First, the number of surgical site infections is based on the documentation of a positive wound culture. Because cultures may not have been performed on all infected wounds, the number of wound infections may be underreported. Second, knowing the exact number of open surgical wounds that were seen during the study period rather than just the number of patients admitted during the study period would have provided a more accurate comparison of open wounds and exactly how many became infected. Third, the sample size is small, making it difficult to generalize these findings to other settings and patient populations. Prospective, randomized controlled studies on sterile-versus-clean technique need to be conducted and replicated to practice evidenced-based care. In this practice setting, surgical site infection rates on the open surgical wounds were monitored for a year following the study with no measurable increase in infection rates. Because the change in wound care procedures does not appear to jeopardize outcomes, policies and procedures have been implemented to reflect the standardization of clean technique for open surgical wounds to save costs and nursing time while maintaining consistency for patient teaching of wound care following discharge.


With the dramatic increases in healthcare costs, healthcare providers must examine their practices to ensure the delivery of high quality, cost-effective, care. In this study, using clean technique when changing dressings for surgical wounds healing by secondary intention did not increase wound infection rates and saved time and money. - OWM


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