Purpose
To determine if wrapping instruments in conjunction with full-cycle steam sterilization affects the incidence of postoperative infection in patients undergoing ophthalmic surgery in a dedicated eye center.
Design
Retrospective, consecutive-case, comparative study.
Methods
Two consecutive groups, each of approximately 19 000 ophthalmic surgical patients, were reviewed for postoperative infection. For both groups, the surgical instruments were sterilized using full-cycle, steam sterilization, with a single major difference. The instruments for the first group were sterilized with equipment located adjacent to the operating room and no wrapping of the instruments was used, whereas for the second group, the sterilization equipment was located at a central facility and the instruments were wrapped before being transported to the operating rooms.
Results
In the unwrapped sterilization group 17 presumed postoperative infections were identified, compared to 9 presumed infections in the wrapped sterilization group. Because the observed infection rates for each group were so low, this apparent difference is not statistically significant ( P = .16). Similarly, differences found in the incidence of culture-positive cases of endophthalmitis (5 for unwrapped vs 3 for wrapped) were not statistically significant ( P = .47).
Conclusions
In a dedicated, high-volume eye facility, the incidence of presumed postoperative infection associated with unwrapped and wrapped full-cycle steam sterilization were shown to be identical within statistical error. This provides strong evidence that if eye surgical facilities carefully clean surgical instruments and follow the industry and manufacturer guidelines, they can, with confidence, use either of these 2 methods of sterilization. This study presents the first concrete data that corroborate the current position of The Joint Commission, American Academy of Ophthalmology (AAO) and American Society of Cataract and Refractive Surgery (ASCRS).
A safe surgical outcome is of primary importance in any surgical procedure and good instrument cleaning and sterilization techniques are essential in this regard. While there are general standards for sterilization and care of instruments, sterilization techniques and standards have not necessarily been designed with modern ophthalmic surgery in mind. Preparing surgical instruments in preparation for surgery is a complex multi-step practice. The best assurance of a sterile product is careful execution of every step in the process coupled with an ongoing quality control program. This includes careful cleaning and sterilization according to manufacturer recommendations.
The most current knowledge relative to instrument processing is included in the Association for the Advancement of Medical Instrumentation (AAMI) “Comprehensive Guide to Steam Sterilization and Sterility Assurance in Health Care Facilities,” the Centers for Disease Control and Prevention (CDC) “Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008,” and the Association of periOperative Registered Nurses (AORN) “Recommended Practices for Sterilization in the Perioperative Practice Setting.” The AORN recommended practices are intended as achievable recommendations representing what is believed to be an optimal level of practice. However, these standards were derived from experience based on general surgery and, until now, there were no data available specific to ophthalmology.
The most widely used and recommended method for sterilization of surgical instruments is full-cycle steam sterilization, a method commonly used in 1 of 2 variations. The first variation, referred to as wrapped, is typically done in a central location and requires that the instruments be wrapped prior to undergoing sterilization so that they can be available for future use and be readily transported substantial distances to the operating theater. This method ties up the instruments for quite some time since the material used to wrap the instruments may take several hours to dry. The sterile wrapped instruments remain sterile unless the wrapping becomes compromised or until they are used for surgery. The second variation, referred to as unwrapped, is conducted with equipment located immediately adjacent to or within the operating room, which lessens the likelihood of contamination during transport. This method requires the immediate use of instruments. As would be expected, this unwrapped variation has substantial economic benefits since instruments can be processed much more quickly, thereby dramatically reducing the number of instruments that must be kept in inventory.
It is important to note that the unwrapped full-cycle variation is sometimes incorrectly called “flash sterilization,” a method used to rapidly sterilize a surgical tool that had not been sterilized or inadvertently had become nonsterile and that is immediately and urgently needed by the surgical team. This flash sterilization method (3 minutes at 270 F at 27–28 pounds of pressure), which may involve substantial compromises, is not a topic of this report. Only the full-cycle unwrapped steam sterilization, with specified ranges of time and pressure related to instrument type, and with mechanical, chemical, and biologic markers ( Geobacillus stearothermophilus ), is relevant. As part of any sterilization method, thorough cleaning of all surgical instruments is also important to prevent toxic anterior segment syndrome (TASS). This study does not deal with TASS, which is a sterile postoperative inflammation, but rather is confined solely to infections and antimicrobial sterilization.
The defining event that prompted this study was The Joint Commission’s review of a high-volume specialty eye hospital during January 2008 that called into question the institution’s long-standing use of full-cycle unwrapped steam sterilization for ophthalmic surgery. In spite of an unbroken record of excellent patient safety, no concerns about this issue in previous Joint Commission reviews, adherence to the detailed method of full-cycle unwrapped steam sterilization outlined by AAMI and AORN, and no evidence-based data on the efficacy of different methods of sterilization for use in ophthalmic surgery, The Joint Commission summarily ordered the facility to immediately convert to full-cycle wrapped steam sterilization or face nonaccreditation. At stake also was the possibility that other centers in the United States doing eye surgery, including specialty eye hospitals and ambulatory surgery centers, that used full-cycle unwrapped steam sterilization or other safe methods would be required to undergo the disruption and huge burden of switching to the particular method of sterilization that, at that time, The Joint Commission deemed preferable.
Subsequently, medical and administrative leadership at the eye hospital, the American Academy of Ophthalmology (AAO), and the American Society of Cataract and Refractive Surgery (ASCRS) engaged in further discussion with The Joint Commission regarding its position on sterilization of ophthalmic instruments. As a result, The Joint Commission and the American Society of Cataract and Refractive Surgery published communiqués regarding The Joint Commission’s updated position on methods of sterilization, which focused on the processes involved in the cleaning and sterilization of instruments.
Methods
Background
The facility is a dedicated eye specialty hospital. It has a medical staff of 150 physicians, 65 of whom are active surgical staff. There is no standing staff, unlike other notable eye centers; rather, it is a center to which ophthalmologists bring their own patients. There are 10 operating rooms (ORs), inpatient beds, and a compounding pharmacy. Only eye procedures, from primary to tertiary, are performed at the facility, and it averages over 10 000 surgical procedures a year.
The institution sponsors continuing medical education and training courses, and although residents and fellows participate with their preceptors, there is no resident or fellowship training program. Over 50% of the active medical staff serve on a hospital committee. The Credentialing/Quality Improvement, Patient Care, and Medical Executive committees review various quality indicators, which include complications and infection rates.
As described above, the method by which the institution used to sterilize surgical instruments, full-cycle unwrapped steam sterilization, had been in place for over 20 years, during which multiple surveys of the hospital and review of the various components of its infection control system had been performed by The Joint Commission. However, because of The Joint Commission’s position on unwrapped sterilization, the facility converted to wrapped steam sterilization on February 21, 2008. Although switching caused weeks of disruption to patient care and cost millions of dollars, it did present an unusual opportunity to gather some actual data about the efficacy of the 2 methods so that future decisions could be made with a stronger scientific basis.
Cohort and Statistics
The patients were divided into 2 consecutive groups and data were collected for 2 equal time periods, before and after the change to the wrapped method. Both groups included a time period of 277 days. The first group included all patients who underwent surgery from April 5, 2006 to February 20, 2008, with whom the unwrapped full-cycle sterilization process had been used. The second group included all patients whose procedures took place from February 21, 2008, the day on which the change to the wrapped method began, through December 31, 2009. It should be noted that the processes of decontamination and cleaning prior to both methods of sterilization were identical. The manufacturer for the steam sterilizers used in the unwrapped group was Steris/Amsco Century (V 116 Pre-Vac Steam Sterilizer; Monterrey, Mexico). The manufacturer for steam sterilization in the wrapped group was Getinge (Model 833HC; parts made in Sweden, assembled in Rochester, New York, USA). Steam sterilizer recommendations were followed for each manufacturer.
The only patients whose data were excluded from our study were those who had received surgery at other institutions and who were later brought to the facility for treatment of postoperative infections arising from activity at those other locations.
Infection Surveillance
The focus of the review was to compare the rates of postoperative infections using the wrapped and unwrapped variations of full-cycle steam sterilization to determine if either resulted in substantially better outcomes. All presumed postoperative infections that occurred within 3 months after surgery were considered. These were identified as part of the hospital’s Infection Control Program. The program includes surveillance, focused studies, outbreak investigation, isolation and control measures, education, and quality improvement initiatives. An Infection Control Practitioner has responsibility for the department performance, assessment, and improvement plans.
Three types of surveillance strategies are used. First, there is targeted surveillance, which includes surveillance for all surgical, diagnostic, and refractive procedures. Infection data are obtained by reviewing daily microbiology reports, patient infection sheets from staff, and any other special reports as requested. Second, problem-oriented surveillance investigates clusters, outbreaks, or increasing infection rates. Third, there are focused studies to investigate 1 or more cases of epidemiologic importance and new or changed procedures.
Following this, the Patient Care and Quality Improvement committees review all of the postoperative infection surveillance. In addition, every 3 months, a survey requesting the surgeon to report infections is sent to each affiliated ophthalmologist along with a list of patients who had undergone surgery at the eye hospital. The Infection Control Practitioner reviews the surveys, and the results are tabulated quarterly and brought to the committees for discussion and, if necessary, investigation. All possible infections are ascribed to the date on which the surgery took place, not when discovered.
Results
During the period of the review, the turnover of active staff varied from 6% to 7% annually, with no significant differences between the groups studied. Similarly, the turnover of surgeons kept relatively constant over both periods and ranged from 4 to 6 surgeons per year. The surgeon response rate to the questionnaire regarding infections ranged from 60% to 70%, with no significant differences in rates from year to year. Finally, no pattern was identified in the cases of infection that correlated to the nursing staff, a particular surgeon, or a given operating room.
In the first group of patients, for whom the unwrapped method was used, the total number of surgeries was 19 008 and the mean age of the patients was 68.72. In the second group, for whom the wrapped method was employed, the total number of surgeries was 19 462 and the mean age of the patients was 70.66 years.
The data indicate that for the first group of patients, there were 17 presumed postoperative infections, the distribution of which was: phacoemulsification 5, cornea 0, cosmetic 0, glaucoma 1, plastic 2, retina (nonvitrectomy) 2, and vitrectomy 7 (3 25-gauge). In the second group, there were 9 presumed postoperative infections, the distribution of which was: phacoemulsification 4, cornea 2, cosmetic 0, plastic 1, retina (nonvitrectomy) 0, vitrectomy 1, and glaucoma 1 ( Table 1 ).
| Procedure | Unwrapped Cases (Infection) | Wrapped Cases (Infection) |
|---|---|---|
| Phacoemulsification | 11 267 (5) | 10 823 (4) |
| Other: | ||
| Corneal | 355 (0) | 485 (2) |
| Cosmetic | 184 (0) | 68 (0) |
| Glaucoma | 859 (1) | 903 (1) |
| Miscellaneous | 664 (0) | 794 (0) |
| Plastic | 1104 (2) | 832 (1) |
| Retina (nonvitrectomy) | 379 (2) | 303 (0) |
| Retina (vitrectomy) | 4197 a (7) | 5254 b (1) |
| Total | 19 008 (17) | 19 462 (9) |
In the first (unwrapped) group, there were 12 cases of presumed endophthalmitis (5 having positive cultures) compared to 5 cases (3 having positive cultures) in the second group ( Table 2 ). There were no clusters of infections in either group.
| Sex | Age (Years) | Procedure | Culture Results | Sterilization Method |
|---|---|---|---|---|
| Unwrapped sterilization method (n = 19 008 procedures) | ||||
| M | 40 | PPV/MP | CNS, Bacillus | Unwrapped |
| F | 54 | 25-gauge PPV/MP | CNS | Unwrapped |
| F | 72 | 25-gauge PPV/MP | CNS | Unwrapped |
| M | 75 | PPV/MP | Pseudomonas | Unwrapped |
| M | 80 | CE/IOL | Streptococcus pneumoniae | Unwrapped |
| Wrapped sterilization method (n = 19 142 procedures) | ||||
| F | 46 | CE/IOL | CNS | Wrapped |
| F | 84 | CE/IOL | Staphylococcus aureus | Wrapped |
| F | 84 | CE/IOL | Enterococcus | Wrapped |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
