Evaluating Use of Flash Sterilization in the OR With Regard to Postoperative Infections
Article Outline
- ABSTRACT
- Flash Sterilization Practices
- The Project
- Results
- Analysis of Costs
- Discussion
- Limitations
- Project Outcomes
- Notes
- Copyright
ABSTRACT
A perioperative RN's primary responsibility is the safe care of patients during surgical procedures. This includes minimizing patients' risks for surgical wound infections by ensuring that surgical instruments are sterile and free of contaminants.1
Flash sterilization is a procedure used by OR staff members to sterilize instruments on an as-needed basis when instruments designated for a procedure become contaminated or sterile instruments are not immediately available. Flash sterilization involves controlling a number of variables to maintain effective sterilization of surgical instruments, and it should be used only in carefully selected clinical situations in which
The greatest concern regarding sterilization of instruments is that if these practices are not followed, a nonsterile instrument may be used during surgery, which might increase the risk for postoperative infection and result in higher patient costs to the treat the infection. The direct and indirect costs of postoperative infections presumably could be decreased if recommended practices for sterilization of surgical instruments were followed consistently, including using flash sterilization only when it is absolutely necessary.
Staff members at Inova Loudoun Hospital, Leesburg, Va, conducted a quality improvement (QI) project to determine if the observed postoperative infection rate among patients undergoing procedures in which instruments were flash sterilized was higher than the recommended standard benchmark rate of 1%.2 The costs of diagnosing and treating postoperative infections compared to the costs of purchasing additional inventory in lieu of flash sterilizing contaminated instruments also was evaluated.
Flash Sterilization Practices
Flash sterilization has become overused and in some cases misused to compensate for an inadequate inventory of surgical instruments.3 The Joint Commission on Accreditation of Healthcare Organizations standards state that flash sterilization should be conducted in an emergency situation only and should be monitored closely.4
Although the literature provides little direct evidence that use of flash sterilization in surgical procedures is causally associated with higher infection rates, recent evidence suggests that flash sterilization is of concern to OR staff members based on the risk of patient infection.5 Routine steam sterilization is carried out by sterilization and processing department staff members, whose primary focus is on handling instruments according to standard procedures, which increases the likelihood of proper sterilization. When an OR staff member conducts flash sterilization, however, his or her attention may not be focused on proper sterilization. An OR staff member also must focus on demands from surgeons, anesthesia care providers, and patients, as well as the technical requirements of the surgical procedure, maintenance of the sterile field, documentation, instrument counts, and billing.6 If OR staff members do not pay close attention to the flash sterilization process, there is no assurance that the mechanism of sterilant penetration has been effective.7 Education is of utmost importance in ensuring that flash sterilization is performed properly, and steps for performing proper sterilization should be integrated into the education of OR staff members.6
The Project
The project was based on a case-series design (ie, a sequential listing of observations with an outcome of interest but for which no controls are selected). It was conducted during a five-month period in 2004 in the OR at Inova Loudoun Hospital. A total of 100 surgical procedures in which flash sterilization was used at least once were evaluated. Surgical procedures were included in the project if the surgeon had agreed to participate before the procedure began. There were no other criteria for inclusion in or exclusion from this project, and no changes were observed in the standard of care for surgical procedures included in this project. The project was reviewed by the institutional review board (IRB) of record for Inova Loudoun Hospital and was ruled to be exempt from IRB oversight requirements.
Staff members collected data on patient factors, surgical factors, and postoperative infection for procedures during which flash sterilization of a surgical instrument was performed. Surgical and patient factors included
Flash sterilization factors included
Occurrence of postoperative infection was based on a surgeon's report postoperatively. For procedures resulting in a postoperative infection, the following information also was collected:
Sample size calculations were based on an estimate of the prevalence of postoperative infection being 1% among patients whose surgical procedures necessitated the use of flash sterilization. A minimum sample size of 95 was derived based on this probability of infection after exposure to instruments that were flash sterilized and using a 2% margin of error.
Results
The 100 surgical procedures included in this project resulted in a total of 121 incidents in which flash sterilization of a single item or instrument set was required. The majority of flash sterilizations (ie, 71%) occurred during orthopedic and podiatry surgical procedures (Table 1). Prophylactic antibiotics were administered in 89% of the procedures. Twenty-five surgeons participated in the project, and more than half of the flash sterilizations (ie, 52%) occurred during procedures performed by four surgeons (ie, three orthopedic surgeons, one podiatrist). Flash sterilizations were conducted most frequently during the morning hours (ie, 6 to 11:59 AM), a finding that may be attributed to the increased number of procedures routinely scheduled during these hours. All patients were classified as ASA class 3 or lower, 79% of the procedures were clean, and 9% were emergency procedures.
Table 1. Surgical and Patient Factors*
| Factor | Percentage of procedures |
|---|---|
| Time of day | |
| 6 to 11:59 AM | 56 |
| Noon to 5:59 PM | 38 |
| 6 to 11:59 PM | 5 |
| Midnight to 5:59 AM | 1 |
| Surgical specialty | |
| Orthopedics | 59 |
| Podiatry | 12 |
| Gynecology | 8 |
| General | 5 |
| Urology | 5 |
| Ear, nose, and throat | 4 |
| Neurology | 4 |
| Plastic surgery | 3 |
| Surgery type | |
| Clean | 79 |
| Clean/contaminated | 21 |
| Prophylactic antibiotics administered | |
| Yes | 89 |
| No | 11 |
| American Society of Anesthesiologists physical status classification | |
| Class 1 | 27 |
| Class 2 | 40 |
| Class 3 | 33 |
| Emergency procedure | |
| Yes | 9 |
| No | 91 |
* For 100 surgical procedures during which one or more surgical instruments were flash sterilized. |
Flash sterilization most frequently was used when surgical instruments from previous procedures were needed and there was not sufficient time to send the instruments to the sterilization and processing department for sterilization (Table 2). Seventy-four single items and 47 instrument sets were flash sterilized (Table 3). The most frequently flash sterilized single items were batteries and retractors and the most frequently flash sterilized instrument sets were total joint trays and manufacturer trays (ie, specific instruments provided in a tray by surgical device manufacturers at a surgeon's request).
Table 2. Reason for Use of Flash Sterilization
| Reason | Number | Percent |
|---|---|---|
| Instrument from previous procedure needed and not available | 94 | 77.7 |
| Dropped single item | 10 | 8.3 |
| Torn wrapper | 4 | 3.3 |
| Indicator failure as noted by a reject on the chemical indicator strip | 1 | 0.8 |
| Other | 12 | 9.9 |
| Total | 121 | 100.0 |
Table 3. Types of Instruments Flash Sterilized
| Type of instrument | Number | Percentage |
|---|---|---|
| Single items | ||
| Battery | 23 | 31.1 |
| Retractor | 9 | 12.2 |
| Anterior cruciate ligament (ACL) instrument (eg, tibial aimer, ACL plugs) | 4 | 5.4 |
| Laminectomy spreader | 4 | 5.4 |
| Manufacturer's instrument | 4 | 5.4 |
| Screw | 4 | 5.4 |
| Endoscope and forceps | 3 | 4.1 |
| Arthroscopy instrument | 2 | 2.7 |
| Drill bit | 2 | 2.7 |
| Glue gun | 2 | 2.7 |
| Laser hand piece | 2 | 2.7 |
| Lead hand | 2 | 2.7 |
| Power equipment piece | 2 | 2.7 |
| Total joint instrument | 2 | 2.7 |
| Baby right-angle retractor | 1 | 1.4 |
| Bipolar | 1 | 1.4 |
| Bone clamp | 1 | 1.4 |
| Charnley retractor | 1 | 1.4 |
| Bipolar coagulation forceps | 1 | 1.4 |
| Osteotome | 1 | 1.4 |
| Pituitary rongeur | 1 | 1.4 |
| Scissors | 1 | 1.4 |
| Tibial nail | 1 | 1.4 |
| Total | 74 | 100.5* |
| Instrument trays and sets | ||
| Total joint tray** | 12 | 25.5 |
| Manufacturers' tray† | 9 | 19.1 |
| Power equipment tray | 4 | 8.5 |
| Orthopedic tray | 3 | 6.4 |
| Pelviscopy tray | 3 | 6.4 |
| Chest tray | 2 | 4.3 |
| Large fragment set | 2 | 4.3 |
| Mini-fragment set | 2 | 4.3 |
| Tonsils and adenoids tray | 2 | 4.3 |
| Vascular extra tray | 2 | 4.3 |
| Bone-holding forceps | 1 | 2.1 |
| Podiatry instrument tray | 1 | 2.1 |
| Laminectomy tray | 1 | 2.1 |
| Microgynecologic tray | 1 | 2.1 |
| Plastic reconstructive tray | 1 | 2.1 |
| Septoplasty tray | 1 | 2.1 |
| Total | 47 | 100.0 |
* Total is greater than 100% due to rounding. |
** Total joint trays provided on consignment by manufacturer or owned by hospital. |
† Manufacturers'trays include ACLtrays per surgeon request. |
Between postoperative days three and 12, three patients were diagnosed with postoperative infections by their surgeon based on a physical examination in which patients presented with symptoms indicative of postoperative infection (eg, elevated temperature, surgical site warm to the touch, redness and pain at surgical site). These diagnoses resulted in a postoperative infection rate of 3% when analyzed by the number of procedures and 2.5% when analyzed by the number of flash sterilizations performed for these procedures. Of the three initially diagnosed postoperative infections, wound site culture results were positive for postoperative infection in only one case, resulting in a positive wound culture postoperative infection rate of 1% based on the number of surgical procedures or 0.8% based on the number of flash sterilizations. The wound cultures did not confirm the diagnosis of postoperative infection in two of the three cases. The clinical diagnosis of postoperative infection in one case was attributed to a noninfectious inflammatory process, and the other case was attributed to a possible immune reaction to the implant used for the total knee replacement.
The three initially diagnosed postoperative infections were all clean, scheduled, orthopedic procedures, in which prophylactic antibiotics were administered preoperatively, all flash sterilization parameters were met, and items were flash sterilized because they were not sterile at the time they were needed (Table 4). Each of the three cases had a different orthopedic surgeon, and the infections were ongoing at the time of postoperative follow-up.
Table 4. Patient and Surgical Procedure Factors for Patients Initially Diagnosed With Postoperative Infections
| Factor | Case 1 | Case 2 | Case 3 |
|---|---|---|---|
| Time of day surgical procedure was performed | Noon to 5:59 PM | 6 to 11:59AM | 6 to 11:59AM |
| Surgical procedure | Anterior cruciate ligament (ACL) reconstruction | Total knee replacement | ACL reconstruction |
| American Society of Anesthesiologists physical status classification | Class 1 | Class 2 | Class 2 |
| Item(s) flash sterilized | 1 ACL tray | 2 total joint trays 1 battery set | 1 ACL instrument |
| Number of postoperative days until infection was diagnosed | 12 | 3 | 7 |
| Type of infection | Systemic and joint | Joint | Joint |
| Hospitalization status | Readmitted to hospital | Continuous hospitalization | Readmitted to hospital |
| Culture result positive for postoperative infection | Yes | No | No |
The difference between the clinical infection rate (ie, 3%) and the benchmark or targeted infection rate recommended in hospital standards (ie, 1%) is statistically significant (z score = 2.0098, P < .0445). This suggests that the postoperative infection rate observed in this QI project is significantly higher than accepted standards and benchmarks and may be attributed to flash sterilizations. The design of the project did not include a control population, so no other statistical tests were warranted.
Analysis of Costs
The analysis of costs included the evaluation of hospital charges for the patients diagnosed with a postoperative infection. When evaluating costs, controversy exists about including indirect costs (ie, lost work time, diminished quality of life, pain, suffering) in the calculations because it is not always possible to assign a monetary value to these costs.8 In this project, only direct medical costs derived from itemized medical charges were used. Charges were included if they were considered to have been incurred as a result of diagnosing and/or treating the initially diagnosed postoperative infection, including charges for hospital room; nursing care; medications (eg, antipyretics, pain medications, antibiotics); IV solutions; laboratory tests; radiological procedures; and/or additional surgical procedures.
Direct medical costs were compared with the costs of increasing the inventory of surgical instruments to avoid the need for flash sterilization and subsequent risks of patient infection in the three procedures that resulted in an initial diagnosis of postoperative infection. The total charge for diagnosis and treatment of infection for the three patients was $43,170. This is $34,288 less than the charge to the institution would have been (ie, $77,458) for purchasing additional inventory that would have been needed to replace items that were flash sterilized in these three cases (Table 5). For two of the three cases, it was less expensive to treat the postoperative infection than it would have been to purchase additional inventory of the items that were flash sterilized during the procedures.
Table 5. Cost of Treating Presumed Postoperative Infections Compared to the Cost of Purchasing Additional Instruments
| Cost of treating presumed postoperative infections | ||||
|---|---|---|---|---|
| Charges | Case 1 | Case 2 | Case 3 | Overall total |
| Readmission cost for postoperative infection | $21,734* | $10,101 | ||
| Cost of extended hospitalization because of postoperative infection | $11,335 | |||
| Total | $21,734 | $11,335 | $10,101 | $43,170 |
| Cost of increasing inventory of items frequently flash sterilized | ||||
|---|---|---|---|---|
| Single items | Case 1 | Case 2 | Case 3 | Overall total |
| 2 maxi batteries ($252 each)** | $504 | |||
| 2 anterior cruciate ligament (ACL) instrument plugs ($25 each) | $50 | |||
| Instrument sets | Case 1 | Case 2 | Case 3 | Overall total |
|---|---|---|---|---|
| 1 ACL tray of a 3-tray set | $28,000 | |||
| 1 total joint tray of a 6-tray set | $47,000† | |||
| 1 total joint tray | $1,904‡ | |||
| Total | $28,000 | $49,408 | $50 | $77,458 |
| Cost of treating infections compared to purchasing additional instruments | ||||
|---|---|---|---|---|
| Case 1 | Case 2 | Case 3 | Overall total | |
| More expensive | $10,051 | |||
| Less expensive | −$6,266 | −$38,073 | −$34,288 | |
* Includes charges for two hospital admissions within two weeks postoperatively including room, nursing care, IV treatment, pain relief medications, antibiotics, laboratory tests, cultures, radiology, surgery, anesthesia, recovery, and placement of a peripherally inserted central catheter. |
** Batteries cannot be purchased sterile and must be flash sterilized before each use. |
† Total joint tray provided on consignment from implant manufacturer. The list price for 6-tray total joint set is $94,000. The charge to the hospital is $47,000. |
‡ Total joint tray owned by hospital. |
Discussion
The use of flash sterilization was highest in orthopedic procedures. At this institution, orthopedic procedures comprise approximately 20% of the surgical procedures performed, the largest percentage by surgical type on a monthly basis. The infection rate in 2004 for orthopedic patients at this institution ranged monthly from 0% to 2.4%, with an average rate of 1.1%.9 The 3% postoperative infection rate in this project is higher than the national average of 1%, a finding which may be attributable to flash sterilization. When calculated by the total number of flash sterilizations and postoperative wound site positive culture results, however, the postoperative infection rate is more in line with the norm. Regardless, if a patient exhibits signs of infection, he or she will incur charges for diagnosis and treatment of postoperative infection.
Overall, from a hospital perspective it was less expensive to diagnose and treat the postoperative infections than it would have been to purchase additional instruments for inventory of the items flash sterilized in the surgical procedures that resulted in an initial diagnosis of postoperative infection. From a clinical perspective, however, it is preferable to purchase additional instruments, minimizing the need for flash sterilization and protecting patients from the subsequent risk of postoperative infection. Purchasing additional instruments may not always be financially feasible, however, and not all items can always be sterilized in advance. For example, batteries cannot be purchased sterile and must be flash sterilized before being used. To avoid flash sterilizing batteries, power equipment can be purchased that allows for sterile encasement of batteries and thus avoids flash sterilization. Procurement of this equipment, however, would increase surgical instrument costs by approximately £29,000.
Limitations
This project did not include a control group of patients for whom no flash sterilized instruments were used. The hospital infection rates were used for comparison because this data already was being collected. This data did not specify whether flash sterilization was used during the specific procedures that resulted in postoperative infection, however, so it was not possible to determine whether there was a difference in postoperative infection rates between surgical procedures for which instruments were and were not flash sterilized. Furthermore, some observations included procedures in which more than one item was flash sterilized, compromising the independence assumption when following outcomes in a patient population (ie, the probability of multiple instruments used in the same procedure increasing the risk of patient infection is dependent on the actual procedure and possibly patient characteristics such as age and severity of illness).
Only direct medical costs were used to compare costs associated with increasing inventory of surgical instruments to avoid the need for flash sterilization, so the overall costs of minimizing flash sterilization through overinventory of surgical instruments may be underestimated and conservative. The indirect costs associated with postoperative infections were not discounted; rather, a methodology was used that is more applicable across multiple settings in which direct medical costs are more standardized and therefore easier to measure.
Project Outcomes
As a secondary objective of this project, the adequacy of the current instrument inventory was evaluated. As a result, the instrument inventory at Inova Loudoun Hospital has been increased, facilitating the use of flash sterilization for emergencies only. To decrease the need for flash sterilization, all special surgical device manufacturer instruments requested by a surgeon for a specific procedure are to be sent to the sterilization and processing department for sterilization at least four hours before the start of that procedure. If this is not possible, additional inventory of these instruments needs to be procured to eliminate the routine use of flash sterilization. With continual change in OR instrument inventory and technology, the relationship between the use of flash sterilization and adequate instrument inventory is a dynamic one that merits regular evaluation to ensure adequate inventory of all surgical instruments to ultimately decrease use of flash sterilization and possibly, postoperative infection rates. Another result of this project is that the institution has increased the OR education requirement for RNs, surgical technologists, and sterilization and processing department staff members to a quarterly review of the standard procedures for flash sterilization and demonstration of proficiency in flash sterilization.
Notes
- “Recommended practices for sterilization in perioperative practice settings” . In: Standards, Recommended Practices, and Guidelines . Denver: AORN, Inc; 2005;p. 459–460
- . Future Directions in Musculoskeletal Research: A Summary Report of the AAOS Research Committee Panel Studies . Rosemont, Ill: American Academy of Orthopedic Surgeons; 2003; Also available at http://www.aaos.org/wordhtml/research/synthesis/panel_future_directions.pdf (accessed 26 Jan 2006)
- . “Step-by-step flash sterilization,” Administrative Eyecare . http://www.asoa.org/services/publications/6-3-12.html (accessed 9 Jan 2006)
- . In: “Improving organization performance,” 1998 Comprehensive Accreditation Manual for Hospitals . Oakbrook Terrace, Ill: Joint Commission on Accreditation of Healthcare Organizations; 1997;p. PI 1–PI 7
- . “Surgical services,” . In: APIC Text of Infection Control and Epidemiology . vol 2: Washington, DC: Association for Professionals in Infection Control and Epidemiology; 2005;p. 46-5–46-6
- . “Flash sterilization: The fundamental issues,” . Infection Control Today . October 2000; http://www.infectioncontroltoday.com/articles/0a1feat1.html (accessed 9 Jan 2006)
- . “Sterilization in a flash,” . Infection Control Today . May 2001; http://www.infectioncontroltoday.com/articles/151topics.html (accessed 9 Jan 2006)
- . “The value of economic modeling studies in the evaluation of treatment strategies for multiple sclerosis” . Value in Health . January/February 2002;5:1–2
- . Report on infection rates . Leesburg, Va: Inova Loudoun Hospital; 2005;
The authors thank the RNs and OR staff members at Inova Loudoun Hospital who participated in this project.
PII: S0001-2092(06)60195-6
doi:10.1016/S0001-2092(06)60195-6
© 2006 AORN, Inc. Published by Elsevier Inc All rights reserved.
