BACKGROUND: STUDY DESIGN: RESULTS: CONCLUSIONS:

Transcription

1 Effectiveness of a Radiofrequency Detection System as an Adjunct to Manual Counting Protocols for Tracking Surgical Sponges: A Prospective Trial of 2,285 Patients Christopher C Rupp, MD, FACS, Mary J Kagarise, RN, MSPH, Stella M Nelson, RN, MA, CNOR, Allison M Deal, MS, Susan Phillips, RN, MBA, CNOR, Janet Chadwick, RN, MBA, CNOR, Tamara Petty, RN, CNOR, Anthony A Meyer, MD, PhD, FACS, Hong Jin Kim, MD, FACS BACKGROUND: STUDY DESIGN: RESULTS: CONCLUSIONS: Despite rigorous manual counting protocols and the classification of retained surgical items (RSIs) as potential never events, RSIs continue to occur in approximately 1 per 1,000 to 18,000 operations. This study s goals were to evaluate the incorporation of a radiofrequency detection system (RFDS) into existing laparotomy sponge- and Raytec-counting protocols for the detection of RSIs and define associated risk factors. All patients undergoing surgery at the University of North Carolina Hospitals from September 2009 to August 2010 were enrolled consecutively. The performance of an RFDS-incorporated accounting protocol for detecting RSIs was prospectively evaluated. Several operative metrics were recorded to identify risk factors for miscounts. A total of 2,285 patients were enrolled. One near miss was detected by the RFDS. Thirty-five miscounts occurred, for a rate of 1.53%. The ultimate locations of miscounted items were surgical site (n 11), within operative suite (n 10), surgical drapes (n 2), and emergency protocol deviations (n 12). Perioperative variables associated with miscounts were higher estimated volume of blood lost, longer operations, higher number of laparotomy sponges used, open surgical approach, after hours operations, change of surgical team during operation, weekend or holiday operations, unanticipated changes in operative plan during surgery, and emergency operations. Body mass index was not associated with miscounts. Surveys completed by participating surgical staff suggested high confidence in the RFDS for prevention of RSIs. The incorporation of the RFDS assisted in the resolution of a near-miss event (1 of 2,285) not detected by manual counting protocols and assisted in the resolution of 35 surgical-sponge miscounts. No known RSIs occurred during the study period. Risk factors for miscounts were identified and can help identify at-risk surgical populations. (J Am Coll Surg 2012;215: by the American College of Surgeons) In 2000, the Institute of Medicine released an evaluation on the state of patient safety within the US hospital environment in the report To Err Is Human: Building a Safer Health System. 1 Within this report, medical errors were Disclosure Information: Nothing to disclose. This study was supported by a grant from RF Surgical Systems, Inc. for materials used during the study period. Received February 29, 2012; Revised June 1, 2012; Accepted June 5, From the University of North Carolina School of Medicine (Rupp, Kagarise, Meyer, Kim), University of North Carolina Health Care System (Nelson, Phillips, Chadwick, Petty), and University of North Carolina Lineberger Comprehensive Cancer Center Biostatistics Core (Deal), Chapel Hill, NC. Correspondence address: Christopher C Rupp, MD, FACS, Department of Surgery, University of North Carolina School of Medicine, 4035 Burnett-Womack Bldg, CB #7081, Chapel Hill, NC crupp@med.unc.edu identified as a substantial problem contributing to increased patient morbidity, mortality, and hospital costs. In response to this report, several organizations developed safety standards for hospital systems, with the goal of eliminating adverse treatment and system-related factors that were determined to be preventable. In 2002, the National Quality Forum included retained surgical items (RSIs) among a list of reportable events that should not occur to patients undergoing care in US hospitals (ie, never events ), a recommendation that continues to this day. 2 The Joint Commission on the Accreditation of Healthcare Organizations considers an RSI a sentinel event that should result in an immediate investigation and response. 3 In addition, Medicare and Medicaid have enacted systems for 2012 by the American College of Surgeons ISSN /12/$36.00 Published by Elsevier Inc

2 Vol. 215, No. 4, October 2012 Rupp et al Radiofrequency Detection of Operative Sponges 525 hospital reimbursement predicated on adherence to set groups of safety standards and checklists. 4 Examples of RSIs are surgical instruments, retractors, needles, and surgical sponges/towels, all of which have been described. 5-7 Although the true incidence of RSIs after operations in the United States is unknown, estimates range from 1 in every 1,000 to 1,500 operations to 1 in every 8,000 to 18,000 operations. 8,9 Although it has been challenging to determine actual risk factors associated with RSIs, data generated from insurance claims have implicated body mass index (BMI; calculated as kg/m 2 ), emergency case status, and unplanned changes in operative procedure as contributing factors. 8 Accurate studies of RSIs have been challenging due to the low incidence of events and long follow-up necessary, given the fact that numerous reports have documented RSIs discovered years, and even decades, after the actual operation. 9,10 In addition, most studies have relied on administrative databases and have been retrospective and anecdotal, limiting the accuracy and usefulness of defining the burden of RSIs in surgery. Although different algorithms exist for each institution within the operating theater to prevent RSIs, most can be categorized as manual counting protocols that are predicated on human input and determination of count correctness, or agreement of item counts between the beginning and end of an operation. Several variations of this concept exist. Perhaps the most widely implemented system is the Sponge ACCOUNTing System, which consists of several structural elements, medical personnel training, and equipment (eg, sponge holder racks) to facilitate accurate accounting of soft goods/sponges. The Sponge ACCOUNTing System was developed as part of the NoThing Left Behind project, a national surgical patient safety project created to prevent RSIs ( It is transparent, verifiable, inexpensive, and simple. However, a system that relies on human performance and activity is subject to error. Retained surgical items continue to occur despite well-established protocols at hospitals in the United States, often in the setting of a correct count. To combat this problem, some institutions have developed protocols of mandatory postoperative x-ray evaluation for RSI detection. 5 This approach can have a better detection rate for RSIs, but it systematically exposes every surgical patient to potentially damaging and unnecessary radiation, which might be unwarranted in light of recent studies suggesting a higher incidence of cancer with more radiation use Fortunately, many institutions and companies have recognized the magnitude of this problem. Several technological adjuncts have been designed and created for RSI prevention and are readily available commercially. Essentially, there are 2 types of existent technologies that differ on the paradigm used to prevent RSIs. The first system relies on reconciliation of counts at the beginning and end of the surgical procedure, namely a count-based system. Technology is used to supplement manual counts by performing counts based on detection of a microchip system embedded in each item used during the procedure. The most commonly used system of this type is the Data-Matrix-Coded sponge-counting system. The second system is detectionbased and predicated on in vivo detection of items used in the procedure rather than count awareness. The most common example of this is radiofrequency detection. A third system, termed radiofrequency identification, is a hybrid of the 2 detection paradigms. Although these systems are available, few rigorous prospective data exist to evaluate their effectiveness. Additionally, no detection system to date has been evaluated as a replacement for traditional manual counting protocols and procedures. Because an RSI is a rare event and the incremental benefits of technology adjuncts for detection are unknown, any clinical trial other than a proof-of-concept trial would have to recruit tens of thousands of patients to have any detectable benefit However, other investigators have used the rate of manual count discrepancies, or miscounts, as a proxy for the detection of missing sponges. 18 The rationale for this is predicated on the fact that a miscount of any surgical item at the conclusion of surgery actually represents a potential RSI. In fact, an RSI is 100 times more likely when a miscount is present. 19 When a miscount is present, the potential RSI is readily identifiable in real time and can be immediately intervened on to prevent an actual RSI. Although the rate of miscount has never been precisely reported in the literature, it occurs more frequently than a true RSI and is readily studied without recruitmentprohibitive numbers. Radiofrequency detection has been used in several commercial sectors with success, including microchip implantation of pets and theft deterrence in retail stores. Radiofrequency technology has recently been applied to laparotomy sponges used during surgery, where the RF emitter has been embedded in the product to prevent dislodgement. Although surgical sponges are not the only RSIs described, they are the most frequent RSIs encountered. 5 Despite implementation of the rigorous Sponge ACCOUNTing System protocols at our institution in 2006, the RSI incidence was not reduced to zero. Before implementation of Sponge ACCOUNTing System protocols, our institutional rate of RSI was 1 RSI per 36,000 operations. After implementation, the rate decreased to 1 RSI per 54,000 operations. A task force was created to

3 526 Rupp et al Radiofrequency Detection of Operative Sponges J Am Coll Surg investigate this issue. Although the ultimate reason for the failure of Sponge ACCOUNTing System protocols to prevent all RSIs at our institution was not clear, the consensus was that human error in counting was the likely reason. Because of this, the recommendations from our institutional task force included the implementation of a technological adjunct to eliminate human error. After short evaluations of the existing systems, we elected to implement an radiofrequency detection system (RFDS) protocol as a detection adjunct to the existing Sponge ACCOUNTing System incorporated protocol. Our goal with our trial was to evaluate the performance of the RFDS in detecting RSIs, specifically laparotomy sponges and Raytecs, after hospitalwide implementation of the technology. A second goal was to define the risk factors associated with miscounts (eg, incorrect surgical sponge accounting at the conclusion of an operation). METHODS Technology used The Radio-Frequency Detection System (RF Surgical Systems Inc.) is a US FDA-approved technology that is readily available in the United States and elsewhere. The system configuration used during the study consists of a console that serves as a power source and monitor, the Blair-Port Wand that performs a systematic in vivo detection of any appropriately RF-labeled item, and radiofrequency-tagged cotton products, including laparotomy sponges and Raytecs. The embedded RF emitter in the cotton product has a minute size and does not inhibit proper use of the respective cotton product. Study design and patients A multidisciplinary panel was created at our institution that included representatives from the departments of surgery, operative nursing, operative planning and administration, information technology, and biostatistics. This panel designed a strategy to implement the RFDS as an adjunct into our current process of operative sponge and Raytec management (ie, Sponge ACCOUNTing System). Institutional Review Board approval was obtained before implementation, and patient consent was waived due to the minimal risk to the patient, noninvasive nature of the technology, and lack of adverse effect to patient rights. Using Health Insurance Portability and Accountability Act-compliant protocols, an electronic data system was created to record several operative variables from the patient record. A secure, password-protected, and encrypted program safeguarded and isolated protected health information. Descriptive variables recorded for all patients included patient age, sex, and BMI. Operation-specific variables recorded included estimated volume of blood lost, total operation time, change in surgical procedure during the operation, and number of laparotomy sponges and Raytecs used. Operation details included primary body cavity entered, open or laparoscopic procedure, and surgical team change during operation. Operations were classified as elective (scheduled), add-on (urgent, to be done same day), or emergency (to be performed within hours). Procedures starting before 7:00 AM or after 5:00 PM were categorized as evening/night procedures, and those occurring on the weekends and/or holidays were categorized as such. Miscounts were documented, as was the need for x-rays to reconcile count discrepancies. The ultimate location of laparotomy sponges and Raytecs detected after a miscount was also recorded. Individuals performing the RFDS scan were asked to rate their experience level with the system, confidence level, ease of use, and overall usefulness of the system for each patient. This survey was created to assess the functionality of the RFDS and has not been validated before implementation. All RSIs and miscounts were recorded during the study period. These events included a miscount of any of the mandatory 2 manual counts with or without discoverable RSIs, as well as true RSIs (defined in the following paragraph). These were collectively categorized as action events. Per institutional policy, procedures without manual counts performed at the beginning of the procedure, or where manual counts were not possible at conclusion of the procedure (ie, emergent body cavity packing) were considered miscounts. For study purposes, these were categorized as emergency-protocol deviations. The definition for an RSI was used according to that published by Cima and colleagues. 5 A true RSI (previously termed retained foreign object,) was defined as any object unintentionally retained in a patient at the time of final wound closure, specifically a laparotomy sponge or Raytec, for the purposes of our study. Cima and colleagues 5 also described a category of patients in which potential RSI events were reported to their institutional sentinel event hotline and no items were discovered on radiologic imaging. These were categorized as near-miss events. We modified the definition of a near miss for purposes of our study to represent patients where standard manual counting protocols did not identify a missed item, but a laparotomy sponge or Raytec was discovered by the RFDS exclusively. The location of such items was recorded, but was not relevant for definition criteria, as it ultimately represents a breakdown of a nontechnologically supported detection protocol.

4 Vol. 215, No. 4, October 2012 Rupp et al Radiofrequency Detection of Operative Sponges 527 Figure 1. Flowchart of institutional counting process with incorporation of radiofrequency detection system (RFDS). *Includes surgical drapes, off surgical field, and in trash receptacle. Implementation protocol All surgical staff at our institution are required to comply with the practices for counting sponges recommended by the Association of Perioperative Registered Nurses. 20 The standard sponge-counting algorithm requires that the individuals in the surgical scrub and circulating positions perform a visual and verbal sponge count at various points of the operation. Similar to many institutions, we perform sponge counts at the beginning of a case, during any addition or removal of sponges from the sterile field, change of nursing personnel, beginning of body cavity closure, and after body cavity closure before procedure completion. As stated previously, our institution adheres to the methods and equipment adjuncts used with the Sponge ACCOUNTing System. A preliminary implementation of the RFDS was performed on a limited basis in the operating rooms of the primary investigators to evaluate the system and determine the temporal placement of the technology system into the existing manual count algorithm. It was determined that the RFDS scan could be performed at any point that body cavity closure was begun, before completion of the surgical procedure. Repeat scans could be performed for any discrepancy or concerns of operative personnel. A flow diagram illustrating the incorporation of the RFDS into our institutional counting process is presented in Figure 1. All nonradiofrequency-labeled laparotomy sponges and Raytecs were removed from all operating theaters and procedure rooms, and replaced with RF-labeled products to avoid incorrect use. Each room was equipped with an RFDS that included a Blair-Port Wand. Surgeons, surgical residents, and all operative personnel were trained on correct RFDS use by instruction from the investigative team, representatives onsite from RF Surgical, Inc. for a training period, and an online instructional video and tutorial. Any member of the operative team could perform the detection procedure once competence in the technique was confirmed by web-based testing. The study began enrollment in September 2009 and was concluded in August Statistical analysis Prospectively collected results from 2,285 operations performed at the University of North Carolina Hospital between September 2009 and August 2010 are presented

5 528 Rupp et al Radiofrequency Detection of Operative Sponges J Am Coll Surg Table 1. Descriptive Statistics and Frequencies for Basic Demographic and Surgery Characteristics Characteristics Sex, n (%) Male 1,144 (50.1) Female 1,141 (49.9) Age, mean (SD), y 51 (19) Body mass index, mean (SD) 28.7 (11.6) Type of operation Open, n (%) 1,635 (71.6) Emergency, n 165 Elective, n 1,394 Add on, n 76 Laparoscopic, n (%) 532 (23.3) Elective, n 487 Emergency, n 27 Add on, n 18 Endoscopic, n (%) 114 (5.1) Emergency case, n Yes 192 No 2,090 here. Descriptive statistics and frequencies for basic demographic and surgery characteristics are provided for the patient population as a whole (Table 1). Associations of these characteristics and the occurrence of a miscount were evaluated using Fisher s exact tests for categorical variables and Wilcoxon rank sum tests for continuous variables. Unadjusted p values are reported. RESULTS During the 10-month study enrollment period, 2,516 patients were entered into the study, with 2,285 completed datasets available for analysis. Evaluation of the remaining 231 datasets revealed missing critical data and the entire entry was therefore excluded. Basic demographic information is provided in Table 1. The distribution of procedures according to the primary operative site is listed in Figure 2. The majority of procedures performed during the study period were confined to the abdominal cavity (58%), with the next most frequent being chest (cardiac and thoracic) procedures (13%). Due to the nature of operations within the abdominoperitoneal cavity, there was crossover into the pelvis. However, procedures were considered abdominal for recording purposes if the majority of the procedure occurred within this peritoneal space. The next most common body cavity was other cavity, which was recorded in 9%. This designation consisted of procedures without a defined body cavity, such as procedures within the retroperitoneum, spinal column, perineum, and breasts. The distribution of procedures according to the basic type of operation performed is listed in Figure 3. The most frequent type of procedure performed was open, elective cases (61%), with laparoscopic, elective the next most common (22%). Emergency procedures (both laparoscopic and open) accounted for 8% of total procedures performed during the study period. Thirty-six action events were identified during the study period (Fig. 4). No true RSIs were identified. One near miss was recorded. The near-miss event occurred in a 48- year-old woman undergoing an elective abdominal procedure. Her BMI was Volume of blood lost was 200 ml. There was no team change during the 6-hour open, elective operation. Forty laparotomy sponges and 10 Raytecs were used. Manual laparotomy sponge and Raytec counts were correct, but a Raytec was detected in the surgical drapes on RFDS evaluation. Thirty-five action events were categorized as miscounts for a rate of 1.53% (35 of 2,285). Of these miscounts, the recovered cotton product was identified as follows: surgical site/body cavity, n 11; off of surgical field but within operative suite, n 10; within surgical drapes, n 2; and no missing sponge identified, n 12 (Fig. 4). All miscounts categorized as no missing sponge were later identified as emergency-protocol deviations. Tables 2 and 3 list the rates of miscounts per primary surgical site and basic type of operation performed, respectively. The highest incidence of miscounts occurred in pelvic operations (6.90%), followed by chest (3.41%) and head/neck cases (2.67%). Of note, abdominal cases had a lower incidence of miscounts than many surgical sites (1.06%). For general surgical procedure type, the highest incidence of miscounts occurred during open, emergency operations (7.88%), followed by open, elective operations (1.36%). Recorded study variables are presented in Table 4.Of the multiple variables evaluated, several were found to be associated with miscounts by statistical analysis. This included higher estimated volume of blood lost (p ), open surgical approach (p 0.004), operations performed after 5 PM but before 7 AM ( after hours ; p 0.005), change of surgical team during the operation (p ), operations occurring on a weekend or holiday (p 0.03), longer duration of operation (p ), higher number of laparotomy sponges (per 10 sponges opened) used (p ), unanticipated change in operative procedure during the operation (p ), and cases defined as emergency cases (p ). Variables that did not differ in rates of miscounts included patient sex, patient age, BMI (p 0.15), and number of Raytecs (per 10 Raytecs opened) used (p 0.05). A questionnaire was completed by the circulating nurse at the completion of each surgical procedure, and results

6 Vol. 215, No. 4, October 2012 Rupp et al Radiofrequency Detection of Operative Sponges 529 Figure 2. Distribution of primary surgical site for operations using radiofrequency detection system. are presented in Table 5. The majority of respondents believed that confidence in the final count was improved with RFDS, that RFDS improved the time to resolve a count discrepancy, RFDS was easy to use, and the process of body cavity closure/operative conclusion was not prolonged by the use of RFDS. DISCUSSION Despite the fact that RSIs are recognized as a considerable operative patient safety challenge, very few objective data exist on the magnitude of the problem. In fact, the true incidence of RSIs after operations in the United States is unknown, with estimates ranging widely, from 1 in every 1,000 to 1 in 18,000 operations. 8,9 More recently, a retrospective study at Mayo Clinic in Rochester, MN reported 34 true RSI events in 191,168 operations during a 4-year period, for an overall incidence of approximately 1 RSI per 5,500 operations. 5 Accordingly, we did not experience a true RSI during our study of 2,285 patients during a 10- month period, which is suggestive of at least a comparable rate of RSIs. Importantly, even less is known about the process to prevent RSIs, and how to standardize this protocol among the wide array of operative settings. The objective of this study was to evaluate this process of RSI prevention during surgical procedures, with the incorporation of RFDS as an adjunct for detection of radiolabeled cotton products (laparotomy sponges and Raytecs). It is well appreciated that the operative suite is a complex and highly unpredictable environment, with several competing tasks occurring at the same time. Presumably simple tasks, such as the counting of individual items, have an inherent error rate. Performing this simple task in a complex work environment exponentially increases the error rate due to multiple distractions and competing tasks. In other environments, studies have shown that by simply adding to the number of items a person must address or presenting minor distractions during the process substantially impairs the subject s ability to perform even a simple or routine Figure 3. Basic type of operation performed.

7 530 Rupp et al Radiofrequency Detection of Operative Sponges J Am Coll Surg Figure 4. Flowchart of true retained surgical items, near misses, and miscounts with subset characterization of miscounted sponges. EPDs, emergency protocol deviations. task. 7,21,22 This is also supported by the recent development of the concept of error traps and the application of the concept to several areas of medicine, including bile duct injuries during cholecystectomy. 23,24 The concept of an error trap is predicated on the fact that we often rely on methods that work well in most circumstances, but are apt to fail under certain conditions. Because it is usually effective, the user gains confidence in it and might fail to appreciate that something is amiss when dangerous circumstances occur. Reliance on manual counting, which has a low but inherent error rate, is just such a circumstance that lends itself to potentially devastating consequences. Our selection process for the use of laparotomy sponges and Raytecs was multifactorial. First, cotton products have Table 2. Rate of Miscounts According to Primary Surgical Site Primary surgical site Incidence of miscounts No. of occurrences/total operations in primary surgical site % Pelvis 2/ Chest 10/ Head/neck* 5/ Extremity 3/ Abdomen 14/1, Other 1/ Skin/soft tissue 0/ *Includes one endoscopic case. Retroperitoneum, spinal column, perineum, and breast. been documented in several studies to be the most frequent RSI during operative or interventional procedures. Second, radiolabeled cotton products are readily available commercially. Conversely, radiolabeled equipment that must undergo repeated sterilization (such as surgical instruments and needles) is not widely available, and the reuse rate has not currently been defined. Additionally, RF energy at wavelengths used by this technology has not been shown to expose humans to any deleterious effects. Lastly, the process of RF detection is not time consuming and has minimal effect on the flow of operative procedures or operative time, a concern that has been discussed previously with the Data-Matrix-Coded sponge-counting system. 18,25 We did have one occurrence of a near miss in our study, the details of which are described in the Results section. We acknowledge that there might be a component of the Table 3. Incidence of Miscounts According to General Type of Procedure Type of operation Incidence of miscounts No. of occurrences/total operations in primary surgical site % Open, emergency 13/ Open, elective 19/1, Open, add on 1/ Laparoscopic, elective 1/ Laparoscopic, emergency 0/ Laparoscopic, add on 0/ Endoscopic 1/

8 Vol. 215, No. 4, October 2012 Rupp et al Radiofrequency Detection of Operative Sponges 531 Table 4. Patient and Operation Characteristics of Miscounts Variable No miscount (n 2,250) Miscount (n 35) p Value Age, mean SD, y BMI, mean SD Estimate volume of blood lost, ml, mean SD Duration of operation, min, mean SD No. of laparotomy sponges used (per 10 sponges opened), mean SD No. of Raytecs used (per 10 Raytecs opened), mean SD Sex, n (%) Female 13/1,144 (1.14) Male 22/1,141 (1.93) 0.13 Approach Laparoscopic 1/532 (0.19) Open 33/1,635 (2.02) Other 1/114 (0.88) Operation time* After hours 9/224 (4.02) Regular hours 26/2,061 (1.26) Surgical team change during case Yes 21/462 (4.55) No 14/1,823 (0.77) Operation day Weekend/holiday 5/117 (4.27) Weekday 30/2,168 (1.38) 0.03 Unanticipated change in operative plan Yes 9/66 (13.6) No 26/2,219 (1.17) Emergency case Yes 13/192 (6.77) No 22/2,090 (1.05) *Defined as operative start time after 5 PM and before 7 AM. Hawthorne effect, with heightened awareness by the surgical staff during the time period of the clinical trial. Because this was a single event, statistical analysis was not appropriate or meaningful. Instead, the specific details of the incident suggested several risk factors for an RSI. These Table 5. Subjective Questionnaire for Use of Radiofrequency Detection System % Agree or strongly agree Statement n % The RFDS improved confidence in the final count. 2,168/2, The RFDS helped improve the time to resolve a count discrepancy. 1,893/2, RFDS ease of use: average to easy (vs difficult) 2,220/2, The RFDS did not interrupt the closing process. 2,273/2, RFDS, radiofrequency detection system. included open operation, 4 laparotomy sponge packs opened, and long procedure duration. However, several risk factors were not present. The discovered RSI was ultimately detected by the RFDS in the surgical drapes. For our study purposes, the ultimate location of the near miss was not as important as the fact that the routine manual counts and protocols failed to detect the object. The ultimate location could very well have been within the patient, given the breakdown in the process of standard operative item accounting. Although this is one isolated case, it does reinforce the concept that RSIs can occur in any operation with any patient or operative characteristic. The ultimate goal of sponge management is to make RSIs a never event. As discussed already, several agencies now expect this standard and have clearly defined mandates for RSIs. Several adjunctive products exist on the market for prevention of RSIs, the most common of which are the Data-Matrix-Coded sponge-counting system and RFDS. Which type of technology to use is highly institu-

9 532 Rupp et al Radiofrequency Detection of Operative Sponges J Am Coll Surg tion dependent. Considerations include ease of use, cost to benefit ratios (incidence of RSIs at each institution, x-ray usage, fiscal impact), management of procedural compliance, preference of operating room and hospital leadership, and availability. 26 This seems reasonable because RSI detection technology is still in a relatively early stage of development, with no clear advantage of one system over another at this time. For RFDS, expected performance of the RFDS as described by the manufacturer is %, which is a high standard that we could not measure, given our small study size. In addition, to our knowledge, factors such as BMI and operative table type/position did not interfere with the functionality or performance of the device. We would like to emphasize that no current system has been specifically evaluated as a replacement to the manual count protocols endorsed by the Association of Perioperative Registered Nurses. As our objective was not to compare the RFDS process with standard operative RSI-detection protocols, we do not believe our data support a conclusion suggesting that standard procedural counting and identification protocols be replaced solely by a specific technology. However, our data does indicate that counting protocols can be augmented by RFDS. A limitation of our study, in contrast to Cima and colleagues, 5 is that our grant s budget precluded developing a study arm to compare our RFDS findings against the gold standard. Where high-resolution x-rays were obtained after all surgical or invasive procedures during their study, it is not our institutional policy to obtain x-rays for every patient unless clinically indicated. This is similar to the majority of health care systems in the United States, where routine high-resolution x-rays are not practical and are obtained on an as-needed basis. Although the results of routine high-resolution post-procedural x-rays are excellent, the rate of true RSIs is still not zero, as 4 RSIs were discovered after 24 hours post-procedure, 2 of which were discovered after discharge of the patient from the hospital. 5 In addition, a policy of universal x-rays has been evaluated and found to be cost-prohibitive for the prevention of RSIs. Regenbogen and colleagues estimated that even if the sensitivity of intraoperative x-rays was perfect and RSIs could be completely prevented, it would cost $1.3 million per RSI event prevented. 26 Even with the use of a selective x-ray use for high-risk cases, the cost would still be $1 million for every RSI prevented. Although the rationale might be different for needle and instrument detection, the use of routine x-rays for sponge management does not appear to be cost-effective for most hospitals. Although we did not perform a formal cost to benefit analysis in this current study, the use of the complete RFD system (including equipment and RF-labeled cotton products) resulted in an estimated added cost of $ However, we acknowledge that this highly dependent on several factors, including hospital contracts, volume of product used, and regional variability. A second limitation of our study is the lack of long-term patient follow-up. Although many reports describe RSI detection within a short amount of time after surgery, there are several reports of RSIs being detected as far out as 40 years from the original procedure Although we have a mean institutional follow-up of 20 months for our study, this interval is not sufficient to conclude that an RSI has not occurred. Such conclusions need to be made after a long follow-up, perhaps several decades. In addition, due to our referral and practice patterns, many of our patients travel great distances to be treated at our tertiary care center. With limited long-term follow-up, it is possible that a patient undergoing a procedure at our institution could have been treated elsewhere for an RSI without our knowledge. We also acknowledge the limitation of a singleinstitution study, which might represent the experience of similar tertiary care centers across the United States, but might not represent the operative protocols at different institutions. The inclusion of any technological adjunct in the operating theater will have to be fundamentally sound and easily incorporated into the counting process without causing a disruption or distraction to the operation itself. One of the secondary goals of the study was to evaluate the ease of incorporation of a technology adjunct into the operative work flow. A series of questions was presented to the operative staff at the conclusion of each operation, and the results are summarized in Table 5. Although this is a subjective assessment, there was an overwhelming positive response about the ease of use, lack of interruption of the operation itself, and improvement in the confidence of the counting process itself. The responses indicate that the operating room staff believed miscounts were more efficiently resolved using the RFDS. In fact, the current form of the technology incorporates an automated mat system that the patient lies on during the operation with a touch-screen console, which has made the process of scanning even more efficient. More directed studies are required to definitively conclude whether or not technology adjuncts are truly viewed as an asset by operating room personnel. These data suggest that it is well received and valued as protection for patients, as well as the individuals providing operative care. Although we did not evaluate the actual time added to the counting process by RFDS due to logistical constraints, anecdotally this added a negligible amount of time, as it can be performed as other processes are occurring. In addition, we did not detect any errors by the RFDS system, but we do

10 Vol. 215, No. 4, October 2012 Rupp et al Radiofrequency Detection of Operative Sponges 533 acknowledge that our study does not have enough power to detect this technical variable. CONCLUSIONS In this prospective clinical study, we found that the incorporation of an RFDS into existing counting protocols enhanced the identification of misplaced surgical sponges and assisted in the resolution of a single near-miss event. Although other strategies exist as adjuncts to manual counting protocols, the incorporation of RFDS was well received by our operative personnel for efficiency, exceptional ease of use, and overall effectiveness. Author Contributions Study conception and design: Rupp, Kagarise, Nelson, Phillips, Chadwick, Petty, Meyer, Kim Acquisition of data: Rupp, Kagarise, Nelson, Kim Analysis and interpretation of data: Rupp, Deal, Kim Drafting of manuscript: Rupp, Deal Critical revision: Kagarise, Nelson, Deal, Phillips, Chadwick, Petty, Meyer, Kim REFERENCES 1. Kohn L. To err is human: an interview with the Institute of Medicine s Linda Kohn. Jt Comm J Qual Improv 2000;26: National Quality Forum. Serious reportable events in healthcare. A consensus report. Washington, DC. Available at: www. qualityforum.org. Accessed November 23, The Joint Commission. Sentinel Event Policy and Procedures. Oakbrook Terrace, IL: The Joint Commission; Medicare program: changes to the hospital inpatient prospective payment system and fiscal year 2008 rates. Fed Regist 2008: Cima RR, Kollengode A, Garnatz J, et al. Incidence and characteristics of potential and actual retained foreign object events in surgical patients. J Am Coll Surg 2008;207: Gayer G, Petrovitch I, Jeffrey RB. Foreign objects encountered in the abdominal cavity at CT. Radiographics 2011;31: Lincourt AE, Harrell A, Cristiano J, et al. Retained foreign bodies after surgery. J Surg Res 2007;138: Gawande AA, Studdert DM, Orav EJ, et al. Risk factors for retained instruments and sponges after surgery. N Engl J Med 2003;348: Rappaport W, Haynes K. The retained surgical sponge following intra-abdominal surgery. A continuing problem. Arch Surg 1990;125: Lauwers PR, Van Hee RH. Intraperitoneal gossypibomas: the need to count sponges. World J Surg 2000;24: Ron E. Ionizing radiation and cancer risk: evidence from epidemiology. Radiat Res 1998;150[Suppl]:S30 S Kleinerman RA. Cancer risks following diagnostic and therapeutic radiation exposure in children. Pediatr Radiol 2006; 36[Suppl 2]: Ron E. Cancer risks from medical radiation. Health Phys 2003; 85: Schonfeld SJ, Lee C, Berrington de Gonzalez A. Medical exposure to radiation and thyroid cancer. Clin Oncol (R Coll Radiol) 2011;23: Greenberg CC, Gawande AA. Beyond counting: current evidence on the problem of retaining foreign bodies in surgery? Ann Surg 2008;247: Berkowitz S, Marshall H, Charles A. Retained intra-abdominal surgical instruments: time to use nascent technology? Am Surg 2007;73: Rattner DW. Invited commentary: making patient safety automatic. Surgery 2005;137: Greenberg CC, Diaz-Flores R, Lipsitz SR, et al. Bar-coding surgical sponges to improve safety: a randomized controlled trial. Ann Surg 2008;247: Egorova NN, Moskowitz A, Gelijns A, et al. Managing the prevention of retained surgical instruments: what is the value of counting? Ann Surg 2008;247: Association of Perioperative Registered Nurses. Recommended practices for sponge, sharp, and instrument counts. In: Perioperative Standards and Recommended Practices. Denver, CO: AORN, Inc.; 2008: Einstein GO, McDaniel MA, Williford CL, et al. Forgetting of intentions in demanding situations is rapid. J Exp Psychol Appl 2003;9: Botvinick MM, Bylsma LM. Distraction and action slips in an everyday task: evidence for a dynamic representation of task context. Psychon Bull Rev 2005;12: Reason J. Human error: models and management. BMJ 2000; 320: Strasberg SM. Error traps and vasculo-biliary injury in laparoscopic and open cholecystectomy. J Hepatobiliary Pancreat Surg 2008;15: Cima RR, Kollengode A, Clark J, et al. Using a data-matrixcoded sponge counting system across a surgical practice: impact after 18 months. Jt Comm J Qual Patient Saf 2011;37: Regenbogen SE, Greenberg CC, Resch SC, et al. Prevention of retained surgical sponges: a decision-analytic model predicting relative cost-effectiveness. Surgery 2009;145: Rajkovic Z, Altarac S, Papes D. An unusual cause of chronic lumbar back pain: retained surgical gauze discovered after 40 years. Pain Med 2010;11: Kiernan F, Joyce M, Byrnes CK, et al. Gossypiboma: a case report and review of the literature. Ir J Med Sci 2008;177: Cevik I, Dillioglugil O, Ozveri H, Akdas A. Asymptomatic retained surgical gauze towel diagnosed 32 years after nephrectomy. Int Urol Nephrol 2008;40: