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Intravenous Contrast Extravasation During CT: A National Data Registry and Practice Quality Improvement Initiative
ORIGINAL ARTICLE
Intravenous Contrast Extravasation During CT: A National Data Registry and Practice Quality Improvement Initiative Thomas M. Dykes, MDa, Mythreyi Bhargavan-Chatfield, PhDb, Raymond B. Dyer, MDc Abstract Purpose: Establish 3 performance benchmarks for intravenous contrast extravasation during CT examinations: extravasation frequency, distribution of extravasation volumes, and severity of injury. Evaluate the effectiveness of implementing practice quality improvement (PQI) methodology in improving performance for these 3 benchmarks. Methods: The Society of Abdominal Radiology and ACR developed a registry collecting data for contrast extravasation events. The project includes a PQI initiative allowing for process improvement. Results: As of December 2013, a total of 58 radiology practices have participated in this project, and 32 practices have completed the 2cycle PQI. There were a total of 454,497 contrast-enhanced CT exams and 1,085 extravasation events. The average extravasation rate is 0.24%. The median extravasation rate is 0.21%. Most extravasations (82.9%) were between 10 mL and 99 mL. The majority of injuries, 94.6%, are mild in severity, with 4.7% having moderate and 0.8% having severe injuries. Data from practices that completed the PQI process showed a change in the average extravasation rate from 0.28% in the first 6 months to 0.23% in the second 6 months, and the median extravasation rate dropped from 0.25% to 0.16%, neither statistically significant. The distribution of extravasation volumes and the severity of injury did not change between the first and second measurement periods. Conclusions: National performance benchmarks for contrast extravasation rate, distribution of volumes of extravasate, and distribution of severity of injury are established through this multi-institutional practice registry. The application of PQI failed to have a statistically significant positive impact on any of the 3 benchmarks. Key Words: Contrast extravasation, CT, National Radiology Data Registry, practice quality improvement J Am Coll Radiol 2015;12:183-191. Copyright 2015 American College of Radiology
INTRODUCTION Intravenous iodinated contrast material extravasation during CT exams using an automated power injector is a commonly encountered complication in busy radiology practices. The incidence of extravasation, as reported in the literature, ranges between 0.1% and 0.9% of all contrast-enhanced CT exams [1]. An aggregate extravasation rate of 0.45% was reported based on a review of 6 series published between 1991 and 2007 that included 867 extravasation events in 190,656 enhanced CT exams [2]. Based on these statistics, a radiology practice that performs 12,000 contrast-enhanced CT exams a
Department of Radiology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania. b ACR, Reston, Virginia. c Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina. Corresponding author and reprints: Thomas M. Dykes, MD, Department of Radiology, H066, 500 University Drive, P.O. Box 850, Hershey, PA 17033-00850; e-mail: [email protected].
ª 2015 American College of Radiology 1546-1440/14/$36.00 n http://dx.doi.org/10.1016/j.jacr.2014.07.021
annually could expect to see 54 extravasations in 1 year, or about 1 extravasation event per week. The Society of Abdominal Radiology (SAR) and the ACR co-developed a practice quality improvement project (PQI) on contrast extravasation that occurs during CT examinations. The primary purpose of this project was to develop 3 national performance benchmarks for intravenous, iodinated contrast extravasation during CT examinations: frequency of extravasation, distribution of extravasation volumes, and distribution of severity of extravasation injury. Previous studies largely reflect the practice experience of a few large, teaching institutions or small series and case reports from a single practice. This is the first multi-institutional study that gathered data from diverse practice groups from across the United States, including both academic and nonacademic settings. A second purpose for this project was to evaluate the effectiveness of implementing PQI methodology in improving performance in contrast extravasation that occurs during contrast-enhanced CT examinations for these 3 benchmarks.
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Participation in this project allows radiology practices to contribute data to the project and also compare their performance to the 3 benchmarks mentioned earlier selected by the SAR and the ACR. The project also allows the participating radiologist or group to review an educational feedback document prepared by the SAR and ACR that outlines practice recommendations and standards gathered from the ACR Manual on Contrast Media [1] and other key literature references; identify areas of performance that need improvement in regard to contrast extravasation; implement improvement strategies; and assess performance a second time to determine if the improvement strategies were effective. Completion of the 2-cycle PQI project offers the participant(s) PQI credit for the maintenance-of-certification requirement from the ABR. The ABR has “pre-approved” successful completion of this project as satisfying the PQI requirement for certification maintenance when it is combined with completion of the PQI attestation in their ABR personal database.
METHODS Data collection was performed under the umbrella of the ACR National Radiology Data Registry (NRDR). The data submitted are anonymous, and this project has an institutional review board certification of exemption under Section 101(b), paragraph 4. The SAR, through consultation with subject matter experts and with their board of directors, developed an online data entry form, established the reporting guidelines and definitions, and selected the performance benchmarks to report to the radiology practices. Enrollment in the project for the participant(s) requires online registration for the group with the ACR NRDR. Registration requires selection and identification of a facility administrator who is responsible for enrolling the participating radiologists seeking PQI credit, selecting the starting date for each 6-month reporting period, collecting and verifying data reported for each extravasation event during the reporting period, and reporting the total number of contrastenhanced CT exams performed during the reporting period. The ACReNRDR website includes an IV (intravenous) Contrast Extravasation Registry User Guide and an IV Contrast Extravasation Registry Data Dictionary containing detailed instructions on completing the reporting forms and definitions (http://www.acr.org/Quality-Safety/National-RadiologyData-Registry/IV-Contrast-Extravasation). The IV Contrast Extravasation Reporting Form (Fig. 1 online) also contains embedded instructions and definitions. Ensuring the validity of data entered is the responsibility of the facility administrator and the participating physicians. There is no external reviewer or site visit by a monitor to validate data. 184
Six months of initial data collection are reported using the online IV Contrast Extravasation Form in the NRDR database. In addition to data on extravasations, facilities report the number of IV contrast injections administered for CT exams during the same period. Following the initial 6 months of data collection, a feedback document is sent to the participating facility. This document includes educational materials prepared by the SAR that summarize the literature on contrast extravasation and an institution-specific report summary tabulating the practice-specific data entered from the IV Contrast Extravasation Form. During initial implementation of this project, the participating facility’s performance was compared to previously reported results from a large, retrospective study [3] in 3 areas: contrast extravasation rate, estimated contrast volume extravasated, and severity of injury. After the project was more mature, and utilizing several months of data collection that included data and results from multiple institutions, benchmark metrics were based on the results available within the registry. Following receipt of the first 6-month feedback document from the ACR, the individual or group self-identified deficiencies and areas that needed improvement and implemented steps for process improvement. Data were collected and submitted to NRDR for a second 6-month period followed by a second feedback report from the ACR. Following receipt of the feedback document from the ACR, interventions that resulted in improved performance could be solidified into permanent departmental guidelines. Performance areas that continued to need improvement could be identified and addressed. The project for that individual or radiology group could be closed at this point, or another cycle of measurement and reporting could be started.
Statistical Analysis Data submitted to the Intravenous Contrast Extravasation (ICE) registry were used to generate aggregates by facility, submission period, patient, and extravasation characteristics. Extravasation rates were calculated based on the reported numbers of contrast injections and CT extravasations. For facilities that submitted 2 periods of data, extravasation rates, extravasation volumes, and severity of injury were compared across the 2 periods. The association of patient and exam characteristics with severity of injury was tabulated and examined for statistical significance using chi-squared tests. All analyses were performed using SAS 9.2 and Excel.
RESULTS All Participating Facilities Data—Benchmark Metrics Initial data collection for the registry started in February 2009. Data from 58 radiology practices through December 31, 2013 Journal of the American College of Radiology Volume 12 n Number 2 n February 2015
that enrolled in this PQI project were included in the analysis. The facilities included community, academic, metropolitan, and rural practices, with a national distribution (Fig. 2). Extravasation rate. There were a total of 454,497 contrastenhanced CT exams and 1,085 extravasation events (Table 1). The extravasation rate was 0.24%. The median extravasation rate for all facilities combined was 0.21%. The 25th percentile extravasation rate for all groups was 0.12%; the 75th percentile rate was 0.31%. Estimated volume extravasated. A total of 56 (5.2%) patients had 0-9 mL extravasated; 554 (51.1%) patients had 10-49 mL extravasated; 345 (31.8%) patients had 50-99 mL extravasated; and 130 (12.0%) patients had 100 mL extravasated (Table 1). Severity of injury. Severity of injury was assessed at 2 weeks following the extravasation event. There were 314 reports that either did not include an evaluation of severity
of injury, or there was no follow-up available to assess the severity of injury. Of the remaining 771 extravasation events that did have evaluations for severity of injury, 729 (94.6%) patients experienced mild extravasation injuries, 36 (4.7%) experienced moderate injuries, and 6 (0.8%) experienced severe injuries (Table 1).
Facilities That Completed 2 Measurement Cycles/ Quality Improvement—Benchmark Metrics Of the 58 participating practices, 32 have completed the 2step PQI cycle. Of the 26 practices that have not completed the second phase of the PQI project, 20 are partway through the process, and 6 have discontinued participation. These 6 practices discontinued participation for a variety of reasons including departure of the lead physician from the practice and lack of institutional support. Table 2 represents the data from the 32 facilities that have completed the 2-step PQI cycle and compares the 3 major performance metrics from the first
Fig 2. Demographics of participating facilities. Journal of the American College of Radiology Dykes, Bhargavan-Chatfield, Dyer n Contrast Extravasation During CT
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Table 1. Benchmark metrics for all participants
Number of CT scans Number of extravasations Mean extravasation rate Estimated volume extravasated, mL 0-9 10-49 50-99 100 Severity of injury* Mild Moderate Severe
All Participating Facilities, N¼58 Overall 454,497 1,085 0.24% Number Percent 56 554 345 130
5.2 51.1 31.8 12.0
729 36 6
94.6 4.7 0.8
*There was either no report of severity of injury or no follow-up available for 314 events to assess severity of injury. These 314 events were excluded from the severity-of-injury analysis.
6-month cycle to the second 6-month measurement cycle after implementation of performance-improvement steps to assess the effectiveness of applying PQI principles. Extravasation rate. For the 32 practices that have completed the 2-step PQI cycle, there were 166,193 enhanced CT scans and 469 extravasations, for an average extravasation rate of 0.28% during the first 6-month measurement period. In the second 6-month measurement period, there were 163,100 contrast-enhanced CT exams and 374 extravasations, for an average extravasation rate of 0.23%. The median extravasation rate for the first 6-month measurement period was 0.25%; for the second 6-month measurement period, it was 0.16%. Of the 32 facilities that completed the 2-step PQI project, 23 had a decrease in the extravasation rate. These changes between the first and second measurement periods were not statistically significant. Estimated volume extravasated. For the first 6-month measurement cycle, the volumes of extravasation for the 469 extravasation events were 25 (5.3%) patients with 0-9 mL, 240 (51.2%) patients with 10-49 mL, 149 (31.8%) with 50-99 mL, and 55 (11.7%) with 100 mL. In the second 6-month measurement cycle, the volumes of extravasation for the 374 extravasation events were 18 (4.8%) patients with 0-9 mL, 198 (52.9%) patients with 1049 mL, 118 (31.6%) patients with 50-99 mL, and 40 (10.7%) patients with 100 mL. These changes between the first and second measurement periods were not statistically significant. Severity of injury. For the first 6-month measurement cycle, 125 patients had either no follow-up for or no entry for severity of injury, leaving 344 patients for whom severity 186
Table 2. Observations from facilities that have completed 2 cycles, N¼32 Initial Period Evaluation* Number of CT scans 166,193 Number of extravasations 469 Mean extravasation rate 0.28% Number Percent Estimated volume extravasated, mL 0-9 25 5.3 10-49 240 51.2 50-99 149 31.8 100 55 11.7 Severity of injury‡ Mild 331 96.2 Moderate 11 3.2 Severe 2 0.6
Second Period Evaluation† 163,100 374 0.23% Number Percent
18 198 118 40
4.8 52.9 31.6 10.7
261 10 1
96.0 3.7 0.4
*Initial measurement period; first 6 months of data collection before application of quality-improvement steps. † Second measurement period after feedback report from the ACR’s practice review and application of quality-improvement steps. ‡ Events for which there was no report of severity of injury, or no follow-up available (125 events in the first 6 months and 102 events in the second 6 months) to assess severity of injury, were excluded from severity-of-injury statistics.
of injury was assessed. A total of 331 (96.2%) patients had mild injury; 11 (3.2%) had moderate injury; and 2 (0.4%) had severe injury. In the second 6-month measurement cycle, 102 patients had either no follow-up for or no entry for severity of injury, leaving 272 patients for whom severity of injury was assessed. A total of 261 (96.0%) patients had mild injury; 10 (3.7%) had moderate injury; and 1 (0.4%) had severe injury. These changes between the first and second measurement periods were not statistically significant.
All Participating Facilities Data—Patient Demographics, Exam Characteristics, and Patient Risk Factors for Extravasation Events Patient age. Eight (0.7%) patients were age 9 years; 25 (2.3%) were age 10-19 years; 56 (5.2%) were age 20-29 years; 84 (7.7%) were age 30-39 years; 130 (12.0%) were age 40-49 years; 198 (18.2%) were age 50-59 years; 221 (20.4%) were age 60-69 years; 190 (17.5%) were age 70-79 years; and 173 (15.9%) were age 80 years. Patient gender. A total of 714 (65.8%) patients were female; 371 (34.2%) were male. Patient status. A total of 409 (37.7%) patients were in the emergency department; 324 (29.9%) were inpatients; and Journal of the American College of Radiology Volume 12 n Number 2 n February 2015
350 (32.3%) were outpatients. Two (0.2%) patients were categorized as other. Injection method. A total of 1,066 (98.2%) patients had mechanical injection; 19 (1.8%) had hand injection. Contrast type. A total of 294 (27.1%) patients had iopamidol (Isovue); 489 (45.1%) had iohexal (Omnipaque); 200 (18.4%) had ioversol (Optiray); 20 (1.8%) had iopromide (Ultravist); and 82 (7.6%) had iodixanol (Visipaque). Injection rate. Ten (0.9%) patients had an injection rate of 0.1-0.9 mL/sec; 209 (19.3%) had a rate of 1.0-1.9 mL/sec; 303 (27.9%) had a rate of 2.0-2.9 mL/sec; 219 (20.2%) had a rate of 3.0-3.9 mL/sec; and 344 (31.7%) had a rate of 4.0 mL/sec. Catheter gauge. Fifteen (1.4%) patients had a 16G catheter; 147 (13.5%) had an 18G catheter; 2 (0.2%) had a 19G catheter; 594 (54.7%) had a 20G catheter; 5 (0.5%) had a 21G catheter; 292 (26.9%) had a 22G catheter; and 30 (2.8%) had a 22G catheter. Catheter type. A total of 1,033 (95.2%) patients had an angiocatheter; 43 (4.0%) had a butterfly type; and 9 (0.8%) had a central line or peripherally inserted central catheter. Catheter location. A total of 661 (60.9%) patients had the catheter in the antecubital fossa; 189 (17.4%) had it in the forearm; 88 (8.1%) had it in the hand; 43 (4.0%) had it in
the wrist; 43 (4.0%) had it in the brachial region; and 1 (0.1%) had it in the foot. Fifty-seven (5.3%) patients had the catheter in other locations. Service that placed the catheter. A total of 344 (31.7%) patients had the catheter placed by radiology personnel; 741 (68.3%) patients had the catheter placed by nonradiology personnel. Extravasation detection accessory. Extravasation detection accessories (EDAs) are add-on devices designed to detect local soft-tissue extravasations from in-dwelling vascular catheters and automatically terminate the injection before large volumes of extravasate occur. Eighty-eight (8.1%) patients had use of an EDA, and 997 (91.9%) patients did not have use of such a device. In events that did involve use of an EDA, 8 (9%) patients had 0-9 mL extravasated; 48 (55%) had 10-49 mL; 28 (32%) had 50-99 mL; and 4 (5%) had 100 mL extravasated. Figure 3 compares the volumes of extravasation between patients for whom an EDA was used and those for whom no EDA was used. A statistically significant association was found between use of an EDA and a shift to lower volumes of extravasate (P ¼ .05). Complete versus partial extravasation. Partway through this project, this data element was added. Entries for this element came from a total of 603 patients. A total of 221 (36.7%) patients had complete extravasation defined as no intravascular contrast on the CT exam. A total of 382
Fig 3. Volume of extravasate: No extravasation detection accessory versus use of an extravasation detection accessory. Journal of the American College of Radiology Dykes, Bhargavan-Chatfield, Dyer n Contrast Extravasation During CT
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(63.3%) had partial extravasation defined as some intravascular contrast on the CT exam. Risk factors for extravasation. More than 1 specific risk factor could be selected for each extravasation event. A total of 697(64.2%) patients had some risk factor identified for the extravasation event, and 388 (35.8%) had no risk factors identified. The most common risk factor identified was difficulty with IV access or multiple venipunctures, reported in 663 (61.1%) patients. Other risk factors reported include lymphedema or limb swelling in 34 (3.1%) patients, arterial or venous insufficiency to the affected limb in 18 (1.7%) patients, and other unspecified risk factors in 106 (9.8%) patients. Initial signs and symptoms of extravasation. More than one presenting sign or symptom could be reported for each extravasation event. A total of 107 (8.1%) patients presented with no signs or symptoms. Soft-tissue swelling was the most common presenting sign, reported in 861 (79.4%) patients. Pain was the most common presenting symptom, found in 434 (40.0%) patients. Other reported signs and symptoms include skin erythema in 86 (7.9%) patients, skin induration in 70 (6.5%) patients, decreased perfusion in 21 (1.9%) patients, skin blistering or ulceration in 4 (0.4%) patients, and compartment syndrome in 2 (0.2%) patients. Sixty-nine (6.4%) had other unspecified presenting signs or symptoms. Initial interventions. More than one intervention could be selected for each extravasation event. A total of 407 (37.5%) patients had hot compresses; 588 (54.2%) had cold compresses; and 65 (6.0%) had both hot and cold compresses. Three hundred forty-one (31.4%) patients had extremity elevation. Surgical consultation was sought for 19 (1.8%) patients. No interventions were reported in 64 (5.9%) patients. Of the 350 outpatients, 138 (39.4%) had observation as an initial intervention. Of these 138 patients, 39 (28.3%) had <1 hour; 44 (31.9%) had 1-2 hours; 35 (25.4%) had 23 hours; 4 (2.9%) had 2-3 hours; and 16 (11.6%) had 4 hours. Correlation of Patient Demographics and Exam Characteristics with Severity of Injury. A total of 771 patients had an assessment for the severity of injury from the extravasation event. Of those patients, 729 (94.6%) had mild injuries, and 42 (5.4%) had moderate-to-severe injuries. Moderate and severe injuries were grouped together for statistical analysis because of the relatively small number of these more significant injuries. No statistically significant correlation was found between severity of injury and patient age, gender, hospital status, injection method, contrast type, injection rate, catheter type, 188
catheter location, use of an extravasation detection device, or service that placed the catheter. A statistically significant association (Table 3) was found between volume of extravasate and severity of injury (P < .0001). A weak correlation was found between use of an 18G catheter (P ¼ .0923) and severity of injury. Six patients had severe injuries (Table 4); an angiocatheter was used for all 6, and none used an EDA.
DISCUSSION This study is the largest single series reporting IV contrast extravasation injuries to date, with 454,497 enhanced CT exams and 1,085 reported extravasation events from 58 diverse radiology practices across the United States. The range of average extravasation rates for practices in this project (0.15%-0.70%) is similar to those reported in previous series [1- 3]. The combined mean extravasation rate of 0.24% is lower than those in previous reports of 0.45% [2] and 0.70% [3]. Practices with extravasation rates between 0.12% and 0.31% fall within the 25th and 75th percentile of all participating practices. Larger volumes of extravasation are generally thought to be associated with a higher risk of moderate-to-severe extravasation injuries [1,3-5]; this view is supported by the data in this study with a statistically significant correlation between volume of extravasate and severity of injury (P < .0001). This is the basis for efforts to detect contrast extravasation as early as possible during contrast injection and for stopping the injection to minimize the volume of extravasation. Figure 4 compares the distribution of volumes of extravasate from our multi-institutional series with 2 previous studies [3,6]. The most frequent volume range of extravasation is the same in all 3 series, 10-49 mL. This range is similar to the average extravasation volume reported in the study by Jacobs et al [7] of 41 mL. However, our series had a larger percentage of extravasations (32%) in the 50-99 mL range, compared with 12% in Wang’s [3] series and 23% in Cochran’s [6] series. Forty-four percent of extravasations in our series involved volumes of 50 mL, higher compared with the series by Wang [3] (26%) and Cochran [6] (37%).
Table 3. Correlation of severity of injury with volume of extravasate* Estimated volume extravasated (mL) 0e9 10e49 50e99 100 Total
Severity of Injury (# of Patients) Mild Moderate/Severe Total 38 0 38 398 10 408 217 17 234 76 15 91 729 42 771
*P < .0001.
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Table 4. Patients with severe injuries Age Patient (years) Gender 1 56 Male 2 64 Female 3 35 Male 4 53 Female 5 10 Male 6 24 Female
Status IP IP IP OP ED ED
Injection Rate Catheter Radiology Volume Extravasated Surgical (mL/sec) Gauge Location Placed Catheter (mL) Procedure 2 18 AC No 150 Yes 4 20 HA No 60 No 2.5 22 AC Yes 98 No 2.5 20 AC Yes 75 No 2.5 20 AC No 100 No 2 22 AC No 80 No
Note: IP ¼ inpatient; OP ¼ outpatient; ED ¼ emergency department; AC ¼ antecubital; HA ¼ hand.
EDA technology has been previously reported [8,9] to reliably decrease the volumes of extravasation when an extravasation event occurs. These devices were used in 88 extravasation events reported in our study. The 88 extravasation events in which an EDA was used, compared with those events in which an EDA was not used, does show a downward trend (Fig. 3) in estimated extravasation volume with statistical significance (chi-squared P ¼ .05). The experience in our series with EDAs, however, is unlike that previously reported in the literature [8,9]. In Powell’s study [9] with injection of saline and dextrose into volunteers, the EDA successfully stopped the injection in all 82 patients at injection rates typically used for diagnostic CT exams, and the average volume of extravasation was 12.5 mL. In Birnbaum’s study [8], the EDA had 100% sensitivity, stopping the 4 confirmed extravasations with a maximum volume of extravasation of 18 mL. In our series, the EDAs did shift the volumes of extravasation toward smaller volumes, but there were still patients with relatively large volumes of extravasate; 28 (32%) patients with 50-99 mL, and 4 (5%) with >100 mL. This study confirms the findings of several previous studies [3-5,7,10-13] that the great majority of extravasation
events result in mild, transient injuries and can be managed conservatively. Some earlier literature [14,15] on management of extravasation injuries suggested that aggressive management and intervention was indicated to prevent longterm sequelae. More recent literature and this series do not support this recommendation. A total of 729 extravasation injuries (94.6%) were graded as mild, 36 (4.7%) as moderate, and 6 (0.8%) as severe. Only 19 (1.8%) had surgical consultation, and only 1 patient required a surgical procedure. The only patient demographic factor or exam characteristic that had a statistically significant correlation with moderate/severe injuries was the volume of extravasate. Our series confirms the findings by Wang et al [3] that using a volume-of-extravasation threshold to predict severity of injury is problematic, as moderate and severe injuries occurred in volumes from 10 mL to >100 mL, although all 6 patients with severe injuries did have extravasation volumes >50 mL, and the 1 patient that required a surgical procedure had an extravasation volume of 150 mL. The necessity for surgical consultation should be based on the signs and symptoms of extravasation and not on a volume threshold [1].
Fig 4. Distribution of volumes of extravasate: Data are from Dykes (current study), Wang et al [3], and Cochran et al [6]. Journal of the American College of Radiology Dykes, Bhargavan-Chatfield, Dyer n Contrast Extravasation During CT
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Of the 350 outpatients who experienced an extravasation event, 138 (39.4%) had observation as an initial intervention. This finding is remarkable given that the ACR Manual on Contrast Media [1] and guidelines published by the European Society of Uroradiology (ESUR) [5,16], and opinions from experts in the field of uroradiology [17-19] state that careful monitoring of the patient after an extravasation event is needed because the severity of an injury is difficult to determine on initial presentation. These sources also indicate that outpatients who have suffered an extravasation injury should be released from the care of a radiologist only after the physician determines that any signs and symptoms that were initially present have resolved or improved, and no new symptoms suggest a more serious injury, such as compartment syndrome. Thirty-two groups completed the 2-step PQI cycle. The application of PQI principles resulted in no statistically significant improvement for the 3 core benchmarks in the composite data of these 32 practices: extravasation rate, distribution of volume of extravasation, and severity of injury. The data collected in this quality improvement project did not include information on interventions and departmental policies that could, if applied, have a positive impact on these benchmarks, including adequate training of personnel, appropriate vein selection for cannulation, adequate catheter length and caliber, and appropriate monitoring of the injection site. All these intervetions and others would be excellent subjects for future investigations. Technologies such as EDAs do have a statistically significant but modest positive impact on lowering extravasation volumes when an event occurs, but not to the same degree as initially reported.
Limitations Our study has important limitations. First, it is retrospective and entirely dependent on the accuracy of data entered into the NRDR database by several different and diverse practices. No data audit or site visit was conducted to verify accuracy of data submitted by the participating practices. Each project administrator has access to guidelines and data definitions, and the contrast-extravasation reporting form includes data definitions. Second, estimation of the volume of extravasation is difficult unless the entire injection was completed and there is no intravenous contrast on the exam. However, the distribution of extravasation volumes in our study is similar to those found in previous studies, suggesting that we used a methodology similar to that used by other investigators. Third, assessment of severity of injury is subjective even with clearly defined criteria. Again, our distribution of severity of injury is very similar to those found in previous studies. Fourth, participation in this study is voluntary and introduces the possibility of selection bias. 190
Practices that already know they do not perform well may opt to not participate. Last, nearly 29% of events did not have adequate followup to determine severity of injury. Although the number of these cases that would have been characterized as moderate injuries is unclear, they probably would not alter the reported numbers of severe injuries, because patients that have severe injuries or surgical interventions typically are closely followed and reported to risk management.
Summary This large, multi-institutional study on intravenous, iodinated contrast material extravasation during CT establishes practice performance benchmarks for average extravasation rate, distribution of extravasation volumes, and distribution of severity of injuries from an extravasation event. It is the first time a large data registry, in this case the NRDR, has been utilized to collect information and metrics on extravasation events from multiple, diverse practices across the country. It is also the first, multiinstitutional application and review of PQI principles in contrast extravasation to determine the impact of the use of PQI on practice performance benchmarks.
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This study confirms previous data that the extravasation rate ranges between 0.15% and 0.70%, with a mean extravasation rate of 0.24% and median of 0.21%. The distribution of volumes of contrast extravasation is similar to that found in previously published studies, with 51% of extravasation volumes falling between 10 mL and 49 mL, and 32% between 50 mL and 99 mL. Mild injuries occurred in 94.6% of extravasations, with only 4.7% of patients having moderate injuries, and 0.8% having severe injuries; conservative management is appropriate in most cases. Our data suggest that larger extravasated contrast volumes correlate with moderate-to-severe injuries, but like other studies, it does not support using a volume threshold to determine referral to surgical specialties or more aggressive management.
ACKNOWLEDGMENTS The authors thank those practices that have participated in the project and provided practice data that form the basis of this article.
ADDITIONAL RESOURCES IV Contrast Extravasation Reporting Form (Figure 1) can be found online at http://www.jacr.org/article/S1546-1440(14) 00408-6/full text. Journal of the American College of Radiology Volume 12 n Number 2 n February 2015
REFERENCES 1. ACR Committee on Drugs and Contrast Media. Extravasation of contrast media. In: ACR Manual on Contrast Media 2013, version 9. Reston, VA: ACR; 2013:17-9. Available at: http://www.acr.org/ Quality-Safety/Resources/Contrast-Manual. Accessed August 8, 2014. 2. Chew FS. Extravasation of iodinated contrast medium during CT: selfassessment module. AJR Am J Roentgenol 2010;195:S80-5. 3. Wang CL, Cohan RH, Ellis JH, et al. Frequency, management, and outcome of extravasation of non-ionic iodinated contrast medium in 69,657 intravenous injections. Radiology 2007;243:80-7. 4. Schaverien MV, Evison D, McCulley SJ. Management of large volume CT contrast medium extravasation injury: technical refinement and literature review. J Plastic. Reconstr Aesthetic Surg 2008;61: 562-5. 5. Bellin M, Jakobsen JA, Tomassin I, et al. Contrast medium extravasation injury: guidelines for prevention and management. Eur Radiol 2002;12:2807-12. 6. Cochran ST, Bomyea K, Kahn M. Treatment of iodinated contrast material extravasation with hyaluronidase. Acad Radiol 2002;9:S544-6. 7. Jacobs JE, Birnbaum BA, Langlotz CP. Contrast media reactions and extravasation: relationship to intravenous injection rates. Radiology 1998;209:411-6. 8. Birnbaum BA, Nelson RC, Chezmar JL, et al. Extravasation detection accessory: clinical evaluation in 500 patients. Radiology 1999;212:431-8.
9. Powell CC, Li JM, Rodino L, Anderson FA. A new device to limit extravasation during contrast-enhanced CT. AJR Am J Roentgenol 2000;174:315-8. 10. Federle MP, Chang PJ, Confer S, Ozgun B. Frequency and effects of ionic and nonionic CT contrast media during rapid bolus injection. Radiology 1998;206:637-40. 11. Sum W, Ridley LJ. Recognition and management of contrast media extravasation. Australas Radiol 2006;50:549-52. 12. Sistrom CL, Gay SB, Peffley L. Extravasation of iopamidol and iohexol during contrast-enhanced CT: report of 28 cases. Radiology 1991;180: 707-10. 13. Cohan RH, Dunnick NR, Leder RA, Baker ME. Extravasation of nonionic radiologic contrast media: efficacy of conservative treatment. Radiology 1990;176:65-7. 14. Gault DT. Extravasation injuries. Brit J Plastic Surg 1993;46:91-6. 15. Loth TS, Jones CDE. Extravasation of radiographic contrast material in the upper extremity. J Hand Surg [Am] 1988;13:395-8. 16. European Society of Urogenital Radiology. Guidelines on contrast media. Available at: http://www.esur.org/guidelines/en/index.php. Accessed March 17, 2014. 17. Memolo M, Dyer R, Zagoria RJ. Extravasation injury with non-ionic contrast material. AJR Am J Roentgenol 1993;160:203. 18. Cohan RH, Ellis JH, Garner WL. Extravasation of radiographic contrast material: recognition, prevention, and treatment. Radiology 1996;200:593-604. 19. Lang EV. Questions and answers. AJR Am J Roentgenol 1996;167:277.
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Intravenous Contrast Extravasation During CT: A National Data Registry and Practice Quality Improvement Initiative Thomas M. Dykes, MDa, Mythreyi Bhargavan-Chatfield, PhDb, Raymond B. Dyer, MDc Abstract Purpose: Establish 3 performance benchmarks for intravenous contrast extravasation during CT examinations: extravasation frequency, distribution of extravasation volumes, and severity of injury. Evaluate the effectiveness of implementing practice quality improvement (PQI) methodology in improving performance for these 3 benchmarks. Methods: The Society of Abdominal Radiology and ACR developed a registry collecting data for contrast extravasation events. The project includes a PQI initiative allowing for process improvement. Results: As of December 2013, a total of 58 radiology practices have participated in this project, and 32 practices have completed the 2cycle PQI. There were a total of 454,497 contrast-enhanced CT exams and 1,085 extravasation events. The average extravasation rate is 0.24%. The median extravasation rate is 0.21%. Most extravasations (82.9%) were between 10 mL and 99 mL. The majority of injuries, 94.6%, are mild in severity, with 4.7% having moderate and 0.8% having severe injuries. Data from practices that completed the PQI process showed a change in the average extravasation rate from 0.28% in the first 6 months to 0.23% in the second 6 months, and the median extravasation rate dropped from 0.25% to 0.16%, neither statistically significant. The distribution of extravasation volumes and the severity of injury did not change between the first and second measurement periods. Conclusions: National performance benchmarks for contrast extravasation rate, distribution of volumes of extravasate, and distribution of severity of injury are established through this multi-institutional practice registry. The application of PQI failed to have a statistically significant positive impact on any of the 3 benchmarks. Key Words: Contrast extravasation, CT, National Radiology Data Registry, practice quality improvement J Am Coll Radiol 2015;12:183-191. Copyright 2015 American College of Radiology
INTRODUCTION Intravenous iodinated contrast material extravasation during CT exams using an automated power injector is a commonly encountered complication in busy radiology practices. The incidence of extravasation, as reported in the literature, ranges between 0.1% and 0.9% of all contrast-enhanced CT exams [1]. An aggregate extravasation rate of 0.45% was reported based on a review of 6 series published between 1991 and 2007 that included 867 extravasation events in 190,656 enhanced CT exams [2]. Based on these statistics, a radiology practice that performs 12,000 contrast-enhanced CT exams a
Department of Radiology, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania. b ACR, Reston, Virginia. c Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina. Corresponding author and reprints: Thomas M. Dykes, MD, Department of Radiology, H066, 500 University Drive, P.O. Box 850, Hershey, PA 17033-00850; e-mail: [email protected].
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annually could expect to see 54 extravasations in 1 year, or about 1 extravasation event per week. The Society of Abdominal Radiology (SAR) and the ACR co-developed a practice quality improvement project (PQI) on contrast extravasation that occurs during CT examinations. The primary purpose of this project was to develop 3 national performance benchmarks for intravenous, iodinated contrast extravasation during CT examinations: frequency of extravasation, distribution of extravasation volumes, and distribution of severity of extravasation injury. Previous studies largely reflect the practice experience of a few large, teaching institutions or small series and case reports from a single practice. This is the first multi-institutional study that gathered data from diverse practice groups from across the United States, including both academic and nonacademic settings. A second purpose for this project was to evaluate the effectiveness of implementing PQI methodology in improving performance in contrast extravasation that occurs during contrast-enhanced CT examinations for these 3 benchmarks.
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Participation in this project allows radiology practices to contribute data to the project and also compare their performance to the 3 benchmarks mentioned earlier selected by the SAR and the ACR. The project also allows the participating radiologist or group to review an educational feedback document prepared by the SAR and ACR that outlines practice recommendations and standards gathered from the ACR Manual on Contrast Media [1] and other key literature references; identify areas of performance that need improvement in regard to contrast extravasation; implement improvement strategies; and assess performance a second time to determine if the improvement strategies were effective. Completion of the 2-cycle PQI project offers the participant(s) PQI credit for the maintenance-of-certification requirement from the ABR. The ABR has “pre-approved” successful completion of this project as satisfying the PQI requirement for certification maintenance when it is combined with completion of the PQI attestation in their ABR personal database.
METHODS Data collection was performed under the umbrella of the ACR National Radiology Data Registry (NRDR). The data submitted are anonymous, and this project has an institutional review board certification of exemption under Section 101(b), paragraph 4. The SAR, through consultation with subject matter experts and with their board of directors, developed an online data entry form, established the reporting guidelines and definitions, and selected the performance benchmarks to report to the radiology practices. Enrollment in the project for the participant(s) requires online registration for the group with the ACR NRDR. Registration requires selection and identification of a facility administrator who is responsible for enrolling the participating radiologists seeking PQI credit, selecting the starting date for each 6-month reporting period, collecting and verifying data reported for each extravasation event during the reporting period, and reporting the total number of contrastenhanced CT exams performed during the reporting period. The ACReNRDR website includes an IV (intravenous) Contrast Extravasation Registry User Guide and an IV Contrast Extravasation Registry Data Dictionary containing detailed instructions on completing the reporting forms and definitions (http://www.acr.org/Quality-Safety/National-RadiologyData-Registry/IV-Contrast-Extravasation). The IV Contrast Extravasation Reporting Form (Fig. 1 online) also contains embedded instructions and definitions. Ensuring the validity of data entered is the responsibility of the facility administrator and the participating physicians. There is no external reviewer or site visit by a monitor to validate data. 184
Six months of initial data collection are reported using the online IV Contrast Extravasation Form in the NRDR database. In addition to data on extravasations, facilities report the number of IV contrast injections administered for CT exams during the same period. Following the initial 6 months of data collection, a feedback document is sent to the participating facility. This document includes educational materials prepared by the SAR that summarize the literature on contrast extravasation and an institution-specific report summary tabulating the practice-specific data entered from the IV Contrast Extravasation Form. During initial implementation of this project, the participating facility’s performance was compared to previously reported results from a large, retrospective study [3] in 3 areas: contrast extravasation rate, estimated contrast volume extravasated, and severity of injury. After the project was more mature, and utilizing several months of data collection that included data and results from multiple institutions, benchmark metrics were based on the results available within the registry. Following receipt of the first 6-month feedback document from the ACR, the individual or group self-identified deficiencies and areas that needed improvement and implemented steps for process improvement. Data were collected and submitted to NRDR for a second 6-month period followed by a second feedback report from the ACR. Following receipt of the feedback document from the ACR, interventions that resulted in improved performance could be solidified into permanent departmental guidelines. Performance areas that continued to need improvement could be identified and addressed. The project for that individual or radiology group could be closed at this point, or another cycle of measurement and reporting could be started.
Statistical Analysis Data submitted to the Intravenous Contrast Extravasation (ICE) registry were used to generate aggregates by facility, submission period, patient, and extravasation characteristics. Extravasation rates were calculated based on the reported numbers of contrast injections and CT extravasations. For facilities that submitted 2 periods of data, extravasation rates, extravasation volumes, and severity of injury were compared across the 2 periods. The association of patient and exam characteristics with severity of injury was tabulated and examined for statistical significance using chi-squared tests. All analyses were performed using SAS 9.2 and Excel.
RESULTS All Participating Facilities Data—Benchmark Metrics Initial data collection for the registry started in February 2009. Data from 58 radiology practices through December 31, 2013 Journal of the American College of Radiology Volume 12 n Number 2 n February 2015
that enrolled in this PQI project were included in the analysis. The facilities included community, academic, metropolitan, and rural practices, with a national distribution (Fig. 2). Extravasation rate. There were a total of 454,497 contrastenhanced CT exams and 1,085 extravasation events (Table 1). The extravasation rate was 0.24%. The median extravasation rate for all facilities combined was 0.21%. The 25th percentile extravasation rate for all groups was 0.12%; the 75th percentile rate was 0.31%. Estimated volume extravasated. A total of 56 (5.2%) patients had 0-9 mL extravasated; 554 (51.1%) patients had 10-49 mL extravasated; 345 (31.8%) patients had 50-99 mL extravasated; and 130 (12.0%) patients had 100 mL extravasated (Table 1). Severity of injury. Severity of injury was assessed at 2 weeks following the extravasation event. There were 314 reports that either did not include an evaluation of severity
of injury, or there was no follow-up available to assess the severity of injury. Of the remaining 771 extravasation events that did have evaluations for severity of injury, 729 (94.6%) patients experienced mild extravasation injuries, 36 (4.7%) experienced moderate injuries, and 6 (0.8%) experienced severe injuries (Table 1).
Facilities That Completed 2 Measurement Cycles/ Quality Improvement—Benchmark Metrics Of the 58 participating practices, 32 have completed the 2step PQI cycle. Of the 26 practices that have not completed the second phase of the PQI project, 20 are partway through the process, and 6 have discontinued participation. These 6 practices discontinued participation for a variety of reasons including departure of the lead physician from the practice and lack of institutional support. Table 2 represents the data from the 32 facilities that have completed the 2-step PQI cycle and compares the 3 major performance metrics from the first
Fig 2. Demographics of participating facilities. Journal of the American College of Radiology Dykes, Bhargavan-Chatfield, Dyer n Contrast Extravasation During CT
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Table 1. Benchmark metrics for all participants
Number of CT scans Number of extravasations Mean extravasation rate Estimated volume extravasated, mL 0-9 10-49 50-99 100 Severity of injury* Mild Moderate Severe
All Participating Facilities, N¼58 Overall 454,497 1,085 0.24% Number Percent 56 554 345 130
5.2 51.1 31.8 12.0
729 36 6
94.6 4.7 0.8
*There was either no report of severity of injury or no follow-up available for 314 events to assess severity of injury. These 314 events were excluded from the severity-of-injury analysis.
6-month cycle to the second 6-month measurement cycle after implementation of performance-improvement steps to assess the effectiveness of applying PQI principles. Extravasation rate. For the 32 practices that have completed the 2-step PQI cycle, there were 166,193 enhanced CT scans and 469 extravasations, for an average extravasation rate of 0.28% during the first 6-month measurement period. In the second 6-month measurement period, there were 163,100 contrast-enhanced CT exams and 374 extravasations, for an average extravasation rate of 0.23%. The median extravasation rate for the first 6-month measurement period was 0.25%; for the second 6-month measurement period, it was 0.16%. Of the 32 facilities that completed the 2-step PQI project, 23 had a decrease in the extravasation rate. These changes between the first and second measurement periods were not statistically significant. Estimated volume extravasated. For the first 6-month measurement cycle, the volumes of extravasation for the 469 extravasation events were 25 (5.3%) patients with 0-9 mL, 240 (51.2%) patients with 10-49 mL, 149 (31.8%) with 50-99 mL, and 55 (11.7%) with 100 mL. In the second 6-month measurement cycle, the volumes of extravasation for the 374 extravasation events were 18 (4.8%) patients with 0-9 mL, 198 (52.9%) patients with 1049 mL, 118 (31.6%) patients with 50-99 mL, and 40 (10.7%) patients with 100 mL. These changes between the first and second measurement periods were not statistically significant. Severity of injury. For the first 6-month measurement cycle, 125 patients had either no follow-up for or no entry for severity of injury, leaving 344 patients for whom severity 186
Table 2. Observations from facilities that have completed 2 cycles, N¼32 Initial Period Evaluation* Number of CT scans 166,193 Number of extravasations 469 Mean extravasation rate 0.28% Number Percent Estimated volume extravasated, mL 0-9 25 5.3 10-49 240 51.2 50-99 149 31.8 100 55 11.7 Severity of injury‡ Mild 331 96.2 Moderate 11 3.2 Severe 2 0.6
Second Period Evaluation† 163,100 374 0.23% Number Percent
18 198 118 40
4.8 52.9 31.6 10.7
261 10 1
96.0 3.7 0.4
*Initial measurement period; first 6 months of data collection before application of quality-improvement steps. † Second measurement period after feedback report from the ACR’s practice review and application of quality-improvement steps. ‡ Events for which there was no report of severity of injury, or no follow-up available (125 events in the first 6 months and 102 events in the second 6 months) to assess severity of injury, were excluded from severity-of-injury statistics.
of injury was assessed. A total of 331 (96.2%) patients had mild injury; 11 (3.2%) had moderate injury; and 2 (0.4%) had severe injury. In the second 6-month measurement cycle, 102 patients had either no follow-up for or no entry for severity of injury, leaving 272 patients for whom severity of injury was assessed. A total of 261 (96.0%) patients had mild injury; 10 (3.7%) had moderate injury; and 1 (0.4%) had severe injury. These changes between the first and second measurement periods were not statistically significant.
All Participating Facilities Data—Patient Demographics, Exam Characteristics, and Patient Risk Factors for Extravasation Events Patient age. Eight (0.7%) patients were age 9 years; 25 (2.3%) were age 10-19 years; 56 (5.2%) were age 20-29 years; 84 (7.7%) were age 30-39 years; 130 (12.0%) were age 40-49 years; 198 (18.2%) were age 50-59 years; 221 (20.4%) were age 60-69 years; 190 (17.5%) were age 70-79 years; and 173 (15.9%) were age 80 years. Patient gender. A total of 714 (65.8%) patients were female; 371 (34.2%) were male. Patient status. A total of 409 (37.7%) patients were in the emergency department; 324 (29.9%) were inpatients; and Journal of the American College of Radiology Volume 12 n Number 2 n February 2015
350 (32.3%) were outpatients. Two (0.2%) patients were categorized as other. Injection method. A total of 1,066 (98.2%) patients had mechanical injection; 19 (1.8%) had hand injection. Contrast type. A total of 294 (27.1%) patients had iopamidol (Isovue); 489 (45.1%) had iohexal (Omnipaque); 200 (18.4%) had ioversol (Optiray); 20 (1.8%) had iopromide (Ultravist); and 82 (7.6%) had iodixanol (Visipaque). Injection rate. Ten (0.9%) patients had an injection rate of 0.1-0.9 mL/sec; 209 (19.3%) had a rate of 1.0-1.9 mL/sec; 303 (27.9%) had a rate of 2.0-2.9 mL/sec; 219 (20.2%) had a rate of 3.0-3.9 mL/sec; and 344 (31.7%) had a rate of 4.0 mL/sec. Catheter gauge. Fifteen (1.4%) patients had a 16G catheter; 147 (13.5%) had an 18G catheter; 2 (0.2%) had a 19G catheter; 594 (54.7%) had a 20G catheter; 5 (0.5%) had a 21G catheter; 292 (26.9%) had a 22G catheter; and 30 (2.8%) had a 22G catheter. Catheter type. A total of 1,033 (95.2%) patients had an angiocatheter; 43 (4.0%) had a butterfly type; and 9 (0.8%) had a central line or peripherally inserted central catheter. Catheter location. A total of 661 (60.9%) patients had the catheter in the antecubital fossa; 189 (17.4%) had it in the forearm; 88 (8.1%) had it in the hand; 43 (4.0%) had it in
the wrist; 43 (4.0%) had it in the brachial region; and 1 (0.1%) had it in the foot. Fifty-seven (5.3%) patients had the catheter in other locations. Service that placed the catheter. A total of 344 (31.7%) patients had the catheter placed by radiology personnel; 741 (68.3%) patients had the catheter placed by nonradiology personnel. Extravasation detection accessory. Extravasation detection accessories (EDAs) are add-on devices designed to detect local soft-tissue extravasations from in-dwelling vascular catheters and automatically terminate the injection before large volumes of extravasate occur. Eighty-eight (8.1%) patients had use of an EDA, and 997 (91.9%) patients did not have use of such a device. In events that did involve use of an EDA, 8 (9%) patients had 0-9 mL extravasated; 48 (55%) had 10-49 mL; 28 (32%) had 50-99 mL; and 4 (5%) had 100 mL extravasated. Figure 3 compares the volumes of extravasation between patients for whom an EDA was used and those for whom no EDA was used. A statistically significant association was found between use of an EDA and a shift to lower volumes of extravasate (P ¼ .05). Complete versus partial extravasation. Partway through this project, this data element was added. Entries for this element came from a total of 603 patients. A total of 221 (36.7%) patients had complete extravasation defined as no intravascular contrast on the CT exam. A total of 382
Fig 3. Volume of extravasate: No extravasation detection accessory versus use of an extravasation detection accessory. Journal of the American College of Radiology Dykes, Bhargavan-Chatfield, Dyer n Contrast Extravasation During CT
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(63.3%) had partial extravasation defined as some intravascular contrast on the CT exam. Risk factors for extravasation. More than 1 specific risk factor could be selected for each extravasation event. A total of 697(64.2%) patients had some risk factor identified for the extravasation event, and 388 (35.8%) had no risk factors identified. The most common risk factor identified was difficulty with IV access or multiple venipunctures, reported in 663 (61.1%) patients. Other risk factors reported include lymphedema or limb swelling in 34 (3.1%) patients, arterial or venous insufficiency to the affected limb in 18 (1.7%) patients, and other unspecified risk factors in 106 (9.8%) patients. Initial signs and symptoms of extravasation. More than one presenting sign or symptom could be reported for each extravasation event. A total of 107 (8.1%) patients presented with no signs or symptoms. Soft-tissue swelling was the most common presenting sign, reported in 861 (79.4%) patients. Pain was the most common presenting symptom, found in 434 (40.0%) patients. Other reported signs and symptoms include skin erythema in 86 (7.9%) patients, skin induration in 70 (6.5%) patients, decreased perfusion in 21 (1.9%) patients, skin blistering or ulceration in 4 (0.4%) patients, and compartment syndrome in 2 (0.2%) patients. Sixty-nine (6.4%) had other unspecified presenting signs or symptoms. Initial interventions. More than one intervention could be selected for each extravasation event. A total of 407 (37.5%) patients had hot compresses; 588 (54.2%) had cold compresses; and 65 (6.0%) had both hot and cold compresses. Three hundred forty-one (31.4%) patients had extremity elevation. Surgical consultation was sought for 19 (1.8%) patients. No interventions were reported in 64 (5.9%) patients. Of the 350 outpatients, 138 (39.4%) had observation as an initial intervention. Of these 138 patients, 39 (28.3%) had <1 hour; 44 (31.9%) had 1-2 hours; 35 (25.4%) had 23 hours; 4 (2.9%) had 2-3 hours; and 16 (11.6%) had 4 hours. Correlation of Patient Demographics and Exam Characteristics with Severity of Injury. A total of 771 patients had an assessment for the severity of injury from the extravasation event. Of those patients, 729 (94.6%) had mild injuries, and 42 (5.4%) had moderate-to-severe injuries. Moderate and severe injuries were grouped together for statistical analysis because of the relatively small number of these more significant injuries. No statistically significant correlation was found between severity of injury and patient age, gender, hospital status, injection method, contrast type, injection rate, catheter type, 188
catheter location, use of an extravasation detection device, or service that placed the catheter. A statistically significant association (Table 3) was found between volume of extravasate and severity of injury (P < .0001). A weak correlation was found between use of an 18G catheter (P ¼ .0923) and severity of injury. Six patients had severe injuries (Table 4); an angiocatheter was used for all 6, and none used an EDA.
DISCUSSION This study is the largest single series reporting IV contrast extravasation injuries to date, with 454,497 enhanced CT exams and 1,085 reported extravasation events from 58 diverse radiology practices across the United States. The range of average extravasation rates for practices in this project (0.15%-0.70%) is similar to those reported in previous series [1- 3]. The combined mean extravasation rate of 0.24% is lower than those in previous reports of 0.45% [2] and 0.70% [3]. Practices with extravasation rates between 0.12% and 0.31% fall within the 25th and 75th percentile of all participating practices. Larger volumes of extravasation are generally thought to be associated with a higher risk of moderate-to-severe extravasation injuries [1,3-5]; this view is supported by the data in this study with a statistically significant correlation between volume of extravasate and severity of injury (P < .0001). This is the basis for efforts to detect contrast extravasation as early as possible during contrast injection and for stopping the injection to minimize the volume of extravasation. Figure 4 compares the distribution of volumes of extravasate from our multi-institutional series with 2 previous studies [3,6]. The most frequent volume range of extravasation is the same in all 3 series, 10-49 mL. This range is similar to the average extravasation volume reported in the study by Jacobs et al [7] of 41 mL. However, our series had a larger percentage of extravasations (32%) in the 50-99 mL range, compared with 12% in Wang’s [3] series and 23% in Cochran’s [6] series. Forty-four percent of extravasations in our series involved volumes of 50 mL, higher compared with the series by Wang [3] (26%) and Cochran [6] (37%).
Table 3. Correlation of severity of injury with volume of extravasate* Estimated volume extravasated (mL) 0e9 10e49 50e99 100 Total
Severity of Injury (# of Patients) Mild Moderate/Severe Total 38 0 38 398 10 408 217 17 234 76 15 91 729 42 771
*P < .0001.
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Table 4. Patients with severe injuries Age Patient (years) Gender 1 56 Male 2 64 Female 3 35 Male 4 53 Female 5 10 Male 6 24 Female
Status IP IP IP OP ED ED
Injection Rate Catheter Radiology Volume Extravasated Surgical (mL/sec) Gauge Location Placed Catheter (mL) Procedure 2 18 AC No 150 Yes 4 20 HA No 60 No 2.5 22 AC Yes 98 No 2.5 20 AC Yes 75 No 2.5 20 AC No 100 No 2 22 AC No 80 No
Note: IP ¼ inpatient; OP ¼ outpatient; ED ¼ emergency department; AC ¼ antecubital; HA ¼ hand.
EDA technology has been previously reported [8,9] to reliably decrease the volumes of extravasation when an extravasation event occurs. These devices were used in 88 extravasation events reported in our study. The 88 extravasation events in which an EDA was used, compared with those events in which an EDA was not used, does show a downward trend (Fig. 3) in estimated extravasation volume with statistical significance (chi-squared P ¼ .05). The experience in our series with EDAs, however, is unlike that previously reported in the literature [8,9]. In Powell’s study [9] with injection of saline and dextrose into volunteers, the EDA successfully stopped the injection in all 82 patients at injection rates typically used for diagnostic CT exams, and the average volume of extravasation was 12.5 mL. In Birnbaum’s study [8], the EDA had 100% sensitivity, stopping the 4 confirmed extravasations with a maximum volume of extravasation of 18 mL. In our series, the EDAs did shift the volumes of extravasation toward smaller volumes, but there were still patients with relatively large volumes of extravasate; 28 (32%) patients with 50-99 mL, and 4 (5%) with >100 mL. This study confirms the findings of several previous studies [3-5,7,10-13] that the great majority of extravasation
events result in mild, transient injuries and can be managed conservatively. Some earlier literature [14,15] on management of extravasation injuries suggested that aggressive management and intervention was indicated to prevent longterm sequelae. More recent literature and this series do not support this recommendation. A total of 729 extravasation injuries (94.6%) were graded as mild, 36 (4.7%) as moderate, and 6 (0.8%) as severe. Only 19 (1.8%) had surgical consultation, and only 1 patient required a surgical procedure. The only patient demographic factor or exam characteristic that had a statistically significant correlation with moderate/severe injuries was the volume of extravasate. Our series confirms the findings by Wang et al [3] that using a volume-of-extravasation threshold to predict severity of injury is problematic, as moderate and severe injuries occurred in volumes from 10 mL to >100 mL, although all 6 patients with severe injuries did have extravasation volumes >50 mL, and the 1 patient that required a surgical procedure had an extravasation volume of 150 mL. The necessity for surgical consultation should be based on the signs and symptoms of extravasation and not on a volume threshold [1].
Fig 4. Distribution of volumes of extravasate: Data are from Dykes (current study), Wang et al [3], and Cochran et al [6]. Journal of the American College of Radiology Dykes, Bhargavan-Chatfield, Dyer n Contrast Extravasation During CT
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Of the 350 outpatients who experienced an extravasation event, 138 (39.4%) had observation as an initial intervention. This finding is remarkable given that the ACR Manual on Contrast Media [1] and guidelines published by the European Society of Uroradiology (ESUR) [5,16], and opinions from experts in the field of uroradiology [17-19] state that careful monitoring of the patient after an extravasation event is needed because the severity of an injury is difficult to determine on initial presentation. These sources also indicate that outpatients who have suffered an extravasation injury should be released from the care of a radiologist only after the physician determines that any signs and symptoms that were initially present have resolved or improved, and no new symptoms suggest a more serious injury, such as compartment syndrome. Thirty-two groups completed the 2-step PQI cycle. The application of PQI principles resulted in no statistically significant improvement for the 3 core benchmarks in the composite data of these 32 practices: extravasation rate, distribution of volume of extravasation, and severity of injury. The data collected in this quality improvement project did not include information on interventions and departmental policies that could, if applied, have a positive impact on these benchmarks, including adequate training of personnel, appropriate vein selection for cannulation, adequate catheter length and caliber, and appropriate monitoring of the injection site. All these intervetions and others would be excellent subjects for future investigations. Technologies such as EDAs do have a statistically significant but modest positive impact on lowering extravasation volumes when an event occurs, but not to the same degree as initially reported.
Limitations Our study has important limitations. First, it is retrospective and entirely dependent on the accuracy of data entered into the NRDR database by several different and diverse practices. No data audit or site visit was conducted to verify accuracy of data submitted by the participating practices. Each project administrator has access to guidelines and data definitions, and the contrast-extravasation reporting form includes data definitions. Second, estimation of the volume of extravasation is difficult unless the entire injection was completed and there is no intravenous contrast on the exam. However, the distribution of extravasation volumes in our study is similar to those found in previous studies, suggesting that we used a methodology similar to that used by other investigators. Third, assessment of severity of injury is subjective even with clearly defined criteria. Again, our distribution of severity of injury is very similar to those found in previous studies. Fourth, participation in this study is voluntary and introduces the possibility of selection bias. 190
Practices that already know they do not perform well may opt to not participate. Last, nearly 29% of events did not have adequate followup to determine severity of injury. Although the number of these cases that would have been characterized as moderate injuries is unclear, they probably would not alter the reported numbers of severe injuries, because patients that have severe injuries or surgical interventions typically are closely followed and reported to risk management.
Summary This large, multi-institutional study on intravenous, iodinated contrast material extravasation during CT establishes practice performance benchmarks for average extravasation rate, distribution of extravasation volumes, and distribution of severity of injuries from an extravasation event. It is the first time a large data registry, in this case the NRDR, has been utilized to collect information and metrics on extravasation events from multiple, diverse practices across the country. It is also the first, multiinstitutional application and review of PQI principles in contrast extravasation to determine the impact of the use of PQI on practice performance benchmarks.
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This study confirms previous data that the extravasation rate ranges between 0.15% and 0.70%, with a mean extravasation rate of 0.24% and median of 0.21%. The distribution of volumes of contrast extravasation is similar to that found in previously published studies, with 51% of extravasation volumes falling between 10 mL and 49 mL, and 32% between 50 mL and 99 mL. Mild injuries occurred in 94.6% of extravasations, with only 4.7% of patients having moderate injuries, and 0.8% having severe injuries; conservative management is appropriate in most cases. Our data suggest that larger extravasated contrast volumes correlate with moderate-to-severe injuries, but like other studies, it does not support using a volume threshold to determine referral to surgical specialties or more aggressive management.
ACKNOWLEDGMENTS The authors thank those practices that have participated in the project and provided practice data that form the basis of this article.
ADDITIONAL RESOURCES IV Contrast Extravasation Reporting Form (Figure 1) can be found online at http://www.jacr.org/article/S1546-1440(14) 00408-6/full text. Journal of the American College of Radiology Volume 12 n Number 2 n February 2015
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