By: Timothy Paice – JD/MBA University of Pittsburgh
An extravasation of contrast media during a computed tomography (CT) scan is a well-recognized complication (1). There are certain aspects of an extravasation that are easily understood and recognizable, those being the impact to the patient and technician, scanner schedule, or the potential need for surgical intervention. One aspect that may not be readily apparent is the potential for a medical professional liability claim, which may be due in part to the difficulty of obtaining empirical data. This article attempts to briefly discuss related issues of an extravasation and then determine the potential liability of an extravasation by examining the average frequency and cost of a potential liability claim.
Although an extravasation is a “well-recognized” complication of CT scans, the frequency that a technician would see an extravasation is fairly low. The reported extravasation rate during CT scans ranges from 0.14% to 0.9%, with an average of 0.43% of CT scans resulting in an extravasation (2-7). Based on this data, a technician operating an average scanner would likely view an extravasation once in 233 CT scans.
There are certain risk factors that contribute to the likelihood of an extravasation, which include patient factors, contrast media type and volume, and injection technique (1). Patient factors include those patients who cannot communicate adequately (e.g., elderly, infants, or patients with altered consciousness), ill or debilitated patients, and patients with abnormal circulation (8). The contrast type and volume can also affect the likelihood and severity of an extravasation. Generally, a patient can tolerate a low-osmolar contrast media better than a high-osmolar; however, a patient may be able to sense an extravasation better with a high-osmolar contrast due to increased reaction with high-osmolar (1). Additionally, large-volume extravasations may lead to a more severe extravasation injury (1). Injection technique can also contribute to the likelihood of an extravasation. Such factors when considering injection technique include the use of a metal needle to that of a plastic cannulae, the site of an injection, and the use of mechanical power injection (1).
In order to lessen the severity of an extravasation, it is important to take preventative measures and provide proper treatment if an extravasation occurs. A critical step of preventing an extravasation is direct monitoring of the injection site by palpation (8). Additionally, the presence of a trained nurse or physician beside the patient during the entire injection would be ideal for detection, but exposure to radiation makes such observation impossible (1). After an extravasation occurs, there are certain conservative measures that can be taken to potentially resolve extravasation injuries. These measures include the recommended elevation of the affected extremity, the application of a warm or cold compress, and a possible surgical consultation for those patients with high volume extravasations or increasing symptoms (8).
There are two schools of thought when classifying an extravasation – (1) classification based on the volume of extravasated contrast media and (2) classification based on the resulting injuries of an extravasation. Classification based on the volume of contrast media is generally categorized into three groups – minor (less than 10mL), moderate (10 – 49mL), or major (50mL or more) (4). Classification based on the resulting injury is also categorized into three groups – mild, moderate, or severe (3).
In order to correlate the empirical data, it is important to determine the appropriate classification system. When examining the settlement and verdict findings, it is readily apparent that the description of resulting payment describes the nature of the injury and not the volume of extravasated contrast media. For this reason, extravasations should be categorized by the nature of the resulting injury – mild, moderate, or severe. A mild reaction is if the patient had minimal signs or symptoms with resolution by conservative treatment within one to two days (3). A moderate reaction is if the patient experienced partial skin loss, as evidenced by blistering or ulceration, or other signs and symptoms that persisted longer than two days (3). A severe reaction is if the patient experienced a reaction that required surgical treatment such as fasciotomy, debridement, or reconstruction (3).
Before examining the likelihood of each categorized extravasation, it would be a worthwhile opportunity to consider the annual number of contrast enhanced CT scans. In 2004, there were 50.1 million CT scans in 7,355 hospital and non-hospital facilities in the U.S. (9). Of the 50.1 million, 29.3 million (or 58%) used an injectable contrast media (9). Based on the number of facilities, in 2004 the average number of CT scans using injectable contrast media was 3,984 (or 10.9 per day). This information can be further digested to the per injector level which may be helpful when considering one’s own facility. Of the 29.3 million CT scans using injectable contrast, 26.1 million (or 89%) used power injectors during the CT scan (9). Additionally, in 2004 the number of CT power injectors was 8,710 which results in an average number of contrast enhanced power injected CT scans of 2,994 (or 8.2 per day) per injector (9).
As previously discussed, an average extravasation occurs one out of 233 CT scans (or 0.43%). Of these extravasations it is important to determine what percent would be mild, moderate, or severe. Based on previous research findings, mild extravasations account for the majority of all extravasations at 90.1%, moderate and severe account for 7.8% and 2.1%, respectively (2-3). Taking the aggregate average of extravasations and correlating that with the categorized severity percentages, it is determined that a mild extravasation occurs once in 258 CT scans, a moderate extravasation occurs once in 2,982 CT scans, and a severe extravasation occurs once in 11,074 CT scans.
To understand what a facility’s vulnerability to extravasations might look like, you can now examine the mentioned frequency and relate this to the aforesaid average annual contrast enhanced CT scans data. Considering first on a per facility level, the average number of CT scans using injectable contrast media was 3,984 which would imply that an average facility experiences a mild extravasation every 24 business days (or once a month*), moderate extravasation every 273 business days (or once in 11 months*), and severe extravasation every 1014 business days (or once in 3.4 years*). Looking next at a more detailed level of a per injector level, the average number of power injected CT scans was 2,994 which would imply that an average power injector experiences a mild extravasation every 31 business days (or once in 1.3 months*), moderate extravasation every 364 business days (or once in 1.2 years*), and severe extravasation every 1,350 business days (or once in 4.5 years*).
After a search of several legal and governmental databases, it was found that previous extravasation settlements and jury verdicts ranged from $750 to $1.5 million (10-13). These particular settlements dated from 1983 to 2004, and in order to digest the settlement and verdict data these findings were adjusted to represent their present value. As a result, the range of empirical settlement and verdict data adjusted to present value is $1,045 to $2.9 million.
In order to better correlate the settlement and verdict data, steps were taken to determine what settlements and verdicts were a result of a mild, moderate, or severe extravasation. Based on the empirical data, none of the settlements and verdicts were a result of a mild extravasation. Moderate extravasations accounted for a minority of settlements and verdicts with an indemnity or award payment ranging from $1,045 to $74,421. The majority of the empirical data was a result of a severe extravasation which ranged from $3,294 to $2.9 million.
The next steps taken were to examine both the moderate and severe extravasation empirical data ranges, and determine what the average potential liability for a moderate or severe extravasation might look like. First, the moderate range of $1,045 to $74,421 was analyzed with the desire of removing the abnormal or outlier cases. In order to remove such cases and thereby illustrate a normal moderate indemnity or award, the probability range was determined. The probability range in the instance of examining settlements and verdicts are those cases between the 25th and 75th percentile or 50% of moderate settlements and verdicts. The probability range for a moderate extravasation was $4,526 to $27,569 with an average potential liability cost of $14,118. The same steps were taken for the severe extravasation settlement and verdict range of $3,294 to $2.9 million. The probability range for a severe extravasation was $32,282 to $171,996 with an average potential liability cost of $94,056
As previously discussed, there are several aspects of an extravasation that a hospital or non-hospital facility should be concerned with. Medical professional liability is one of the least understood facets. This is illustrated when considering the potential liability of a moderate and severe extravasation being $14,118 and $94,056, respectively. Furthermore, at a per facility level, a moderate extravasation occurs on average once in 11 months and a severe extravasation occurs on average once in 3.4 years. These figures demonstrate that even a small percentage problem such as a moderate or severe extravasation can be a considerable financial liability. Therefore to minimize liability, every effort should be made to prevent and mitigate any extravasation that a facility may see, and should be handled with diligence by the technicians, radiologists, and staff alike.
* Assuming 25 business days a month & 300 business days per year.
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3 Cohan RH, Bullard MA, Ellis JH, et. al. Local reactions after injection of iodinated contrast material: detection, management, and outcome. Acad Radiol 1997; 4:711-718.
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6 Jacobs JE, Birnbaum BA, Langlotz CP. Contrast media reactions and extravasation: relationship to intravenous injection rates. Radiology 1998; 209:411-416.
7 Federle MP, Chang PJ, Confer S, et. al. Frequency and effects of extravasation of ionic and nonionic ct contrast media during rapid bolus injection. Radiology 1998; 206:637-64
8 American College of Radiology (ACR). Manual on contrast media, 5th ed., 2004. Reston, VA: ACR.
9 2004 CT census market summary report. (2005). Des Plaines, IL: IMV Medical Information Division, Inc.
10 US Department of Health and Human Services, National Practitioner Data Bank. Washington, DC: Department of Health and Human Services; March 2006.
11 Medical Professional Liability (MPL) Reporting Claims Database. Tallahassee, FL: Florida Office of Insurance Regulation; 2006.
12 Lexis-Nexis
13 Westlaw