Technology and Industry: Assessing renal function before administering contrast media

In many clinical situations, contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) is the best option for achieving a timely and accurate diagnosis. The use of intravenous (IV) contrast media is not without risk, however. In addition to the potential for allergic reactions, some patients, particularly those with decreased renal function, face the risk of contrast-induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF).

With the increasing volume of contrast-enhanced imaging studies performed in the United States, the risk of such adverse events is a major concern for clinicians and patients. In fact, renal failure following contrast administration has been reported to occur in 0.1% to 13% of all patients who receive contrast media. ¹ Among hospitalized patients, CIN is the third most common cause of acute renal failure. ² Patients at the greatest risk for CIN (Table 1) are typically those with previously impaired renal function, with diabetes, with hypertension, and the elderly, ³ as well as those who undergo multiple contrast injections within a short time period. ⁴

Therefore, it is essential that clinicians perform a thorough risk assessment on all patients prior to the injection of any contrast media. One important aspect of this risk assessment is the determination of kidney function status. Recently, E-Z-EM, Inc. (Lake Success, NY) introduced a new, hand-held device designed to assist in this process.

EZ Chem

The EZ Chem Blood Analyzer (Fig-ure 1) is a point-of-care device that provides serum creatinine level readings within 30 seconds using only a drop of blood. Similar to a glucometer, this hand-held device was designed to provide rapid results in the imaging suite.

"We came up with the idea," explained Brad S. Schreck, Senior Vice President- Global Sales, Marketing, and Engineering at E-Z-EM, "to help with patient safety and workflow efficiency. For example, when a hospital patient comes to the radiology department for a CT or MRI, laboratory blood work results, specifically creatinine levels, are not always included in the patient's chart. If that information is not available, it may take 45 minutes to 2 hours before the radiology department can get blood test results from the laboratory, even within the same facility." Such a delay, he continued, results in a long wait for the patient and decreased efficiency within the radiology department. At independent imaging centers, the problem can be worse, he noted. "At an imaging center, if they do not have the test results, what do they do?" asked Schreck. "In the past, they would do one of two things: they would either take the risk and give contrast, which is a danger to the patient, or they would cancel the scan, which plays havoc with both the schedule and revenue."

With EZ Chem, the clinician can obtain these results immediately prior to the scheduled study. To use the system, the clinician scans or manually enters the operator name and patient identification and inserts a test strip. The clinician then uses a lancet to obtain a 1.2 µL sample of blood, which is placed on the end of the strip. The blood is automatically titrated into the device and analyzed. In 30 seconds, a creatinine level is displayed and a glomerular filtration rate (GFR) is calculated.

The unit, which measures 6 × 3.25 × 1.8 inches, can store up to 1000 patient tests, 200 quality control tests, and 4000 operators within its memory. The 0.8-lb device is battery-powered and sits in a desk-mounted docking/charging station. "You can walk around with it and then put it back in the charger at the end of the day," said Schreck.

Integration software

E-Z-EM also manufactures the EmpowerCTA and EmpowerMR injector systems and has developed software to integrate the EZ Chem results with the injectors and to network the injectors together. "We integrated the whole package," explained Schreck.

The company's IRiS software (Injector Reporting information System) is able to track the EZ Chem creatinine level findings, GFR calculations, patient demographics, contrast data, and the injection protocol. It can also be used to monitor the amount of contrast used per injection and in total across the healthcare facility.

"With our IRiS software, a database allows the system to keep data for each patient on each injector and on the main computer system," he said. "We can network all of the injectors within a hospital or imaging center and collect a database of all patients: how much contrast they received; how much was wasted; if they had an extravasation; what their creatinine values were; what the GRF calculations were; if there was an overpressure alarm, etc. All of this information from the injector can be transferred to the database."

"A hospital may have 1 to 10 injectors, on average. We can network all of the injectors together, and all of the data from those injectors can be collected on a computer system so that the radiology administrator or anyone in the hospital can use it, particularly for budgeting for contrast purchases."

"At E-Z-EM, we want to provide not only a delivery system but also a database system and a contrast management system for the patient. So we do everything: we provide an injector to infuse the contrast and an instrument (EZ Chem) to make it safer for the patient; we provide the IRiS system-an information reporting system designed to network all the systems together; and we provide the radiology administrator with data on all the patient results that he or she can use to improve efficiency."

"The key is efficiency within a radiology department or imaging center," concluded Schreck, "and these products provide the value of being able to increase efficiency and also make it safer for a patient."