An interventional study of CM Temperature (20° C) and CM Temperature (37° C) in Contrast Media, Comfort and Temperature, sponsored by Maastricht University Medical Center. Completed at 1 site in Netherlands. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2021-04-02.
Sponsored by Maastricht University Medical Center · Not applicable, Interventional, and Other
Abdominal computed tomographic (CT) is an important prognostic tool with regard to the detection of oncological, infectious and other abdominal disorders.
The total iodine load (TIL) is regarded as a decisive factor in the opacification of parenchymal structures. The EICAR trial demonstrated that injection with high flow rates of prewarmed contrast media (CM) was safe and patients did not experience any pain, stress of discomfort during injection. Flow rates as high as 8.8 ml/s were injected without any discomfort. All concentrations used (e.g. 240, 300 and 370 mg I/ml) in this study were prewarmed. According to the recent recommendations (ESUR guidelines 10.0) it should be considered to warm iodine-based CM before administration. The hypothesis is that although using CM at room temperature (\~23°C [\~73°F]) might result in lower attenuation of the liver parenchyma than would be achieved using CM pre-warmed to body temperature, diagnostic image quality, patient safety and comfort will not be compromised by not pre-warming CM in this setting. According to the guidelines, it is regarded as best clinical practice to pre-warm CM. Surprisingly, these recommendations are merely based on a hypothetical assumption. In the literature, there are no studies evaluating this topic and it has never been clearly shown to result in a better patient comfort. For this reason, many clinics do not pre-warm their CM in daily clinical routine. Only one study evaluated subjective comfort in hysterosalpingography (HSG), in which CM is injected in to the cavity of the uterus. This study found that prewarmed CM alleviates the pain and decreased the incidence of vasovagal episodes during HSG. To the best of our knowledge, no study showed that prewarmed CM in CT resulted in higher patient comfort, in comparison to CM at room temperature (20° C).
Up till now, all CM in the department is prewarmed. In case this study does not show a difference in patient comfort, prewarming the CM can be stopped, resulting in a considerable simplified workflow.
The hypothesis is that usage of CM at room temperature (20° C) might result in a decreased level of patient comfort in abdominal CT, in comparison to pre-heated (37° C) CM, with no significant difference in diagnostic attenuation of the liver parenchyma between groups.
Abdominal computed tomography (CT) scans are performed daily on a regular basis. Since its advent, rapid technical advances in CT continuously improved image quality. Besides scan technique, the contrast media (CM) injection protocol is the crucial factor in abdominal imaging. Parenchymal contrast enhancement is determined by patient related factors (e.g. cardiac output, blood volume and patient weight), the CM injection protocol and the scan protocol. Much literature has been performed with regard to optimizing CM application and the scan protocol. Flow rate of the CM and patient discomfort have been thoroughly investigated in our department. Heating CM up to body temperature has been daily clinical routine in our department for years.
According to the recent recommendations (ESUR guidelines 10.0) it is advised to warm iodine-based CM before administration. Warming the CM is expected to result in a higher patient comfort, based on clinical observation. Kok et al. showed in phantom experiments that high temperature, low iodine concentration and low viscosity significantly decreases injection pressure. Subsequently, as increased temperature reduces the viscosity of the CM, the decreased viscosity is hypothesized to reduce the risk of extravasation. A decreased viscosity might also have a substantial impact on individual tailored CM injection protocols in daily routine scanning as it is speculated that a decrease of viscosity and subsequent decrease in peak injection pressure could influence patient comfort during injection. The EICAR trial showed that prewarmed CM can be safely injected at high flow rates, without patient discomfort, pain or stress. However, the latter was not compared to CM at room temperature.
Different CM concentrations are used in different hospitals throughout the world. The higher the concentration, the higher the viscosity of the CM. In present study, only one CM concentrations (e.g. 300 mg/ml) will be used, which is used in daily clinical practice for years. Heating the CM decreases the viscosity. It is therefore expected that the preheated CM in a concentration of 300 mg/ml has a lower viscosity in comparison to the CM at 20° C.
Pre-warming CM might be regarded as best clinical practice. No studies have been performed to investigate this statement, nor is there any literature that shows that prewarmed CM has a favorable patient comfort compared to CM injected at room temperature. For these reasons, there remains to be some reluctance and many clinics still not pre-warm their CM. One study, in which CM is injected in to the cavity of the uterus to check for any anatomical variants and causes for infertility, showed a preference for prewarmed CM in hysterosalpingography (HCG). This study found that prewarmed CM alleviates the pain and decreased the incidence of vasovagal episode during the HCG.
The hypothesis is that although using CM at room temperature (\~23°C [\~73°F]) might result in lower attenuation of the liver parenchyma than would be achieved using CM pre-warmed to body temperature, diagnostic image quality, patient safety and comfort will not be compromised by not pre-warming CM in this setting. Pre-warming CM requires special equipment and more complex planning and logistics. On the other hand, pre-warming CM may yield higher attenuation levels, comfort and image quality. In case this study does not show a significant difference in patient comfort and diagnostic quality between groups, pre-warming the CM can be stopped, resulting in a considerable simplified workflow.
Maastricht University Medical Center is the lead sponsor of 835 studies on the registry; 122 are open to participants now.
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Exclusion criteria
CM is administered to the patient at a temperature of 20° C.
Other: CM Temperature (20° C) · Other: Weight
CM is administered to the patient at a temperature of 37° C.
Other: CM Temperature (37° C) · Other: Weight
CM will be administered at 20° C (room temperature).
CM will be administered at 37° C (pre-heated).
The patients' weight is measured prior to scanning by a technician on a weighing scale available in the scanner room.
Liver attenuation
Mean attenuation in Hounsfield Units (HU) is based on three liver segments, preferably segments 2, 5 and 8 (Couinaud classification). Absolute difference in mean attenuation of the liver parenchyma between groups was calculated with a two-sided 95% confidence interval of the difference.
Time frame: Expected within one month after the CT is performed
Patient comfort
Patient (dis)comfort during and after injection of CM with varying temperatures, rated on a questionnaire
Time frame: Immediately after CT
Pain during injection
Assessed with a questionnaire with the option yes/no
Time frame: Questionnaire immediately after CT
Pain rate
Assessed with a 11-point numeric rating scale (0=no pain; 10=very severe pain)
Time frame: Questionnaire immediately after CT
Different physiological reactions and sensations injection
Questionnaire has to be filled in which people can tick a box if they had feelings of shivering/goosebumps/or being cold. There is some free space to write down other sensations.
Time frame: Immediately after the CT
Objective image quality - Signal-to-noise ratio
mean attenuation of the liver divided by the mean standard deviation
Time frame: Within one month after the CT is performed
Objective image quality - Contrast-to-noise ratio
Mean liver attenuation minus HU of the left paraspinal muscle, divided by the SD of the attenuation of the paraspinal muscle
Time frame: Within one month after the CT is performed
Subjective image quality
Rated in consensus on a 5-point Likert scale by two readers
Time frame: Within one month after the end of the study
Body weight
Weight is measured on a weighing scale
Time frame: Right before the scan is performed
CM volume
The milliliter of CM administered
Time frame: Information is expected to be collected from the Certegra form available in Impax within 1 month
Flow rate
Flow rate of the contrast media in ml/s
Time frame: Information is expected to be collected from the Certegra form available in Impax within 1 month
Injection site
Injection site of the CM
Time frame: Information is expected to be collected from the Certegra form available in Impax within 1 month
Catheter Gauge
Catheter size used for CM injection
Time frame: Information is expected to be collected from the Certegra form available in Impax within 1 month
Effective milliamperes (mAs)
The effective mAs used in the specific patient
Time frame: Information is expected to be collected from the Certegra form available in Impax within 1 month
CT Dose Index (CTDI)vol
CTDIvol (in mGy) the patient received
Time frame: Information is expected to be collected from Impax within 1 month
Dose-length product (DLP)
DLP (in mGycm) the patient received
Time frame: Information is expected to be collected from Impax within 1 month
Tube voltage
Tube voltage used in the specific scan
Time frame: Information is expected to be collected from Impax within 1 month
Plan to share: Yes — The results will be published in international peer reviewed journals in order to spread new insights regarding contrast media temperature in abdominal CT imaging. Both positive and negative results will be published according to the guidelines of the 'Centrale Commissie Mensgebonden Onderzoek' (CCMO).
Supporting information: Csr
This study is completed, as verified in Mar 2021. You cannot join it, but the record below documents what was studied.
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Maastricht University Medical Center