Current Clinical Concerns in CT: Results : IV Contrast Administration
Peripheral venous catheter location
1. I find our techs are very nervous when it comes to rapid contrast injections (3-5 cc/sec). Do you or any of your techs have recommendations for catheters, best position, and testing the catheter prior to use? Do your techs routinely test with saline?
| Answer: We use 18 or 20 g catheters and prefer the antecubital fossa. We inject 3-4 cc/sec routinely, but do test the line with saline. We also stay in the scanning room for the first 20 - 25 seconds after we begin the injection and monitor the injection site. |
2. I have worked at several institutions, and currently our radiologists insist that you can not obtain and use IV access in the hand or lower forearm. Do you know of any supporting documentation or can you provide insight into this? Also, what gauge should be used when performing IV contrast studies?
| Answer: We do inject in the hand. One just needs to be extremely careful when injecting the IV contrast. |
3. I was wondering if it is OK to utilize the lower extremity with a power injector for CTA or any CT exam for that matter, if this is the only venous access the patient has. As long as a 16 or 18 gauge angiocath is in place, the PSI's are lowered on the power injector, and delay is adjusted, would this be a safe procedure?
| Answer: With caution it would be safe. You will have to adjust your scan delay as it will be increased. |
4. In general, which arm is preferred for IV contrast administration in the chest, and why? I've had different radiologists insist on opposite upper extremities for differing reasons, i.e. upper thorax artifact, etc. What do you recommend?
| Answer: There is no perfect answer. The right arm is best when you need timing as it is more of a direct shot into the heart and so more reproducible. The left is best when venous anatomy is the study question (i.e. SVC patency) as it opacifies the left vessels better. The key to me when all is said and done, is the best venous access. |
5. Our radiologist has recently decreed that the power injector can only be used if the IV needle is placed in the antecubital fossa; otherwise the tech has to hand inject. I see problems because the antecubital fossa is the hardest to monitor, and also because the elbow is usually bent when the arms are placed over the head, and this access tends to extravasate. He claims this is the "standard of practice". Is it? At night, the ER patients come with peripheral IV's placed in the ER.
| Answer: Although the antecubital fossa is preferred, a power injector can be used anywhere as long as the access is satisfactory. The key thing is to have good venous access regardless of the site of entry. |