Tag Archives: CT

Natural History of the Splenic Blush

In my last post, I described the two types of solid organ “blushes.” I also described my thoughts on the natural history of these findings. Now, a multicenter study on the natural progression of the splenic “blush” has just been published. I found this paper very interesting, because it challenged some of my own existing beliefs. But once I read it, my enthusiasm faded.

The Western Trauma Association sponsored a multicenter (17 Level I and II centers) review of data collected prospectively over an unspecified period of time. Patients were excluded if their injury was older than 24 hours, if they had a previous splenic injury, and if they had any number of diseases or hereditary conditions that might affect the spleen. Strict definitions of nonbleeding and actively bleeding injuries were applied, and detailed information on intervention and outcomes was collected.

Here are the factoids:

  • 200 patients were enrolled from 17 centers, but the paper does not state how long that took
  • 20% were low grade (1 or 2) and 80 % high grade (3-5)
  • 29% had a pseudoaneurysm, and 83% showed extravasation, which means that several patients had both
  • 15% underwent early splenectomy, 59% underwent angiography, and 26% were observed
  • For those with initial angiography, 6% had repeat angio and 7% eventually underwent splenectomy
  • Of those were were initially observed, 9% had delayed angio and 8% underwent splenectomy
  • Based on a read by an expert radiologist, an actively bleeding injury was associated with a 41% splenectomy rate
  • The authors conclude that the majority of patients with spleen injury with pseudoaneurysm or extravasation are managed with angio and embolization and that splenectomy remains a rare event (??)

Bottom line: This paper just doesn’t do it for me. The biggest problem is that it is what I call a “we do it the way we do it” study. It examines how 17 different centers evaluate and treat patients with significant splenic injury. There was no guidance or guideline on how to treat, so they each did it their way. And the number of patients was small.

They don’t tell us anything about the use or effectiveness of angio by grade. Or whether the specific hospitals routinely rely on angio rather than just going to the OR for high grade injuries (typically if angio response times are long).

Unfortunately, this paper gives the appearance of containing a lot of interesting stuff. But a 15% initial splenectomy rate is not a “rare event” in my book. Everything published here is at odds with what I’ve observed over the years for centers with well developed management guidelines and easy access to angio (< 5% splenectomy rate in hemodynamically stable patients with nonoperative management).

My recommendation is to send all stable patients with pseudoaneursym and/or extravasation to angio immediately! Yes, some will have nothing found by the time they get to angio, and you’ll have to come up with a plan at that point. But most have something wrong, and it won’t stop until it’s been plugged up (or your patient bleeds to death, whichever comes first)!

This article has all the right buzzwords: multicenter, prospective data, etc. But it’s already been moved to my recycle bin. 

Related post:

Reference: Natural history of splenic vascular abnormalities after blunt injury: A Western Trauma Association multicenter trial. J Trauma 83(6):999-1005, 2017.

Chest CT vs Chest X-Ray After Chest Tube Insertion

Two days ago, I discussed getting the traditional chest x-ray routinely after chest tube insertion. The answer was yes, it is important even if it appears to be functioning correctly. But yesterday, I also showed you how the chest x-ray can lie.

Remember this image?

Looks perfect! But it’s a 2-D view and you don’t know where the tube is in the anterior-posterior axis. It turns out to be in the patient’s subcutaneous tissues of his back, near his scapula!

So what if this is a trauma activation patient and you are getting ready to send your patient for a chest CT shortly? Should you follow the usual dogma and still get a conventional chest x-ray prior to leaving the trauma bay?

The answer is no! Typically, your trauma activation patient should have rapid access to the CT scanner, so you won’t have to wait very long. And the additional 3-D information is very helpful in making sure the tube is placed exactly where you want it.

Bottom line: If you are planning on obtaining a chest CT anyway in your trauma patient, don’t bother with a conventional chest x-ray first to check chest tube position. But DON’T order a chest CT for this reason alone! Remember, the chest CT is only for detecting aortic injury in blunt trauma. It should not be used for diagnosing fractures, hemothorax, or pneumothorax. Or chest tube position!

Related posts:

 

Lab Values From Intraosseous Blood

The intraosseous access device (IO) has been a lifesaver by providing vascular access in patients who are difficult IV sticks. In some cases, it is even difficult to draw blood in these patients by a direct venipuncture. So is it okay to send IO blood to the lab for analysis during a trauma resuscitation?

A study using 10 volunteers was published last year (imagine volunteering to have an IO needle placed)! All IO devices were inserted in the proximal humerus. Here is a summary of the results comparing IO and IV blood:

  • Hemoglobin / hematocrit – good correlation
  • White blood cell count – no correlation
  • Platelet count – no correlation
  • Sodium – no correlation but within 5% of IV value
  • Potassium – no correlation
  • Choloride – good correlation
  • Serum CO2 – no correlation
  • Calcium – no correlation but within 10% of IV value
  • Glucose – good correlation
  • BUN / Creatinine – good correlation

Bottom line: Intraosseous blood can be used if blood from arterial or venous puncture is not available. Discarding the first 2cc of marrow aspirated improves the accuracy of the lab results obtained. The important tests (hemoglobin/hematocrit, glucose) are reasonably accurate, as are Na, Cl, BUN, and creatinine. The use of IO blood for type and cross is not yet widely accepted by blood banks, but can be used until other blood is available. NOTE: your lab may try to refuse the specimen due to “other stuff” (marrow) in the specimen. Have them run it anyway!

Related post:

Reference: A new study of intraosseous blood for laboratory analysis. Arch Path Lab Med 134(9):1253-1260, 2010.

CT Contrast Via Intraosseous Catheter

The standard of care in vascular access in trauma patients is the intravenous route. Unfortunately, not all patients have veins that can be quickly accessed by prehospital providers. Introduction of the intraosseous device (IO) has made vascular access in the field much more achievable. And it appears that most fluids and medications can be administered via this route. But what about iodinated contrast agents via IO for CT scanning?

Physicians at Henry Ford Hospital in Detroit published a case report on the use of this route for contrast administration. They treated a pedestrian struck by a car with a lack of IV access sites by IO insertion in the proximal humerus, which took about 30 seconds. They then intubated using rapid sequence induction, with drugs injected through the IO device. They performed full CT scanning using contrast injected through the site using a power injector. Images were excellent, and ultimately the patient received an internal jugular catheter using ultrasound. The IO line was then discontinued.

This paper suggests that the IO line can be used as access for injection of CT contrast if no IV sites are available. Although it is a single human case, a fair amount of studies have been done on animals (goats?). The animal studies show that power injection works adequately with excellent flow rates.

The authors prefer using an IO placement site in the proximal humerus. This does seem to cause a bit more pain, and takes a little practice. A small xylocaine flush can be administered to reduce injection discomfort in awake patients. Additionally, the arm cannot be raised over the head for the torso portion of the scan.

Bottom line: CT contrast can be injected into an intraosseous line (IO) with excellent imaging results. Insert the IO in a site that you are comfortable with. I do not recommend power injection at this time. Although the marrow cavity can support it, the connecting tubing may not. Have your radiologist hand-inject and time the scan accordingly. And don’t be surprised if your radiology department doesn’t have a protocol for this!

Note: long term effects of iodinated contrast in the bone marrow are not known. For this reason, and because of smaller marrow cavities, this technique is not suitable for pediatric patients.

Related posts:

Reference: Intraosseous injection of iodinated computed tomography contrast agent in an adult blunt trauma patient. Annals Emerg Med 57(4):382-386, 2011.

Do We Need Cervical MRI Scans If The CT Is Negative?

The debate on how to clear the cervical spine just never ends. We have finally come to some degree of agreement that certain patients (awake, alert, not impaired or head injured, without distracting injury) can undergo clinical clearance alone.

But if those criteria are not met, what next? Universally, adults receive a CT scan of the cervical spine. In the majority of centers, this is coupled with a good clinical examination. And if both are negative, the collar can be removed.

But recent literature suggest that a good, high-quality cervical CT read by a skilled neuroradiologist may be good enough. This has been demonstrated in several papers involving patients who are comatose or other-wise unable to participate with a clinical exam.

Many centers and trauma professionals are still reluctant to remove the cervical collar without that clinical examination. A new study asked the question: would an MRI provide additional, significant information over and above the CT scan in those patients who could not be examined or had persistent neck pain?

A consortium of 8 Level I and II trauma centers in New England participated in this study coordinated by Yale. Blunt trauma patients who underwent MRI after negative cervical CT were considered for the study. On further review, if they received the scan because they could not be clinically evaluated, or if they had complaints of persistent neck pain, they were enrolled. CT scanners with at least 64-slice capabilities were required. There was no mention of the qualifications or special experience of the radiologists reading the images at each center.

Here are the factoids:

  • 767 patients were enrolled in this 30-month study. A total of 43% were for persistent neck pain, 44% for inability to examine, and 9% for both.
  • Nearly a quarter had an abnormal MRI scan:
    • 17% ligamentous injury
    • 4% soft tissue swelling
    • 1% disk injury
    • 1% dural hematoma
  • The collar was removed in most (88%) patients with a normal MRI, but in only 13% with ab-normal MRI
  • 11 patients underwent a surgical procedure and half had neurologic signs or symptoms. 10 of them had ligamentous injury, 1 had dural hematoma, and 1 had both

Bottom line: Looks almost compelling, right? One would think that we had better get an MRI on all of these patients! But read more closely, please. Yes, injuries were found. But did they really “require” an intervention? For some injuries, it’s a chip shot. A three column ligamentous injury equals stabilization in any textbook. But management of lesser injuries is less clear. And could some of these injuries have been recognized by a skilled neuroradiologist reading the CT image?

So what to do? There is not enough data for a universal protocol yet. Unfortunately, you will need to develop your own institutional policy based on the experience and opinions of your spine and neurosurgeons. They are the ones who will have to deal with the decision making during and after these studies. Until the definitive study comes along.

Reference: Cervical spine MRI in patients with negative CT: A prospective, multicenter study of the Research Consortium of New England Centers for Trauma (ReCONECT). J Trauma 82(2):263-269, 2017.