All posts by The Trauma Pro

Incidental Finding: Gas In The Spleen After Embolization

March 16, 2017 The Trauma Pro Leave a comment

Most solid organ injury practice guidelines include angioembolization in part of the pathway. But very few require re-imaging at any point to see how the liver or spleen are coming along.

But every once in a while another condition arises, or symptoms worsen unexpectedly, causing us to get another CT scan that includes the abdomen and pelvis. And sometimes we see things that we wouldn’t normally see, like air bubbles in the organ that was embolized.

So what is okay, and what requires some kind of intervention? Our friends at ShockTrauma in Baltimore looked at this in 2001 and can provide some pretty good guidance. They reviewed patients who underwent CT scan both before and after embolization over about 2.5 years. They performed the post-embolization scans for specific indications like fevers, elevated WBC count (!), increasing abdominal pain, or an episode of hypotension. A total of 53 patients were studied.

Here are the factoids:

24 patients underwent embolization of the main splenic artery, 22 had selective embolization of part of the spleen, and 7 had both
Splenic infarcts occurred in 63% of patients with main artery embolization, but were large (> 50% of the parenchyma) in only 20% of those
Infarcts occurred in 100% of selective embolizations, but were small (< 50%) in 93% of cases
Infarcts occurred in 71% of patients with both main and selective embolization, and most were small (80%)
Seven (13%) patients developed gas bubbles in the spleen, and was usually present for 1-7 days before disappearing
One patient developed increasing gas with pneumoperitoneum and underwent splenectomy for a splenectomy for abscess

This picture that shows tiny bubbles in the spleen parenchyma that represent “normal” gas after embolization:

And the following one shows an air/fluid collection in the spleen that indicates an abscess:

Bottom line: Tiny bubbles in the spleen (and probably the liver) occur normally after angioembolization. They usually develop within an area of infarction, and most are benign. It is possible for them to evolve into a splenic abscess, but unlikely. Many embolization patients develop fevers at some point, and most have an elevated WBC count. So in most cases, you can ignore this incidental finding, as long as your patient has mild symptoms.

However, if the patient develops high fevers, very elevated WBC (> 25K), increasing abdominal or flank pain, and the spleen develops an air/fluid level, an abscess is forming. Despite what your radiologist might suggest, catheter drainage is not a good idea. The tubes are too small to remove the slurry that is generally found within the abscess. A trip to the OR is the only effective treatment, and splenectomy is generally the only option.

Related posts:

Reference: CT Findings after Embolization for Blunt Splenic Trauma. J Vasc Intervent Radiol 12(2):209-214, 2001.

Head

Everything You Wanted To Know About: Cranial Bone Flaps

March 15, 2017 The Trauma Pro Leave a comment

Patients with severe TBI frequently undergo surgical procedures to remove clot or decompress the brain. Most of the time, they undergo a craniotomy, in which a bone flap is raised temporarily and then replaced at the end of the procedure.

But in decompressive surgery, the bone flap cannot be replaced because doing so may increase intracranial pressure. What to do with it?

There are four options:

The piece of bone can buried in the subcutaneous tissue of the abdominal wall. The advantage is that it can’t get lost. Cosmetically, it looks odd, but so does having a bone flap missing from the side of your head. And this technique can’t be used as easily if the patient has had prior abdominal surgery.

2. Some centers have buried the flap in the subgaleal tissues of the scalp on the opposite side of the skull. The few papers on this technique demonstrated a low infection rate. The advantage is that only one surgical field is necessary at the time the flap is replaced. However, the cosmetic disadvantage before the flap is replaced is much more pronounced.

3. Most commonly, the flap is frozen and “banked” for later replacement. There are reports of some mineral loss from the flap after replacement, and occasional infection. And occasionally the entire piece is misplaced. Another disadvantage is that if the patient moves away or presents to another hospital for flap replacement, the logistics of transferring a frozen piece of bone are very challenging.

4. Some centers just throw the bone flap away. This necessitates replacing it with some other material like metal or plastic. This tends to be more complicated and expensive, since the replacement needs to be sculpted to fit the existing gap.

So which flap management technique is best? Unfortunately, we don’t know yet, and probably never will. Your neurosurgeons will have their favorite technique, and that will ultimately be the option of choice.

Reference: Bone flap management in neurosurgery. Rev Neuroscience 17(2):133-137, 2009.

Philosophy

Pet Peeve: “High Index of Suspicion”

March 10, 2017 The Trauma Pro Leave a comment

How often have you heard this phrase in a talk or seen it in a print article:

“Maintain a high index of suspicion”

What does this mean??? It’s been popping up in papers and textbooks for at least the last 20 years. And to me, it’s meaningless. You try to figure out that sentence!

An index is a number, usually mathematically derived in some way. Yet whenever I see or hear this phrase, it doesn’t really apply to anything that is quantifiable. What the author is really referring to is “a high level of suspicion”, not an index.

This term has become a catch-all to caution the reader or listener to think about a (usually) less common diagnostic possibility. As trauma professionals, we are advised to do this about so many things, it really has become sad and meaningless.

Bottom line: Don’t use this phrase in your presentations or your writing. It’s stupid. And feel free to chide any of your colleagues who do. Give us some concrete tips so we don’t miss the diagnosis!

Reference: High index of suspicion. Ann Thoracic Surg 64:291-292, 1997.

Trauma Systems

Are State Trauma Systems Cost-Effective?

March 8, 2017 The Trauma Pro Leave a comment

Every state in the US now has a formal trauma system. Several studies are available that document the advantages of these systems in terms of outcomes and survival. Trauma professionals get this. But the governmental agencies and legislators who help create, fund, and maintain them tend to focus on cost as well.

Arkansas was the last state in the union to implement a trauma system. A study in press from the University of Arkansas details their experience. They examined the impact of the new system on mortality, patient care, and attempted to calculate a return on investment from the taxpayers in an effort to show the added value.

The study was commissioned by the Arkansas Department of Health and carried out by the state Trauma Advisory Council. It was led by out of state investigators in an effort to maintain impartiality. A comprehensive review of records was performed by a panel of 5 surgeons, 1 emergency physician, 2 trauma program managers, 1 ground and 1 flight paramedic. Preventable and potentially preventable deaths were identified and analyzed in depth. Value of life lost was calculated by using a conservative $100,000 per year lost. A total of 290 charts were reviewed pre-system, and 382 post-trauma system implementation using proportional sampling of about 2500 trauma deaths in one year.

Here are the factoids:

A significantly higher percentage of patients were triaged to Level I trauma centers after the system was implemented
Preventable mortality was decreased from 30% to 14% (!!)
This means that 79 extra lives were saved due to implementation of the trauma system
Non-preventable deaths with opportunity for improvement remained constant at about 55%
Non-preventable deaths without opportunity for improvement increased from 16% to 38% (!)
Using the most conservative VLL calculation, this equates to $2.4M in savings per life saved
This adds up to $186M in savings to the taxpayers of Arkansas, a 9-fold return on their investment of $20M in the trauma system.

Bottom line: Wow! This nicely done studies gives us excellent insight into the hows and whys of the value of an organized state trauma system. It is likely that the triage system directed more patients to the most appropriate level of care, leading to fewer preventable deaths. And it enticed hospitals to up their game and make the move toward formal trauma center designation. This improved education and training at those centers, leading to better patient care.

There is a wealth of information in this study, and I recommend that everyone with an interest in or are already participating in their state trauma system read it in its entirety. Hospitals that are reluctant to join or are lagging in meeting criteria need to recognize that they are not serving their communities as well as they think. And legislators must realize that the financial impact of even a small investment has real and significant consequences to their constituents.

Related posts:

Reference: Does the Institution of a Statewide Trauma
System Reduce Preventable Mortality and Yield
a Positive Return on Investment for Taxpayers? JACS in press, 2017.

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