All posts by The Trauma Pro

Geriatric Outcome Prediction From The P.A.L.LI.A.T.E Consortium

April 24, 2017 The Trauma Pro Leave a comment

The continuing rise in geriatric trauma cases seen at trauma centers has necessitated the creation of new infrastructure for evaluating, treating, and assessing outcomes in injured elders. The ability to predict the likely outcome after trauma is extremely important in shaping the management of these patients after discussion with them and their families. Unfortunately, the tools we have for those prognostications are rather complicated, yet rudimentary.

The gold standard to date is TRISS, which combines physiologic data (revised Trauma Score) at the time of first encounter with anatomic injury information (Injury Severity Score). This allows the calculation of a validated probability of survival (Ps).

However, TRISS is unwieldy and frequently cannot be calculated due to missing data. A consortium was created to address these shortcomings. Of course, they chose a name with an unwieldy acronym: Prognostic Assessment of Life and LImitations After Trauma in the Elderly (PALLIATE).

This group developed the Geriatric Trauma Outcome Score (GTOS) in 2015. They recently published a study comparing GTOS with the gold standard TRISS. This could be important since GTOS is easier to calculate, with less opportunity for missing data since it relies only on age, ISS, and presence of blood transfusion.

They calculated outcomes of nearly 11,000 patients at three centers, and found that GTOS worked as well as TRISS. The major advantage was that GTOS requires only three variables:

GTOS = Age + (ISS x 2.5) + (22 if blood transfused in first 24 hours)

Then, just to make your head spin a little more, the GTO score value gets plugged into this logistic model equation:

Bottom line: GTOS is helpful in some ways, but not in others. It does allow calculation of the probability of survival in elderly patients as well as traditional methods, but with more readily available data points.

However, it is just a probability. It may predict that someone like your patient has a 3% probability of survival, but it cannot tell specifically that your patient is in the 3% vs the 97%. The consortium was trying to make it easier and more objective for clinicians to discuss care plans with family. But this is not really the case.

And a bigger problem is that it gives us no guidance as to quality of life or level of independence for those patients who will probably survive. These factors are, by far, the most important ones when having those hard discussion with patient and/or family. We still need a tool that will guide us on functional outcomes, not just life or death.

Related posts:

Reference: A comparison of prognosis calculators for geriatric trauma: A P.A.L.LI.A.T.E. consortium study. J Trauma, publish ahead of print DOI: 10.109, 2017.

Pet Peeve

Pet Peeve: (Not So) Clever Medical Study Acronyms

April 21, 2017 The Trauma Pro Leave a comment

I’m not a big fan of acronyms, although they do serve a purpose. We use them all the time providing medical care. CBC. CTA. CXR. ROSC. And a zillion others. And they can actually be helpful so you don’t have to say or write down some ridiculously long phrase. OMG.

But what really bothers me is the rise of researchers designing clever acronyms for medical studies. The first one , the University Group Diabetes Program (UGDP), was developed in the 1970s. It was actually shortened by journals and media to make for an easier presentation, not by the group themselves.

But then in the 1980s, the Multiple Risk Factor Intervention Trial (MRFIT) came along. It evaluated the impact of multiple interventions on cardiovascular mortality. Mr. Fit. Get it? This was the first of an ever growing number of studies that chose acronyms that were either cleverly related to the work in some way, or that made a catchy new word to help people remember it.

And the number of these acronyms has been growing rapidly. From 1992 to 2002, they increased from 245 to 4100, a 16-fold increase. There are now so many acronyms that many simple ones are being reused. And it seems like studies without an acronym are becoming the minority.

Plus, we’ve moved away from creating pure acronyms like UGDP that are derived from the first letter of each word. Now we use multiple letters from a word, skip some words altogether, or don’t even bother to use the words at all. There are MICHELANGELO, MATISSE, PICASSO, and EINSTEIN studies that were given the name just for the positive association. Nothing to do with the study at all.

This is all a warm-up for my next post, which reviews a geriatric trauma prognosis calculator from the PALLIATE consortium (Prognostic Assessment of Life and Limitations After Trauma in the Elderly). Groan! The title itself almost made me not want to read it. But I am compelled. Tune in Monday.

Reference: SearCh for humourIstic and Extravagant acroNyms and Thoroughly Inappropriate names For Important Clinical trials (SCIENTIFIC): qualitative and quantitative systematic study. BMJ. 2014;349:g7092.

Head

Tips For Taking Care Of CSF Leaks

April 19, 2017 The Trauma Pro Leave a comment

The management of CSF leaks after trauma remains somewhat controversial. The literature is sparse, and generally consists of observational studies. However, some general guidelines are supported by large numbers of retrospectively reviewed patients.

Ensure that the patient actually has a CSF leak. In most patients, this is obvious because they have clear fluid leaking from ear or nose that was not present preinjury. Here are the options when the diagnosis is less obvious (i.e. serosanguinous drainage):
- The “halo” or “double ring sign” is a form of pillow chromatography. The blood components separate from the CSF as they move through the pillow fabric, creating a clear ring or halo surrounding a bloody spot. This is the cheapest, fastest test and is actually fairly reliable.
- High resolution images of the temporal bones and skull base. If an obvious breach is noted, especially if fluid is seen in the adjacent sinuses, then a CSF leak is extremely likely.
- Glucose testing. CSF glucose is low compared to serum glucose.
- Beta 2 transferrin assay. Don’t do it!! This marker is very specific to CSF. However, the test is expensive and results may take several days to a few weeks to receive. Most leaks will have closed before the results are available, making this a poor test.
Place the patient at bed rest with the head elevated. The basic concept is to decrease intracranial pressure, which in turn should decrease the rate of leakage. This same technique is used for management of mild ICP increases after head injury.
Consider prophylactic antibiotics carefully. The clinician must balance the likelihood of meningitis with the possibility of selecting resistant bacteria. If the likelihood of contamination is low and the patient is immunocompetent, antibiotics may not be needed.
Ear drops are probably not necessary. They may confuse the picture when gauging resolution of the CSF leak.
Wait. Most tramatic leaks will close spontaneously within 7-10 days. If it does not, a neurosurgeon or ENT surgeon should be consulted to consider surgical closure.

References:

Brodie HA, Thompson TC. Management of complications from 820 temporal bone fractures. Am J Otol, 1997;18:188-197.
Brodie HA. Prophylactic antibiotics for posttraumatic cerebrospinal fluid fistulas. Arch Otolaryngol Head, Neck Surg. 123:749-752.

Tips

Another Worthless Test? Serum / Urine Myoglobin

April 18, 2017 The Trauma Pro Leave a comment

We often rely on diagnostic testing to augment our physical examination skills. These tests may be in the form of imaging that allows us to see things that we normally cannot, or measurements of body composition using laboratory testing.

If you look at the “menu” of tests that your hospital laboratory offers, it is very extensive. You can order just about any assay imaginable on any body fluid or tissue. Diagnosis of many of the clinical diseases or disorders that we treat has come to rely on some of these assays.

Let’s take rhabdomyolysis, for example. I’ve been writing about compartment syndrome in the last few posts. One of the byproducts of a full-blown compartment syndrome is muscle breakdown. Two of the well-known substances released from injured muscle are creatine kinase (CK) and myoglobin.

Many textbooks advise the clinician to monitor levels of these substances, since myoglobin is toxic to nephrons and may lead to kidney injury. So most trauma professionals routinely write orders for serial CK, myoglobin, as well as creatinine to monitor renal function.

But most clinicians do not know their laboratory as well as they think. Your lab has the capability to perform commonly requested tests rapidly and on site. But what about assays that are rarely ordered? Does it make sense to have the reagents necessary for these uncommon tests on hand at all times? They degrade over time, and may very well expire before they are ever used, costing money to replace.

So most hospital labs send uncommon assays out to larger labs that perform the test for a large geographic area. But how does the “send out” specimen get to that lab? By courier (if local) or more commonly, by delivery service (if remote). And obviously, this takes time. And some assays are complex and may take hours or days to perform.

At my hospital lab, a serum or urine myoglobin assay is a “send out” test. And if you ask, the lab will tell you that it takes 3-4 business days to get the result. So if you send it out Wednesday, you will have the result the following Monday! Does it make any sense to get serial myoglobins? Or even a single myoglobin test? By the time you get the result, your patient will be treated and gone!

Bottom line: Think about the tests that you order very carefully. If you are ordering something out of the ordinary, check with your lab. Is it a “send out” test? How long does it take to get a result? And more importantly, how expensive is it? These tend to be pricey due to the low frequency of processing.

Then do the math. Is it worth the wait and expense? Or can you get the same information using routine, in house testing? In the case of rhabdomyolysis, serum CK levels are good markers, as is visual inspection of the urine. If it’s any darker than a light yellow, there may be myoglobin present. A quick and dirty way to confirm is some inexpensive testing: a urine specimen that is dipstick positive for blood, and with microscopic analysis shows few if any RBCs usually means myoglobin. Voila! Diagnosis now, not in 4 days.

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