All posts by TheTraumaPro

Could There Be A Simpler GCS?

The Glasgow Coma Scale (GCS) has been around forever. Or really, for about 45 years. It was actually developed in the early 1970s and known as the Coma Index. It was further refined into the GCS, when 1 was selected as the minimum component score. Ever since, it has been used as a common language among clinicians to communicate gross neurologic function and trends.

But it is still somewhat complicated. Oh no it’s not, you say? Then why do so many trauma resuscitation rooms have it posted on the wall? There are three components, each with a different number of possible values. And frankly, some are harder to remember than others. Decerebrate vs decorticate, right?

So what if someone told you that a single GCS component works just about as well as the whole bunch? Researchers have been piecing this together for years, focusing on the motor component of GCS (mGCS). There are two flavors of simplified score: mGCS and Simplified Motor Score (SMS). The mGCS is just what it sounds like: the full motor component of GCS, ranging from 1-6. The SMS is further simplified from the mGCS: mGCS of 1-4 tranlsates to SMS 0, mGCS 5 = SMS 1, and mGCS 6 = SMS 2. In my opinion, this is actually more complicated because you have to remember not only the 6 mGCS levels, but also the cutoffs to convert it to SMS.

Finally, a group from Oregon Health Sciences University in Portland performed a nice meta-analysis of the best individual studies.

Here are the factoids:

  • Only papers that compared total GCS (tGCS) to mGCS or SMS were included, and only if they analyzed a receiving operator characteristic curve. The statistics appeared sound.
  • tGCS was very slightly better than either mGCS or SMS at predicting:
    • in-hospital mortality
    • neurosurgical intervention
    • emergency intubation
    • severe TBI

Bottom line: Overall, the total GCS is slightly (just a few percent) better at doing the things listed above, compared to the motor score alone or the “simplified” (really?) motor score. Is this clinically significant in the field? Probably not. And its mere simplicity makes it appealing. 

However, there is one major problem to adopting the mGCS for use outside the hospital. Inertia. As I mentioned, we have been using the full GCS score for almost 50 years. Pretty much every trauma professional is familiar with the GCS or knows where to look up the details. But I suspect that those clincicians who assume care of the patient once in the hospital, and especially the intensive care unit (neurosurgeons) will never allow the use of an abbreviated scale. Good idea, but sorry, it won’t catch on in the real world.

May Trauma MedEd Is Coming Soon!

I’m going to send out the next edition of the Trauma MedEd newsletter on May Day! This issue is dedicated to hospitals that transfer trauma patients to upstream trauma centers. It will be full of tips on how to make the decision, and how to send them safely.

Here are some of the topics:

  • Predicting patients that require transfer. Is it possible to do it sooner?
  • Imaging issues. To scan or not to scan, that is always the question.
  • Value of the RTTD Course.
  • The Checklist. Make sure you get all the essentials done before you send.
  • And a few other tidbits…

As always, this issue will go to all of my subscribers first. If you are not yet one of them, click this link to sign up and/or download back issues.

Unfortunately, non-subscribers will have to wait until I release the issue on this blog, about 10 days later. So sign up now!

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

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: (Not So) Clever Medical Study Acronyms

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.

Tips For Taking Care Of CSF Leaks

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:

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