Tag Archives: prediction

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.

Using The CT Scan As A Crystal Ball For Trauma?

Two abstracts that are being presented at the American College of Surgeons Clinical Congress this week use CT scans to predict interesting things. They are things that you would not think a CT scanner should be able to do.

So can we use arcane measurements of things found on CT scan to make accurate predictions about our patients? Sure, if we see very low density bubbles (free air) in the abdomen, it’s pretty likely that some kind of abdominal catastrophe has occurred. Or if their is a large amount of high density fluid (blood) in the left chest after a stab wound, the patient will probably require a chest tube.

But what about other measurements that wouldn’t seem to be related to anything? Could we have found a magic crystal ball here, or is it just wishful thinking?

The first abstract evaluated the ability of the waist to hip ratio (WHR) to predict outcomes after trauma. Obviously, this is the width of the waist divided by the width of the body at the hips.

waist-hips-ratio1

Here are the factoids for this study:

  • 555 patients were analyzed retrospectively over 1 year at a Level I trauma center.
  • In-hospital complications and death were specifically analyzed
  • Using a receiver operating characteristic curve, the authors determined that a magic ratio of 1 was the best predictor
  • Complications were significantly higher in the group with WHR>1 (50% vs 19%) as was mortality (17% vs 7%)
  • Regression analysis showed that patients with WHR>1 were 4x more likely to have a complication and 3x more likely to die
  • WHR was only weakly correlated with BMI

Bottom line: WTF? How can this be, you ask? Just because your patient is a bit “fusiform” in shape, they have a rougher time after trauma? Well, in this case there may actually be some basis for the findings. There are thousands of articles in the literature that have identified that this shape actually is associated with higher complications and mortality in general. And there are already some published trauma papers that have confirmed this association. Interestingly, the BMI was less predictive that the WHR in this study, so this may be a better surrogate measure for obesity.

The number of patients enrolled is reasonable, and the statistics look sound (for just being an abstract). So there may be something here. However, before you start using the “measure tool” on your CT console on every trauma patient, wait for the confirmatory prospective studies to come along. 

Tomorrow, a look at a not-so-good study of this type, looking at an even more arcane metric on the CT scan.

Reference: Computed tomorgraphy-measured waist to hip ratio: a reliable predictor of outcomes after trauma. ACS Scientific Forum, trauma abstracts, 2016.

ABC: A Quick & Dirty Way to Predict Massive Transfusion

It’s nice to have blood available early when major trauma patients need it. Unfortunately, it’s not very practical to have several units of O neg pulled for every trauma activation, let alone activate a full-blown massive transfusion protocol (MTP). Is there any way to predict which trauma patient might be in need of enough blood to trigger your MTP?

The Mayo Clinic presented a paper at the EAST Annual Meeting a few years ago that looked at several prediction systems and how they fared in predicting the need for massive transfusion. Two of the three systems (TASH – Trauma Associated Severe Hemorrhage, McLaughlin score) are too complicated for practical use. The Assessment of Blood Consumption tool is simple, and it turns out to be quite predictive.

Here’s how it works. Assess 1 point for each of the following:

  • Heart rate > 120
  • Systolic blood pressure < 90
  • FAST positive
  • Penetrating mechanism

A score >=2 is predictive of massive transfusion. In this small series, the sensitivity of ABC was 89% and the specificity was 85%. The overtriage rate was only 13%.

The investigators were satisfied enough with this tool that it is now being used to activate the massive transfusion protocol at the Mayo Clinic. Although the abstract is no longer available online, it appears to be remarkably similar to a paper published in 2009 from Vanderbilt that looks at the exact same scoring systems. Perhaps this is why it never saw print? But the results were the same with a sensitivity of 75% and a specificity of 86%.

Here’s a summary of the number of parameters vs the likelihood the MTP would be activated:

ABC Score         % requiring massive transfusion
0                                1%
1                               10%
2                               41%
3                               48%
4                             100%

Bottom line: ABC is a simple, easy to use and accurate system for activating your massive transfusion protocol, with a low under- and over-triage rate. It doesn’t need any laboratory tests or fancy equations to calculate it. If two or more of the parameters are positive, be prepared to activate your MTP, or at least call for blood!

Related post:

References: 

  • Comparison of massive blood transfusion predictive models: ABC, easy as 1,2,3. Presented at the EAST 24th Annual Scientific Assembly, January 26, 2011, Session I Paper 4. (No longer available online)
  • Early prediction of massive transfusion in trauma: simple as ABC (assessment of blood consumption)? J Trauma 66(2):346-52, 2009.

Predicting Escalation Of Domestic Violence

Most trauma professionals will have the opportunity to provide care for victims of domestic violence some time during their career. We are on the front lines and can unfortunately see the damage first hand. From time to time, the abuse escalates to a point where the woman (typically) is murdered. Is there a way to predict this fatal progression so it can be avoided?

The answer is yes! The Danger Assessment Tool (DAT) was developed 25 years ago and has been validated. Even though the instrument is old, it remains extremely helpful. The unfortunate thing is that at least half of the women involved do not recognize the grave peril they are in.

Some key points that were uncovered in the development of the DAT:

  • If a gun or other weapon is used to threaten, the risk of being murdered increases 20-fold
  • If there is merely a gun in the house, the risk of murder increases 6 times
  • If the abuser threatens murder, the risk of being killed increases 15-fold
  • Other indications of increased risk of death include heavy substance abuse, extreme jealousy, stepchild in the household, attempts to choke and forced sex

Bottom line: Domestic violence is criminal. We must go beyond the physical treatment and make sure these individuals are safe. Use the Danger Assessment Tool routinely to help identify women most at risk of losing their lives and bring all your social services resources to bear to keep them safe!

Download: Danger Assessment Tool

References:

  • Campbell, Jacquelyn C., Assessing Dangerousness: Violence by Sexual Offenders, Batterers, and Child Abusers, Newbury Park, CA: Sage Publications, 1995.
  • Campbell, Jacquelyn C. , Phyllis W. Sharps, and Nancy Glass, “Risk Assessment for Intimate Partner Violence,” in Clinical Assessment of Dangerousness: Empirical Contributions, ed. Georges-Franck Pinard and Linda Pagani, New York: Cambridge University Press, 2000: 136–157.

Predicting Escalation Of Domestic Violence

Most trauma professionals will have the opportunity to provide care for victims of domestic violence some time during their career. We are on the front lines and can unfortunately see the damage first hand. From time to time, the abuse escalates to a point where the woman (typically) is murdered. Is there a way to predict this fatal progression so it can be avoided?

The answer is yes! The Danger Assessment Tool (DAT) was developed 25 years ago and has been validated. Even though the instrument is old, it remains extremely helpful. The unfortunate thing is that at least half of the women involved do not recognize the grave peril they are in.

Some key points that were uncovered in the development of the DAT:

  • If a gun or other weapon is used to threaten, the risk of being murdered increases 20-fold
  • If there is merely a gun in the house, the risk of murder increases 6 times
  • If the abuser threatens murder, the risk of being killed increases 15-fold
  • Other indications of increased risk of death include heavy substance abuse, extreme jealousy, stepchild in the household, attempts to choke and forced sex

Bottom line: Domestic violence is criminal. We must go beyond the physical treatment and make sure these individuals are safe. Use the Danger Assessment Tool routinely to help identify women most at risk of losing their lives and bring all your social services resources to bear to keep them safe!

Download: Danger Assessment Tool

References:

  • Campbell, Jacquelyn C., Assessing Dangerousness: Violence by Sexual Offenders, Batterers, and Child Abusers, Newbury Park, CA: Sage Publications, 1995.
  • Campbell, Jacquelyn C. , Phyllis W. Sharps, and Nancy Glass, “Risk Assessment for Intimate Partner Violence,” in Clinical Assessment of Dangerousness: Empirical Contributions, ed. Georges-Franck Pinard and Linda Pagani, New York: Cambridge University Press, 2000: 136–157.