Category Archives: General

Aspirin For DVT Prophylaxis In Trauma

May 2, 2017 The Trauma Pro Leave a comment

The use of mechanical and pharmacologic prophylaxis for prevention of deep venous thrombosis (DVT) and venous thromboembolism (VTE) in trauma patients is nearly universal. However, no matter how closely we adhere to existing guidelines, some patients will develop these conditions. Indeed, about 80% of patient who suffer some type of VTE event were receiving prophylaxis at the time.

Trauma is a major factor in causing hypercoagulability. Although current chemoprophylaxis focuses on clotting factors, platelets play a big part in the clot formation process. Our usual drugs, though (various flavors of heparin), have no effect on them.

What about adding aspirin to the regimen? My orthopedic colleagues have been requesting this for years. There is a reasonable amount of data in their literature that it is effect in patients with knee arthroplasty only. As usual, it is misguided to try to generalize management based on experience from one specific body region or operation.

A single Level I trauma center reviewed its data on aspirin prophylaxis for trauma patients. They reviewed their registry data from 2006 to 2011. They identified 172 trauma patients with duplex ultrasound proven DVT. These patients were matched with 1,901 control patients who underwent at least one duplex and never developed DVT. Matching was performed carefully to ensure that age, probability of death, number of DVT risk factors, and presence of TBI were similar. The total number of matched patients studied was 110.

And here are the factoids:

About 7% of patients with DVT were on aspirin at the time of their injury, vs 14% of the matched controls
7% were taking warfarin, and 4% were taking clopidogrel
Analysis showed that patients taking aspirin had a significantly decreased chance of DVT after injury
On further analysis, it was found that this effect was only significant if some form of heparin was given for prophylaxis as well.

Bottom line: So before you run off and start giving your patients aspirin, think about what this study really said. Patients taking aspirin before their injury and coupled with heparin after their injury have a lower rate of DVT. It gives us no guidance as to whether adding aspirin after the fact, or using aspirin alone, are useful. And we still don’t know if any of this decreases pulmonary embolism or mortality rates.

Related posts:

Reference: Aspirin as added prophylaxis for deep vein thrombosis in trauma: a retrospective case-control study. J Trauma 80(4):625-30, 2016.

General

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.

General, What the heck?

What The Heck? Part 2: Progressive Back Pain After Heavy Lifting

April 14, 2017 The Trauma Pro 1 Comment

Yesterday, I described a case of a young athlete who developed progressive back pain after rapidly increased his deadlift weights. He presented to the hospital with back pain and inability to get up from a supine position. He had firm and tender paraspinal muscles in his lower back, but no other findings.

What to do next? Obviously, we need a bit more information on the bony structures. Other than run of the mill muscle strain, a compression fracture would be the next most common diagnosis. In this young, healthy athlete, a simple set of AP and lateral spine images should be sufficient. But if you opted for a CT scan, I won’t argue. In either case, the images were normal.

Since there is significant muscle pain and tenderness, a lab panel with a few extras is in order, as well. The usual electrolytes, etc were normal. Creatinine was 0.9, but CPK was 60,000!

Now what are you thinking? What’s the diagnosis, and what is the decision tree for treatment?

Add your comments below, or tweet them out. I’ll finish this topic up in the next post.

General

Autotransfusing Blood Lost Through The Chest Tube

April 4, 2017 The Trauma Pro Leave a comment

Autotransfusing blood that has been shed from the chest tube is an easy way to resuscitate trauma patients with significant hemorrhage from the chest. Plus, it’s usually not contaminated from bowel injury and it doesn’t need any fancy equipment to prepare it for infusion.

It looks like fresh whole blood in the collection system. But is it? A prospective study of 22 patients was carried out to answer this question. A blood sample from the collection system of trauma patients with more than 50 cc of blood loss in 4 hours was analyzed for hematology, electrolyte and coagulation profiles.

The authors found that:

The hemoglobin and hematocrit from the chest tube were lower than venous blood (Hgb by about 2 grams, Hct by 7.5%)
Platelet count was very low in chest tube blood
Potassium was higher (4.9 mmol/L), but not dangerously so
INR, PTT, TT, Factor V and fibrinogen were unmeasurable

Bottom line: Although shed blood from the chest looks like whole blood, it’s missing key coagulation factors and will not clot. Reinfusing it will boost oxygen carrying capacity, but it won’t help with clotting. You may use it as part of your massive transfusion protocol, but don’t forget to give plasma and platelets according to protocol. This also explains why you don’t need to add an anticoagulant to the autotransfusion unit prior to collecting or giving the shed blood!

Reference: Autotransfusion of hemothorax blood in trauma patients: is it the same as fresh whole blood? Am J Surg 202(6):817-822, 2011.

General

Trauma In Pregnancy 5: C-Section – When?

February 17, 2017 The Trauma Pro Leave a comment

The perimortem C-section (PMCS) is a heroic procedure designed to salvage a viable fetus from a moribund mother. Interestingly, in some mothers, delivery of the fetus results in return of spontaneous circulation.

The traditional teaching is that PMCS should be started within 4-5 minutes of the mother’s circulatory arrest. The longer it is delayed, the (much) lower the likelihood that the fetus will survive.

The reality is that it takes several minutes to prepare for this procedure because it is done so infrequently in most trauma centers. Recent literature suggests the following management for pregnant patients in blunt traumatic arrest (BTA):

Cover the usual BTA bases, including securing the airway, obtaining access and rapidly infusing crystalloid, decompressing both sides of the chest, and assessing for an unstable pelvis
Assess for fetal viability. The fundus must measure at least 23 cm.
Assess for a shockable vs non-shockable rhythm. If shockable, do two cycles of CPR before beginning the PMCS. If non-shockable, move straight to this procedure.

Bottom line: Any time you receive a pregnant patient in blunt arrest, have someone open the C-section pack while you assess and try to improve the mother’s viability. As soon as you complete the three tasks above, start the procedure! You don’t need to wait 4 minutes!

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