Welcome to the current newsletter. In this one, I’ll be presenting and discussing some of the “Laws of Trauma” that I’ve observed over the years. I think you’ll find them interesting and amusing, and hopefully valuable. As a bonus, I’ll also include a copy of Norm McSwain’s Rules of Patient Care. Enjoy!
Most patients with major traumatic injuries are handled in a very systematic way by both EMS and trauma centers. We have routines and protocols designed to provide rapid, quality care to these individuals. But over the years, I’ve begun to appreciate the fact that there is a very small subset of these patients who are different.
I term these patients as having an “egg timer injury”. These are patients who have only a certain number of minutes to live. This fact requires us to change the usual way we do things in order to save their lives or limbs. The usual routine may be too slow.
And unfortunately, no one can tell us exactly how many minutes are left on the timer. We only know that it’s ticking. Here are some examples of such injuries:
- Pericardial tamponade
- Penetrating injury to the torso with profound hypotension
- Orbital compartment syndrome
In each case, speed is of the essence. What can we do to decrease the time to definitive intervention? For prehospital providers, you may need to bypass a closer hospital that might not have the necessary resources at a particular time of day. Once at the hospital, the patient may need to bypass the emergency department and proceed straight to the OR. Or you may need to do a lateral canthotomy yourself, rather than waiting for an ophthalmologist to drive in only to have the patient lose their vision because of the delay.
Bottom line: Remember that protocols are not necessarily etched in stone. They will cover 99.9% of cases you see. But that remaining 0.1%, the patients with the “egg timer injury”, will require you to think through what you know about the patient at the time, and make decisions about their care that may have a huge outcome on their life or livelihood. And as always, if you find that you must do things differently in the best interest of your patient, be sure to document what you knew and your thought processes thoroughly so you explain and/or justify your decision-making when you are invariably asked.
Syncope accounts for 1-2% of all ED visits, and is a factor in some patients with blunt trauma, especially the elderly. If syncope is suspected, a “syncope workup” is frequently ordered. Just what this consists of is poorly defined. Even less understood is how useful the syncope workup really is.
Researchers at Yale retrospectively looked at their experience doing syncope workups in trauma patients. They were interested in seeing what was typically ordered, if it was clinically useful, and if it impacted length of stay.
A total of 14% of trauma patients had syncope as a possible contributor to their injury. The investigators found that the following tests were typically ordered in these patients:
- Carotid ultrasound (96%)
- 2D Echo (96%)
- Cardiac enzymes (81%)
- Cardiology consult (23%)
- Neurology consult (11%)
- EEG (7%)
- MRI (6%)
Most of this testing was normal. About 3% of cardiac enzymes were abnormal, as were 5% of carotid imaging and 4% of echocardiograms.
Important! Of the patients who underwent an intervention after workup, 69% could have been identified based on history, physical exam, or EKG and did not depend on any of the other diagnostic tests.
Is it possible to determine a subset of this population that may show a higher yield for this screening? Surgeons at Temple University in Philadelphia found that there was little utility in using carotid duplex studies. They did note that patients with a history of heart disease were more likely to have an abnormal EKG, and that an abnormal EKG predicted an abnormal echo. Overall, only patients with a history of significant cardiac comorbidity, older age, and higher ISS had findings requiring intervention.
Bottom line: Don’t just reflexively order a syncope workup when there is a question of this problem. Think about it first, because the majority of these studies are nonproductive. They are not needed routinely in trauma patients with “syncope” as a contributing factor. Obtain a good cardiac history, and if indicated, order an EKG and go from there. See the practice guideline proposed by the Temple group below. And be sure to include the patients primary doctor in the loop!
- Routine or protocol evaluation of trauma patients with suspected syncope is unnecessary. J Trauma 70(2):428-432, 2011.
- Syncope workup: Greater yield in select trauma population. Intl J Surg, accepted for publication June 27, 2017.
Deep venous thrombosis (DVT) and pulmonary embolism (PE), collectively known as venous thromboembolism (VTE), are major concerns in all hospitalized patients. A whole infrastructure has been developed to stratify risk, monitor for the presence of, and provide prophylactic and/or therapeutic drugs for treatment. But if you critically look at the literature from the past 20 years or so, we have not made much progress.
One of the newer additions to our arsenal has been to figure a way to determine the “optimal” dose of enoxaparin. Three options are now available: weight-based dosing, confirmation by thormboelastography (TEG), and anti-factor Xa assay. Let’s look at another paper that focuses on the last item.
Anti-factor Xa levels provide a way to monitor low molecular weight heparin activity. A number of papers published have sought to determine a level that predicts adequate activity. Although they are not of the greatest size or quality, a range of 0.2-0.4 IU/ml seems to be the consensus.
A large number of patients at a busy Level I trauma center were retrospectively studied to see if achieving a peak anti-factor Xa level of at least 0.2 IU/ml would result in less VTE. All patients were started on enoxaparin 30mg SQ bid within 48 hours of admission. Anti-factor Xa was measured 4 hours after the third dose. If the level was less than 0.2 IU/ml, the dose was increased by 10mg per dose. The cycle was repeated until anti-factor Xa was therapeutic.
Here are the factoids:
- All patients with a Greenfield Risk Assessment Profile (RAP) of 10 or more (high risk) were included; duplex ultrasound surveillance for lower extremity DVT was performed weekly
- 194 patients were included, with an average RAP of 9 and ISS of 23 (hurt!)
- Overall VTE rate was 7.4%, with 10 DVT and 5 PE (!)
- Median time to diagnosis was 14 days
- Initial anti-factor Xa levels were therapeutic in only one third of patients, and another 20% reached it after dose increases. 47% never achieved the desired level, even on 60mg bid dosing.
- There was no difference in DVT, PE, or VTE rates in patients who did vs did not achieve the goal anti-factor Xa level
- Injury severity and obesity correlated with inability to reach the desired anti-factor Xa level
Bottom line: In this study, achieving or not achieving the goal anti-factor Xa level made no difference whether the patient developed VTE or not. And it was difficult to achieve anyway; only about half ever made it to the desired level. How can this happen?
Well, there are still many things we don’t understand about the genesis of VTE. There are probably genetic factors in every patient that modify their propensity to develop it after trauma. And there are certainly additional mechanisms at play which we do not yet understand.
For now, we will continue to struggle, adhering to our existing protocols until we can figure out the real reason(s) VTE happens, the best ways to prevent, and the best methods to treat.
- Anti-Xa levels: who cares -Part 1
- Anti-Xa levels: who cares – Part 1.5
- Anti-Xa levels: who cares – Part 2
- Anti-Xa levels: who cares – Part 3
Reference: Relation of Antifactor-Xa peak levels and venous thromboembolism after trauma. J Trauma accepted for publication Aug 2, 2017.
This is another one of my most popular posts. Many patients (and more than a few doctors) have a hard time grasping the fact that the medications that we prescribe often do more than just one thing. They actually do many, many things most of the time. Sometimes too many. Here’s the post:
One of the cornerstones of allopathic medicine is the use of drugs to treat disease conditions. And unfortunately, one of the side effects of using drugs to treat problems is the production of side effects(!).
In trauma care, even something as simple as treating pain from an injury can create major problems. Give a narcotic pain medication. The patient gets nauseated and vomits. Try a different narcotic. The patient develops constipation. Give stool softeners and cathartics. Diarrhea. Then pseudo-obstruction develops. Give neostigmine. The patient becomes bradycardic. Give… well, you get the picture.
How common are side effects? Very! Did anyone see the first TV commercials for Chantix, the smoking cessation drug? It was about 3 minutes long because of the long list of side effects that were described. I’m surprised anyone was willing to risk them just to stop smoking cigarettes.
A recent study looked at the number of side effects listed on the labels of 5,602 medications approved by the FDA. There were a grand total of 534,125 adverse drug effects described in the packaging. Some interesting statistics:
- The number of adverse effects for ranged from 0 to 525(!) for a single drug
- The median number of adverse effects was 49, the average was 70
- Drugs with the most side effects are used in neurology, psychiatry and rheumatology
- Newer drugs had significantly more adverse effects than older ones
It’s certainly easy to bash pharmaceutical companies on their products. But some of these findings may be due to more rigorous testing and monitoring, as well as nuances in the populations in which these drugs are used.
Bottom line: Drugs are chemicals! Each chemical has a number of effects, some of which are desirable, and some of which are not. The drug companies choose to market a drug based on one desired effect (e.g. control of nausea). Just remember, when you give that medication, you will probably get the desired effect, but you will just as likely also get some of the other 69 possible side effects. Be prepared, and prescribe sensibly.
Reference: A quantitative analysis of adverse events and “overwarning” in drug labeling. Arch Int Med 171(10):944-946, 2011.