Category Archives: General

IVC Filters: Another Nail In The Coffin?

IVC filter insertion has been one of our tools for preventing pulmonary embolism for decades. Or so we thought. Its popularity has swung back and forth over the years, and has been in the waning stage now quite some time. This pendulum like motion offers an opportunity to study effectiveness when coupled with some of the large datasets that are now available to us.

IVC filters have been used in two ways: prophylactically in patients at high risk for pulmonary embolism (PE) who cannot be anticoagulated for some reason, and therapeutically once a patient has already suffered one. Over the years, guidelines have changed, and have frequently been in conflict. Currently, the American College of Chest Physicians does not recommend IVC filters in trauma patients, while the Eastern Association for the Surgery of Trauma promote their use in certain subsets.

A Pennsylvania group performed a large, retrospective review of three databases, the  Pennsylvania Trauma Outcome Study (462K patients), the National Trauma Data Bank (5.8M patients), and the National Inpatient Sample. All were patients with an emergent trauma-related admission.

Here are the most interesting factoids:

  • About 2% of all patients underwent IVC filter insertion, and 94% were inserted prophylactically
  • About 90% of patients with a prophylactic filter had at least one predictor for PE, which means that the remaining 10% had none (!)
  • Conversely, about 86% of patients who developed a PE had at least one risk factor, meaning that 14% had no recognized risk factors (!!)
  • The use of IVC filters peaked in 2006-2008 at 2-4%, then falling steadily over the following 5-7 years to less than 1%
  • PE rates peaked in 2008, then declined by 30% in the PTOS sample and stayed steady in the NTDB

Bottom line: The use of IVC filters peaked in 2008 and has been in decline since then. But interestingly, the rates of PE and fatal PE have been steady to declining, depending on the data set. Obviously, there are always some shortcomings for studies like this. Remember, IVC filters are intended to prevent fatal PE. It is possible that some fatal PEs were not identified in these databases. Furthermore, it was not possible to obtain any information on the use of chemical prophylaxis in these patients. 

Overall, there has been no increase in PE and fatal PE rates over the time period that IVC filter usage has been decreasing. This suggests that these devices have not had their intended effect. Trauma professionals need to very seriously consider the specific indications in any patient they are considering for insertion. They may not have the protective effect you think.

Related posts:

Reference: Vena Cava Filter Use in Trauma and Rates of Pulmonary Embolism, 2003-2015. JAMA Surg 152(8):724-732, 2017.

By Request: Drugs Are Chemicals??

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.

The August Trauma MedEd Newsletter Is Coming Soon: The Laws of Trauma

I’m going to send out the next edition of the Trauma MedEd newsletter early next week. 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.

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!

Delayed Diagnoses In Children Revisited

A couple of years ago I wrote about a paper that examined patterns in delayed diagnoses in injured children. It was a single-hospital study of children treated at a Level II pediatric trauma center. In that study, the overall rate of delayed diagnosis was 4%. The orthopedic component looked high but was not really broken down in detail.

A soon-to-be-published study looked at more recent experience with this issue, specifically in pediatric patients with orthopedic injury. They specifically evaluated all pediatric patients with bone, joint, peripheral nerve, and tendon injuries treated at their Level I pediatric trauma center over a nearly 6 year period. Orthopedic surgery consults were obtained at the discretion of the trauma or primary service.

How good was their discretion? Here are the factoids:

  • 1009 trauma activations were reviewed, of which 196 (19%) were eventually diagnosed with an orthopedic injury
  • There were 18 children (9%) with a delayed diagnosis, defined as one discovered 12 hours or longer after admission. Most were missed on initial exam or imaging
  • The injuries were literally all over the place. There was no obvious pattern.
  • Six of these were detected on tertiary survey
  • Average time to discovery was 3 days, and the average age of these children was 11 years
  • Children with a delayed diagnosis tended to be much more seriously hurt (ISS 21 vs 9), and more likely to have a significant head injury (GCS 12 vs 14)
  • One child required surgery for the delayed diagnosis, the rest were managed with splinting/casting or observation

Bottom line: Delayed diagnoses happen in children, too. And typically, they are due to a failure in the physical exam. Sometimes there is nothing to discover on the exam. But often times, if the mechanism is fully taken into account and a really good  exam is performed, these injuries may be found early.

I don’t consider an injury found on tertiary exam to be a delayed diagnosis, as long as it is performed within a reasonable time frame (24-48 hours max). It’s a well established fact that some injuries will not manifest as pain or bruising until the next day, or longer. So pick a maximum time interval (but don’t make it too early either) and do a tertiary survey on all children who are trauma activations, have multiple injuries, or have a significant mechanism. 

Related posts:

Reference: Incidence of delayed diagnosis of orthopaedic injury in pediatric trauma patients. J Ortho Trauma epub ahead of print, April 29, 2017.