All posts by TheTraumaPro

Undergrading Spleen Injury

We love our CT scans! They’re so high tech, with such detailed images popping up on the monitor so quickly. To take advantage of the detail, we’ve come up with fancy grading systems that can be used to direct care. But are they all they’re cracked up to be?

CT grading of spleen injury is a prime example. We’ve got a nice, detailed system that looks at laceration depth, subcapsular hematoma size and vascular injury. We can use it to predict the likelihood of needing an operation and where we should admit someone in the hospital (ICU vs ward). And when we see the injury on the screen, we believe that we can accurately apply the scoring system to these beautiful images.

But unfortunately, it’s not that simple.Scanning obtains multiple images in an axial plane and lays them out for us to look at. However, the spleen (and most other organs) and not shaped like a cube. It is curved, with complex nooks and crannies that can look like cracks. Moderate to large hematoma around the spleen can obscure lacerations. And the hilum is even more complicated and variable in shape.

Because of this, CT scans of the abdomen tend to underestimate the true extent of injury, especially in the higher grades. Grade I and II injuries are usually accurate, but in Grades III-V, the scan tends to undergrade by 1 (30% of cases) or 2 grades (45% of cases) when re-graded at surgery.

Bottom line: Grade I and II injuries are generally managed in a lower intensity setting and almost never require operation. But beware of the higher grades! It is very likely that it’s higher than you think. This means that if your patient slowly becomes tachycardic or their blood pressure softens, believe the clinical evidence. Don’t rely on a CT scan that was done hours ago that may be hiding a more severe injury than you think! (This applies to liver injuries as well)

Related posts:

Reference: Correlation of operative and pathological injury grade with computed tomographic grade in the failed nonoperative management of blunt splenic trauma. Euro J Trauma Emerg Surg – Online First 2 Mar 2012.

What Percent Pneumothorax Is It?

What percent pneumothorax?

Frequently, radiologists and trauma professionals are coerced into describing the size of a pneumothorax seen on chest xray in percentage terms. They may say something like “the patient has a 30% pneumothorax.”

The truth is that one cannot estimate a 3D volume based on a 2D study like a conventional chest xray. Everyone has seen the patient who has no or a minimal pneumothorax on a supine chest xray, only to discover one of significant size with CT scan.

Very few centers have or use the software that can determine the percentage of chest volume taken up with air. There are only two percentages that can be determined by viewing a regular chest xray: 0% and 100%. Obviously, 0% means no visible pneumothorax, and 100% means complete collapse. Even 100% doesn’t really look like 100% because the completely collapsed lung takes up some space. See the xray at the top for a 100% pneumothorax.

If you line up 10 trauma professionals and show them a chest xray with a pneumothorax, you will get 10 different estimates of their size. And there aren’t any guidelines as to what size demands chest tube insertion and what size can be watched.

Bottom line: The solution is to be as quantitative as possible. Describe the pneumothorax in terms of the maximum distance the edge of the lung is from the inside of the chest wall, and which intercostal space the pneumothorax extends to. So instead of saying “the patient has a 25% pneumo,” say “the pneumothorax is 1 cm wide and extends from the apex to the fifth intercostal space on an upright film.”

Repeat Imaging: What Good Is It?

I’ve written previously about how often imaging gets repeated once a trauma patient gets transferred to a trauma center (click here). There are many reasons, including clinical indications, need for advanced imaging (reconstructions), or lack of contrast. But at least 20% have to be repeated because the media is incompatible or not sent with the patient. Sounds like a problem, but is it a significant one?

A recent retrospective analysis of about 2,000 transfers to a Level I center looked at the reasons for repeat imaging and changes in outcome due to it. The paper found several interesting things:

  • Repeat imaging was more likely in more severely injured patients
  • Hospitals that transferred more patients to the trauma center tended to do more scans before transfer
  • Patients who had repeat imaging stayed in the ED longer waiting for definitive disposition
  • Repeat images did not improve outcomes (LOS, DC home, mortality)
  • A rough estimate of $354 more in charges was attributed to repeat imaging

Bottom line: Repeat imaging is wasteful, expensive and increases time in the ED. And don’t forget about the radiation exposure. With all the emphasis on pushing hospitals to use an electronic medical record, there needs to be a similar push to standardize methods for transferring radiographic images between hospitals to address the problem of repeat imaging.

Related posts:

Reference: Repeat imaging in trauma transfers: A retrospective analysis of computed tomography scans repeated upon arrival to a Level I trauma center. J Trauma 72(5):1255-1262, 2012.

Is Applying Or Removing That Cervical Collar Dangerous?

Cervical collars are applied to blunt trauma patients all the time. And most of the time, the neck is fine. It’s just those few patients that have fracture or ligamentous injury that really need it. 

I’ve previously written about how good some of the various types of immobilization are at limiting movement (click here). But what happens when you are actually putting them on or taking them off? Could there be dangerous amounts of movement then?

Several orthopaedics departments studied this issue using an electromagnetic motion detector on “fresh, lightly embalmed cadavers” (!) to determine how much movement occurred when applying and removing 1- and 2-piece collars. Specifically, they used an Aspen 2-piece collar, and an Ambu 1-piece. They were able to measure flexion/extension, rotation and lateral bending.

There were no significant differences in rotation (2 degrees) and lateral bending (3 degrees) when applying either collar type or removing them (both about 1 degree). There was a significant difference (of 0.8 degrees) in flexion/extension between the two types (2-piece flexed more). Movement was similarly small and not significantly different in either collar when removing them.

Bottom line: Movement in any plane is less than 3-4 degrees with either a 1-piece or 2-piece collar. This is probably not clinically significant at all. Just look at my related post below, which showed that once your patient is in the rigid collar, they can still flex (8 degrees), rotate (2 degrees) and move laterally (18 degrees) quite a bit! So be careful when using any collar, but don’t worry about doing damage if you use it correctly.

Related post:

Reference: Motion generated in the unstable cervical spine during the application and removal of cervical immobilization collars. J Trauma 72(6):1609-1613, 2012.

Extubating Trauma Patients In The ED

Many patients are intubated in the emergency department who need brief control of their airway or behavior. In some cases, the condition requiring intubation resolves while they are still in the department. Most of the time these patients are admitted, typically to an ICU bed, for extubation. This is expensive and uses valuable resources. Is it possible to safely extubate these patients and possibly send them home?

Maryland Shock Trauma and Mount Sinai Medical Center looked at their experience in extubating selected patients in the ED. They looked at a series of 50 patients who were intubated for combativeness, sedation, or seizures. A specific protocol was followed to gauge whether or not extubation should be attempted.

None of the patients who were extubated per protocol required unplanned reintubation. One patient underwent planned reintubation when taken to the OR for an orthopedic procedure. 16% of patients were able to be discharged home from the ED.

Bottom line: A subset of patients who are intubated in the emergency department can be extubated once the inciting factor has resolved. These factors include sedation for painful procedures and combativeness. Following this protocol can reduce admission rates and reduce the use of scarce intensive care unit resources.

Click here to download a copy of the ED extubation protocol.

Related post: Trauma 20 years ago: ED intubation for head injury

Reference: Trauma patients can be safely extubated in the emergency department. J Emerg Med 40(2):235-239, 2011.

NOTE: The EMCrit blog, written by Scott Weingart, covered this topic in November 2010. He is the first author on the paper and has created a nice podcast on the topic. You can find his blog here, and you can download the podcast here.