Tag Archives: radiology

Imaging

If A Tree Falls In A Forest…

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Time for a little philosophy today. There seem to be two camps in the world of initial diagnostic testing for trauma: selective scanning vs scan everything. I admit that I am one of the former. Yes, the more tests you do, the more things you will find. Some will be red herrings. Some may be true positives, but are they important? Here’s the key question:

“If a tree falls in a forest and no one is around, does it make a sound?”

There is a clinical corollary to this question in the field of trauma:

“If an injury exists but no one diagnoses it, does it make a difference (if there would be no change in treatment)?”

Here’s an example. On occasion, my colleagues want to order diagnostic studies that won’t make any clinical difference, in my opinion. A prime example is getting a chest CT after a simple blunt assault. A plain chest xray is routine, and if injuries are seen or the physical exam points to certain diagnoses, appropriate interventions should be taken. But adding a chest CT does not help. Nothing more than the usual pain management, pulmonary toilet, and an occasional chest tube will be needed, and those can be determined without the CT.

Trauma professionals need to realize that we don’t need to know absolutely every diagnosis that a patient has. Ones that need no treatment are of academic interest only, and can lead to accidental injury if we look for them too hard (radiation exposure, contrast reaction, extravasation into soft tissues to name a few). This is how we get started on the path to “defensive medicine.”

Bottom line: Think hard about every test you order. Consider what you are looking for, what you might find, and if it will change your management in any way. If it could, go ahead. But always consider the benefits versus the potential risks, or what I call the “juice to squeeze ratio.”

Tomorrow I’ll look at some of the “scan all” vs “scan selectively” literature. Which camp are you in?

References:

  • George Berkeley, A Treatise Concerning the Principles of Human Knowledge, 1734, section 45.
  • paraphrased by William Fossett, Natural States, 1754.
General

The 30:60 Rule For Interventional Radiology

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Interventional radiology (IR) can be a very helpful adjunct to the evaluation and management of trauma patients. I’m going to talk specifically about using it for blunt trauma today because the use in penetrating trauma can be a little more nuanced.

For blunt trauma, IR is used primarily to stop bleeding. In a smaller subset of patients, this tool is used to evaluate pulse deficits. There are two basic principles that apply in either case, and I’ve wrapped them up into a single concept: the 30:60 rule for interventional radiology. 

Of course, the second law of trauma still applies: hypotensive patients cannot leave the ED to go anywhere but the OR. Once you make sure you are not violating that one, you can start the process of going to IR.

The two portions of the rule are times: the time for the IR team to arrive to start the evaluation, and the maximum time allowed for them to succeed, hence the 30:60 numbers.

The maximum acceptable time for the patient to wait until the IR team is ready for them is typically 30 minutes. US trauma center verification requires a reasonable arrival time frame, and the vast majority of hospitals have a 30 minute expectation if the team is not already in place. This response time needs to be monitored by the trauma performance improvement program (PI) and addressed if it ever exceeds the limit.

The second number is the maximum time the radiologist is given to be successful. Like other physicians, radiologists like to do a good job and finish the work they start. If they find a particularly tortuous splenic artery to navigate, they will persist at trying to get through it in order to do a selective embolization and kill the smallest piece of spleen possible. Unfortunately, this takes time and radiation (lots). And a bleeding patient is running out of time.

The good thing is that there are surgical alternatives to most of the tasks the radiologist is working on. True, some are much more difficult surgically, like managing a shattered liver or dealing with a bleeding pelvis. In those cases, I may let the interventionalist work a little longer while I keep up with blood transfusions and monitor patient status.

Bottom line:

  • Expect a 30 minute response time from the IR team
  • Let the radiologist know they have about 60 minutes to succeed. If it looks like they can’t make that, have them go to plan B (e.g. main splenic artery embolization instead of selective)
  • Make sure an experienced trauma physician is watching the patient for decompensation and is managing fluids and blood products (no pressors!)
  • If the patient decompensates at any point, they are done in IR and must proceed to OR
General

But The Radiologist Made Me Do It!

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The radiologist made me order that (unnecessary) test! I’ve heard this excuse many, many times. Do these phrases look familiar?

  1. … recommend clinical correlation
  2. … correlation with CT may be of value
  3. … recommend delayed CT imaging through the area
  4. … may represent thymus vs thoracic aortic injury (in a 2 year old who fell down stairs)
Some trauma professionals will read the radiology report and then immediately order more xrays. Others will critically look at the report, the patient’s clinical status and mechanism of injury, and then decide they are not necessary. I am firmly in the latter camp.
But why do some just follow the rad’s suggestions? I believe there are two major camps:
  • Those that are afraid of being sued if they don’t do everything suggested, because they’ve done everything and shouldn’t miss the diagnosis
  • Those that don’t completely understand what is known about trauma mechanisms and injury and think the radiologist does
Bottom line: The radiologist is your consultant. While they are good at reading images, they do not know the nuances of trauma. Plus, they didn’t get to see the patient so they don’t have the full context for their read. First, talk to the rad so they know what happened to the patient and what you are looking for. Then critically look at their read. If the mechanism doesn’t support the diagnosis, or they are requesting unusual or unneeded studies, don’t get them! Just document your rationale clearly in the record. This provides best patient care, and minimizes the potential complications (and radiation exposure) from unnecessary tests.
Related post: 

Reference: Pitfalls of the vague radiology report. AJR 174(6):1511-1518, 2000.

General

The 30:60 Rule For Interventional Radiology

Leave a comment

Interventional radiology (IR) can be a very helpful adjunct to the evaluation and management of trauma patients. I’m going to talk specifically about using it for blunt trauma today because the use in penetrating trauma can be a little more nuanced.

For blunt trauma, IR is used primarily to stop bleeding. In a smaller subset of patients, this tool is used to evaluate pulse deficits. There are two basic principles that apply in either case, and I’ve wrapped them up into a single concept: the 30:60 rule for interventional radiology. 

Of course, the second law of trauma still applies: hypotensive patients cannot leave the ED to go anywhere but the OR. Once you make sure you are not violating that one, you can start the process of going to IR.

The two portions of the rule are times: the time for the IR team to arrive to start the evaluation, and the maximum time allowed for them to succeed, hence the 30:60 numbers.

The maximum acceptable time for the patient to wait until the IR team is ready for them is typically 30 minutes. US trauma center verification requires a reasonable arrival time frame, and the vast majority of hospitals have a 30 minute expectation if the team is not already in place. This response time needs to be monitored by the trauma performance improvement program (PI) and addressed if it ever exceeds the limit.

The second number is the maximum time the radiologist is given to be successful. Like other physicians, radiologists like to do a good job and finish the work they start. If they find a particularly tortuous splenic artery to navigate, they will persist at trying to get through it in order to do a selective embolization and kill the smallest piece of spleen possible. Unfortunately, this takes time and radiation (lots). And a bleeding patient is running out of time.

The good thing is that there are surgical alternatives to most of the tasks the radiologist is working on. True, some are much more difficult surgically, like managing a shattered liver or dealing with a bleeding pelvis. In those cases, I may let the interventionalist work a little longer while I keep up with blood transfusions and monitor patient status.

Bottom line:

  • Expect a 30 minute response time from the IR team
  • Let the radiologist know they have about 60 minutes to succeed. If it looks like they can’t make that, have them go to plan B (e.g. main splenic artery embolization instead of selective)
  • Make sure an experienced trauma physician is watching the patient for decompensation and is managing fluids and blood products (no pressors!)
  • If the patient decompensates at any point, they are done in IR and must proceed to OR
General

But The Radiologist Made Me Do It!

Leave a comment

The radiologist made me order that (unnecessary) test! I’ve heard this excuse many, many times. Do these phrases look familiar?

  1. … recommend clinical correlation
  2. … correlation with CT may be of value
  3. … recommend delayed CT imaging through the area
  4. … may represent thymus vs thoracic aortic injury (in a 2 year old who fell down stairs)
Some trauma professionals will read the radiology report and then immediately order more xrays. Others will critically look at the report, the patient’s clinical status and mechanism of injury, and then decide they are not necessary. I am firmly in the latter camp.
But why do some just follow the rad’s suggestions? I believe there are two major camps:
  • Those that are afraid of being sued if they don’t do everything suggested, because they’ve done everything and shouldn’t miss the diagnosis
  • Those that don’t completely understand what is known about trauma mechanisms and injury and think the radiologist does
Bottom line: The radiologist is your consultant. While they are good at reading images, they do not know the nuances of trauma. Plus, they didn’t get to see the patient so they don’t have the full context for their read. First, talk to the rad so they know what happened to the patient and what you are looking for. Then critically look at their read. If the mechanism doesn’t support the diagnosis, or they are requesting unusual or unneeded studies, don’t get them! Just document your rationale clearly in the record. This provides best patient care, and minimizes the potential complications (and radiation exposure) from unnecessary tests.
Related post: 

Reference: Pitfalls of the vague radiology report. AJR 174(6):1511-1518, 2000.