Tag Archives: diagnosis

What’s The Best Test For Blunt Cerebrovascular Injury?

Blunt injury to the carotids or vertebrals (BCVI) is a little more common than originally thought, affecting about 1% of blunt trauma patients. We have many tools available to help us diagnose the problem: duplex ultrasound, CT angiography (CTA), MR angiography (MRA), and even good old conventional 4 vessel angiography

But which one is “best?” This is a tough question, because there is always some interplay between clinical accuracy and cost. The surgical group at the Medical College of Wisconsin – Milwaukee did a nice job teasing some answers from existing literature on the topic. The authors tried to take a comprehensive look at costs, including money spent to prevent stroke, the cost of complications of therapy, and the overall cost to society if the patient suffers a stroke.

Here are the factoids:

  • For patients at risk for BCVI, the stroke rate is 11% without screening, 6% with duplex ultrasound screening, 4% with MRA, and 1% with either CTA or conventional angiography
  • From a societal standpoint (includes the lifetime costs of stroke for the patient), CTA is the most cost effective at $3,727 per patient
  • From the hospital standpoint (does not include lifetime cost), no screening is the most cost effective, but has the highest stroke rate (11%)
  • CTA prevents the most strokes, and costs about $10,000 per patient while decreasing societal costs by about $32,000 per patient screened

Bottom line: The “best” test for patients at risk for blunt cerebrovascular injury is the CT angiogram. It minimzes the stroke rate, and provides information on all four vessels supplying the brain, which is probably why the duplex ultrasound has a higher miss rate (can’t see the vertebrals or into the skull). But how do you decide who is at risk for this problem. Tune in tomorrow!

Reference: Screening for Blunt Cerebrovascular Injuries is Cost-Effective. J Trauma 70(5):1051-1057, 2011.

Delayed Diagnosis In Kids: How Often?

Delayed or missed diagnoses happen. It’s a reflection on the state of technology and our own diagnostic acumen. Unfortunately, a few cases of delayed diagnosis result in morbidity, potential lawsuits, and rarely, death.

How often does delayed diagnosis occur? A few spot check type articles were published about 15 years ago, but little has been done to slice and dice the data. And as usual, the old data ranged widely in its assessment of the incidence of this problem (1-18% !). However, I managed to find a (somewhat) more recent one that gives a little clearer picture of this issue.

A single pediatric hospital in Indiana reported its experience from 1997 to 2006. This interval included the time that it was verified as a Level II Trauma Center (2000 onwards). They included children 0-14 who had sustained “major trauma.” This was defined as multiple system injuries, high-energy impacts, and gunshots. In this study, delayed diagnosis was defined as one found after a stable patient was admitted to their room. In patients taken directly to OR, it was one found after the patient left the recovery room.

Here are the factoids:

  • 1100 patients met study criteria. 98% were blunt trauma.
  • Only 44 patients had delayed diagnoses of 47 injuries
  • Average time to diagnosis was 4 days (range 8 hours to 28 days)
  • 34% of diagnoses were made within 24 hours
  • 3 diagnoses were made at a followup visit, all for upper extremity/should fractures
  • 80% of delayed diagnoses required a change in therapy, most commonly a sling or cast. 15% required surgery.
  • The long-term delayed diagnosis rate was 4%

Bottom line: Delayed diagnosis remains an issue in patient of all ages. The reported 4% rate subjectively seems about right to me. The most important lesson from this study is the extremely high percentage of delayed diagnoses that required further therapy. This is why it is so important to implement a specific system (the tertiary survey) to seek out these diagnoses.

A tertiary survey is a repeat head-to-toe physical exam and a review of all radiographic imaging performed to date. The trauma center should define the time interval from admission, and I recommend no more than 24-48 hours. We do not count any diagnoses found during this exam as being delayed. However, if a tertiary exam was not performed, or injuries are found after it was completed, we do consider it delayed an run it through our performance improvement process.

Related posts:

Reference: Ten-Year Retrospective Study of Delayed Diagnosis of Injury in Pediatric Trauma Patients at a Level II Trauma Center. Pediatric Emerg Care 25(8)-489-493, 2009.

Bowel Sounds, Or Just Plain BS?

“Bowel sounds are normal”

How often do you see this on an H&P? Probably a lot more often than they are actually listened for, I would wager. But what do they really mean? Are they important to trauma professionals?

(Un)fortunately, there’s not a whole lot of research that’s looked at this mundane item. And pretty much all of it deals with surgical pathology (e.g. SBO) or the state of the postop abdomen. Over the years, papers have been published about the basics, and I will summarize them below:

  • Where to listen? Traditionally, auscultation is carried out in all four abdominal quadrants. However, sound transmission is such that listening centrally is usually sufficient.
  • Listen before palpation? Some papers suggest that palpation may stimulate peristalsis, so you should listen first.
  • How long should you listen? Reports vary from 30 seconds to 7 minutes (!)
  • Significance? This is the big question. We’re not expecting to find hyperactive or high pitched sounds suggestive of surgical pathology here. Really, we’re just looking for sounds or no sounds.

But does it make a difference whether we hear anything or not?

Bottom line: In trauma, we don’t care about BS! We’ve all had patients with minimal injury and no bowel sounds, as well as patients with severe abdominal injury and normal ones. We certainly don’t have time to spend several minutes listening for something that has no bearing on our clinical assessment of the patient. Skip this unnecessary part of the physical exam, and continue on with your real evaluation!

Reference: A critical review of auscultating bowel sounds. Br J Nursing 18(18):1125-1129, 2009.

Bowel Sounds, Or Just Plain BS?

“Bowel sounds are normal”

How often do you see this on an H&P? Probably a lot more often than they are actually listened for, I would wager. But what do they really mean? Are they important to trauma professionals?

(Un)fortunately, there’s not a whole lot of research that’s looked at this mundane item. And pretty much all of it deals with surgical pathology (e.g. SBO) or the state of the postop abdomen. Over the years, papers have been published about the basics, and I will summarize them below:

  • Where to listen? Traditionally, auscultation is carried out in all four abdominal quadrants. However, sound transmission is such that listening centrally is usually sufficient.
  • Listen before palpation? Some papers suggest that palpation may stimulate peristalsis, so you should listen first.
  • How long should you listen? Reports vary from 30 seconds to 7 minutes (!)
  • Significance? This is the big question. We’re not expecting to find hyperactive or high pitched sounds suggestive of surgical pathology here. Really, we’re just looking for sounds or no sounds.

But does it make a difference whether we hear anything or not?

Bottom line: In trauma, we don’t care about BS! We’ve all had patients with minimal injury and no bowel sounds, as well as patients with severe abdominal injury and normal ones. We certainly don’t have time to spend several minutes listening for something that has no bearing on our clinical assessment of the patient. Skip this unnecessary part of the physical exam, and continue on with your real evaluation!

Reference: A critical review of auscultating bowel sounds. Br J Nursing 18(18):1125-1129, 2009.