Tag Archives: abdomen

How To: The Serial Abdominal Exam

How often have you seen this in an admitting history and physical exam note? “Admit for observation; serial abdominal exams.” We say it so often it almost doesn’t mean anything. And during your training, did anyone really teach you how to do it? For most trauma professionals, I believe the answer is no.

Yet the serial abdominal exam is a key part of the management of many clinical issues, for both trauma patients as well as those with acute care surgical problems.

Here are the key points:

  • Establish a baseline. As an examiner, you need to be able to determine if your patient is getting worse. So you need to do an initial exam as a basis for comparisons.
  • Pay attention to analgesics. Make sure you know what was given last, and when. You do not need to withhold pain medications. They will reduce pain, but not eliminate it. You just need enough information to determine if the exam is getting worse with the same amount of medication on board.
  • Perform regular exams. It’s one thing to write down that serial exams will be done, but someone actually has to do them. How often? Consider how quickly your patient’s status could change, given the clinical possibilities you have in mind. In general, every 4 hours should be sufficient. Every shift is not. And be thorough!
  • Document, document, document. A new progress note should be written, dated and timed, every time you see your patient. Leave a detailed description of how the patient looks, vital signs, pertinent labs, and of course, exact details of the physical exam.
  • Practice good handoffs. Yes, we understand that you won’t be able to see the patient shift after shift. So when it’s time to handoff, bring the person relieving you and do the exam with them. You can describe the pertinent history, the exam to date, the analgesic history, and allow them to establish a baseline that matches yours. And of course, make sure they can contact you if there are any questions.

AAST 2019 #2: Predicting Abdominal Operation After Blunt Trauma – The RAPTOR Score

Patients with blunt abdominal injury, particularly those with seat belt signs, can be diagnostically very challenging. If the patient is stable and does not have peritonitis, CT scan is typically the first stop after the trauma resuscitation room. As many trauma professionals know, the radiographic findings can be subtle and/or not very convincing.

The trauma group at the University of Tennessee in Memphis sought to identify specific findings that might help us better identify patients that will need laparotomy. They retrospectively identified all their mesenteric injuries over a five-year period. A single blinded radiologist (is this an oxymoron or not?) reviewed all 151 patient images who underwent laparotomy, looking for predictors of bowel or mesenteric injury.  All of the predictors were then converted into a scoring system called RAPTOR (radiographic predictors of therapeutic operative intervention; kind of a stretch?). These predictors were then subjected to multivariate regression analyses to try to tease out if there were any independent predictors of injury.

Here are the factoids:

  • A total of 151 patients were identified over the 5 year period; 114 underwent laparotomy
  • Of the 114 operated patients, two thirds underwent a therapeutic laparotomy and the other third were nontherapeutic
  • There no missed injuries in the non-operated patients
  • The components of the RAPTOR score were culled from all the potential findings, and were determined to be
    • Multifocal hematoma
    • Acute arterial extravasation
    • Bowel wall hematoma
    • Bowel devascularization
    • Fecalization (of what??)
    • Free air
    • Fat pad injury (??)
  • Linear regression then showed that only three of these, extravasation, bowel devascularization, and fat pad injury to be independent predictors of injury
  • If three or more RAPTOR variables were present, then the sensitivity, specificity, and positive predictive values for injury were 67%, 85%, and 86%, and an area under the receiver operating characteristic curve (AUROC) of 0.91

The authors concluded that the RAPTOR score provided a simplified approach to detect patients who might benefit from early laparotomy and not serial abdominal exams. They go further and say it could potentially be an invaluable tool when patients don’t have clear indications for operation.

It looks like there are two things going on here at the same time. First, a new potential scoring system is being piloted. And second, a regression analysis is being used to examine the data as well. 

But first, let’s back up to the beginning. This is a retrospective study, with a relatively small size. This makes it far harder to ensure that the results will be significant, or at least meaningful. Use of a single radiologist can also be problematic, especially since many of the CT findings with this mechanism of injury are subtle. 

The reported performance of the RAPTOR score is a bit weak. The listed statistics show that it accurately identified only two thirds of those who needed an operation and 85% of those who didn’t. The AUROC for the regression is very good, though. Could a good old-fashioned serial exam scenario be better?

Bottom line: It will be interesting to hear the background on RAPTOR vs regression, and find our how the authors will use or are using these tools.

Here are my questions for the presenter and authors:

  • Why did you decide to create a scoring system that uses a set of variables that may be dependent on each other? Isn’t the regression equation better?
  • Has this information changed your practice? It seems that the two of the three regression variables are fairly obvious reasons to operate (active extravasation and devascularization). Do you really need the rest?
  • Has this study helped you decrease the non-therapeutic laparotomy rate for blunt abdominal injury?
  • And please define fecalization and fat pad injury!

I’m looking forward to hearing this presentation!

Reference: RADIOGRAPHIC PREDICTORS OF THERAPEUTIC OPERATIVE INTERVENTION AFTER BLUNT ABDOMINAL TRAUMA: THE RAPTOR SCORE. AAST 2019 Oral Paper 6.

 

Stab To The Abdomen: The WTA Algorithm

I’ve spent the last week discussing the hypothetical case of a young patient with a stab to the abdomen. I worked through some of the thought processes regarding physical exam, imaging, and choices for management. Fortuitously, it would seem, The Journal of Trauma published an algorithm on this very topic from the Western Trauma Association (WTA).

The WTA Algorithm Committee reviewed existing data to start the process of developing this algorithm. As could be expected, very little high quality data was available. So the final algorithm is a synthesis of existing lesser quality studies, expert opinion from the committee members, and commentary from the membership.

Here are some of the highlights:

  • Unstable patients go straight to the operating room (A)
  • Patients who cannot be examined (unconscious, head injured, intoxicated) should be evaluated for peritoneal penetration with local wound exploration, ultrasound, CT, or laparoscopy. If positive or equivocal, proceed to exploration. (B)
  • Patients who can be examined should be managed by location of the stab. Flank injuries are lower risk and should be scanned. Anterior stabs can be evaluated using observation, local would exploration, or CT scan,
  • Positive results generally proceed to laparotomy. The algorithm states that laparaoscopy “may be performed in select stable patients by a highly skilled surgeon experienced in minimally invasive surgical techniques.”

As with any algorithm or practice guideline, nothing is etched in stone. These tools are good for about 90% of the clinical situations you will encounter. If you end up off the beaten path, you will need to use your best judgment to provide best treatment for your patient. Just remember to document your rationale, because you may very well have to justify it to your peers.

Click the diagram below to see a full size version.

Reference: Evaluation and management of abdominal stab wounds:
A Western Trauma Association critical decisions algorithm. J Trauma 85(5):1007-1015, 2018.

What Would You Do? A Teensy Weensy Stab To The Abdomen – Part 4

We’ve gotten the young man with the teensy weensy stab to the abdomen with a bit of omental evisceration to the operating room. Now what should we do? We’ve already decided that he needs an exploration because of the known penetration. How should we go about it?

There are two choices: diagnostic laparoscopy vs laparotomy. Which is better? Let’s talk about laparoscopy first. This tool has been around now for over 25 years. There has been variable acceptance for use in trauma during that time because it tends to take more time and may have a higher rate of missed injury. Both factors have major implications in patients who have active bleeding and small injuries, respectively.

On the plus side, a truly negative (nontherapeutic) exploration tends to be more benign, with rapid recovery, faster time to discharge, and potentially fewer complications when evaluated with a scope. But on the minus side, small injuries can be notoriously difficult to find. What does that small wisp of blood mean? This is not nearly as clear as the meaning of other colors (green, brown). The decision to open can be difficult, particularly for surgeons who perform a high number of laparoscopies in the non-trauma portion of their practice.

Trauma laparotomy is traditionally a large operation with a generous incision and meticulous exploration. This can lead to significant postop pain and morbidity, particularly when no significant pathology is found. Unfortunately, the literature appears to be quite polarized. The surgeon is either pro-laparoscopy, or pro-big incision, and tends to brace their preferred procedure almost exclusively.

But there is a middle ground, and that is what I would choose in a case like this. The surgeon must consider the likelihood of reliably finding the size of internal injury based on his or her assessment of the external wound, as well as the probability that the exploration would be non-therapeutic. So in this case, I would worry that a bowel injury could be only a few millimeters in size and might be missed using only the laparoscope. But I also think that there is a good chance there may not be an injury at all, so I would not be inclined to start with a huge incision.

My choice is to perform a “mini-laparotomy”, making an incision just large enough to explore all of the bowel and visualize the retroperitoneum. I can generally do this through an incision large enough to get my palm into the abdomen, about 6cm. I am confident that I can easily find all injuries, and make the incision larger if warranted. Postoperative pain is better, and discharge if no injuries were found can happen in 1-2 days.

Unfortunately, I can’t find any papers that examine this middle ground between laparoscopy and full laparotomy. But I’ll keep looking! How would you have managed this case? Comment or tweet, please!

In my next post, I’ll review the official algorithm for evaluating stabs to the abdomen recently published by the western Trauma Trauma Association.

References: 

  1. The role of laparoscopy in management of stable patients with
    penetrating abdominal trauma and organ evisceration. J Trauma 81(2):307-311, 2016.
  2. Diagnostic Laparoscopy for Trauma: How Not to Miss Injuries. J Laparoscopic Adv Surg Tech 28(5):506-513, 2018.

What Would You Do? Teensy Weensy Stab To The Abdomen – Part 3

In my last post, I described the plight of a young man who had sustained a stab to the abdomen. It appeared that a very tiny bit of omentum was hanging out of the wound. What to do?

I listed three options:

  • Local wound exploration
  • CT scan of the abdomen
  • Proceed to the operating room

So let’s work through these. First, local wound exploration (LWE).

LWE is a diagnostic procedure to determine if a sharp wound has actually or potentially penetrated a vital area. It is usually performed in the neck to determine if the platysma has been violated, or in the abdomen top check for peritoneal violation. In this case, you would use it if you just couldn’t believe that the bit of odd fat was actually omentum, or if you were unsure what you were looking at. You could also grab it (gently) and give it a little tug. If more comes out, you’ve made your diagnosis. Fortunately, this is rarely necessary because omentum has a very distinctive appearance. You know it when you see it.

What about probing the wound? One of my mentors, John Weigelt, used to ask, “Michael, does your finger / q-tip / instrument have an eyeball on the end of it?” His point was that probing is like so many other medical tests: diagnostic if positive, but unsettling if it’s not. What happens if the wound does penetrate, but you can’t find the path that the knife/bullet took? You can only call that indeterminate. I suppose you could take an approach that includes probing first, then proceeding to full LWE if that is negative.

I’ll describe the proper technique for local wound exploration in a later post.

And what about CT scan? This is another unsatisfying test, because it is very likely to be negative with small wounds. The fascial defect in this case will be very small, and can easily be missed on the scan. Not recommended.

Given all this discussion, my vote is to proceed to the operating room. I know this is omentum, and I know that there is a good likelihood that there will be an injury that needs repair. So let’s go get it done.  But what procedure should I do, and how should I do it? That’s the subject for my next post.

As always, please leave comments below or tweet them out!