All posts by TheTraumaPro

Can Lead Poisoning Occur After A Gunshot?

This is a fairly common question from victims of gunshots and their families. As you know, bullets are routinely left in place unless they are superficial. It may cause more damage to try to extract one, especially if it has come to rest in a deep location. But is there danger in leaving the bullet alone?

One of the classic papers on this topic was published in 1982 by Erwin Thal at Parkland Hospital in Dallas. The paper recounted a series of 16 patients who had developed signs and symptoms of lead poisoning (plumbism) after a gunshot or shotgun injury. The common thread in these cases was that the injury involved a joint or bursa near a joint. In some cases the missile passed through the joint/bursa but came to rest nearby, and a synovial pseudocyst formed which included the piece of lead. The joint fluid bathing the projectile caused lead to leach into the circulation.

The patients in the Parkland paper developed symptoms anywhere from 3 days to 40 years after injury. As is the case with plumbism, symptoms were variable and nonspecific. Patients presented with abdominal pain, anemia, cognitive problems, renal dysfunction and seizures to name a few.

Bottom line: Any patient with a bullet or lead shot that is located in or near a joint or bursa should have the missile(s) promptly and surgically removed. Any lead that has come to rest within the GI tract (particularly the stomach) must be removed as well. If a patient presents with odd symptoms and has a history of a retained bullet, obtain a toxicology consult and begin a workup for lead poisoning. If levels are elevated, the missile must be extracted. Chelation therapy should be started preop because manipulation of the site may further increase lead levels. The missile and any stained tissues or pseudocyst must be removed in their entirety.

Granted, this is a very old paper. Over the years, a few papers on the topic have popped up from time to time. In my next post, I’ll review a meta-analysis on this topic that was published just last year.

Reference: Lead poisoning from retained bullets. Ann Surg 195(3):305-313, 1982.

Fractures From Gunshots: Open Fracture Or Not?

Penetrating trauma has been increasing over recent years, especially here in sleepy St. Paul MN. On occasion, we all see patients who have sustained gunshots that have caused fractures. The persistent question has been: open fracture or not?

Do these patients need antibiotics? A wound washout? Are they at risk for lead poisoning? Unfortunately, there are no consistent answers in the textbooks. The orthopedic trauma group and MetroHealth in Cleveland sent surveys to 385 members of the Orthopedic Trauma Association (OTA) to see if there was some consensus.

A total of 173 of the surveys were completed, which is actually a very good success rate.  About 72% were in practice at a Level I center, 18% at a Level II, and 10% at Level III/IV or non-trauma centers.

There was considerable heterogeneity among the responses. Here are the summaries for the specific questions asked:

How would you treat a gunshot injury near bone without fracture?

The majority of respondents recommended non-operative treatment and some form of antibiotics. However, there was no consensus regarding route of administration or duration. About 75% were in favor of a single dose of IV antibiotics, and half of those also recommended addition oral antibiotics. The presence of a retained bullet did not change management.

How would you treat a gunshot with a stable fracture to the fibula?

Three quarters of the respondents recommended the same management as above (IV antibiotics + oral), although about 10% would admit for IV antibiotics and 10% would do a washout or debridement. Only 7% recommended no antibiotics or debridement.

How would you treat a gunshot traversing the  knee joint with a retained bullet?

About half stated they would explore the joint and the other half would not. Nearly all recommended antibiotics, with the majority in favor of a single dose IV followed by some duration of oral.

Is the union rate of a tibial shaft fracture from a gunshot treated surgically different than a non-gunshot fracture?

Half of the participants thought it would be the same, a quarter thought it would be higher, and a quarter lower.

What about a gunshot with a displaced tibia fracture without other skin wounds?

About half recommended fixation with irrigation and debridement with perioperative antibiotics. A quarter would do the same, but without the irrigation and debridement. About 10% would extend the antibiotic duration.

How would you handle a gunshot traversing bowel that results in a stable pelvic fracture?

There was no agreement here at all. The majority (61%) would not debride the fracture, but would recommend IV antibiotics. Most of those recommended at least 24 hours of coverage. The remaining surgeons recommended surgical debridement, and were evenly split over brief vs longer antibiotic duration.

Bottom line: This is a “How we do it study” that is based on science as interpreted by these orthopedic surgeons. In general, OTA members behave as if they consider gunshots to bone as open fractures. More than 90% recommend antibiotics any time a bullet touches the bone. But once the fracture requires operative management, it is treated like a non-gunshot fracture from the standpoint of debridement and antibiotics.

The most interesting part of this survey was the total lack of consistency in the answers. It is clear that there is wide variation in the practice patterns of these surgeons, which usually signifies a lack of good data pertaining to the problem.

In my next post, I’ll discuss the lead poisoning question I mentioned above.

Reference: Variation in treatment of low energy gunshot injuries – a survey of OTA members. Injury 49:570-574, 2018.

 

 

When To Obtain A Dedicated Facial CT

Initial CT scan evaluation for blunt trauma patients is fairly standardized. The usual palate consists of scans of the head, cervical spine, chest, abdomen and pelvis. Some choose their “colors” individually, and others just slop everything on the canvas.

However, there are a few other scans that are occasionally helpful and/or necessary. Think soft tissue views, or CT angiogram of the neck, or CT angiogram of potential extremity vascular injuries.

Another study that is occasionally needed but many times unnecessarily ordered is the dedicated CT of the facial bones. This study spans the entire area from mandible to frontal sinus and is performed using finer cuts to display greater detail.

The unfortunate truth is that a large number of dedicated facial CTs either do not show fractures, or show fractures that don’t require operation. The scan does deliver a nice dose of radiation, though. Is there any way to be more selective about ordering it?

About 10 years ago, a plastic surgery group in Madison developed what came to be called the “Wisconsin criteria” for ordering facial imaging.  Here they are:

  • Bony step-off
  • Periorbital ecchymosis
  • GCS < 14
  • Malocclusion
  • Missing teeth

The authors claimed 97% sensitivity and 2.6% missed fracture rate, although external validation suggested those numbers were a bit generous. The Plastic Surgery group from the University of Minnesota and Regions Hospital recently re-studied these criteria with a large number of patients, looking at accuracy as well as cost-savings.

They performed a retrospective review of 1000 patients (based on a power analysis) who had a facial CT and adequate documentation of the Wisconsin criteria in the chart. Here are the factoids in table form:

(click table for larger copy)

  • Periorbital ecchymosis was the most common criterion, which had the highest sensitivity of 70% (terrible)
  • The other criteria fared even worse from a sensitivity standpoint
  • But if you roll them all up together, the presence of any one of the five yielded a 90% sensitivity (true positives) and 52% specificity (true negatives)
  • The negative predictive value was 93% if none of the criteria were present, which means it’s a good tool for ruling out the need for a CT scan
  • The overall missed fracture rate was 2.8%, and only 0.12% for ones that required operation
  • Cost savings by limiting CT to patients who met the criteria was over $300K in 2014

Bottom line: What to do? It’s clear that using the absence of any of the Wisconsin criteria to avoid a facial CT scan is helpful. This makes sense, because 4 of the 5 criteria are findings on facial exam. But it also means that a lot of scans will still get done for low sensitivity criteria. 

How about this? Since nearly all of these patients will have head and cervical CT scans, review the head scan first for facial fractures. Single, non-displaced fractures are nearly always nonoperative in nature. If patterns of fractures are present, or there are significant displacements, a dedicated facial scan will be very helpful in determining operative management.

But remember, the head CT does not include the mandible. A good physical exam and occlusion check is mandatory, and any suspicion of injury should prompt a full scan of the face.

Thanks to Chris Stewart, the lead author on this study for sending it to me for review.

Rreference: Validation of the “Wisconsin criteria” for obtaining dedicated facial imaging and its financial impact at a Level I trauma center. Craniomaxillofacial Trauma & Recon 13(1):4-8, 2020.

The Trauma Activation Pat-Down?

Yes, this is another one of my pet peeves. During a trauma activation, we all strive to adhere to the Advanced Trauma Life Support protocols. Primary survey, secondary survey, etc. Usually, the primary survey is done well.

But then we get to the secondary survey, and things get sloppy.

police_frisk1

The secondary survey is supposed to be a quick yet thorough physical exam, both front and back. But all too often it’s quick, and not so thorough. There is the usual laying on of the hands, but barely. Abdominal palpation is usually done well. But little effort is put into checking stability of the pelvis. The extremities are gently patted down with the hope of finding fractures. Joints are slightly flexed, but not stressed at all.

Is it just a slow degradation of physical exam skills? Is it increasing (and misguided) faith in the utility of the CT scanner? I don’t really know. But it’s real!

Bottom line: Watch yourself and your team as they perform the secondary survey! Your goal is to find all the injuries you can before you go to imaging. This means deep palpation, twisting and trying to bend extremities looking for fractures, stressing joints looking for laxity. And doing a good neuro exam! Don’t let your physical exam skills atrophy! Your patients will thank you.

Serial Hemoglobin / Hematocrit – Huh? Part 1

In my last post, I waxed theoretical. I discussed the potential reasons for measuring serial hemoglobin or hematocrit levels, the limitations due to the rate of change of the values, and conjectured about how often they really should be drawn.

And now, how about something more practical? How about an some actual research? One of the more common situations for ordering serial hemoglobin draws occurs in managing solid organ injury. The vast majority of the practice guidelines I’ve seen call for repeating blood draws about every six hours. The trauma group at the University of Florida in Jacksonville decided to review their experience in patients with liver and spleen injuries. Their hypothesis was that hemodynamic changes would more likely change management than would lab value changes.

They performed a retrospective review of their experience with these patients over a one year period. Patients with higher grade solid organ injury (Grades III, IV, V), either isolated or in combination with other trauma, were included. Patients on anticoagulants or anti-platelet agents, as well as those who were hemodynamically unstable and were immediately operated on, were excluded.

Here are the factoids:

  • A total of 138 patients were included, and were separated into a group who required an urgent or unplanned intervention (35), and a group who did not (103)
  • The intervention group had a higher ISS (27 vs 22), and their solid organ injury was about 1.5 grades higher
  • Initial Hgb levels were the same for the two groups (13 for intervention group vs 12)
  • The number of blood draws was the same for the two groups (10 vs 9), as was the mean decrease in Hgb (3.7 vs 3.5 gm/dl)
  • Only the grade of spleen laceration predicted the need for an urgent procedure, not the decrease in Hgb

Bottom line: This is an elegant little study that examined the utility of serial hemoglobin draws on determining more aggressive interventions in solid organ injury patients. First, recognize that this is a single-institution, retrospective study. This just makes it a bit harder to get good results. But the authors took the time to do a power analysis, to ensure enough patients were enrolled so they could detect a 20% difference in their outcomes (intervention vs no intervention). 

Basically, they found that everyone’s Hgb started out about the same and drifted downwards to the same degree. But the group that required intervention was defined by the severity of the solid organ injury, not by any change in Hgb.

I’ve been preaching this concept for more than 20 years. I remember hovering over a patient with a high-grade spleen injury in whom I had just sent off the requisite q6 hour Hgb as he became hemodynamically unstable. Once I finished the laparotomy, I had a chance to pull up that result: 11gm/dl! 

Humans bleed whole blood. It takes a finite amount of time to pull fluid out of the interstitium to “refill the tank” and dilute out the Hgb value. For this reason, hemodynamics will always trump hemoglobin levels for making decisions regarding further intervention. So why get them?

Have a look at the Regions Hospital solid organ injury protocol using the link below. It has not included serial hemoglobin levels for 18 years, which was when it was written. Take care to look at the little NO box on the left side of the page.

I’d love to hear from any of you who have also abandoned this little remnant of the past. Unfortunately, I think you are in the minority!

Click here for the Regions Hospital Solid Organ Injury Protocol

Reference: Serial hemoglobin monitoring in adult patients with blunt solid organ injury: less is more. J Trauma Acute Care Open 5:3000446, 2020.