Journal Feed Weekly Wrap-Up
- May 29th, 2021
- Clay Smith
- categories:
#1: Management of Low-Velocity GSWs to Extremities
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There is a lack of evidence-based treatment standards for low-velocity gunshot wounds (GSW). This review focuses on the best available evidence for the management of civilian, low velocity GSWs to an extremity.
Why does this matter?
Remember in the 17th century when we thought infection from GSWs was secondary to gunpowder poisoning and those bullets ‘needed out’? Well, we’ve come a long way. But if you trained like I did, GSW management was/is a reality in your practice (shout out to my former co-residents in New Orleans). Here is the undeniable truth: gunshot injuries continue to increase in the United States. Yet despite the increasing frequency of civilian GSWs, the management of these injuries is debated. Specifically, while protocols for the treatment of several traumatic injuries have been developed and standardized, the optimal management of low-velocity, gunshot injuries remains uncertain.
“Shot through the arm…and it’s ok (most of the time)” – Jon Bovi
High points listed below. This article also reviews GSWs management by anatomic location (listed in Table I). Those interested should review the available evidence.
Initial Evaluation:
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Adhere to your initial ATLS surveys.
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Each would should be considered an entrance site, with number of wounds equating to number of retained bullets.
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Document a baseline neurovascular exam and obtain ankle-brachial indices (ABIs) if concern for vascular injury.
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Mark wounds with metallic markers prior to radiographic evaluation.
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Consider patient compliance when making treatment decisions, as many patients with GSWs are lost to follow up.
Antibiotics:
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Most surgeons agree that operatively treated fractures receive antibiotics.
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Debate persists regarding antibiotic regimens for non-op GSWs.
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No data exists to support superiority of oral vs. IV antibiotics.
Vascular Injury:
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Diagnose in a timely fashion and have a low threshold to obtain ABI (<0.9 gets CTA).
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~70% of arterial injury have associated nerve injury.
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Vascular injuries may be at higher risk for infection.
Irrigation and Debridement:
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Skin healing by secondary intention is best (i.e. don’t sew up bullet holes).
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Formal wound exploration not recommended (former president William McKinley can attest).
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Removal of symptomatic subcutaneous positioned bullets is recommended.
Intra-Articular GSWs:
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Retained bullet (or fragment) should be removed to reduce mechanical wear, associated infection, and possible lead toxicity.
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In absence of retained intra-articular bullet (or fragment), evidence does not support routine articular debridement.
Table II provides grades of ortho recommendations for common management questions.
From cited article
Source
Management of Civilian Low-Velocity Gunshot Injuries to an Extremity [published online ahead of print, 2021 Mar 23]. J Bone Joint Surg Am. 2021;10.2106/JBJS.20.01544. doi:10.2106/JBJS.20.01544
#2: CT with Contrast for Kidney Stones?
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Contrast-enhanced CT has a very high negative predictive value (100%) for obstructive urolithiasis and appears to accurately and safely exclude obstructing ureteral calculi for patients with acute flank pain. In addition, IV contrast improves the diagnostic yield for other acute abdominopelvic pathology and perhaps should be the test of choice for patients presenting with acute flank pain.
Why does this matter?
Flank pain is a very common chief complaint encountered in the acute care setting. Historically, a non-contrast CT of the abdomen/pelvis (NCCT) has been the gold standard for diagnosing acute obstructing urolithiasis. However, 54-67% of patients presenting to the ED with flank pain do not have urolithiasis, and there are several conditions that mimic renal colic such as diverticulitis, appendicitis, cholecystitis, ovarian cyst rupture, etc. where IV contrast would improve the diagnostic accuracy of the test. But can a contrast-enhanced CT (CECT) safely and accurately exclude obstructing ureteral calculi?
When in doubt, light em’ up!
This was a retrospective cohort analysis of patients with acute flank pain who received CT abdomen/pelvis imaging. A total of 1286 CT scans were reviewed, and the prevalence of obstructive urolithiasis was 44.0% (351/797) in the NCCT group and 18.7% (86/459) in the CECT group. Based on 200 consecutive studies in each of the two groups, negative predictive values (NPV) were calculated based on follow up abdominal imaging within 7 days from original presentation. NPV for obstructive urolithiasis was 99.5% in the NCCT group and 100% in the CECT group. This study had some limitations including the retrospective design and use of re-presentation for repeat imaging to determine the NPV. However, it appears that CECT is just as good as NCCT for excluding obstructing urolithiasis and has the additional benefit of improved diagnostic accuracy for a variety of other conditions.
Furthermore, CECT has additional advantages compared to NCCT for diagnosis of ureteral obstruction including secondary signs of obstruction such as a delayed nephrogram and increased ureteral enhancement. What’s more, the American College of Radiology and the National Kidney Foundation recently released a consensus statement in 2020 stating the risk of acute renal injury after IV contrast administration is far lower than previously believed, and the available evidence is reassuring that significant acute kidney injury, death, and need for renal replacement therapy are rare after IV contrast administration. Of course, the study we covered yesterday is one of the most convincing yet that contrast does not cause long term kidney injury.
I don’t know about you, but based on this study, a contrast-enhanced CT will be my test of choice the next time I order a CT scan for a patient who presents with acute flank pain.
Source
Can obstructive urolithiasis be safely excluded on contrast CT? A retrospective analysis of contrast-enhanced and noncontrast CT. Am J Emerg Med. 2021 Mar 22;47:70-73. doi: 10.1016/j.ajem.2021.03.059. Online ahead of print.
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Febrile infants <90 days who were COVID positive had lower rates of serious bacterial infection (SBI) when compared to age and gender matched COVID negative febrile infants.
Why does this matter?
We know SBI is less prevalent among RSV or influenza positive infants. Would the same be true of COVID+ infants?
Is COVID the culprit?
This was a retrospective study at a single center that included 53 COVID(+) febrile infants <90 days compared with 53 age and gender matched febrile controls who were COVID negative. They found the risk of SBI (UTI, bacterial enteritis, bacteremia, or bacterial meningitis) was much lower in COVID(+) infants 8% vs 34%. The most common SBI was UTI, 6% COVID(+) vs 23% COVID(-). There were no cases of bacteremia or meningitis among COVID(+) infants. Rates of SBI were higher in this study than in past papers. However, this was in the midst of the pandemic when patients were only brought in by parents if absolutely necessary, which may have skewed these numbers toward higher acuity. COVID(+) infants more often had respiratory symptoms and had lower WBC counts and CRP than controls. This provides some reassurance that infants who test positive for COVID-19 are less likely to have SBI, but I don’t think we can completely avoid a workup based on this single center, small, retrospective study.
Source
Risk of Serious Bacterial Infections in Young Febrile Infants With COVID-19. Pediatr Emerg Care. 2021 Apr 1;37(4):232-236. doi: 10.1097/PEC.0000000000002380.
