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Reference: Curry SD, et al. Systematic Review of CT Angiography in Guiding Management in Pediatric Oropharyngeal Trauma. Laryngoscope. March 2023

Date: January 30, 2024

Guest Skeptic: Dr. Alexandra (Ali) Espinel is an Associate professor of pediatrics and otolaryngology at Children’s National Hospital and George Washington University. She is also the director of the Pediatric Otolaryngology Fellowship at Children’s National Hospital.

Case: You’re working the morning shift in the emergency department (ED) when you encounter a 3-year-old boy and his family. His parents tell you that he was getting ready to go off to daycare and brushing his teeth while standing on a step stool by the sink. He slipped and the toothbrush poked him in the back of the mouth. Initially, his parents noticed that he was bleeding from his mouth and saw what looked like a wound towards the back of his throat. The boy cried immediately afterwards but has otherwise been acting like himself. On your exam, you notice a small penetrating intraoral injury just lateral to the soft palate without evidence of continued bleeding. His parents ask you, “Is he going to be, okay? We’re glad he’s not bleeding anymore. Do you think he needs any imaging to see if he hurt anything?”

Background: Kids like to put things in their mouths. Kids like to run around. Sometimes, kids may fall while having something in their mouth which may cause damage to their oropharynx.

The ensuing damage can vary. It could be blunt trauma or penetrating trauma. We get concerned about injuries to the soft palate because of possible deep space neck infection and the risk of injury to the carotid artery behind it which has been associated with thrombosis, dissection, and cerebral infarctions.

These super scary complications have been reported in the literature but seem relatively rare. We have many clinical decision tools for imaging in pediatric head trauma [1] or abdominal trauma [2]. But we do not have any of the same tools for oropharyngeal injury which means that there is wide variation about which imaging studies are ordered.

Clinical Question: What is the role of CT angiography (CTA) in the diagnosis and management of pediatric oropharyngeal trauma?

 Reference: Curry SD, et al. Systematic Review of CT Angiography in Guiding Management in Pediatric Oropharyngeal Trauma. Laryngoscope. March 2023

  • Population: Patients <18 years old with trauma to the oropharynx. They included meta-analyses, systematic reviews, randomized control trials (RCTs), case-control and cohort studies, case series and case reports.
    • Excluded: Oropharyngeal trauma combined with other severe head injury or multisystem trauma, not primary research, non-English publication
  • Intervention: CTA
  • Comparison: No CTA
  • Outcome: radiologic and clinical outcomes including infection, injury to vasculature, cerebrovascular injury, and neurologic abnormalities.
  • Type of Study: Systematic Review and Meta-Analysis of diagnostic studies.

Authors’ Conclusions: “Imaging with CTA yielded radiological abnormalities in a few instances. These results do not support the routine use of CTA in screening pediatric oropharyngeal trauma when balanced against the risk of radiation, as it rarely resulted in management changes and was not shown to improve outcomes.”

Quality Checklist for Systematic Review Diagnostic Studies:

  1. The diagnostic question is clinically relevant with an established criterion standard. Yes
  2. The search for studies was detailed and exhaustive. No.
  3. The methodological quality of primary studies was assessed for common forms of diagnostic research bias. Yes.
  4. The assessment of studies was reproducible. Yes
  5. There was low heterogeneity for the primary outcome. Yes.
  6. The summary diagnostic accuracy is sufficiently precise to improve upon existing clinical decision-making models. No.

Results: The initial search identified 5,078 papers after duplicates were excluded. Only eight studies were included in the final analysis. All those studies were retrospective cohort studies. Only five of eight studies reported rates of CTA use.

Key Results: Routine use of CTA in screening pediatric oropharyngeal trauma is not recommended.

These eight studies encompassed a total of 662 patients. Among those patients, 293 underwent CT imaging of some kind, and 255 patients were specified as undergoing CTA.

Some patients also underwent carotid angiography (3.4% of patients who underwent CT or CTA) for indications that included free air near the carotid, a bruit on neck exam, hematoma next to the carotid artery, carotid spasm, history of tonsil injury and profuse bleeding, and carotid artery exposure with arterial compression.

There were two cases in which CTA showed disruption of the carotid intima without a thrombus. These two patients were treated with aspirin. Some patients were admitted to the hospital for observation.

Only six out of the eight studies reported antibiotic treatment. Importantly, no patients were reported to have a cerebrovascular injury or need vascular surgery.

Heterogeneity:

Heterogeneity measurements in meta-analyses help us detect variations in the included studies. The authors use the I2 statistic which they report as 0%, meaning no heterogeneity amongst the included studies. This is not surprising as the included eight studies were all retrospective cohort studies with similar methology in this systematic review.

Funnel Plot Asymmetry:

When we look at the in Figure 3, there’s some asymmetry there.

Sources of asymmetry can include publication bias, and a tendency to publish studies with positive findings. There is also English language bias where studies with “negative” findings are published in non-English journals.

Methodological quality also impacts asymmetry as most studies included are on the base of the pyramid representing smaller studies which may have less methodological rigor and overestimate effects. [3,4]

Risk of Bias:

In the category of pre-intervention bias that included confounding and participant selection, there was a serious risk of bias due to confounding in all eight studies and a moderate to serious risk of bias in participant selection. In the category of post-intervention bias, there was a moderate to serious risk of bias due to missing data.

We can see an example of this in Table 1 of the paper where half of the studies did not report any follow-up while the other four studies reported rates of follow-up ranging from 21 to 52% at different time frames.

Unfortunately, this study is an example of the GIGO phenomenon (garbage in, garbage out). All these studies are low-level evidence, missing outcomes of interest, and prone to bias. Collecting all of them together may create an illusion of certainty that is not there.

Practice Variation:

There is variation in practice based on institutional policies or individual practitioners. The authors report that the use of CTA ranged in studies from 0% to 100%. Between 4-100% of cases were admitted to the hospital. Antibiotic treatment (when it was reported) ranged from 58-100%. Operative management ranged from 1-23%.

The decision to obtain imaging can also depend on who we consult in the emergency department. The involvement of subspecialists like an otolaryngologist may increase the likelihood of intervention or imaging.

Clinical Decision Making:

The problem with the included studies in this systematic review is that we can’t determine what clinical factors influenced decisions to obtain imaging, start antibiotics, admit to the hospital for observation, or pursue operative management.

We also don’t have details of the extent of the injury. Maybe in a patient who has oropharyngeal trauma without much evidence of injury outside of a red mark on their soft palate, we would be less inclined to perform CTA or imaging of any kind. But if the same patient had a penetrating injury with active bleeding, we may be a bit more hesitant to not perform a CTA.

Ultimately, CTA does not definitively rule out future cerebrovascular ischemia as that can occur within a span of hours to days.

Comment on Authors’ Conclusion Compared to SGEM Conclusion: We agree with the authors’ conclusion based on the studies they included, but there is a lack of high-level evidence.

SGEM Bottom Line: We don’t know the role of CT angiography (CTA) in pediatric oropharyngeal trauma because there is a lack of high-quality evidence to inform our care.

Case Resolution: You are reassured by your physical exam of the patient. You consult your friendly otolaryngologist who based on your description of the child, exam, and mechanism recommends a trial of oral antibiotics for prophylaxis. You engage in shared decision-making with the family and discuss the potential harms and benefits of obtaining imaging. They state that given how good the boy is looking and acting now, they feel comfortable with going home and watching him carefully.

Clinical Application: Perform a good examination of your patient! Imaging is not always needed, especially if the injury is midline or paramedian or only soft palate and does not go into the lateral pharyngeal wall. There are currently no standards of care from professional associations about how to manage these types of injuries and remains a highly debated topic.

Most times management is not changed by CT angiography.  It can be useful in very specific clinical scenarios which include profuse bleeding, neuro status change, crepitus in the neck, or findings on CT with contrast (flow void of carotid, fluid extravasation, significant air in carotid space).

What Do I Tell the Patient/Family? Your child has a small cut from where the toothbrush poked him in the mouth. There is no bleeding from the area. I am reassured that he looks well and is acting appropriately. Sometimes we get concerned about this kind of injury because there are some blood vessels behind it. Let’s discuss some of the options and decide together.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

References:

  1. Kuppermann N, Holmes JF, Dayan PS, et al. Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study. Lancet. 2009;374(9696):1160-1170.
  2. Holmes JF, Lillis K, Monroe D, et al. Identifying children at very low risk of clinically important blunt abdominal injuries. Ann Emerg Med. 2013;62(2):107-116.e2.
  3. Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ. 1997;315(7109):629-634.
  4. Sterne JAC, Sutton AJ, Ioannidis JPA, et al. Recommendations for examining and interpreting funnel plot asymmetry in meta-analyses of randomised controlled trials. BMJ. 2011;343:d4002.