88 / 232
our institution. For evaluation of equivocal PTA, we
have eliminated CT scans from our workup protocol alto-
gether. Patients are managed medically if they have a
negative US. Whether or not they are admitted for ini-
tiation of treatment is contingent on severity of symp-
toms and overall clinical picture. If the US is positive,
history and physical exam dictate treatment. If the
physical exam also suggests PTA, then drainage is
attempted pending consent. If the physical exam is
equivocal, then medical therapy is attempted first. In
cases of a difficult or limited exam, one may elect to
attempt drainage of larger abscesses (
>
15 mm) seen on
US while attempting medical management of ones that
are smaller and/or less symptomatic. As has been
described in previous studies on pediatric deep neck
space infections as well as pediatric PTA, some fluid col-
lections are likely to respond to antibiotic therapy
alone.
16,18–20
In our study, six children were transferred to our
institution with prior CT scans. All of these patients
were enrolled and received a transcervical US per study
protocol. Although the aim of the study was not to com-
pare these two modalities, it is worth noting that the
final US read was identical to the CT findings in five of
six cases. In the one case where the two modalities dif-
fered, the physical exam and CT were suggestive of PTA,
whereas the US was negative. When that child was
taken to the operating room for drainage, no purulence
was found.
In summary, we believe that there are several sig-
nificant advantages to using ultrasound as the primary
diagnostic tool for equivocal pediatric PTA. In addition
to cost reduction compared to CT, the other obvious
advantage is the avoidance of undue radiation exposure
in children. Given how well US is tolerated and how
quickly it can be performed, one may also argue that
sedation requirements will be lower than when using
other imaging modalities that may require intravenous
injections and/or sedation simply to complete the exam.
Moreover, US provides real-time imaging with excellent
assessment of the tonsils and peritonsillar space. Inter-
estingly, the images from this study may even begin to
help differentiate intratonsillar from peritonsillar proc-
esses, both of which may present with a largely swollen
and asymmetric oropharynx.
Perhaps the largest impediment to the use of US is
the interuser variability. Although the technique itself is
rather simple, interpreting the images accurately
involves appreciating the nuances of this modality.
Despite these limitations, the authors still find the exam
and its interpretation to be well within the skill set of
radiologists, otolaryngologists, and emergency physicians
alike.
Our study was limited by our small sample size and
our inability to enroll a random or continuous sample of
patients. Missing follow-up may have biased our results,
as it is certainly possible that patients presented to
other hospitals with recurrent or persistent symptoms
after having been evaluated and treated initially at
ours. Last, it was impossible to ensure that clinicians
were universally blinded to all radiographic results,
ultrasound, or outside CT impressions. This lack of
blinding may have biased clinical decision making in
some circumstances.
Overall, our study results support the use of trans-
cervical US in the workup of pediatric PTA. Although
not all children who present with signs and symptoms
consistent with a PTA warrant imaging, the authors
believe that US will prove to be the optimal modality in
evaluating these patients when imaging is indicated. In
addition to being safe and well-tolerated, statistically
significant data show that US is highly predictive in
identifying those patients with equivocal PTA who are
likely to improve without the need for surgical interven-
tion. Furthermore, US findings (more so than clinical
diagnosis or age) are highly correlative with the pres-
ence or absence of PTA. Even so, additional prospective
studies are needed to better elucidate the role this tech-
nology will play in these patients and to better define
which PTAs can be best managed medically versus
surgically.
CONCLUSION
This study is the first to investigate the efficacy of
transcervical ultrasound in the diagnosis of pediatric
PTA. Our results show that ultrasound is a reliable and
useful tool in the evaluation of these children and is
highly correlative with surgical findings and clinical out-
comes. The authors believe that this study should bol-
ster a transition away from CT as the imaging modality
of choice. Although the authors still maintain that there
is a role for CT in the evaluation of complex head and
neck infections, we also emphasize the physician’s role
in the thoughtful use of this modality in light of docu-
mented concerns over radiation exposure in children.
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Fig. 5. This generalized basic management algorithm has been
adopted by our institution. CT
5
computed tomography;
PTA
5
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Laryngoscope 125: December 2015
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