2017 Sec 1 Green Book

TABLE I. Patient Demographics.

No. of Patients

Mean Age (SD), yr

Median Age (IQR), yr

Age Range, yr

Gender

Race

Ultrasound cohort

43

12.0 (5.3)

13 (7–17)

2–20

M: 23, F: 20 W: 7, A: 35, H: 1

A 5 African American; H 5 Hispanic; IQR 5 interquartile range; SD 5 standard deviation; W 5 white.

US would accurately predict the presence of purulence in children being evaluated for possible PTA.

tive and negative predictive values were calculated based on our results. Multivariate regression analysis was conducted analyzing any correlations between age, sex, otolaryngologist clinical diagnosis, and US findings with the presence/absence of PTA. RESULTS Forty-three patients were enrolled in this study from May 2013 to April 2014. The demographic and age distribution of these patients can be seen in Table I. Using the definitions described earlier, we compared the US findings to procedural findings and/or clinical man- agement outcomes (Table II). The US was positive for PTA in 17 (39.5%) patients. Of these patients, nine were found to have had true-positive PTA by our definition. The greatest measurable dimension of these abscesses ranged from 7 mm to 32 mm, with a mean of 25 mm. Of the eight false-positive ultrasounds, the diameter of the abscesses ranged from 11 mm to 28 mm with a mean of 18 mm. The size differences between these two groups, which was statistically significant, can be viewed in Table III. Of the eight false positives, three patients had drainage procedures without procurement of pus, and five were medically managed successfully. The diameter of the abscess cavity on US in these five patients ranged from 11 mm to 21 mm, with a mean of 15 mm. Of the three patients undergoing negative procedures, two had bedside needle aspiration without evidence of purulence, and one underwent a negative incision and drainage in the operating room based on clinical exam. Three patients diagnosed with PTA clinically but managed medically also had US findings consistent with abscess. Either these patients responded promptly to initiation of medical management, or the parent opted to forego elec- tive surgical intervention as initial therapy. US did not reveal a PTA in 26 (60.5%) of the chil- dren enrolled. The breakdown of the US diagnoses for these patients can be seen in Table IV. Two of these chil- dren underwent drainage procedures following clinical diagnosis of PTA but with no purulence identified in

MATERIALS AND METHODS After obtaining institutional review board approval, a con- venience sample of children and adolescents with suspected PTA per the evaluating provider were prospectively enrolled in the study. The diagnosis of PTA was based on a history of sore throat and/or fever, neck pain, trouble swallowing, and voice changes in conjunction with physical exam findings such as asymmetric tonsils, palatal edema, uvular deviation, trismus, and peritonsillar fullness or erythema. Children < 2 years old, those with significant airway compromise, and those being eval- uated for retropharyngeal processes were excluded from the study. A physician board certified in pediatrics or pediatric emergency medicine evaluated each patient and then obtained consultation from the otolaryngology service. Patients were managed based on clinical impression alone, but all enrolled patients underwent a transcervical US to evaluate for PTA. The transcervical technique utilizes a high-frequency probe placed below the inferior border of the mandible to visualize the submandibular gland, deep to which the tonsil and peritonsillar space can be assessed. A blinded radiologist ( A . B .) viewed and analyzed all final US images. The results of the US were compared to the results of pro- cedural interventions and clinical patient outcomes. A positive US was defined as an anechoic or hypoechoic pocket in the peri- tonsillar plane suggestive of abscess. A true-positive PTA was defined as purulence discovered during surgical intervention in the setting of a positive US. A false-positive PTA was defined as the absence of purulence during surgical intervention or suc- cessful medical management in the setting of a positive US. A true-negative PTA was defined as no purulence noted during procedural intervention or clinical improvement with medical management alone in the setting of a negative US. Last, a false-negative PTA was defined as purulence discovered during surgery in the setting of a negative US. Following discharge, patients’ medical records were retro- spectively reviewed for treatment failures, defined as those patients managed initially medically who ultimately underwent drainage of a PTA. Statistical analysis with Fisher exact test was performed using GraphPad Prism software GraphPad Soft- ware, Inc., La Jolla, CA), and sensitivity, specificity, and posi-

TABLE II. Ultrasound Results and Surgical Findings.

TABLE III. Comparison of True Positive and False Positive Abscess Cavity Dimensions.

Ultrasound Results

True Positive

False Positive

Surgical Intervention

Positive

Negative

Total

No.

9

8

Range, mm Mean, mm

7–32

11–28

None or negative I&D

8 9

26

34

25

18

Positive I&D

0

9

P value

< .05

Total

17

26

43

I&D 5 Incision and drainage.

P value calculated using two-tailed Mann-Whitney test.

Laryngoscope 125: December 2015

Fordham et al.: Transcervical US in Pediatric PTA

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