Incidence of operative endoscopy findings in recurrent croup
OBJECTIVE: Develop an evidence-based model for predicting operative endoscopy findings in patients with recurrent croup.
STUDY DESIGN: Case series with chart review.
SETTING: Tertiary care children's hospital.
SUBJECTS AND METHODS: Retrospective chart review was performed on 124 patients who received consultation for recurrent croup between 2000 and 2009. Direct laryngoscopy and bronchoscopy findings were categorized as normal, mildly abnormal (incidental findings or grade I subglottic stenosis), moderately abnormal (grade II subglottic stenosis), or severely abnormal (grade III-IV subglottic stenosis).
RESULTS: Of 124 consultations for recurrent croup, 81 patients (average age 3.5 years) underwent operative endoscopy. Normal examinations occurred in 33 of 81 (41%). Abnormal findings were encountered with the following frequency: mildly abnormal, 40 of 81 (49%); moderately abnormal, 6 of 81 (7.5%); and severely abnormal, 2 of 81 (2.5%). Relative risk (RR) of either moderately abnormal or severely abnormal findings was increased for patients who had a history of previous intubation (RR = 9.8; P = .002), prematurity (RR = 6.4; P = .01), or inpatient consultation (RR = 5.3; P = .028). The rate of moderately or severely abnormal findings in patients without the risk factors of intubation and age younger than 1 year was 0 of 48 (0%; confidence interval, 0%-7.4%). Mild abnormalities in this group were encountered in 27 of 48 (56%).
CONCLUSION: Mild airway abnormalities are common in children with recurrent croup and cannot be ruled out based on history. In the absence the risk factors of previous intubation, age younger than 1 year, or inpatient consultation, the incidence of a significantly abnormal finding is quite low. A predictive model based on this evidence is discussed.