National trends in retropharyngeal abscess among adult inpatients with peritonsillar abscess.

Abstract

To describe national trends in retropharyngeal abscess (RPA) complicating peritonsillar abscess (PTA) and to determine factors associated with RPA in patients with PTA. Cross-sectional analysis. Nationwide Inpatient Sample, 2003-2010. PTA patients ≥18 years old, with or without RPA, were extracted according to ICD-9-CM codes. The cohort was analyzed with descriptive statistics and multivariate regression modeling to identify factors associated with RPA. Of the 91,647 (95% CI: 86,433-95,449) patients identified with PTA, 885 (1.0%) also had a concurrently coded RPA. The annual rate of concomitant RPA increased from 0.5% (95% CI: 0.3%-0.8%) to 1.4% (95% CI: 1.0%-2.0%) between 2003 and 2010 (P < .001). PTA patients with RPA more frequently underwent tonsillectomy (23.5% vs 11.1%), endotracheal intubation (7.1% vs 1.5%), and mechanical ventilation (13.2% vs 2.0%) than those without RPA (all P < .001). PTA patients with RPA were significantly older (41 vs 34 years old), had a longer hospital stay (6.4 vs 2.5 days), and had more procedures (2.5 vs 0.9) when compared to patients without RPA (all P < .001). Upon multivariate regression analysis, factors associated with RPA included the age groups of 40 to 64 years (odds ratio, 2.256; P < .001) and 65 and older (odds ratio, 2.086; P = .045). Median total charges for PTA inpatients with concomitant RPA were approximately $8700 greater (P < .001) when compared to patients with PTA alone. The incidence of RPA among adult inpatients with PTA is increasing, and patients with RPA have higher in-hospital resource utilization. Further studies may help validate factors predictive of RPA to enable prevention or earlier identification.