Correlation between imaging characteristics and microbiology in patients with deep neck infections: A retrospective review of one hundred sixty-one cases

Background: This study reviews our recent experience with deep neck infections in order to propose recommendations in selecting presumptive antibiotics according to imaging characteristics and identifying predisposing factors of life-threatening complications. Methods: The records of 161 patients treated for deep neck infections at the Department of Otolaryngology-Head and Neck Surgery, China Medical University Hospital from 2002 to 2012 were reviewed retrospectively. The demographic data, comorbidities, source of infections, complications, duration of hospital stay, imaging characteristics, and bacteriologic studies were evaluated. The involved neck space was determined by computed tomography (CT) scan with contrast. Complications included mortality and life-threatening conditions. Results: The most common cause of deep neck infections in our study was odontogenic infection (20.5%), followed by pharyngo-tonsillitis (18.6%), and lymphadenitis (10.5%). The most commonly involved neck space was the submandibular space (40.9%), followed by the carotid space (37.2%), and the para-pharyngeal space (33.5%). Gas formation was detected in 31 (19.3%) cases. Infections of the different neck spaces and patients with gas formation noted on CT scan showed a specific distribution of common microorganisms. Streptococcus spp. was the most common pathogen in submandibular/sublingual space infections. Klebsiella pneumoniae infection accounted for 53.1% of peri-tonsillar/para-pharyngeal space infections, and 40% of carotid space infections. When gas formation was noted on CT imaging, anaerobic infection was the most common pathogen. Chronic kidney disease, diabetes mellitus (DM), multiple space infection, and gas formation present on CT scan were independent predictors of complications (p<0.05). Conclusion: The imaging characteristics and microbiology of patients with deep neck infections are correlated and can facilitate the optimal selection of antibiotics. We can administer more precise presumptive antibiotics according to the identified involved neck space on CT scan. Patients with predisposing factors of life-threatening complications require early aggressive multi-disciplinary management to prevent severe sequelae.