In the Deep End: 2 Cases of Odontogenic Descending Necrotising Mediastinitis (DNM)

Introduction:
Descending necrotising mediastinitis (DNM) is a rare, potentially fatal, complication of a primary odontogenic or pharyngeal infection that spreads along the cervical fascial planes into the mediastinum. Odontogenic sources represent up to 58% of cases in some reports. This report describes the management of two patients with DNM.

Case Report:
Case 1: A 28-year-old healthy female patient with one week of increasing facial and neck swelling, odontalgia and odynophagia.
Case 2: A 24-year-old male patient (asthmatic, ASD) with 48 hours of rapid-onset of bilateral neck swelling, pain, odynophagia and dyspnoea.

Both patients were tachycardic with indurated neck swellings and cellulitis, trismus, and grossly carious teeth. Bloodwork showed leukocytosis and elevated CRP.

Initial management for both involved urgent anaesthetic review, transcervical incision & drainage of collections with drain placement, and extraction of carious teeth. Culture-directed IV antibiotics were administered following ICU transfer.

Subsequent CT imaging confirmed the presence of drainable collections and need for surgical intervention. Both patients developed mediastinitis with pleural effusions, requiring drainage and placement of chest tubes.

Discussion:
Management of these cases required a multidisciplinary approach (OMFS, Cardiothoracics, Anaesthetics/Critical Care, Radiology, Microbiology) and both patients were discharged after extensive treatment courses.
Case 1: 53-day admission (45 in ICU), 8 general anaesthetics.
Case 2: 20-days admission (9 in ICU), 3 general anaesthetics.

Odontogenic infections, though common, have the potential for significant morbidity and mortality. DNM represents a challenging clinical entity that requires a prolonged and complex course of treatment. Oral and Maxillofacial Surgeons must be prepared to manage these cases and multidisciplinary input is essential.