Criteria for mediastinitis – one or more of the following:
(1) culture from mediastinium tissue or fluid (obtained by needle aspiration, needle biopsy or surgery) is positive for micro-organisms
(2) evidence of infected mediastinal tissue seen directly at a surgical operation
(3) evidence of an infection involving mediastinal tissues seen in histopathologic examination of a biopsy taken at surgery or needle biopsy
(4) all of the following:
(4a) 1 or more of the following
(4a1) fever > 38°C
(4a2) chest pain
(4a3) sternal instability
(4a4) age <= 1 year AND hypothermia (< 37°C rectal)
(4a5) age <=1 year AND apnea
(4a6) age <= 1 year AND bradycardia
(4b) no other recognized cause
(4c) one or more of the following
(4c1) purulent discharge from the mediastinum
(4c2) micro-organism isolated from blood or mediastinal discharge fluid
(4c3) mediastinal widening on imaging studies
where:
• Age <=1 year may refer to an infant (age <= 12 months).
An infection of the sternum following medial sternotomy for open heart surgery is classified as surgical site infection (SSI) with mediastinitis.