Abstract Objectives: To determine the immediate post-operative course and outcome of pediatric patients with complicated acute mastoiditis (CAM) following surgical treatment. Study Design: A retrospective chart review of children diagnosed with CAM who underwent mastoid surgery during 2012-2019. Setting: Tertiary care university hospital. Participants: the study includes 33 patients, divided into two groups: 17 patients with subperiosteal abscess (SPA) alone - single complication group (SCG) and 16 patients with SPA and additional intracranial or intratemporal complications -multiple complications group (MCG). Main Outcome Measures: post-operative fever course and pattern (POF). Results :33 patients belong to the SCG 17(51%) and 16(49%) belonged to the MCG, respectively. 6/17(35.3%) SCG patients experienced POF vs. 12/16(75%) in the MCG (P=0.012). At post-operative day 2 (POD2), 10/13(77%) febrile patients belonged to MCG and 3/13(23%) to SCG (P=0.013). POF was recorded until POD6 in both groups. Seven patients, all from MCG with POF, underwent second imaging with no new findings. Conclusion: Following a cortical mastoidectomy for CAM, POF is not unusual in the first 6 days and seem to be benign condition. POF is more common, higher, and persistent for a longer duration in MCG compared with SCG. At POD 6, fever is expected to normalize in both groups, so if fever persists further evaluation should be considered.

Objectives: To determine the immediate post-operative course and outcome of pediatric patients with complicated acute mastoiditis (CAM) undergoing simple mastoidectomy. Study Design: A retrospective chart review of children diagnosed with CAM who underwent a mastoidectomy during 2012-2019. Setting: Tertiary care university hospital. Participants: 33 patients were divided into two groups: 17 patients with subperiosteal abscess (SPA) alone- single complication group (SCG) and 16 patients with SPA and additional complications (sigmoid sinus vein thrombosis, perisinus fluid/abscess, epidural abscess)-multiple complications group (MCG). Main Outcome Measures: post-operative data were collected. Demographics, microbiology data, inflammatory parameters, hospitalization length, and POF pattern were recorded, compared, and analyzed. Results: Of 162 acute mastoiditis patients, 33(20.4%) underwent surgery due to CAM; 17(51%) and 16(49%) belonged to the SCG and MCG, respectively. 6/17(35.3%) SCG patients experienced POF vs. 12/16(75%) in the MCG (P=0.012). At post-operative day 2 (POD2), 10/13(77%) febrile patients belonged to MCG and 3/13(23%) to SCG (P=0.013). POF was recorded until POD6 in both groups. Seven patients, all from MCG with POF, underwent second imaging with no new findings; A total of 18 positive cultures were reported. Fusobacterium necrophorum counted for 8/18(44.5%) of all positive cultures, 7/9(77.8%) in the MCG vs. 1/9(11.1 %) in the SCG, P=0.004. Streptococcus pneumoniae was reported only in SCG (5/9, 55.5%, vs. 0/9, P=0.008). Conclusion: Post-mastoidectomy fever due to CAM is not unusual and seems to be a benign condition for the first 5-6 days following surgery. MCG patients are more prone to develop POF. F. necrophorum is more likely to be associated with MCG, and S. pneumoniae is common in SCG patients. Keywords: Mastoiditis, post-operative fever, complications, microbiology