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

Objective: To examine the relationship between Intra-operative hyperthermia (IOH) and post-operative fever (POF) and local complications in children undergoing CI surgery. Study Design: Retrospective cohort study Setting: Tertiary care University Hospital. Participants: The study includes all pediatric CI surgery procedures conducted in one hospital in Israel between 2007 and 2017, A total of 213 CI procedures were performed on 191 children (ages 9 months to 17 years; mean 3.54 years) Main outcome and measure: Clinical data included demographics, type of surgery (unilateral, bilateral), presence of IOH and POF, and local infectious complications within one month after surgery Results: Ten patients (4.9%) developed IOH, of which two developed POF. Of the remaining non-IOH cases (95.1%), 29 children (14.3%) developed POF. IOH correlated with cases of bilateral CI (80% bilateral CI versus 20% unilateral CI; p = 0.002). IOH also correlated with the duration of operation (289 min versus 189 min, respectively; p = 0.025). Local complications were recorded in 30 patients: two that developed POF in the IOH group, and 28 (14.3%) in the non-IOH group. No correlation was observed between the occurrence of either IOH or POF, and the occurrence of local complications. Conclusions: IOH and POF are not uncommon in children undergoing CI surgery, yet, in the present study cohort, both conditions are not associated with the development of local infectious complications. In addition, IOH does not appear to predict the development of POF.