Association Between Postoperative Fever and Readmission Rates in Lumbar Fusion Patients

STUDY DESIGN: This is a retrospective observational study. OBJECTIVE: This study evaluates the impact of postoperative fever on the rate of readmission among lumbar fusion patients. SUMMARY OF BACKGROUND DATA: Postoperative fever is a common event across surgical specialties that often triggers an extensive work-up that can significantly increase hospital costs and length of stay, although the results are usually negative for infection. There is a paucity of literature studying postoperative fever in lumbar fusion patients. MATERIALS AND METHODS: A retrospective chart review of all the patients who underwent elective posterior lumbar spinal fusion from January, 2018 to November, 2018 was conducted. Fever was defined as a temperature >100.4ºF. Patients were categorized into 4 groups based on their highest recorded temperature postoperatively. The association between demographic variables, tests ordered per patient, length of stay, and readmission rates per group were analyzed using a t test, and 1-way analysis of variance for continuous outcomes, and the Fisher exact test for categorical variables. RESULTS: Of 107 patients, 58% had no fever recorded, 17.75% had temperatures between 100.5 and 100.90ºF, 18.69% temperatures between 101 and 101.90ºF, and 4.67% of patients temperatures equal or higher than 102.0ºF. The number of tests per patient increase with the range of temperatures analyzed (P<0.01), but the rate of readmission of all the 4 groups are not significantly different (0.107). There is no significant difference in the number of febrile episodes per day between patients who were and who were not readmitted (0.209). CONCLUSIONS: A diagnostic testing policy guided by clinician assessment of symptoms and physical exam may limit unnecessary testing and reduce hospital length of stay and cost without sacrificing patient safety.