Risk of post-tonsillectomy hemorrhage in pediatric patients with recent influenza or COVID-19 infection

Introduction: Postoperative hemorrhage is a significant complication of tonsillectomy with or without adenoidectomy. This retrospective cohort study evaluates whether COVID-19 or influenza infection within defined preoperative intervals increases hemorrhage risk in patients under 18 years of age. Methods: Using the TriNetX database, we identified pediatric patients who underwent tonsillectomy with or without adenoidectomy and had documented COVID-19 or influenza infection within six, three, or one month before surgery. Cohorts included patients with COVID-19 only, influenza only, and a control group with neither infection. Propensity score matching was performed. Risk ratios (RR) and 95% confidence intervals (CI) for postoperative hemorrhage were calculated for postoperative days 0–1, 2–5, and 6–10. Results: Influenza infection within six, three, or one month before surgery was not associated with an increased risk of postoperative hemorrhage at any time point. COVID-19 infection was associated with a significantly increased risk of secondary hemorrhage (postoperative days 2–5 and 6–10) across all preoperative intervals. No increase in primary hemorrhage (postoperative days 0–1) was observed with COVID-19 at any interval. Conclusion: Pediatric patients with a COVID-19 infection within six, three, or one month prior to tonsillectomy with or without adenoidectomy are at increased risk of secondary postoperative hemorrhage. Recent influenza infection does not confer increased risk of either primary or secondary hemorrhage. Clinicians should counsel families regarding the elevated risk associated with recent COVID-19 and consider additional perioperative precautions in affected patients.