Assessment of the association between posttonsillectomy hemorrhage and weather conditions

Background: The most common complication after tonsillectomy is bleeding. We investigated whether performing the procedure during the summer or the winter affects the bleeding rate. Objectives: To investigate whether there is an association between meteorological conditions and the occurrence of post-tonsillectomy hemorrhage (PTH) in the southern Israel Negev region. Methods: All patients who underwent tonsillectomy from 2001–2013 at the Soroka Medical Center were included. We collected patient demographic data and indications for surgery. Meteorological data were obtained from a weather station operated by the Israel Ministry of Environmental Protection. Results: Of 4438 patients who underwent tonsillectomy, with or without adenoidectomy, 432 (9.73%) experienced hemorrhage. Patients who suffered from PTH were significantly older: median 9.61 years vs. 4.7 years, P < 0.0001. When comparing age patients without PTH to those who bled within 0–3 days after surgery, there was a higher risk for bleeding during the warmer seasons: relative risk (RR) 1.38, 95% confidence interval ([95%CI] 1.07–1.77), 1.45 (95%CI 1.17–1.80), and 1.62 (95%CI 1.27–2.06) comparing the winter to spring, summer, and fall, respectively. A statistically significant positive association was also found with the average temperature on the day of surgery. Bleeding more than 3 days after surgery was less likely in summer: RR 0.82, 95%CI 0.69–0.97. We found no association with temperature on the day of surgery and PTH after postoperative day 3. Conclusions: Seasonality, and to an extent temperature, seem to play only a minor role in PTH.