Assessment of the Association Between Post-tonsillectomy 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 age 9.61 years vs.4.7 years, P < 0.0001. When comparing 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), RR 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.