[The Austrian Tonsil Study 2010 - Part 2: Postoperative haemorrhage]

Postoperative haemorrhage is the most common and serious complication of tonsil and adenoid surgery. Definitions, frequency and risk factors of postoperative bleedings are however, controversially discussed in the literature.

In a prospective multicenter cohort study all tonsillectomies (TE), adenotonsillectomies (TE + AE), tonsillotomies (TO), adenotonsillotomies (TO + AE) and adenoidectomies (AE) performed within 9 months from October 1st, 2009 - June 30th, 2010 were collected and evaluated. Postoperative haemorrhage was defined as any bleeding after extubation and was classified into 7 grades A1, A2, B1, B2, C, D and E depending on the therapy needed and the postoperative day.

Data from 9 405 patients of 32 ENT-departments in Austria were analysed. Overall postoperative haemorrhage rate for TE was 16.0%, for TE + AE 11.8%, for TO±AE 2.3% and for AE 0.8%. Surgical revision was necessary in almost one third of patients with a postoperative bleeding event (TE 5.3%, TE + AE 4.1%, TO 0.8% und AE 0.3%). Multiple haemorrhage occurred in every 5th patient, who experienced postoperative bleeding (1.7% of all patients). The frequency of haemorrhage depended on the type of surgery and the age of the individual. Severe bleedings requiring surgical revision were more frequent in children between 6 and 15 years and AE. 9 patients (1.2% of all patients with haemorrhage) experienced a dramatic haemorrhage (grade D), with the need of blood transfusions and difficult surgical control. No deaths occurred during the study period.

Due to a new classification postoperative bleeding episodes could be precisely defined and postoperative risk factors were quantified. Considering all postoperative bleedings, including minor and anamnestic ones, the haemorrhage rate over all types of surgeries was 7.9% (2.7% of all patients required a surgical revision). Tonsillectomy (with or without adenoidectomy) carries the highest statistical risk of postoperative bleeding, with 4.9% of all patients requiring surgical intervention. Patients who experience one - albeit minimal - postoperative haemorrhage, have a 5 times higher risk for further bleeding requiring surgical control, and should therefore be carefully monitored.