Diurnal and monthly variations in secondary post-tonsillectomy haemorrhage rates
Reviewed by Madhup K Chaurasia

Several studies have looked into variable haemorrhagic rates with different methods of surgery and clinical backgrounds. Few have looked into non-clinical factors such as environment and diurnal influence on occurrence of post-tonsillectomy bleeding. This extensive study comprises 5357 tonsillectomy patients from January 2002 to December 2020, of which 76 (1.4%) had to return to the theatre for arrest of bleeding. Cases not requiring surgical arrest of bleeding have not been included. None had bleeding tendencies. Diurnal periods were set as daytime (0700-1800), evening (1800-2200) and night 2200-0700). It was noted that 50% had secondary haemorrhage in the ‘nighttime’ (out of hours) compared to 18% in ‘daytime’ and 14% in the ‘evening’. This agrees with two other studies and can be attributed to minimal activity of factors II, VII and X overnight and possibly due to pharyngeal relaxation and dehydration which may result in bacterial proliferation. In terms of monthly variation, there were 14 haemorrhages (2.96%) in July and only two (0.44%) in January. This was statistically significant, as there were more haemorrhages occurring in the British ‘autumn’ (September to November) and ‘summer’ (June to August) than in other months. Generally, there were more episodes in warmer months, but this was not statistically significant. There is a mention of some studies which show higher bleeding rates in winter. The practicalities of scheduling higher-risk patients may be difficult, considering the need and the wide temperature variations that occur even within the defined British seasons.

Secondary post-tonsillectomy haemorrhage: is there evidence of diurnal and monthly variation in haemorrhage rates?
Lancer HR, Beech T, Weller M.
J LARYNGOL OTOL
2023;137(9):1017–21.