title: The influence of weather on the frequency of secondary post-tonsillectomy haemorrhage.
abstract: The aim of this study was to determine whether certain weather variables influence the secondary post-tonsillectomy haemorrhage rate and to examine the influence of a change in these variables on secondary haemorrhage. This was a prospective study carried out in a tertiary referral institution. All patients undergoing bilateral tonsillectomy over a one-year period were included. Local weather data, including daily temperature (max/min), relative humidity and water vapour pressure, were acquired. All patients readmitted to our department with secondary post-tonsillectomy haemorrhage were recorded. Of 346 patients undergoing tonsillectomy, 32 developed secondary haemorrhage (9.2 per cent). A significant negative correlation was found between secondary haemorrhage rate and the average monthly temperature (max/min) and water vapour pressure (Pearson's correlation = -0.8) (p < or = 0.002). These results suggest that performing tonsillectomy in warmer weather when the water vapour pressure is higher may reduce the secondary haemorrhage rate.
authors.affiliation: Department of Otolaryngology, Ninewells Hospital and Medical School, Dundee, UK.
authors.forename: M S W
authors.initials: MS
authors.lastname: Lee
authors.forename: M-L
authors.initials: ML
authors.lastname: Montague
authors.forename: S S M
authors.initials: SS
authors.lastname: Hussain
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000209:etiology* / Q000517:prevention & control; D011446:Prospective Studies; D012621:Seasons; D013696:Temperature; D014068:Tonsillectomy / Q000009:adverse effects*; D014887:Weather