Influence of atmospheric conditions on post tonsillectomy secondary haemorrhage
Reviewed by Madhup K Chaurasia

Haemostasis in epistaxis and a good few other conditions outside the field of otolaryngology seem to be affected by the weather. It is generally thought that dry and hot environment encourages secondary post tonsillectomy haemorrhage. Variations in water vapour pressure, but not humidity has been correlated with post tonsillectomy bleeding. The studies so far have been short and variables have been multiple. It appeared that carrying out such a study in Darwin, Australia, where variations in humidity and water vapour pressure rather than temperature create ‘dry’ and ‘wet’ seasons, would help to elucidate specific effect of these variables. Of the 941 patients who underwent tonsillectomy, 74 (7.7) had secondary haemorrhage. This was higher in older children and males. However, no difference was found between ‘wet’ and ‘dry’ seasons, nor months with low or high water vapour pressure. The variance in temperature could not be determined because of minimal changes of temperature over the year in Darwin. The study also evokes the concept that variations noted in previous studies relate to changes in temperature rather than humidity or water vapour pressure. Although no definitive findings have emerged from this study, the authors have interestingly pointed towards confounding influences possibly affecting secondary post tonsillectomy bleeding, such as use of air-conditioning and different methods used for the operation. Using these variables, future studies may be quite informative and useful. 

(Ton)silly seasons? Do atmospheric conditions actually affect post-tonsillectomy secondary haemorrhage rates?
Cadd B, Rogers M, Patel H, Crossland G.
THE JOURNAL OF LARYNGOLOGY AND OTOLOGY
2015;129:702-5.