title: Ambient temperature and volume of perihematomal edema in acute intracerebral haemorrhage: the INTERACT1 study.
abstract: BACKGROUND
  As no human data exist, we aimed to determine the relation between ambient temperature and volume of perihematomal 'cerebral' edema in acute spontaneous intracerebral haemorrhage (ICH) among Chinese participants of the pilot phase, Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT1).
  
  
  METHODS
  INTERACT1 was a multicenter, open, blind outcome assessed, randomized controlled trial of intensive (systolic target <140 mmHg) vs. guideline-recommended (systolic target <180 mmHg) blood pressure (BP) lowering in 404 patients with acute ICH. Data on ambient temperature (mean, minimum, maximum, and range) on the day of each participant's ICH obtained from China Meteorological Data Sharing Service System were linked to other data including edema volumes. Multivariable regression analyses were performed to evaluate association between ambient temperature and edema volumes. A generalized linear regression model with a generalized estimating equations approach (GEE) was used to assess any association of ambient temperature and change in edema volume over 72 h.
  
  
  RESULTS
  A total of 250 of all 384 Chinese participants had complete data that showed positive associations between ambient temperature (mean and minimum temperatures) and edema volumes at each time point over 72 h after hospital admission (all P < 0·05). All temperature parameters except diurnal temperature range were positively associated with edema volume after adjustment for confounding variables (all P < 0·02).
  
  
  CONCLUSIONS
  An apparent positive association exists between ambient temperature and perihematomal edema volume in acute spontaneous ICH.
authors.affiliation: The George Institute for Global Health, Royal Prince Alfred Hospital, Sydney, Australia; Sydney Medical School, University of Sydney, Sydney, Australia.
authors.forename: Danni
authors.initials: D
authors.lastname: Zheng
authors.forename: Hisatomi
authors.initials: H
authors.lastname: Arima
authors.forename: Emma
authors.initials: E
authors.lastname: Heeley
authors.forename: Anne
authors.initials: A
authors.lastname: Karpin
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: John
authors.initials: J
authors.lastname: Chalmers
authors.forename: Craig S
authors.initials: CS
authors.lastname: Anderson
mesh_terms: D000328:Adult; D044466:Asian People; D001929:Brain Edema / Q000209:etiology / Q000473:pathology*; D002543:Cerebral Hemorrhage / Q000150:complications / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D013696:Temperature
keywords: INTERACT; ambient temperature; clinical trials; intracerebral haemorrhage; perihematomal edema volume