title: An association between systolic blood pressure and stroke among patients with impaired consciousness in out-of-hospital emergency settings.
abstract: BACKGROUND
  Stroke is difficult to diagnose when consciousness is disturbed. However few reports have discussed the clinical predictors of stroke in out-of-hospital emergency settings. This study aims to evaluate the association between initial systolic blood pressure (SBP) value measured by emergency medical service (EMS) and diagnosis of stroke among impaired consciousness patients.
  
  
  METHODS
  We included all patients aged 18 years or older who were treated and transported by EMS, and had impaired consciousness (Japan Coma Scale ≧ 1) in Osaka City (2.7 million), Japan from January 1, 1998 through December 31, 2007. Data were prospectively collected by EMS personnel using a study-specific case report form. Multiple logistic regressions assessed the relationship between initial SBP and stroke and its subtypes adjusted for possible confounding factors.
  
  
  RESULTS
  During these 10 years, a total of 1,840,784 emergency patients who were treated and transported by EMS were documented during the study period in Osaka City. Out of 128,678 with impaired consciousness, 106,706 who had prehospital SBP measurements in the field were eligible for our analyses. The proportion of patients with severe impaired consciousness significantly increased from 14.5% in the <100 mmHg SBP group to 27.6% in the > =200 mmHg SBP group (P for trend <0.001). The occurrence of stroke significantly increased with increasing SBP (adjusted odd ratio [AOR] 1.34, 95% confidence interval [CI] 1.33 to 1.35), and the AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 5.26 (95% CI 4.93 to 5.60). The AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 9.76 in subarachnoid hemorrhage (SAH), 16.16 in intracranial hemorrhage (ICH), and 1.52 in ischemic stroke (IS), and the AOR of SAH and ICH was greater than that of IS.
  
  
  CONCLUSIONS
  Elevated SBP among emergency patients with impaired consciousness in the field was associated with increased diagnosis of stroke.
authors.affiliation: Department of Traumatology and Acute Critical Medicine, Osaka University Graduate School of Medicine, 2-5 Yamada-oka, Suita, Osaka 565-0871, Japan. taroirisawa@yahoo.co.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Irisawa
authors.forename: Taku
authors.initials: T
authors.lastname: Iwami
authors.forename: Tetsuhisa
authors.initials: T
authors.lastname: Kitamura
authors.forename: Chika
authors.initials: C
authors.lastname: Nishiyama
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Sakai
authors.forename: Kayo
authors.initials: K
authors.lastname: Tanigawa-Sugihara
authors.forename: Sumito
authors.initials: S
authors.lastname: Hayashida
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishiuchi
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Shiozaki
authors.forename: Osamu
authors.initials: O
authors.lastname: Tasaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawamura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hiraide
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimazu
mesh_terms: D003244:Consciousness Disorders / Q000150:complications*; D003625:Data Collection / Q000379:methods; D004632:Emergency Medical Services; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology; D013599:Systole