title: The haemodynamic response to pre-hospital RSI in injured patients.
abstract: BACKGROUND
  Laryngoscopy and tracheal intubation provoke a marked sympathetic response, potentially harmful in patients with cerebral or cardiovascular pathology or haemorrhage. Standard pre-hospital rapid sequence induction of anaesthesia (RSI) does not incorporate agents that attenuate this response. It is not known if a clinically significant response occurs following pre-hospital RSI or what proportion of injured patients requiring the intervention are potentially at risk in this setting.
  
  
  METHODS
  We performed a retrospective analysis of 115 consecutive pre-hospital RSI's performed on trauma patients in a physician-led Helicopter Emergency Medical Service. Primary outcome was the acute haemodynamic response to the procedure. A clinically significant response was defined as a greater than 20% change from baseline recordings during laryngoscopy and intubation.
  
  
  RESULTS
  Laryngoscopy and intubation provoked a hypertensive response in 79% of cases. Almost one-in-ten patients experienced a greater than 100% increase in mean arterial pressure (MAP) and/or systolic blood pressure (SBP). The mean (95% CI) increase in SBP was 41(31-51) mmHg and MAP was 30(23-37) mmHg. Conditions leaving the patient vulnerable to secondary injury from a hypertensive response were common.
  
  
  CONCLUSIONS
  Laryngoscopy and tracheal intubation, following a standard pre-hospital RSI, commonly induced a clinically significant hypertensive response in the trauma patients studied. We believe that, although this technique is effective in securing the pre-hospital trauma airway, it is poor at attenuating adverse physiological effects that may be detrimental in this patient group.
authors.affiliation: Kent, Surrey and Sussex Air Ambulance Trust, Kent, UK. zaneperkins@gmail.com
authors.forename: Z B
authors.initials: ZB
authors.lastname: Perkins
authors.forename: M
authors.initials: M
authors.lastname: Gunning
authors.forename: J
authors.initials: J
authors.lastname: Crilly
authors.forename: D
authors.initials: D
authors.lastname: Lockey
authors.forename: B
authors.initials: B
authors.lastname: O'Brien
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017732:Air Ambulances / Q000706:statistics & numerical data; D000768:Anesthesia, General / Q000379:methods*; D000779:Anesthetics, Local / Q000008:administration & dosage*; D062186:Arterial Pressure; D002648:Child; D002675:Child, Preschool; D003657:Decision Making; D004635:Emergency Medicine / Q000379:methods* / Q000592:standards; D005260:Female; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000209:etiology / Q000628:therapy*; D015601:Injury Severity Score; D007442:Intubation, Intratracheal / Q000009:adverse effects*; D007828:Laryngoscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D014947:Wounds and Injuries / Q000150:complications / Q000503:physiopathology / Q000628:therapy*
chemical_list: D000779:Anesthetics, Local