title: Comparison of direct and Doppler arterial blood pressure measurements in rabbits during isoflurane anaesthesia.
abstract: OBJECTIVE
  To measure the level of agreement between Doppler measured (DOP) arterial blood pressure (ABP) in the forelimb and directly measured (DIR) auricular systolic ABP (SAP) and mean ABP (MAP) in isoflurane-anaesthetized rabbits.
  
  
  METHODS
  Prospective clinical study.
  
  
  METHODS
  Data were analysed from 17 of 24 healthy rabbits, weighing 1.3-2.8 kg.
  
  
  METHODS
  Rabbits were anaesthetized for neutering using a standardized protocol. A 26G catheter placed in an auricular artery was connected via heparinised saline filled non-compliant tubing (regularly flushed) to a calibrated pressure transducer (zeroed level with the thoracic inlet) to obtain DIR ABP. A cuff was placed proximal to the carpus (approximately level with the thoracic inlet) and a Doppler transducer sited over the dorsal carpal branch of the radial artery to obtain DOP ABP. Simultaneous DIR and DOP ABP recordings were made every 5-10 minutes during anaesthesia. Agreement was assessed as described by Bland JM & Altman (2007).
  
  
  RESULTS
  Mean ± SD cuff width: limb circumference ratio was 0.50 ± 0.04. Mean between-method differences ± SD, DIR SAP- DOP and DIR MAP- DOP, were +1 ± 8 and -13 ± 8 mmHg respectively. The 95% limits of agreement between DIR SAP and DOP and between DIR MAP and DOP were -14 to +17 and -28 to +2 mmHg respectively. Differences between DIR SAP and DOP were ≤ 10 mmHg 85% of the time. Defining hypotension as either DIR SAP < 80 mmHg or DIR MAP < 60 mmHg, and taking DOP ABP of <80 mmHg to indicate hypotension, sensitivity and specificity were 92% and 67% respectively.
  
  
  CONCLUSIONS
  Good agreement was found between DIR SAP and DOP. Doppler measurements below 80 mmHg are a reliable indicator of arterial hypotension.
  
  
  CONCLUSIONS
  DOP is acceptable for monitoring ABP in isoflurane-anaesthetized rabbits and is useful for detection of hypotension.
authors.affiliation: School of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol, UK. louise.harvey@bristol.ac.uk
authors.forename: Louise
authors.initials: L
authors.lastname: Harvey
authors.forename: Toby
authors.initials: T
authors.lastname: Knowles
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Murison
mesh_terms: D000769:Anesthesia, Inhalation / Q000662:veterinary*; D018685:Anesthetics, Inhalation; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001795:Blood Pressure Determination / Q000379:methods / Q000662:veterinary*; D005260:Female; D007530:Isoflurane; D017078:Laser-Doppler Flowmetry / Q000662:veterinary; D008297:Male; D011817:Rabbits
chemical_list: D018685:Anesthetics, Inhalation; D007530:Isoflurane