title: Equivalence between invasive and oscillometric blood pressures at different anatomic locations in healthy normotensive anaesthetised horses.
abstract: BACKGROUND
  Accurate blood pressure measurement is essential for effective clinical assessment and appropriate interventions in anaesthetised horses. Information on the accuracy of oscillometry for blood pressure measurement on the appendages of mature horses is limited.
  
  
  OBJECTIVE
  To assess equivalence between invasive and oscillometric blood pressures at different anatomic locations in horses.
  
  
  METHODS
  Prospective experimental study using 6 healthy mature horses.
  
  
  METHODS
  Blood pressure was measured invasively in the right transverse facial artery and noninvasively by oscillometry in nondependent limbs and tail of laterally recumbent sevoflurane- or desflurane-anaesthetised horses. Cuff widths of 5-12 cm were tested on the tail, metatarsus, metacarpus and distal radius/ulna. Equivalence between mean arterial pressure (MAP) oscillometric and MAP invasive was assessed using a linear mixed effects model with a significance level of P≤0.05.
  
  
  RESULTS
  Twenty paired measurements were obtained for each cuff size in each of the locations, totalling 340 measurements. There was only one location (tail) and one cuff width (6 cm; cuff width-to-tail circumference ratio of 0.25) that resulted in equivalence between MAP measured with the oscillometric and the invasive methods (P = 0.8). All other locations (metacarpus, radius/ulna, metatarsus) and cuff widths were not equivalent (P≤0.01).
  
  
  CONCLUSIONS
  A cuff width-to-tail circumference ratio of 0.25 is recommended for accurate oscillometric blood pressure measurement in mature, laterally recumbent anaesthetised normotensive horses. Studies with variable haemodynamics are warranted. Oscillometric measurements at other extremities and/or with other cuff sizes cannot be recommended for clinical use.
authors: Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California Davis, Davis, USA.
authors: C C
authors: CC
authors: Tearney
authors: Department of Surgical and Radiological Sciences, University of California Davis, Davis, USA.
authors: A G P
authors: AG
authors: Guedes
authors: Department of Surgical and Radiological Sciences, University of California Davis, Davis, USA.
authors: R J
authors: RJ
authors: Brosnan
mesh_terms: D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination / Q000662:veterinary*; D015924:Blood Pressure Monitors / Q000662:veterinary*; D005260:Female; D006736:Horses / Q000502:physiology*; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D009991:Oscillometry / Q000295:instrumentation / Q000662:veterinary*
keywords: blood pressure cuff; cardiovascular monitoring; horse; indirect blood pressure; noninvasive blood pressure