Correct occlusive bladder width for indirect blood pressure measurement in horses

Area of Science:

• Veterinary Medicine
• Cardiovascular Physiology
• Equine Research

Background:

• Accurate indirect blood pressure measurement in horses is essential for clinical monitoring.
• The influence of occlusive cuff size, specifically bladder width (BW) to tail girth (TG) ratio, on measurement accuracy is not well-established.

Purpose of the Study:

• To investigate the influence of occlusive bladder width on indirect blood pressure measurements in anesthetized horses.
• To determine the optimal bladder width to tail girth ratio for accurate systolic and diastolic pressure readings.
• To compare blood pressure measurements from the middle coccygeal artery and greater metatarsal artery.

Main Methods:

• Indirect blood pressure measurement using Doppler ultrasound on the middle coccygeal artery in 6 anesthetized horses.
• Investigated the effect of tail hair (clipped vs. unclipped) on optimal bladder width (BW)/tail girth (TG) ratios.
• Compared direct blood pressure measurements from the middle coccygeal and greater metatarsal arteries.

Main Results:

• Optimal BW/TG ratios for systolic and diastolic pressure varied between clipped and unclipped tails, but regression equations were not significantly different.
• The combined data (TTB) yielded an optimal BW/TG ratio of 0.339 for systolic and 0.983 for diastolic pressure.
• A BW/TG ratio of 0.482 resulted in an approximate 8.8% underestimation of systolic and overestimation of diastolic pressure.

Conclusions:

• A standardized BW/TG ratio can be used for indirect blood pressure measurement in horses, regardless of tail hair status.
• The study provides specific optimal BW/TG ratios for accurate equine blood pressure assessment.
• Direct blood pressure measurements showed no significant difference between the middle coccygeal and greater metatarsal arteries when averaged across all horses.