Agreement between invasive and oscillometric arterial blood pressure measurements using the LifeWindow multiparameter monitor and two cuff sizes in anesthetized adult horses.

OBJECTIVE

To assess agreement between oscillometric noninvasive blood pressure (NIBP) measurements using LifeWindow monitors (LW9xVet and LW6000V) and invasive blood pressure (IBP). To assess the agreement of NIBP readings using a ratio of cuff width to mid-cannon circumference of 25% and 40%.

STUDY DESIGN

Prospective, randomized clinical study.

ANIMALS

A total of 43 adult horses undergoing general anesthesia in dorsal recumbency for different procedures.

METHODS

Anesthetic protocols varied according to clinician preference. IBP measurement was achieved after cannulation of the facial artery and connection to an appropriately positioned transducer connected to one of two LifeWindow multiparameter monitors (models: LW6000V and LW9xVet). Accuracy of monitors was checked daily using a mercury manometer. For each horse, NIBP was measured with two cuff widths (corresponding to 25% or 40% of mid-cannon bone circumference), both connected to the same monitor, and six paired IBP/NIBP readings were recorded (at least 3 minutes between readings). NIBP values were corrected to the relative level of the xiphoid process. A Bland-Altman analysis for repeated measures was used to assess bias (NIBP-IBP) and limits of agreement (LOAs).

RESULTS

The 40% cuff width systolic arterial pressure [SAP; bias 7.9 mmHg, LOA -26.6 to 42.3; mean arterial pressure (MAP): bias 4.9 mmHg, LOA -28.2 to 38.0; diastolic arterial pressure (DAP): bias 4.2 mmHg, LOA -31.4 to 39.7)] performed better than the 25% cuff width (SAP: bias 26.4 mmHg, LOA -21.0 to 73.9; MAP: bias 15.7 mmHg, LOA -23.8 to 55.2; DAP: bias 10.9 mmHg, LOA -33.2 to 54.9).

CONCLUSIONS AND CLINICAL RELEVANCE

Using the LifeWindow multiparameter monitor in anesthetized horses, the 40% cuff width provided better agreement with IBP; however, both cuff sizes and both monitor models failed to meet American College of Veterinary Internal Medicine Consensus Statement Guidelines.