Effect of a Standardized Sedation Protocol on Portal Vein Velocity Measurements in Hospitalized Dogs Using...

Area of Science:

• Veterinary Medicine
• Diagnostic Imaging
• Cardiovascular Physiology

Background:

• Portal vein velocity (PVV) serves as an indirect measure of portal pressure.
• Established PVV reference ranges exist for healthy, non-sedated dogs.
• Factors influencing PVV, beyond body weight, remain largely unexplored.

Purpose of the Study:

• To evaluate the impact of a medetomidine and butorphanol sedation protocol on canine PVV.
• To determine if post-sedation PVV falls below the threshold indicative of portal hypertension (10 cm/s).

Main Methods:

• Prospective comparative study involving 15 client-owned dogs.
• Triplex-Doppler ultrasound for PVV measurements pre- and post-sedation.
• Standardized intravenous sedation with medetomidine (2-3 µg/kg) and butorphanol (0.3 mg/kg).

Main Results:

• Mean PVV significantly decreased from 14.9 ± 3.98 cm/s pre-sedation to 10.4 ± 3.73 cm/s at 3 minutes post-sedation (p < 0.001).
• The proportion of dogs with PVV below 10 cm/s increased from 20% pre-sedation to 60% post-sedation.
• No significant effect of age, sex, or weight on PVV was observed.

Conclusions:

• Medetomidine and butorphanol sedation significantly reduces PVV in dogs.
• Post-sedation PVV values can fall into ranges typically associated with portal hypertension.
• Clinicians must consider sedation's effect on PVV when interpreting hepatic and portal hemodynamics.