Noninvasive Estimation of Central Venous Pressure in Anesthetized Dogs by Measurement of Hepatic Venous Blood Flow Velocity and Abdominal Venous Diameter

Abstract

Determination of central venous pressure (CVP) is relevant to patients with right heart disease, hypovolemia, and following intravenous fluid therapy. We hypothesized that changes in CVP in dogs could be predicted by measurements of hepatic vein diameter, caudal vena cava (CVC) diameter, and hepatic venous flow velocities. Nine healthy American Foxhounds were anesthetized. Following baseline recordings, intravenous fluids were administered to increase CVP. Volume administration created treatment periods with CVP ranges of 5, 10, 15, 20, and 25 mm Hg. Flow velocities in the right medial hepatic vein were recorded using pulsed wave Doppler ultrasound. Hepatic vein, CVC, and aorta diameters were determined with B-mode ultrasound. Variables were compared across the treatment periods by ANOVA for repeated measures. Relationships between CVP, Doppler, and B-mode variables were evaluated using Spearman's rank correlations, multiple linear regression, and repeated measures linear regression. The a-, S- and v-wave velocities were augmented significantly with volume loading. The best part (semipartial) correlation coefficients predicting increasing CVP were identified with v-wave velocity (0.823), S-wave velocity (-0.800), CVC diameter (0.855), and hepatic vein diameter (0.815). Multiple linear regression indicated that CVP in this study could be predicted best by a combination of CVC and hepatic vein diameter and the v-wave velocity (r = 0.928). Ultrasound imaging identified gallbladder and pancreatic edema consistently, likely related to acute volume loading. These findings may be applicable in the assessment of volume status, dogs with right heart disease, and during serial monitoring of dogs receiving fluid or diuretic therapy.

Establishment of reference values of the caudal vena cava by fast‐ultrasonography through different views in healthy dogs

“…Using allometric scaling, the predicted value of CVC D‐PV‐B for a 20‐kg dog at the PV site would be 0.89 cm, which is similar to the estimated mean CVC D of a 20 kg American Foxhound (0.96 cm) calculated in a previous study . Allometric scaling was used for parameters related to BW (CVC amin‐HV‐B , CVC amax‐HV‐B , Ao max‐HV‐B , CVC D‐PV‐B , CVC D‐PV‐M , and Ao D‐PV‐B ) with 95% prediction intervals for dogs ranging in weight from 3 to 70 kg.…”

“…In veterinary medicine, 2 studies reported a positive correlation between CVP and caudal vena cava diameter (CVC D ) in anesthetized dogs receiving IV fluids and positive pressure ventilation . Three recent studies evaluating CVC diameter, CVC collapsibility (CVC CI ), and the CVC to Ao ratio (CVC/Ao) showed promise in evaluation of intravascular volume status in dogs .…”

“…15 In veterinary medicine, 2 studies reported a positive correlation between CVP and caudal vena cava diameter (CVC D ) in anesthetized dogs receiving IV fluids and positive pressure ventilation. 16,17 Three recent studies evaluating CVC diameter, CVC collapsibility (CVC CI ), and the CVC to Ao ratio (CVC/Ao) showed promise in evaluation of intravascular volume status in dogs. [18][19][20] Another study on healthy dogs undergoing general anesthesia and mechanical ventilation 21 reported that the CVC CI is a reliable predictor of fluid responsiveness.…”

Comparison of cardiac output measurements using transpulmonary thermodilution and conventional thermodilution techniques in anaesthetized dogs with fluid overload

“…The rates of infusion of LRS and HES were based on data provided in a previous report in which serious complications such as seizure and dyspnoea were not observed (Nelson et al. ). Neither of these complications occurred in the present study.…”

Liver

“…250 Normal gallbladder volume in the dog is reported to be 1.0 mL/kg or less after withholding food for 12 hours. 264 Thrombosis or space-occupying masses may also obstruct and dilate the caudal vena cava and hepatic veins, causing hepatomegaly and ascites. 251 These studies may be helpful in the identification of dogs and cats A B C Figure 9-55 Feline cholangitis/cholangiohepatitis.…”