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Caval-aortic ratio and caudal vena cava diameter in dogs before and after blood donation
Vicente J Herreria-Bustillo1, Ella Fitzgerald1, Karen R Humm1
1From Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, UK.
Insights
Ultrasound measurements of the caudal vena cava diameter (CVCd) and its ratio to the aortic diameter (CVCd:Aod) in Greyhounds did not significantly change after blood donation. This suggests this method is insensitive to mild blood loss in dogs.
Area of Science:
- Veterinary Ultrasound
- Cardiovascular Physiology
- Canine Hemodynamics
Background:
- Assessing blood volume changes in dogs is crucial for clinical management.
- Ultrasound offers a non-invasive method to evaluate vascular parameters.
- The caudal vena cava diameter (CVCd) and its ratio to aortic diameter (CVCd:Aod) may reflect intravascular volume status.
Purpose of the Study:
- To determine if donating 1 unit of blood causes a significant decrease in CVCd and CVCd:Aod ratio in Greyhounds.
- To evaluate the utility of iliac CVCd and CVCd:Aod measurements in detecting mild blood loss.
Main Methods:
- Eight healthy Greyhounds were assessed using ultrasound before and after donating 1 unit of blood.
- M-mode images of the caudal vena cava and aorta were obtained at the iliac location.
- Caudal vena cava diameter (CVCd) and aortic diameter (Aod) were measured, and the CVCd:Aod ratio calculated. Paired t-tests were used for statistical analysis.
Main Results:
- Mean CVCd was 15.84 mm pre-donation and 15.82 mm post-donation (P=0.99).
- Mean CVCd:Aod ratio was 0.93 pre-donation and 1.00 post-donation (P=0.34).
- No statistically significant differences were found in CVCd or CVCd:Aod ratio after blood donation.
Conclusions:
- Ultrasound measurement of CVCd and CVCd:Aod ratio at the iliac site did not detect changes associated with 1 unit of blood donation in Greyhounds.
- This imaging technique may not be sensitive enough to identify mild-to-moderate blood loss in this canine population.
Objective:
To investigate whether the donation of 1 unit of blood results in a significant decrease in the caudal vena cava diameter (CVCd) and the caudal vena cava diameter to aortic diameter (CVCd:Aod) ratio measured at the iliac location.
Interventions:
Eight healthy client-owned Greyhounds underwent ultrasound of their caudal vena cava and aorta before and after blood donation. The principal investigator obtained M-mode images of the blood vessels from all dogs and a secondary investigator measured the CVCd and aortic diameter in a blinded manner from stored images. The ratio of CVCd:Aod was then calculated. After assessing for normality, paired-sample t-tests were performed to compare mean values before and after donation.
Main Results:
The mean (±SD) CVCd before and after blood donation were 15.84 mm (±5.06 mm) and 15.82 mm (±5.42 mm) and the CVCd:Aod ratios were 0.93 (±0.23) and 1.00 (±0.27), respectively. There was no statistical difference between pre- and postdonation values for CVCd (P = 0.99) or CVCd:Aod (P = 0.34).
Conclusion:
The measurement of CVCd and CVCd:Aod ratio with ultrasound at the iliac location failed to detect mild-to-moderate blood loss produced by the donation of 1 unit of blood in Greyhounds.
