Assessment of hemodynamic parameters and caudal vena cava-to-aorta ratio pre- and post-pericardiocentesis in dogs with cardiac tamponade.

Objectives: To evaluate haemodynamic parameters and ultrasonographic measurements of the caudal vena-cava-to-aorta ratio at the splenorenal view in canine cardiac tamponade before and 30 minutes after pericardiocentesis.

Materials and methods: Dogs presenting with cardiac tamponade at two veterinary hospitals were included. Triage examination, noninvasive systolic arterial blood pressure, shock index, venous lactatemia and POCUS results were recorded at admission and 30 minutes after pericardiocentesis.

Results: This prospective observational study included 22 dogs, and all had an increased caudal vena-cava-to-aorta ratio. After pericardiocentesis, there were significant changes in vital signs, including a decrease in the median heart rate by 42.1%, a decrease in the median respiratory rate by 40.1%, and an increase in the median rectal temperature from 37.8°C (range: 35.6 to 39.2) to 38.1°C ( 36.1 to 38.7). In regards of hemodynamic parameters, the median systolic arterial pressure increased significantly by 23.2%, the shock index decreased significantly by 52.8%, the median lactate level decreased significantly from 6.1 mmol/L (1.4 to 14.7) to 3.6 mmol/L (1.1 to 13.6), and the median caudal vena-cava-to-aorta ratio decreased significantly by 37.5%, from 1.76 (1.35 to 2.13) to 1.12 (0.91 to 1.51).

Clinical significance: This study demonstrated an increased caudal vena-cava-to-aorta ratio in dogs with cardiac tamponade and a rapid haemodynamic improvement in dogs with cardiac tamponade within 30 minutes  of the pericardiocentesis, resulting in excellent short-term prognosis.