title: Correlation of the ratio of caudal vena cava diameter and aorta diameter with systolic pressure variation in anesthetized dogs.
abstract: OBJECTIVE
  To evaluate the correlation coefficient of the ratio between diameter of the caudal vena cava (CVC) and diameter of the aorta (Ao) in dogs as determined ultrasonographically with systolic pressure variation (SPV).
  
  
  METHODS
  14 client-owned dogs (9 females and 5 males; mean ± SD age, 73 ± 40 months; mean body weight, 22 ± 7 kg) that underwent anesthesia for repair of skin wounds.
  
  
  METHODS
  Anesthesia was induced. Controlled mechanical ventilation with a peak inspiratory pressure of 8 cm H2O was immediately started, and SPV was measured. During a brief period of suspension of ventilation, CVC-to-Ao ratio was measured on a transverse right-lateral intercostal ultrasonographic image obtained at the level of the porta hepatis. When the SPV was ≥ 4 mm Hg, at least 1 bolus (3 to 4 mL/kg) of Hartmann solution was administered IV during a 1-minute period. Bolus administration was stopped and the CVC-to-Ao ratio measured when SPV was < 4 mm Hg. Correlation coefficient analysis was performed.
  
  
  RESULTS
  28 measurements were obtained. The correlation coefficient was 0.86 (95% confidence interval, 0.72 to 0.93). Mean ± SD SPV and CVC-to-Ao ratio before bolus administration were 7 ± 2 mm Hg and 0.52 ± 0.16, respectively. Mean ± SD SPV and CVC-to-Ao ratio after bolus administration were 2 ± 0.6 mm Hg and 0.91 ± 0.13, respectively.
  
  
  CONCLUSIONS
  In this study, the CVC-to-Ao ratio was a feasible, noninvasive ultrasonographically determined value that correlated well with SPV.
authors.forename: Caterina
authors.initials: C
authors.lastname: Meneghini
authors.forename: Roberto
authors.initials: R
authors.lastname: Rabozzi
authors.forename: Paolo
authors.initials: P
authors.lastname: Franci
mesh_terms: D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D001011:Aorta / Q000033:anatomy & histology* / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D004285:Dogs / Q000033:anatomy & histology* / Q000502:physiology; D005260:Female; D008297:Male; D014682:Vena Cava, Inferior / Q000033:anatomy & histology* / Q000502:physiology