Influence of Normovolemic Anemia on Doppler‐derived Blood Velocity Ratios of Abdominal Splanchnic Vessels in Clinically Normal Dogs

Abstract

Doppler spectra of the abdominal aorta (AAo), cranial mesenteric artery (CMA), celiac artery (CA), and left renal artery (LRA) were obtained from 11 fasted, clinically healthy, conscious Beagles before and after inducing severe acute normovolemic anemia (mean +/- standard deviation hematocrit 16.0 +/- 0.77%). Peak systolic, end diastolic, and time-averaged mean velocities were measured. The different vessels were compared with each other. Peak systolic velocity ratio and time-averaged mean velocity ratio of splanchnic vessels to corresponding variables of the AAo were computed and compared between and within vessels during physiologic and anemic states. There was no difference between LRA and AAo, CMA or CA regarding time-averaged mean velocity, time-averaged mean velocity ratio, or end diastolic velocity during the physiological state. During the anemic state, LRA mean time-averaged mean velocity (P < or = 0.008) and mean end diastolic velocity (P < or = 0.041) were significantly lower than those of AAo, CMA, and CA. Mean time-averaged mean velocity ratio of the LRA was also significantly (P < or = 0.004) lower than the CMA and CA ratios, and significantly (P = 0.014) lower during anemic state than physiologic state of the same vessel. End diastolic and time-averaged mean velocities of the AAo, CMA, and CA increased proportionally during anemia, but there was a relatively less increase in the same variables of the LRA, suggesting less increase in blood flow. Doppler-ratios allowed a noninvasive comparison between splanchnic and aortic hemodynamics. Velocity ratios might be useful for clinical detection of relative hemodynamic changes between different vessels.

Hemorrhagic Shock in Polytrauma Patients: Early Detection with Renal Doppler Resistive Index Measurements

“…Patients with occult bleeding generally have relative hypovolemia or normovolemic anemia, which may result in vasoconstriction and increased vascular resistance ( 40,41 ). Because increased tissue resistance to perfusion slows the diastolic velocity more than it slows the systolic velocity, these changes cause an increase in the RI that can be measured in parenchymal organs such as the kidneys ( 16 ).…”

Early detection with renal Doppler resistive index measurements of hemorrhagic shock in polytrauma patients

“…13 This may be because only patients who were initially hemodynamically stable and without biochemical signs of hypoperfusion and had a very short delay between departure from the trauma scene to ED admission and US examination were included. Thus, we hypothesize that most of the patients were normovolemic at arrival in the ED despite having occult bleeding.…”

Sedation effect of midazolam, ketamine, and butorphanol on spectral Doppler ultrasound values in femoral and large abdominal arteries in cats

“…In the first case, a statistically significant reduction in TAMEAN and EnDV was observed. Although TAMEAN has a linear relationship with blood flow and thus can be a good predictor of hemodynamic changes where the sectional area of the vessel remains the same (KOMA et al, 2005); and since the final moment of diastole (EnDV) is the ideal period to assess vascular resistance (CARVALHO et al, 2008), these velocity changes did not induce changes in RI and/or PI, which are indices that serve as indicators of indirect peripheral vascular resistance (NOVELLAS et al, 2007;REIS et al, 2014). Interestingly, both RI and PI are more reliable data than direct velocity estimation by Doppler ultrasound, as they are not angle dependent, allowing small and tortuous vessels to be better evaluated (NOVELLAS et al, 2007).…”

“…There are studies in the literature describing the Doppler velocimetric parameters of the celiac artery and cranial mesenteric artery found in healthy fasting and postprandial dogs (RIESEN et al, 2002;KIRSCHER et al, 2003;KIRCHER, 2007), with disorders in organs supplied by these vessels (GASCHEN et al, 2005;KIRCHER, 2007), including atopic dermatitis (BRUET et al, 2013) and acute normovolemic anemia (KOMA et al, 2005). However, no such data was found in the literature in cats.…”