[Vasopressin intravenous infusion causes dose dependent adverse cardiovascular effects in anesthetized dogs].
Arginine vasopressin (AVP) has been broadly used in the management of vasodilatory shock. However, there are many concerns regarding its clinical use, especially in high doses, as it can be associated with adverse cardiovascular events.



To investigate the cardiovascular effects of AVP in continuous IV infusion on hemodynamic parameters in dogs.



Sixteen healthy mongrel dogs, anesthetized with pentobarbital were intravascularly catheterized, and randomly assigned to: control (saline-placebo; n=8) and AVP (n=8) groups. The study group was infused with AVP for three consecutive 10-minute periods at logarithmically increasing doses (0.01; 0.1 and 1.0 U/kg/min), at them 20-min intervals. Heart rate (HR) and intravascular pressures were continuously recorded. Cardiac output was measured by the thermodilution method.



No significant hemodynamic effects were observed during 0.01 U/kg/min of AVP infusion, but at higher doses (0.1 and 1.0 U/kg/min) a progressive increase in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) were observed, with a significant decrease in HR and the cardiac index (CI). A significant increase in the pulmonary vascular resistance index (PVRI) was also observed with the 1.0 U/kg/min dose, mainly due to the decrease in the CI.



AVP, when administered at doses between 0.1 and 1.0 U/kg/min, induced significant increases in MAP and SVRI, with negative inotropic and chronotropic effects in healthy animals. Although these doses are ten to thousand times greater than those routinely used for the management of vasodilatory shock, our data confirm that AVP might be used carefully and under strict hemodynamic monitoring in clinical practice, especially if doses higher than 0.01 U/kg/min are needed.
Martins
Luiz Cláudio
LC
Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Sabha
Maricene
M
Paganelli
Maria Ondina
MO
Coelho
Otávio Rizzi
OR
Ferreira-Melo
Silvia Elaine
SE
Moreira
Marcos Mello
MM
de Cavalho
Adriana Camargo
AC
Araujo
Sebastião
S
Moreno
Heitor
H
D000704:Analysis of Variance; D000758:Anesthesia; D000818:Animals; D002319:Cardiovascular System / Q000187:drug effects*; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D007262:Infusions, Intravenous; D008297:Male; D023421:Models, Animal; D011897:Random Allocation; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000008:administration & dosage* / Q000009:adverse effects; D014667:Vasopressins / Q000008:administration & dosage* / Q000009:adverse effects
D014662:Vasoconstrictor Agents; D014667:Vasopressins