Cardiovascular effects of intravenous pimobendan in dogs with acute respiratory acidosis
- PMID: 35080109
- DOI: 10.1111/vec.13178
Cardiovascular effects of intravenous pimobendan in dogs with acute respiratory acidosis
Abstract
Objective: Acidosis decreases myocardial contractile and myofibrillar responsiveness by reducing the calcium sensitivity of contractile proteins, which could reduce the effectiveness of pimobendan. We aimed to assess the cardiovascular effects of pimobendan in dogs subjected to acute respiratory acidosis.
Design: Randomized crossover study with a 2-week washout period.
Setting: University Laboratory.
Animals: Six healthy research Beagle dogs.
Interventions: Anesthetized dogs were administered 2 doses of IV pimobendan during conditions of eucapnia (Paco2 35-40 mm Hg) and hypercapnia (Paco2 90-110 mm Hg). Eucapnia was maintained by positive pressure ventilation and hypercapnia was induced by adding exogenous CO2 to the anesthesia circuit. Heart rate (HR), systemic arterial blood pressure, cardiac output (CO), systemic and pulmonary vascular resistance (SVR and PVR, respectively), and pulmonary arterial pressure (PAP) were measured at baseline and 60 min after administering 0.125 mg/kg (low) and 0.25 mg/kg (high) pimobendan intravenously. Blood gas and biochemical analyses were performed at baseline and at the end of the experiment.
Measurements and main results: The median baseline blood pH was 7.41 (range: 7.33-7.45) and 7.03 (range: 6.98-7.09) under conditions of eucapnia and hypercapnia, respectively. The serum concentrations of epinephrine and norepinephrine and the HR, CO, and PAP were higher, and SVR was lower at baseline in hypercapnic dogs. Pimobendan dose-dependently increased CO in eucapnia (baseline: 3.6 ± 0.2 L/kg/m2 [mean ± SE], low: 5.0 ± 0.4 L/kg/m2 , high: 5.8 ± 0.5 L/kg/m2 , P < 0.001) and hypercapnia (baseline: 4.9 ± 0.5 L/kg/m2 , low: 5.8 ± 0.5 L/kg/m2 , high: 6.2 ± 0.5 L/kg/m2 , P < 0.001), and increased HR and decreased SVR and PVR under both conditions (P < 0.001). In hypercapnia, the degree of increase or decrease of these cardiovascular measurements (except for PAP) by pimobendan was less than that in the eucapnic dogs.
Conclusions: Pimobendan maintains function as an inodilator in anesthetized dogs with induced respiratory acidosis.
Keywords: canine; hypercapnia; hypercarbia; inodilator; phosphodiesterase inhibitor.
© Veterinary Emergency and Critical Care Society 2022.
Similar articles
-
Cardiovascular effects of intravenous colforsin in normal and acute respiratory acidosis canine models: A dose-response study.PLoS One. 2019 Jul 10;14(7):e0213414. doi: 10.1371/journal.pone.0213414. eCollection 2019. PLoS One. 2019. PMID: 31291253 Free PMC article.
-
A Quick Reference on Respiratory Acidosis.Vet Clin North Am Small Anim Pract. 2017 Mar;47(2):185-189. doi: 10.1016/j.cvsm.2016.10.012. Epub 2016 Dec 8. Vet Clin North Am Small Anim Pract. 2017. PMID: 27939862 Review.
-
Effects of clinically relevant acute hypercapnic and metabolic acidosis on the cardiovascular system: an experimental porcine study.Crit Care. 2013 Dec 30;17(6):R303. doi: 10.1186/cc13173. Crit Care. 2013. PMID: 24377654 Free PMC article.
-
Cardiopulmonary effects of hypercapnia during controlled intermittent positive pressure ventilation in the horse.Can J Vet Res. 1995 Jul;59(3):213-21. Can J Vet Res. 1995. PMID: 8521355 Free PMC article.
-
Acute respiratory acidosis decreases left ventricular contractility but increases cardiac output in dogs.Circ Res. 1990 Sep;67(3):628-35. doi: 10.1161/01.res.67.3.628. Circ Res. 1990. PMID: 2118837
Cited by
-
Hemodynamic effect of pimobendan following intramuscular and intravenous administration in healthy dogs: A pilot study.Front Vet Sci. 2022 Oct 12;9:969304. doi: 10.3389/fvets.2022.969304. eCollection 2022. Front Vet Sci. 2022. PMID: 36311676 Free PMC article.
References
REFERENCES
-
- Boyle KL, Leech E. A review of the pharmacology and clinical uses of pimobendan. J Vet Emerg Crit Care. 2012;22(4):398-408.
-
- Carceles MD, Aleixandre F, Fuente T, et al. Effects of rolipram, pimobendan and zaprinast on ischaemia-induced dysrhythmias and on ventricular cyclic nucleotide content in the anaesthetized rat. Eur J Anaesthesiol. 2003;20(3):205-211.
-
- van Meel JC, Diederen W. Hemodynamic profile of the cardiotonic agent pimobendan. J Cardiovasc Pharmacol. 1989;14(2):S1-6.
-
- Boswood A, Häggström J, Gordon SG, et al. Effect of pimobendan in dogs with preclinical myxomatous mitral valve disease and cardiomegaly: the EPIC study-a randomized clinical trial. J Vet Intern Med. 2016;30(6):1765-1779.
-
- Fuentes VL, Corcoran B, French A, et al. A double-blind, randomized, placebo-controlled study of pimobendan in dogs with dilated cardiomyopathy. J Vet Intern Med. 2002;16(3):255-261.
Publication types
MeSH terms
Substances
LinkOut - more resources
Full Text Sources
Research Materials