Iranian Veterinary Journal

Iranian Veterinary Journal

Evaluation of electrocardiogram changes in normovolemic hypotensive dogs treated with fluids alone or in combination with ephedrine or dobutamine

Document Type : Research Paper

Authors
Pardis Varzandeh 1
Bahman Mosallanejad 2
Hadi Imani 3
Mohammad Razi Jalali 2
Seyed Reza Fatemi Tabatabaei 4
1 PhD Student in Small Animal Internal Medicine, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
2 Professor, Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
3 Associate Professor, Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
4 Professor, Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
10.22055/ivj.2022.363499.2503
Abstract
    Normovolemic hypotension can occur due to vasodilation or loss of vascular tone sympathetic nervous system. The aim of the present study was to evaluate electrocardiographic changes and rhythm disorders in normotensive dogs with isoflurane-induced hypotension and treated with ephedrine, dobutamine and fluid therapy. Twenty-nine adult male and female dogs of Mixed breed, weighing 20.1 ± 4.3 kg and in the age range 1.5-2.5 years-old were selected. Anesthesia was induced and maintained with propofol and 1.5% isoflurane in 100% oxygen, respectively. Then, hypotension was induced by deep anesthesia provided with 3% isoflurane. The dogs were given one of five treatments of 1- Ringer's solution (1 ml/kg/min, n=5), 2- Ringer's solution (1 ml/kg/min) with intravenous administration of ephedrine (RE, 0.2 mg/kg, n=6, 3- Ringer's solution (1 ml/kg/min) with intravenous infusion of dobutamine (RD, 5 µg/kg/min, n=6), 4- Intravenous administration of ephedrine (E, 0.2 mg/kg, n=6) and 5- Intravenous infusion of dobutamine (D, 5 µg/kg/min, n=6). By the time the direct blood pressure reached above 60 mmHg after challenge, treatment was discountinued, and the amount of isoflurane was reduced. If there were no responses, the treatment was repeated once again. Electrocardiogram was obtained from all animals at defined time points. Heart rate after treatment was significantly higher in the ringer's with dobutamine (184.2 ± 14.75) than in ephedrine (99.6± 23.8) and dobutamine (108.8± 20/29). Heart rate in the ringers with ephedrine after treatment (110.5 ± 26.46) was significantly higher than the baseline. The changes in P wave, QRS, PR interval, QT, heart electrical axis, and ST segment shape were insignificant. It was concluded that the addition of ephedrine or dobutamine to conventional fluid therapy in normovolemic hypotensive dogs can be associated with higher heart rate values. According to the obtained results, dobutamine with ringer's solution increased the heart rate more than the other groups.
Keywords
Hypotension
Dobutamine
Ephedrine
Electrocardiogram
Dog

Subjects

Adamson, P. B., Suarez, J., Ellis, E., Kanaly, T., & Vanoli, E. (2004). Ephedrine increases ventricular arrhythmias in conscious dogs after myocardial infarction. Journal of the American College of Cardiology, 44(8), 1675-1678.
Chen, H. C., Sinclair, M. D., & Dyson, D. H. (2007). Use of ephedrine and dopamine in dogs for the management of hypotension in routine clinical cases under isoflurane anesthesia. Veterinary Anaesthesia and Analgesia, 34, 301-311.
Chitsaz, S., Avizeh, R., Najafzadeh Varzi, H., & Baniadam, A. (2023). Comparison of serum oxytetracycline concentration after intravenous and intraosseous administration in dogs. Iranian Veterinary Journal, 19, 23-28.
Davis, H. (2016). Management of Patients in Shock. In: Battaglia, A. M., & Steele, A. M. Small animal emergency and critical care for veterinary technicians, (3th Edition) Elsevier, Publication, Missouri, Pp: 223-233.
Dubin, A., Lattanzio, B., & Gatti, L. (2017). The spectrum of cardiovascular effects of dobutamine-from healthy subjects to septic shock patients. Brazilian Journal of Intensive Care, 29(4), 490-498.
Dyson, D. H., & Sinclair M. D. (2006). Impact of dopamine or dobutamine infusions on cardiovascular variables after rapid blood loss and volume replacement during isoflurane-induced anesthesia in dogs. American Journal of Veterinary Research, 67, 1121-1130.
Gholami, S., Baniadam, A., Sabiza, S., & Jalali, S. M. (2025). Comparison of the effect of intraosseous and intravenous administration of midazolam-ketamine on clinical, cardiopulmonary and hematological parameters in dogs. Iranian Veterinary Journal, 52, 52-63.
Goya, S., Wada, T., Shimada, K., Hirao, D., & Tanaka, R. (2018). Dose-dependent effects of isoflurane and dobutamine on cardiovascular function in dogs with experimental mitral regurgitation. Veterinary Anaesthesia and Analgesia, 45(4), 432-442.
Guly, H. R., Bouamra, O., & Lecky, F. E. (2008). The incidence of neurogenic shock in patients with isolated spinal cord injury in the emergency department. Resuscitation, 76(1), 57-62.
Haskins, S. C. (2012). Shock. In: D. K, Macintire, K. J, Drobatz, S. C, Haskins, & W. D, Saxon. Manual of Small Animal Emergency and Critical Care Medicine, (2th Edition) West Sussex, Pp: 30-40.
Harold, D., Jensen, T., Johnson, A., Knowles, P., Meyer, R., & Rucinsky, R. (2013). AAHA/AAFP fluid therapy guidelines for dogs and cats. Journal of American Animal Hospital Association, 49, 149-159.
Hoffman, B. B. (2001). Catecholamines, sympathomimetic drugs, & adrenergic receptor antagonists. Goodman and Gilman's the pharmacological basis of therapeutics, 12e.
Kudnig, S. T., & Mama, K. (2002) Perioperative fluid therapy. Journal of the American Veterinary Medical Association, 221, 1112-1121.
Klabunde, R., (2011). Cardiovascular physiology concepts, (2th Edition) Wolters Kluwer Publication, Lippincott Williams & Wilkins, Pp: 206-2011.
Laforcade, A. D., & Silverstein, D. C. (2015). Shock. In: Silverstein, D. C., & Hopper, K. Small Animal Critical Care Medicine. Second ed. Elsevier, Publication, Missouri, Pp: 26-30.
Martin, M. (2015). Small Animal ECGs: An Introductory Guide, (3rd Edittion) John Wiley & Sons. West Sussex, 1-14.
Mazzaferro, E., & Wagner, A. E. (2001) Hypotension during anesthesia in dogs and cats: recognition, causes and treatment. Compendium, 23, 728-737.
Nelson, R. W., & Couto, C. G., (2019). Small animal internal medicine-E-book. Elsevier Health Sciences, Pp: 43-84. 
Plumb, D. C. (2018). Plumb's Veterinary Drug Handbook: Desk. John Wiley & Sons, (9th Edition), Pp: 17-49.
Ramsey, I. (2017). BSAVA Small Animal Formulary 10th edn-Part A: Canine and Feline, ed. Ramsey, I, British Small Animal Veterinary Association, Gloucester, England, Pp: 149-150.
Santilli, R., Moïse, N. S., Pariaut, R., & Perego, M. (2019). Electrocardiography of the Dog and Cat, (2th Edition) Milan: Edra, Pp: 52-89.
Secher, N. H., & Van Lieshout, J. J., (2005). Normovolaemia defined by central blood volume and venous oxygen saturation. Clinical and Experimental Pharmacology and Physiology, 32(11), pp. 901-910.
Silverstein, D., & Hopper, K. (2014). Small animal critical care medicine-E-Book. Elsevier Health Sciences. Pp: 27-98.
Sousa, M. G., Pereira-Neto, G. B., Carareto, R., Gerardi, D. G., & Camacho, A. A., (2005). Assessment of electrocardiographic parameters in healthy dogs undergoing dobutamine stress testing: Veränderungen elektrokardiographischer Parameter bei gesunden Hunden während Dobutamin Stressuntersuchungen. Schweizer Archiv für Tierheilkunde, 147(12), 541-545.
Summers, R. L., Baker, S. D., Sterling, S. A., Porter, J. M., & Jones, A. E., (2013). Characterization of the spectrum of hemodynamic profiles in trauma patients with acute neurogenic shock. Journal of Critical Care, 28(4), 531-541.
Tilley, L. P., & Goodwin, J. (2001). Manual of canine and feline cardiology, (3th Edition) WB Saunders, Philadelphia, USA., pp. 43-70.
Tilley, L. P., & Smith, Jr., F. W. K. (2016). Electrocardiography. In: Jr., F. W. K. Smith, L. P., Oyama, M. A., & Sleeper, M. M. Manual of Canine and Feline Cardiology Missouri: Elsevier, (5th Edition), 49-76.  
Valverde, A., Gianotti, G., Rioja-Garcia, E., & Hathway, A. (2012). Effects of high-volume, rapid-fluid therapy on cardiovascular function and hematological values during isoflurane-induced hypotension in healthy dogs. Canadian Journal of Veterinary Research, 76, 99-108.
Wagner, A., Dunlop, C., & Chapman, P. (1993) Effects of ephedrine on cardiovascular function and oxygen delivery in isoflurane-anesthetized dogs. American Journal of Veterinary Research, 54, 1917-1922.
 Yang, C. F., Chen, M. Y. C., Chen, T. I., & Cheng, C. F. (2014). Dose-dependent effects of isoflurane on cardiovascular function in rats. Tzu Chi Medical Journal, 26(3), 119-122.