Iranian Veterinary Surgery Association (IVSA) Iranian Journal of Veterinary Surgery 2008-3033 14 2 2019 10 01 Ultrasonographic Assessment of Caudal Vena Cava to Aorta Ratio as a Novel Endpoint in Hemorrhagic Shock Resuscitation in Dogs 125 132 92138 10.22034/ivsa.2019.176714.1181 EN Reza Azargoun Graduated of Small Animal Internal Medicine, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. 0000-0002-5442-5552 Reza Avizeh Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Alireza Ghadiri Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Hadi Imani Rastabi Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. 0000-0002-1564-7240 Mahdi Pourmahdi Department of Food Hygiene, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran. Journal Article 2019 03 19 <strong>Objective-</strong> The aim of this study was to assess ultrasonography-derived caudal vena cava to aorta ratio (CVC/Ao) as a novel endpoint in the resuscitation of experimental hemorrhagic shock in dogs.<br /><strong>Design-</strong> Experimental study.<br /><strong>Animals-</strong> Ten adult mongrel healthy dogs.<br /><strong>Procedures-</strong> After induction of anesthesia (control assessments), hemorrhagic shock was induced by blood withdrawal to a mean arterial pressure of 40 to 50 mmHg within 30 minutes and then maintained in a hypovolemic situation for an additional 30 minutes (second and third stages of assessments). Afterward, the dogs were randomly assigned to two groups which received 20 ml/kg lactated Ringer's solution or 5 ml/kg Hydroxyethyl starch, in four consecutive 15 minutes intervals (fourth stage of assessments). One hour after the last resuscitation step, final ultrasonographic assessments were performed.<br /><strong>Results-</strong> Hemorrhagic shock caused a significant decrease in the CVC and Ao diameters as well as the CVC/Ao (2.14 ± 0.28 cm, 0.85 ± 0.07 cm and 0.4 ± 0.06, respectively) (p<0.05). Following the fluid resuscitation, CVC/Ao increased and returned to pre-shock values in both groups.<br /><strong>Conclusion and clinical relevance-</strong> Findings indicated that serial ultrasonographic assessment of the CVC/Ao can be a useful endpoint in the resuscitation of dogs with hemorrhagic shock. https://www.ivsajournals.com/article_92138_2c87012918518225f804bb2426c52142.pdf