Shock, Hypovolemic Basic Information Definition A reduction in perfusion that results in inadequate organ perfusion and tissue oxygenation Clinical Presentation Disease Forms/Subtypes • Hemorrhagic • Maldistributive (sepsis, endotoxemia) • Traumatic History, Chief Complaint • Ataxia, collapse • History of observed trauma • Weak, inappetent foals, often after dystocia • History of overt hemorrhage or recent foaling • Anorexia, colic, or signs of abdominal pain • Increased respiratory rate or labored breathing Physical Exam Findings Physical examination findings may be normal in early, compensated shock. • Depression, stupor • Tachycardia, bright-red mucous membranes (progressing to purple), poor pulse quality, physiologic murmurs • Tachypnea, crackles, pleural friction rubs • Reduced gastrointestinal borborygmi • Hyperthermia or hypothermia Etiology and Pathophysiology • Etiology Severe hemorrhage (guttural pouch mycosis, uterine artery rupture, trauma) Sepsis (neonatal septicemia, enterocolitis, metritis, pleuritis) Gastrointestinal accidents (large colon volvulus, gastric rupture) (Figure 1) Hyperthermia (endurance rides, long distance hauling) • Pathophysiology Reduced tissue perfusion caused by a decrease in circulating volume decreases the delivery of oxygen to tissues. Decreased circulating volume may result from loss of fluid (hemorrhage) or a relative decrease in volume (sepsis and endothelial disruption, causing vascular leak syndrome). Local hypoxia results in the conversion to anaerobic metabolism for energy production, with metabolic acids (lactate) as a byproduct. Severe blood loss (>40% of circulating volume) or hypovolemia with severe hypotension (mean pressures, 30–40 mm Hg) may lead to irreversible shock and death caused by: Cellular dysfunction and death from free radical production Activation of the inflammatory and coagulation cascades Endothelial disruption permitting endotoxemia and bacterial translocation FIGURE 1 Hyperemic mucous membranes in a horse with a gastric rupture demonstrating hypovolemic shock caused by dehydration, systemic inflammation, and endotoxemia. Diagnosis Differential Diagnosis • Cardiogenic • Hypoxic • Anaphylactic • Neurogenic< div class='tao-gold-member'> Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Aggressive Stallion Behavior Aflatoxin Toxicosis Biliary Atresia Black Widow Spider Toxicosis Stay updated, free articles. Join our Telegram channel Join Tags: Clinical Veterinary Advisor The Horse Jul 24, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Shock, Hypovolemic Full access? Get Clinical Tree
Shock, Hypovolemic Basic Information Definition A reduction in perfusion that results in inadequate organ perfusion and tissue oxygenation Clinical Presentation Disease Forms/Subtypes • Hemorrhagic • Maldistributive (sepsis, endotoxemia) • Traumatic History, Chief Complaint • Ataxia, collapse • History of observed trauma • Weak, inappetent foals, often after dystocia • History of overt hemorrhage or recent foaling • Anorexia, colic, or signs of abdominal pain • Increased respiratory rate or labored breathing Physical Exam Findings Physical examination findings may be normal in early, compensated shock. • Depression, stupor • Tachycardia, bright-red mucous membranes (progressing to purple), poor pulse quality, physiologic murmurs • Tachypnea, crackles, pleural friction rubs • Reduced gastrointestinal borborygmi • Hyperthermia or hypothermia Etiology and Pathophysiology • Etiology Severe hemorrhage (guttural pouch mycosis, uterine artery rupture, trauma) Sepsis (neonatal septicemia, enterocolitis, metritis, pleuritis) Gastrointestinal accidents (large colon volvulus, gastric rupture) (Figure 1) Hyperthermia (endurance rides, long distance hauling) • Pathophysiology Reduced tissue perfusion caused by a decrease in circulating volume decreases the delivery of oxygen to tissues. Decreased circulating volume may result from loss of fluid (hemorrhage) or a relative decrease in volume (sepsis and endothelial disruption, causing vascular leak syndrome). Local hypoxia results in the conversion to anaerobic metabolism for energy production, with metabolic acids (lactate) as a byproduct. Severe blood loss (>40% of circulating volume) or hypovolemia with severe hypotension (mean pressures, 30–40 mm Hg) may lead to irreversible shock and death caused by: Cellular dysfunction and death from free radical production Activation of the inflammatory and coagulation cascades Endothelial disruption permitting endotoxemia and bacterial translocation FIGURE 1 Hyperemic mucous membranes in a horse with a gastric rupture demonstrating hypovolemic shock caused by dehydration, systemic inflammation, and endotoxemia. Diagnosis Differential Diagnosis • Cardiogenic • Hypoxic • Anaphylactic • Neurogenic< div class='tao-gold-member'> Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Aggressive Stallion Behavior Aflatoxin Toxicosis Biliary Atresia Black Widow Spider Toxicosis Stay updated, free articles. Join our Telegram channel Join Tags: Clinical Veterinary Advisor The Horse Jul 24, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Shock, Hypovolemic Full access? Get Clinical Tree
