BMC Edema, Hyperemia & Shock PDF

Edema, and Shock Yahya Al-Ghamdi, MD Courtesy of Saeed Asiry, MD Edema: increased fluid in the interstitial tissue spaces. Background Normal fluid homeostasis is maintained by vessel wall integrity, intravascular pressure and osmolarity within certain physiologic ranges. Changes i...

Edema, and Shock Yahya Al-Ghamdi, MD Courtesy of Saeed Asiry, MD Edema: increased fluid in the interstitial tissue spaces. Background Normal fluid homeostasis is maintained by vessel wall integrity, intravascular pressure and osmolarity within certain physiologic ranges. Changes in intravascular volume, pressure, or protein content, or alterations in endothelial function will affect the movement of water across the vascular wall. Background Edema: Causes Increased hydrostatic pressure Heart failure Venous obstruction Decreased oncotic (osmotic) pressure: (decreased albumin) Decreased Production: Liver failure, malnutrition Increased excretion: Nephrotic syndrome Lymphatic obstruction Sodium retention Inflammation Hyperemia & Congestion Hyperemia & Congestion Both refer to an increase in blood volume within a tissue, but they have different underlying mechanisms. Hyperemia Congestion What Active process Passive process How Arteriolar dilation, increased blood Impaired outflow of venous blood flow Examples Physiologic: Skeletal muscle during Venous obstruction (ovarian exercise torsion) Pathologic: Acute inflammation Cardiac failure Liver congestion - Gross examination: Areas of red- brown and slightly depressed (owing to cell loss) and are adjacent to surrounding zones of uncongested tan liver, resembling nutmeg surface (thus: nutmeg liver) - Microscopic examination shows centrilobular congestion with hepatocyte necrosis Hemorrhage: the extravasation of blood from vessels, is most often the result of damage to blood vessels or defective clot formation.  Hemorrhage Caused by problems in: Blood vessels Platelets Coagulation factors Hemorrhage External Internal: Hematoma Petechiae: 1-2 mm à Platelets problems Purpura: 3-5 mm à Vascular problem Ecchymoses (bruises): 1-2 cm à Subcutaneous hematoma (common cause: blunt trauma)  Hemorrhage Clinical significance: Depends on volume, rate, and site Loss of iron à iron deficiency anemia Hypovolemic shock Shock Shock A state in which diminished cardiac output or reduced effective circulating blood volume impairs tissue perfusion and leads to cellular hypoxia If not corrected, leads to death Shock - Types Shock Less commonly, shock can result from a loss of vascular tone associated with anesthesia or secondary to a spinal cord injury (neurogenic shock) Anaphylactic shock results from systemic vasodilation and increased vascular permeability that is triggered by an immunoglobulin E–mediated hypersensitivity reaction Shock Stages An initial nonprogressive stage > vital organ perfusion is maintained A progressive stage characterized by tissue hypoperfusion and onset of worsening circulatory and metabolic derangement, including acidosis An irreversible stage in which cellular and tissue injury is so severe that even if the hemodynamic defects are corrected, survival is not possible Question A 66 year old with hepatitis C was found to have generalized edema. What is the likely cause of this edema? A. Decreased Urea synthesis B. Decreased Albumin synthesis C. Secondary heart failure D. Increased hydrostatic pressure E. Nephrotic syndrome Question Which of the following is an example of hyperemia? a) Testicular varicocele b) Pulmonary edema c) Septic shock d) Sunburn Question A 60-year-old male presents to the emergency department with a sudden drop in blood pressure, confusion, and cold clammy skin. He had a history of myocardial infarction six months ago and was on aspirin and beta-blockers. His blood pressure is 80/50 mm Hg, and heart rate is 110 bpm. Which type of shock is most likely in this patient? a) Hypovolemic shock b) Cardiogenic shock c) Septic shock d) Anaphylactic shock Question A 35-year-old female presents with a high fever, chills, rapid breathing, and confusion. On examination, she has warm, flushed skin, tachycardia, and hypotension (90/60 mm Hg). Laboratory tests reveal leukocytosis. Which type of shock should be suspected? a) Hypovolemic shock b) Cardiogenic shock c) Septic shock d) Neurogenic shock References Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Philadelphia, PA: Elsevier Saunders; 2014, 9th Edition Kumar V, Abbas AK, Aster JC. Robbins Basic Pathology. Philadelphia, PA: Elsevier Saunders; 2017,10th Edition www.amboss.com Thank You Questions? [email protected]