Fluid And Hemodynamic Disorders Flashcards
Increased interstitial fluid
Edema
Where is hydrothroax? Hydropericardium? Hydroperitoneum and other name for this?
Thoracic cavity
Pericardial sac
Peritoneal cavity- ascites
Causes of edema?
Increased hydrostatic pressure Reduced plasma osmotic pressure Lymphatic obstruction Sodium retention Inflammation
What causes increased hydrostatic pressure?
Impaired venous return and arteriolar dilatation
Causes of impaired venous return?
CHF
Constrictive pericarditis
Ascites
Venous obstruction or compression
Causes of arteriolar dilatation?
Heat
Neurohumoral dysregulation
What causes venous obstruction or compression?
Thrombosis
External pressure (mass)
Lower extremity inactivity
What leads to reduced plasma osmotic pressure?
Protein-losing glomerulopathies
Cirrhosis (ascites)
Malnutrition
Protein-losing gastroenteropathy
What leads to lymphatic obstruction?
Inflammatory
Neoplasticism
Postsurgical
Postirradiation
What leads to sodium retention?
Excessive salt intake with renal insufficiency
Increased tubular reabsorption of sodium
Renal hypoperfusion
Increased renin-angiotensin-aldosterone secretion
Active process, arteriolar dilation leads to increased blood flow and engorgement of vessels with oxygenated blood
Hyperemia
Passive process, reduced outflow of blood (heart failure, venous obstruction, etc.) causes increased volumes of deoxygenated blood, increased pressure, and stasis
Congestion
What are the 3 classic sites of congestion?
Lungs (acute and chronic)
Liver (acute and chronic)
Extremities (venous obstruction)
A release of blood into the extravascular space?
Hemorrhage
Hemorrhage in skin, mucous membranes, or serosal surfaces:
1-2mm
More than 3mm
More than 1-2cm
Petechiae
Purpura
Ecchymosis
What will extensive hemorrhage result in?
Shock
What does the clinical significance of hemorrhage depend on?
The volume and rate of blood loss
- Rapid loss less than 20% total blood volume or slow loss of larger amounts may have little impact
- small hemorrhages in certain locations may be devastating (cerebral hemorrhages)
What type of hemostatsis occurs when exposed subendothelial ECM causes platelet adherence and activation to form a platelet plug?
Primary hemostasis
What type of hemostasis occurs when tissue factor with factor VII activates coagulation cascade to generate thrombin which converts fibrinogen to fibrin to form a mesh work to stabilize the platelet plug?
Secondary hemostasis
What type of thrombi occurs at sites of endothelial injury and are typically non-occlusive?
Arterial
-coronary, cerebral, and femoral arteries
What type of thrombi occurs in sites of stasis and are almost ALWAYS OCCLUSIVE?
Venous
-90% involve veins of lower extremities
What are thrombi on heart valves called?
Vegetations
What happens to thrombi? (Life cycle of a thrombi)
Propagate Embolism Dissolve Organize/recanalize Microbial seeding (rare)
Detached intramuscular solid, semisolid, or gaseous mass carried by the blood to a site distant from the point of origin
Emboli
Accounts for about 200K deaths/year in US. Can cause sudden death and right heart failure. Tend to be hemorrhagic because of dual blood circulation, results in parodic all emboli in atrial or ventricular septal defects. Small lead to infarction. Large lead to death. Multiple ones causes pulmonary hypertension with right heart failure. Usually originate from DVT of leg above knee
Pulmonary emboli
Usual cause is from marrow of broken long bones. Somethings is accompanied by a rash. Cause be seen in various organs along with marrow elements following CPR.
Fat emboli
Can be a consequence of decompression sickness from gas (esp. nitrogen) bubbling in tissues. Most common iatrogenic cause is introduction of greater than 100cc air into a vessel during procedure.
Air emboli
What are the 3 components of Virchow’s Triad?
Endothelial injury
Stats is or turbulent blood flow
Hypercoagulability
Grave, but uncommon complication of labor/delivery. High maternal mortality rate (80%). Caused by rupture of membranes and concurrent tear of uterine vessels. Items present in amnion are present in embolus and are pathognomonic.
Amniotic fluid embolism
Caugulation necrosis corresponding to a particular vascular distribution caused by either arterial or venous occlusion. 99% are thromboembolic in nature.
Infarcts
What type of infarct is generally venous, in loose tissues, tissues with dual circulation (liver, lung, bowel), in congested tissues, and can occur when flow is re-established to a site of previous arterial occlusion and necrosis?
Red (hemorrhagic)
What type of infarct is generally arterial and in more “solid organs”?
White (occlusive)
The following factors influence what?
- nature of vascular supply
- rate of development of the occlusion
- tissue vulnerability to hypoxia
- oxygen content of blood
Factors that influence the development of an infarct
What represents circulatory collapse with resultant hypo-perfusion and decreased oxygenation of tissue?
Shock
- 2 causes
1. Decreased cardiac output as occurs in hemorrhage or severe left ventricular failure
2. Widespread peripheral vasodilation, as occurs in sepsis or severe trauma, with hypotension often begin a prominent feature
What are the 3 major types of shock?
Hypovolemic
Cardiogenic
Septic
Circulatory collapse resulting from he acute reduction in circulating blood volume caused by severe hemorrhage or massive loss of fluid from the skin, from extension burns or from severe trauma OR loss of fluid from the GI tract through severe vomiting or diarrhea.
Hypovolemic shock
Circulatory collapse resulting from pump failure of the left ventricle most often caused by massive MI.
Cardiogenic shock
Most characteristically associated with gram-negative infections, which cause gram-negative endotoxemia; also occurs with gram-positive and other infections.
Septic shock
What type of shock is most often associated with severe trauma and reactive peripheral vasodilation?
Neurogenic shock
What are the stages of shock?
nonprogressive (early) stage
progressive stage
irreversible stage
Which stage of shock is associated with compensatory mechanisms, including increased heart rate and increased peripheral resistance to maintain perfusion of vital organs?
nonprogressive (early) stage
What stage of shock is characterized by tissue hypoperfusion and the onset of circulatory and metabolic imbalance including metabolic acidosis from lactic acidemia?
progressive stage- compensatory mechanisms are no longer adequate
What stage of shock is associated with organ damage and metabolic disturbances that are so severe that survival is not possible?
irreversible stage
What is the most important anatomic finding with shock?
acute tubular necrosis of the kidney which is potentially reversible with appropriate medical management
What are the causes of DIC?
major trauma- esp crush injuries overwhelming infections (gram neg.) obstetric complications (abruption, amniotic fluid emboli) mucin-secreting adenocarcinomas prostatic surgery venomous snake bites
Treatment for DIC?
eliminate underlying causes if possible, otherwise therapy is supportive
Related disorders characterized by diffuse microvascular occlusion of arterioles and capillaries by thrombi mainly composed of platelets, not fibrin.
thrombotic thormbocytopenic purpura/hemolytic uremic syndrome
