Fluid & Hemodynamic Disorders Flashcards
(53 cards)
Edema factors
Redistribution of body fluids
loss of fluids
retention of fluids
disruption of circulation
Edema
when boundaries of normal variation exceeded - over hydration, dehydration occurs (water is 60% of total body weight) 2/3 intracellular, 1/3 intercellular spaces; blood: blood fluids must be in counterbalance with other fluid compartments
Edema definition
Excess fluid in tissues or body cavities
localized or generalized
Anasarca - generalized edema
Fluid in circulating blood is separated from interstitial fluid by blood vessel wall (semipermeable membrane)
Movement across this barrier is determined by several factors
Edema of specific organs
Cerebral edema - brain Pulmonary edema - lungs Pitting edema of lower extremities Periorbital (facial) edema Hydrothorax Macular edema - eyes Ascites (hydroperitoneum) - edema within the peritoneal cavity Pleural effusions - edema in the pleural cavity Anasarca
edema classification
Exudate: high in protein and cells, typical of inflammation
Transudate: high in protein (but less than exudate), low in cells, may accumulate due to: increased hydrostatic pressure reduced oncotic pressure lymphatic obstruction sodium retention
Hydrostatic pressure
at the arterial end of a capillary, hydrostatic pressure exceeds the hydrostatic pressure on the venous side of the capillary promoting the passage of fluids into the interstitial fluid
Oncotic pressure
AKA colloid osmotic pressure
The pressure due to the presence of colloids in the blood
Colloids - any large molecule such as starch or protein
Colloids act like a sponge
Types of edema (5)
Inflammatory edema Hydrostatic edema Oncotic edema Obstructive edema Hypervolemic edema
Inflammatory edema
Fluid leaks through the vessel wall which has been made more permeable (exudate)
Hydrostatic edema
intravascular pressure promotes the transmembranous passage of fluids (transudate)
Oncotic edema
Decreased plasma proteins or decrease in colloid osmotic pressure (liver disease, malnutrition)
- particularly proteins
- Specifically albumin
Obstructive edema
very rare; can be caused by parasites or worms (Africa) or tumour cells
Hypervolemic edema
kidney dysfunction leadig to the retention of sodium and water
Hyperemia
Too much blood
Increase of blood flow to different tissues in the body due to the presence of metabolites and/or a change in general conditions
Hyperemia 3 types
- active
- reactive
- passive
Active hyperemia
Aka functional hyperemia
The increased blood flow that occurs when tissue is active and requires more metabolites
Typically occurs during blushing, exercise or acute inflammation
Reactive hyperemia
occurs in response to a profound increase in blood flow to an organ after being occluded
There will be a shortage of oxygen and a build-up of metabolic waste
e.g. ischemic compressions
passive hyperemia
aka congestion caused by increased venous backpressure typically a consequence of heart failure often occurs in chronic form can lead to cyanosis (bluish tissues)
Hemorrhage
Loss of blood from the circulatory system
Can occur internally - blood leaks from blood vessels inside the body
can occur externally, either through a natural opening such as the mouth, or through a break in the skin
Hemorrhage - how much blood loss can be endured?
10-15% of total blood volume can be endured without clinical consequences (blood donation typically takes 8-10 % of the donor’s blood volume)
When hemorrhage becomes dangerous or fatal?
When it causes hypovolemia (low blood volume) or hypotension (low blood pressure)
Classification of hemorrhage
Duration: Acute, Chronic, Recurrent
Source: Cardiac, Aortic, Arterial, Capillary, Venous
Cardiac hemorrhage
may result from gunshot or stabbing
may result from softening of heart wall through myocardial infarct
often fatal
Aortic hemorrhage
often caused by trauma (e.g.car accident)
Can occur due to aortic wall weakening and dilation (aortic aneurysm)
