Hemodynamics I Flashcards
Define edema
swelling of tissue due to increased fluid in interstitial tissue spaces
Define ascites
fluid in the abdominal cavity
Anasarca:
generalized edema
Hyperemia:
(erythema) an active increase in arterial blood flow
Congestion:
passive decrease in venous outflow
Hemorrhage:
extravasation of blood due to blood vessel rupture
Hematoma:
hemorrhage enclosed within tissue
Petechiae:
tiny (1-2 mm) hemorrhages due to platelet deficiency
Hemostasis:
(1) the maintenance of blood in a free-flowing liquid state in normal blood vessels and (2) the formation of a blood clot (hemostatic plug) at a site of vascular injury
Platelets:
anucleate cellular components of blood important in initiation and propagation of clotting
Thrombosis:
inappropriate formation of blood clot in a blood vessel (usually occlusive)
Hypercoagulability:
an abnormal tendency to form blood clots
Coagulopathy:
an abnormal tendency to bleed
Embolism:
a detached intravascular solid, liquid or gaseous mass carried by the blood to a site distant from its point of origin
Infarction:
an area of ischemic necrosis
Describe the presentation and cause of edema
it can be localized or generalized
common cause of generalized edema is heart failure
What is a hydrothorax?
fluid in the pleural cavity (pleural effusion)
Generalized edema due to, for instance, renal failure may appear initially where?
in tissues with a loose connective tissue matrix such as around the eyes, causing periorbital edema.
What is the 1st sign of nephrotic syndrome?
periorbital edema noticed by the mother of a 2-6 yr old which is the age range which is typically noted
How can you test for pitting edema?
If finger pressure on edematous subcutaneous tissue leaves a temporary impression
What are the 5 pathophysiologic categories of edema?
(1) increased hydrostatic pressure,
(2) decreased plasma osmotic pressure,
(3) lymphatic obstruction,
(4) sodium retention,
(5) inflammation.
The four most common causes of edema are
- increased hydrostatic pressure,
- decreased plasma oncotic pressure,
- sodium retention
- inflammation.
***What causes leg edema? lung? general lower body?***
increased hydrostatic pressure due to deep venous thrombosis
if edema is in lungs then it is due to left heart failure
if it is in the lower body then due to right heart failure
Describe dependent edema
distribution is not specific for increased hydrostatic pressure but edema is worse in the legs when standing and worse in thesacrum when recumbent
Describe how the heart and kidneys can cause 2 different types of edema at the same time
- Heart failure causes decreased renal blood flow,
- which activates the renin-angiotensin-aldosterone system.
- Increased aldosterone causes retention of sodium (and water),
- then causes edema due to sodium retention,
- creating edema of two different types at the same time.
Edema from decreased plasma osmotic pressure is a feature of what?
the nephrotic syndrome due to protein loss through the kidneys
Edema from hepatic cirrhosis is due to what?
increased hydrostatic pressure in the portal venous system
decreased plasma osmotic pressure due to protein loss into ascites and deficient hepatic protein synthesis.
What is the major protein for maintaining plasma oncotic pressure?
albumin which accounts for nearly half of the total plasma protein
How does severe hypoalbuminemia lead to more decreased plasma oncotic pressure?
causes secondary hyperaldosteronism (like heart failure), adding an element of edema due to sodium retention to the edema of decreased plasma oncotic pressure.
Describe edema due to sodium retention. What usually causes it?
always generalized, with increased hydrostatic pressure (and, to a lesser extent, dilutional decrease in plasma osmotic pressure).
It is usually caused by heart failure (or renal failure).
Describe edema due to inflammation
can be localized (at site of infection) or generalized (with SIRS or sepsis).
What is lymphedema? Describe its location in the body
due to lymphatic obstruction.
It is usually localized and caused by tumor, inflammation, surgery, radiation or scar.
What will lymphedema due to breast cancer look like?
can make the skin resemble an orange peel
What is the main and secondary causes of pulmonary edema?
The most common cause of pulmonary edema is left heart failure;
other causes include the acute respiratory distress syndrome (ARDS), hypersensitivity reactions, pneumonia and renal failure.
What does pulmonary edema look like when it is in the alveoli?
clear frothy fluid (pink if blood is mixed in it) in the alveoli (airspaces)
When does pulmonary edema become more severe?
when the clear frothy fluid reaches the airways
What is the major symptom of pulmonary edema? sign?
The major symptom of pulmonary edema is dyspnea (shortness of breath)
the major sign is pulmonary crackles (an inspiratory crackling sound on listening to the lungs with a stethoscope, formerly called “rales”).
T/F cerebral edema can be localized or generalized. describe
true
localized => (around an abscess or tumor) or generalized (with encephalitis, etc.)
Generalized brain swelling causes swollen gyri and narrow sulci over all of the hemispheres.
When can cerebral edema be fatal?
if it is due to herniation (protrusion) of cerebellar tonsils into foramen magnum compressing the brainstem respiratory center.
What is this an example of?
Hyperemia
(due to photosensitivity)
[note the red color]
{arterial}
What is this an example of?
Congestion
(due to superior vena cava obstruction)
[note the blue color] => {venous}
What is the primary cause of hyperemia and what are the results?
Inflammation is the overwhelmingly most common cause of hyperemia.
Hyperemia causes an abnormal reddish coloration due to the presence of excess oxygenated blood in a tissue.
What is the result of congestion?
Congestion causes cyanosis, an abnormal bluish coloration due to the presence of excess deoxygenated blood in a tissue.