Download Hemodynamic disorders • Edema • Hyperemia and congestion

Hemodynamic disorders
• Edema
• Hyperemia and congestion
• Hemorrhage
(Hyperhydration, dehydration - important
topics, but not discussed here)
Edema
Accumulation of protein-poor fluid in the interstitial
spaces and the body cavities.
Localized
• Involves one organ or part of the body
• Clinically important examples:
Brain edema, lung edema, hydrothorax, ascites
Generalized
• Involves the entire body (in subcutis: anasarca)
• Clinical sign: pitting edema (depression in the skin
by pressing on it with a finger)
Features and pathogenesis of edema
Protein-poor transsudate; main ingredient: water,
specific gravity <1012
Remember the Starling’s forces:
Hydrostatic blood pressure forces water out of
capillaries at the arterial end, but the plasma oncotic
pressure attributable to albumin sucks it back into
capillary beds at the venous end. A small amount of
water drains from the tissues through lymphatic
channels.
Robbins Basic Pathology
9th edition
Elsevier Saunders 2013
Features and pathogenesis of edema
Protein-poor transsudate; main ingredient: water,
specific gravity <1012
Remember the Starling’s forces:
Hydrostatic blood pressure forces water out of
capillaries at the arterial end, but the plasma oncotic
pressure attributable to albumin sucks it back into
capillary beds at the venous end. A small amount of
water drains from the tissues through lymphatic
channels.
Types:
• Venous
• Hypoalbuminemic
• Lymphatic
• Sodium retention-associated
Venous edema
Increased hydrostatic pressure due to impaired
venous return forces fluid out the capillaries that
exceeds that of plasma oncotic pressure and so
water remains in the tissues.
Localisation follows gravity
Heart failure induces venous edema: reduced
systolic output (forward failure) is
accompanied by inadequate emptying of the
heart chambers (backward failure)  edema
and congestion (see later) in the venous
circulation
Sudden onset of left-sided heart failure (HF)
leads to the elevation of hydrostatic pressure in
lung capillaries  lung edema
Lung edema: the lungs 2 to 3 times exceed their normal
weight; sectioning reveals a foamy mixture of air, edema fluid,
and RBCs
Trachea
8
Chronic right-sided HF
leads to elevated hydrostatic pressure in capillaries of
the systemic circulation, and in turn,
systemic edema and serous effusions develop:
- hydrothorax
- hydropericardium
- ascites
Hydrothorax in chronic right-sided HF
10
Increased hydrostatic pressure in the portal venous
circulation (portal hypertension) by cirrhosis of
liver (shown) is an important cause of ascites
11
Edema of one of the lower legs
due to unilateral thrombotic obstruction of femoral
vein
Hypoalbuminemic edema
Low albumin concentration reduces the plasma
oncotic pressure so that the water cannot be sucked
back into the capillary bed at the venous end.
Common causes of hypoalbuminemia:
• Inadequate intake, as in protein-deficient diet
(kwashiorkor)
• Decreased synthesis in the liver, as seen in
cirrhosis of liver
• Increased loss via the urine in glomerular diseases
associated with heavy proteinuria
Lymphatic edema
Lymphatic obstruction decreases drainage of water
from the tissues. Typically, this is a localized form of
edema involving certain parts of the body
• Edema of the arm following surgical dissection
of axillary lymph nodes involved by breast cancer
Severe lymphedema of arm after mastectomy, surgical
dissection of the axillary lymph nodes and irradiation of the
axillary region because of breast cancer.
15
Lymphatic edema
Lymphatic obstruction decreases drainage of water
from the tissues. Typically, this is a localized form of
edema involving certain parts of the body
• Edema of the arm after surgical dissection
of axillary lymph nodes involved by breast cancer
• Elephantiasis - obstruction of inguinal lymph nodes
by filaria worms (filariasis)  chronic edema of
lower extremities and external genitalia
Sodium retention-associated edema
• Primary sodium retention, with obligatorily
associated water retention, causes both increased
hydrostatic pressure (owing to hypervolemia) and
reduced osmotic pressure
• Sodium retention occurs in bilateral renal disease
Hyperemia and congestion
Both indicate increased volume of blood in the
capillaries and venules of particular tissues/organs.
Active hyperemia results from increased blood
inflow because of arteriolar dilation
• Skeletal muscle during exercise
• Sites of inflammation
• Facial skin during blushing
The affected tissue is bright red because the blood
concerned is oxygenated.
Congestion (passive hyperemia)
Results from impaired venous outflow from a tissue.
• Systemic, as in cardiac failure
• Local, resulting from an isolated venous obstruction
Congestion of capillary beds is closely related to the
development of venous edema, so that congestion
and edema usually run together.
Acute left-sided HF pulmonary congestion + edema
• Alveolar capillaries are filled with RBCs
• Intraalveolar edema
Acute right-sided HF  acute hepatic
congestion
• Central veins and sinusoids are distended with
blood
• Hepatocyte degeneration around central veins
may occur
• + fatty change in periportal hepatocytes
Passive hyperemia of liver: hypoxic/fatty hepatocytes around
central veins are pale yellow, the better oxigenated portal parts
are red.
22
Chronic venous congestion
The organ has a blue-red color (cyanosis) because
stagnation of blood in the capillaries leads to
deoxygenation of the hemoglobin.
The stagnation of blood causes chronic hypoxic injury
of parenchymal cells and induration of the organ
(firm by palpation because of replacement of dead
parencymal cells by connective tissue).
Capillary ruptures at the sites of chronic congestion
causes small foci of hemorrhage. The breakdown and
phagocytosis of RBCs results in clusters of
hemosiderin-laden macrophages
(Prussian blue staining: positive).
Chronic left–sided HF chronic pulmonary
congestion: brown induration of lungs
Light microscopy (LM):
• Thickened and fibrotic septa
• Hemosiderin-laden macrophages in the alveoli
• Intraalveolar edema with focal hemorrhages
Chronic left–sided HF  chronic pulmonary congestion:
brown induration of lungs
25
Hemosiderin-laden macrophages in alveoli in chronic
congestion of lungs
Prussian blue staining verifies the hemosiderin in macrophages
Chronic right-sided HF  cyanotic induration of
liver, spleen and kidneys
Gross:
Firm, enlarged organs, bluish-red (cyanotic)
appearance of cut surfaces
Cyanotic induration of kidney
Congestive splenomegaly. Weight: up to 500 gm, the organ is firm,
the capsule is thickened, the malphigian corpuscles are indistinct
Hemorrhage
Extravasation of blood. The source of bleeding may be
• Rupture
- Arterial aneurysm (circumscribed dilation of an
artery)
- Dilated esophageal veins (varices)
• Erosion
- Artery by peptic ulcer of duodenum
- Vessels by malignant tumor (e.g., cc of uterine
cervix)
• Capillary bleeding
- Chronic congestion
- Hemorrhagic diatheses ( tendency to bleed
from insignificant injury)
Classification and nomenclature of hemorrhage
• Surface
- External, internal
• Enclosed within a tissue
Suffusion (2-dimensional)
Hematoma (3-dimensional); may be
- insignificant (bruise)
- lethal (retroperitoneal, subarachnoidal)
Subcutaneous suffusion due to trauma
Subarachnoidal haematoma
33
Iatrogenic (adverse condition in a patient resulting
from treatment) hematoma around the carotid
artery as complication of catheterization
34
Petechiae: minute, 1-2 mm hemorrhages into skin,
mucous membranes or serosal surfaces, seen in
thrombocytopenia, defective platelet function or
clotting factor deficits
35
Purpura: slightly larger (>3 mm) hemorrhages, may
be associated with similar pathologies, as well as
vasculitis, or increased vascular fragility
Purpuras
in small
vessel
vasculitis
Sándor Husz, MD,
SZTE Dermatology
36
Ecchymoses: 1-2 cm subcutaneous
hematomas after trauma
The RBCs in these local hemorrhages are
degraded and phagocytosed by macrophages.
Color changes in hematoma:
• Hemoglobin (red-blue)
• Bilirubin (red)
• Biliverdin (blue-green)
• Hemosiderin (gold-brown)
Accumulation of blood in cavities and the
Fallopian tube
• Hemothorax
• Hemopericardium
• Hemoperitoneum (hemascos)
• Hemarthros
• Hemocephalus
• Hemosalpinx
Hemopericardium because of myocardial rupture (lethal)
39
Cerebral bleeding associated with
hemocephalus
Other terms in association with hemorrhage
• Hematuria: appearance of blood in the urine
• Hematemesis: vomiting of blood; sign of
esophageal and gastric hemorrhage
• Hematochezia: bleeding through the rectum
• Melena: sign of upper GI tract bleeding. The blood is
digested partly by HCl. The black pigment hematein is
passed in the feces
• Epistaxis: bleeding from the nose
• Hemoptysis: bleeding from the lungs; literally it
means spitting of blood
• Metrorrhagia: is not related to menstrual bleeding
Clinical significance of hemorrhage
Depends on the volume and rate of blood loss.
Rapid removal of up to 20% of the blood volume may
have little impact in healthy adults; greater and rapid
losses result in hemorrhagic shock.
The site of bleeding is also important. Bleeding that
would be trivial in the subcutaneous tissues may
cause death if located in the brain, because the skull
is an unyielding structure. Intracranial bleeding 
increased intracranial pressure and herniation 
death
Recurrent external blood loss (peptic ulcer/GI tumor
or severe menstrual bleeding)  iron deficiency
anemia
Clinical significance of hemorrhage
Puncturing vessels can cause iatrogenic hematomas
– be skilled!