Post on 28-Mar-2015
Hemodynamic disturbance
DR. USHA.M
HEMODYNAMICS
Literally means “Blood movement” is the study of blood flow.
Hemodynamic disturbance
1. Edema
2. Hyperemia & congestion
3. Hemorrhage
4. Thrombosis
5. Infarction
6. Shock
Edema Normal body water distribution:-
Two compartments:
1. Intracellular – comprising of two- thirds of total body fluid.
2. Extracellular – comprising of one- third of total body fluid.
1. Interstitial compartment- 75%
2. Intra vascular compartment – 25%
Normal fluid exchange There are two ends for a capillary1. Arteriolar end2. Venous endThe pressure is high in the arteriolar end then
the venous end.Normally the fluid moves out from the vessel in arteriolar end into interstitial tissue. From interstitial tissue same fluid moves back into vessel at venous end.The small amount of fluid which is left in interstitial space is cleared by lymphatics.
Starling forces
Normal fluid pressures1. Osmotic pressureIs exerted by the chemical constituents of the
body fluids Eg. Electrolytes – crystalloid osmotic
pressure proteins (albumin)- oncotic osmotic
pressure.2. Hydrostatic pressurePressure within the blood vessel.
Edema
Is accumulation of excessive fluid in the interstitial spaces.
Classification of edema according to distribution of fluid
1. Localized edema
involving one organ or part of the body.
eg-pleural effusion,ascitis,pericardial effusion ,etc.
2. Generalized edema
Involving the entire body- ANSARCA
Pathogenesis of edema:-
1. Increased hydrostatic pressure
2. Increased permeability of the vessel wall
3. Decreased oncotic pressure
4. Sodium retention in the kidneys
5. Obstruction of lymph flow
1. Hydrostatic edema
Results from increased intra vascular pressure (hydrostatic pressure).
Causes :-1. Impaired venous return congestive cardiac failure constrictive pericarditis, ascitis (liver disease)2. Venous obstruction thrombi, tumor3. Arteriolar dilatation heat, inflammation
2. Increased vascular permeability Commonest cause is
inflammation.Release of inflammatory mediators like histamine, bradykinin, PAF & others leads to increased permeability.
Other causes: Injury,
3.Decreased plasma oncotic pressure
1.Decresed synthesis in the liver – end stage liver disease.
2.Incresed loss in urine(nephrotic syndrome) or stool (protein losing enteropathy)
3.Inadequte intake-kwashiokar
Sodium RetentionSodium Retention
Excessive salt intake with renal Excessive salt intake with renal insufficiencyinsufficiency
Increased tubular Increased tubular reabsorptionreabsorption of of sodiumsodium
Renal Renal hypoperfusionhypoperfusion
Increased Increased reninrenin--angiotensinangiotensin--aldosteronealdosterone secretionsecretion
Lymphatic obstruction
Elephantiasis Edema of the arm following surgical
resection of axillary lymph nodes Edema of hand following post irradiation
fibrosis.
Feature Transudate Exudate
Definition Ultra filtrate of plasma
Edema of inflamed tissue
Endothelial changes
No changes endothelial permeability
Character Non inflammatory edema
Inflammatory edema
TRANSUDATE & EXUDATE
Feature Transudate Exudate
Protein Low(<1g/dl) High (>2.5g/dl)
Glucose Same as plasma
Low(,60mg/dl)
Specific gravity
Low(1.015) High(>1.018)
PH >7.3 <7.3
LDH low High
Cells Few Many
Example CCF Infections
Volume Repletion ReactionVolume Repletion Reaction
Goldman: Cecil Textbook of Medicine, 22nd ed.
Renal edema
Causes:-
1. Nephorotic syndrome
2. Glomerulonephritis
3. Acute tubular injury
Nephorotic edema Heavy proteinuria hypoproteinemia
Activation of renin decreased plasmaAngiotensin oncotic pressureMechanism
Retention of Na &water
edema
Nephritic edema Glomerulonephritis
glomerular lesion
I decreased filtration followed by increased absoption of Na & water by tubules
Na & water retention
edema
Acute tubular injury
Toxins , drugs
ATN
Fails to excrete Na & water
edema
Cardiac edema congestive cardiac failure
↓ cardiac output
↑ central venous renal hypoperfusion
Pressure
activation of renin angiotensin
↑ capillary hydrostatic aldosterone mechanism
pressure
Na & water retention
edema
Pulmonary edema causes :-
1. Left heart failure
2. ARDS
3. Shock
4. Infections - pneumonia
left ventricular failure
↑ hydroastatic pressure
↑ pressure in pulmonary veins
↑ pressure in pulmonary capillaries
interstitial edema
pressure on alveolar wall &breaks alveolar
linning
alveolar edema
Hepatic Oedema
hepatic pathology(e.g. cirrhosis)
↓obstruction of portal venous system
↓ increased hydrostatic pressure
&↓albumin synthesis d.t. hepatocyte damge
↓hypoproteinaemia
↓transudate oedema (ascitis).
Ascites
Cerebral edema
Causes:-
1. Infection - encephalitis,meningitis
2. Brain infarct, hemorrhage
3. Trauma
4. Tumors
Localised Oedema: acute inflammatory oedema
- ↑ vascular permeability exudate- ↑ hydrostatic pressure of capillaries
hyperaemia- ↑ osmotic pressure of interstitial fluid- ↑ fluidity of ground substance
allergic (hypersensitivity) oedema- histamine release ↑ vascular
permeability exudate (e.g. allergic rhinitis)
Pitting & non pitting edema
is clinical terms for subcutaneous edema of leg.
Pitting Oedema
Pitting EdemaPitting Edema
Clinical Features of Oedema Considerable quantities must accumulate before
clinically apparent (oedema can be assessed by weighing the patient
approx. 5 litres) Generalised Cardiac Oedema
- gravitational distribution- pitting oedema holds depression for a few
minutes Renal Oedema
- fluid retention- generally distributed in C.T. puffy face/eyelids
Serous Cavities- e.g. hydrothorax/ascites
Brain Oedema- swollen; narrow sulci & flattened gyri
Pulmonary Oedema- exudate- prone to infection e.g. bronchopneumonia- rales
Hemorrhage
Indicates extravasation of blood due to rupture of vessel.
Classification based on origin
1. Cardiac- penetrating wound
rupture of ventricles in MI
2. Arterial – trauma
rupture of aneurysm
3. Capillary – trauma, surgery
4. Venous – trauma, surgery
Petechiae, Pupura, Ecchymoses
Refers to the hemorrhage into the skin & mucosae.
Petechiae- pinpoint hemorrhage ( < 1mm)
Purpura- 1mm- 1cm in diameter
Echymoses- >1cm
Petechiae
Purpura
Ecchymosis
Hematoma
Is grossly visible accumulation of extravasted blood in tissue.
First it is red, then as the blood is deoxygenated it becomes dusky & bluish red.
Body cavity hemorrhage
Hemothorax – accumulation of blood in pleural cavity
Hemopericardium – in pericardial cavity
Hemoperitonium – in peritonial cavity
Hemoarthrosis – in intra – articular space
Hematocephalus – in ventricles of brain
Hematuria
Is appearance of blood in urine.
1. Microscopic – detectable by microscopic examination of urine.
2. Macroscopic – visible to naked eye
Hematuria signifies disease of kidney or urinary tract
Hematemesis
Is vomiting of blood. Sign of esophageal & gastric
hemorrhage like rupture of esophageal varices & peptic ulcer bleeding.
Hematochezia
Bleeding through rectem. Sign of diseases in large intestine.
Melena
Black colored blood in stools. Indicates bleeding in upper GIT. Blood is partialy digested by HCLof
gastric juice & transformed into a black pigment called hematein.This pigmentis not digested in the intestines & is passed in the feces.
Epistaxis & HemoptysisEpistaxis & Hemoptysis
Epistaxis is bleeding from the nose. Hemoptysis is bleeding from lungs.
Menorrhagia & Metrorrahagia
Menorrhagia is heavy menstrual bleeding.
Metrorrhagia occurs at any time & is not related to menstrual cycle.
Effects of Hemorrhage Site of hemorrhage
– brain, pericardium, pleural spac Rate of blood loss
– acute• loss of > 20% of blood volume may cause
hypotension or hypovolemic shock• hemoglobin concentration not altered
– non-acute• volume loss compensated by shift of fluid from
extravascular to intravascular compartment• hemoglobin concentration decreased
HYPEREMIA & CONGESTION Is increase in volume of blood in a
particular tissue. Hyperemia is an “active process” , the
increased blood influx results from arteriolar dilatation.
Congestion, also known as “passive hyperemia”, results due to stagnation of blood because of venous obstruction.
Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 27 June 2005 07:26 PM)
© 2005 Elsevier
Normal
Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 27 June 2005 07:26 PM)
© 2005 Elsevier
Hyperemia
Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 27 June 2005 07:26 PM)
© 2005 Elsevier
Congestion
Examples:-
Hyperemia:-
1. Inflammation
2. Blushing – adrenergic stimulation
3. Exercise – incresed blood flow to the muscle.
Congestion:-
Obstruction of veins due to thrombi or backward pressure due to heart failure.
Color of hyperemic & congested tissue:- Hyperemic tissue contains increased
amounts of oxygenated blood & therefore the tissue appears bright red.
Congested tissue contains increased amounts of deoxygenated blood & appears blue.
Hyperemic tissue is warm, while congested blood is cold & clammy.
Chronic venous congestion (CVC):- In CVC there is long standing there is
accumulation of deoxygenated blood & hence there is damage to the tissue.
Mechanism heart failure
left heart failure right heart failure
Pressure into pressure into the
Pulmonary vein systemic venous system
CVC LUNGS CVC LIVER SPLEEN KIDNEY
CVC Lung
Causes:-
Left heart failure
Gross :-
The lungs are heavy. Lungs appear brown- BROWN INDURATION OF LUNGS.
CVC Lungs
Micro:-
Rupture of congested vessel results in edema & hemorrhage. Lysis of RBC’s releases hemosiderin pigment which is taken up by macrophages – HEART FAILURE CELLS.
CVC Liver
Causes:-
1. Right heart failure
2. Occlusion of inferior vena cava or portal vein.
GROSS APPEARANCE:-
NUTMEG APPEARANCE – Alternate areas of red & yellow .
CVC Liver
Micro:- Periportal zone
midzonal
Centrilobular
CVC Liver (MICRO)
Blood fills up the central vein & sinusoids around it. Followed by centrilobular hepatocytes necrosis.
In the long standing cases the necrotic area is replaced by fibrous tissue.
The areas with blood appears red & areas with fibrosis appears whitish yellow- NUTMEG APPEARANCE.
CVC Spleen
Causes:-
1. Right heart failure
2. Portal hypertension
GROSS:-
Spleen is enlarged & congested.
CVC Spleen (micro)
Red pulp appears congested.
GAMMA GANDY BODIES OR SIDEROFIBROTIC NODULES:-
Deposits of hemosiderin & calcium salts on fibrous tissue.
Gamma gandy bodies
CVC Kidney
Cause:-
1. Right heart failure
2. Obstruction of renal vein
Gross:-
Kidney is congested.
CVC Kidney (micro)
Glomeruli – shows mesangial proliferation.
Tubules – shows degenerative changes (cloudy swelling).