Ischemia detailed explanation by Astha Kushwaha

1. Ischemia
- by Astha Kushwaha

2. Definition
 Ischemia is defined as deficient blood supply to a part
of tissue or organ.
Or
 Ischemia is a condition in which the blood flow (and
thus oxygen) is restricted or reduced in a part of the
body

3.  The Cessation of blood supply maybe complete
(complete ischemia) or partial (partial ischemia).
 Ischemia may be reversible, in which case the affected
tissue will recover with the restoration of blood flow, or
irreversible, which can result in tissue death.
Ischemia

4. Ischemia
canleadto
 1. Hypoxia – due to deprivation of oxygen to tissues
 2. Malnutrition – of cells due to inadequate supply of
nutrients to the tissues ( i.e glucose , amino acids,etc)
 3. Inadequate clearance – of metabolites which results
in accumulation of metabolic waste in affected tissue.

5. Etiology
 A number of cause may produce ischemia.
 It depends upon two factors
1) external factors
2) internal factors
Extrenal factors:- Trauma or injury leading to
compression , laceration or shearing of blood vessels may
lead to partial or complete ischemia.
Trauma can also lead to inflammation causing an
obstruction in the blood flow sometimes even leading to
odema.

6. Etiology
Internal factors:-
 Thrombosis
 Embolism
 Atherosclerosis
 Sickle cell Anemia
 Hypoglycemia
 Hypotension
 Arteiovenous malformations

8. Causesinheart
Inadequate cardiac output resulting from heart block,
ventricular arrest and Ventricular fibrillation from
various causes may cause hypoxic injury to the brain.
 1) if the arrest continues for 15, seconds consciousness
is lost.
 2) if the condition lasts for more than 4 minute,
irreversible ischemic damage to the brain occur.
 3) if it is prolonged for more than 8 minutes, death is
inevitable

9. Causesin
arteries
The commonest and most important cause of ischemia
are due to obstruction in arterial blood supply .These are
under :
 Luminal occlusion of artery
a) Thrombosis b) embolism
 Causes in arterial wall
a) vasospasm. b) Arteriosclerosis
 Outside pressure on an artery.
a) tight plaster. b) Tourniquet

10. Causesinveins
 Blockage of Venous drainage may lead to engorgement
and obstruction to arterial blood supply resulting in
ischemia

11. Causesinthe
microcirculation
Ischemia main result from occlusion of arterios,
capillaries and venuos. The causes are as under:
 Luminal occlusion in microvasculature
1. By red cells example in sickle cell anaemia
2. By fat embolism
 Causes in micro vasculature wall
1. Vasculitis
2. Frost bite
 Outside pressure on micro vasculature
1. Bed sores

12. EFFECTS:
Theeffectsofischaemiaare
variableandrangefrom‘no
change’to‘suddendeath
 1. No effects on the tissues, if the collateral channel
develop adequately so that the effect of ischaemia fails
to occur.
 2. Functional disturbances. These result when collateral
channels are able to supply blood during normal activity
but the supply is not adequate to withstand the effect of
exertion.
 3. Cellular changes. Partial and gradual ischaemia may
produce cellular changes such as cloudy swelling, fatty
change, ischaemic atrophy and replacement fibrosis.
 4. Sudden death. The cause of sudden death from
ischaemia is usually myocardial and cerebral infarction.

13. Riskfactors
 Heart disease
 diabetes
 high blood pressure
 high cholesterol or triglycerides
 obesity or overweight
 physical inactivity
 stress
 tobacco or alcohol use
 trauma
 underlying vascular disease
 venous thromboembolism

14. Signand
symptomsin
heart
 Chest pain (angina)
 Shortness of breath
 Tachycardia
 Shoulder or back pain
 Neck, jaw, or arm pain
 Sweating/clamminess
 Nausea/vomiting
 Fatigue
 Dizziness or lightheadedness

15. Signand
symptomsin
brain
 Sudden headache
 Dizziness
 Vomiting
 Fainting
 Vision problems/blindness
 Problems moving the body, problems with coordination,
numbness
 Weakness in arm or leg or one side of face
 Problems speaking/slurred speech

16. Signand
symptomsin
legs
 Severe pain in legs and feet while at rest
 Sores on the feet or legs that don’t heal
 Foot pain or numbness
 Shiny, smooth skin on legs and feet
 Thickened toenails
 Coldness or weakness in the legs
 Dry, black skin (dry gangrene) in the legs or feet

17. Signand
symptomsin
intestine
 Sudden, severe stomach pain
 Diarrhea
 Severe pain within 15-60 minutes after eating
 Nausea/vomiting
 Gas (flatulence)
 Bloating
 Weight loss
 Blood in the stool.

18. Is Ischemia
Serious?
 Ischemia can be very serious, even fatal.
 Ischemia in the heart can lead to heart attack
(myocardial infarction)
 Ischemia in the brain can lead to stroke
 Ischemia in the legs can lead to severe leg pain and
difficulty walking and/or infections and loss of the limb
 Ischemia in the intestines can lead to death of part of
the intestines

19. Thank you 🌸