Presentation on Hypoxia in which I tried to cover all the essential points

3.  Hypoxia is O2 deficiency at the tissue
level.
 A pathological condition in which the
whole body as a whole or a region of
the body is deprived of adequate
oxygen supply.
 It is the decrease below normal levels
of oxygen in inspired gases, arterial
blood, or tissues, without reaching
anoxia.

4.  High altitude.
 Low hemoglobin level.
 Decreased oxygen supply to an area.
 Low oxygen carrying capacity.
 Poor tissue perfusion.
 Impaired ventilation.
 Decreased diffusion of oxygen.

5.  Inadequate oxygenation of the blood
in the lungs because of extrinsic
reasons.
• Deficiency of oxygen in the
atmosphere.
• Hypoventilation (neuromuscular
disorders).

6.  Pulmonary disease.
• Hypoventilation caused by
increased airway resistance or
decreased pulmonary compliance.
• Abnormal alveolar ventilation-
perfusion ratio.
• Diminished respiratory membrane
diffusion.

7.  Venous to arterial shunts.
 Inadequate oxygen transport to the
tissues by the blood.
• Anemia or abnormal hemoglobin.
• General circulatory deficiency.
• Localized circulatory deficiency.
• Tissue edema.

8.  Inadequate tissue capability of using
oxygen.
• Poisoning of cellular oxidation
enzymes.
• Diminished cellular metabolic
capacity for using oxygen, because
of toxicity, vitamin deficiency, or
other factors.

9.  Hypoxic hypoxia.
 Anemic hypoxia.
 Stagnant hypoxia.
 Histotoxic hypoxia.

11. Hypoxemic hypoxia.
Arterial hypoxia.
Hypoxic hypoxia is a result of insufficient
oxygen available to the lungs or decreased
oxygen tension.

12. Low arterial pO2 .
Low arterial O2 content.
Low arterial % O2 saturation of hemoglobin.
Low A-V pO2 difference.

13. Low oxygen tension
in inspired air.
• High altitude.
• Breathing in closed
space.
• Breathing gas
mixture containing
low pO2.

14. Respiratory disorders
associated with
decreased pulmonary
ventilation.
• Asthma.
• Brain tumor.
• Sleep apnoea.
• Pneumothorax.
• Bulbar polio myelitis.

15. Respiratory disorders
associated with inadequate
oxygenation of blood in
lungs.
• Emphysema.
• Fibrosis.
• Pulmonary hemorrhage.
• Pneumonia.
• Bronchiolar obstruction.
• Bronchiectasis.

16. Cardiac disorders.
• Congestive heart failure.
• Low cardiac output.
Hypoxic hypoxia is characterized by reduced
oxygen tension in arterial blood while all the
other features are normal.

18. • Hypoxia in which arterial pO2 is normal but
the amount of haemoglobin available to carry
oxygen is reduced.

19. • Decreased no. of RBCs
• Decreased haemoglobin content in blood
• Formation of altered haemoglobin
• Combination of haemoglobin with gases other
than O2 and CO2.

20. • Anemic hypoxia is characterized by low
oxygen carrying capacity of blood while the
other features remain normal.

22. • Ischaemic hypoxia.
• Hypoxia in which the blood flow to the tissues
is so low or slow that adequate oxygen is not
delivered to them despite a normal arterial pO2.

23. • Congestive cardiac failure.
• Hemorrhage.
• Surgical stroke.
• Vasospasm.
• Thrombosis.
• Embolism.

24. • Stagnant hypoxia is characterized by
decreased velocity of blood flow while the
other features remain normal.

26. o Hypoxia in which the amount of oxygen
delivered to the tissues is adequate , but
because of the action of a toxic agent the
tissue cells cannot make use of the oxygen
supplied to them.

27. o Cyanide poisoning:
Cyanide destroys the cellular oxidative
enzymes completely paralyzing the
cytochrome oxidase system.

29. TYPES OF
HYPOXIAS
ARTERIAL pO2
HEMOGLOBIN
COUNT
RATE OF
BLOOD FLOW
TO TISSUES
Hypoxic
hypoxia
Decreases Normal Normal
Anemic
hypoxia
Normal Decreases Normal
Stagnant
hypoxia
Normal Normal Decreases
Histotoxic
hypoxia
Normal Normal Normal

30. TYPES OF HYPOXIAS CAUSES
Hypoxic hypoxia Decreases inspired pO2; decreased
pulmonary ventilation ; defective V/P
ratio
Anemic hypoxia Total Hb content decreases due to anemia;
haemorrhage; presence of abnormal Hb
Stagnant hypoxia Circulatory failure; haemorrhage; heart
failure
Histotoxic hypoxia Cyanide poisoning

31. TYPES OF
HYPOXIA
ARTERIAL pO2
ARTERIAL O2
CONTENT
ARTERIAL % -
O2 SATURATION
OF
HEMOGLOBIN
Hypoxic
hypoxia
Decreased Decreases Decreases
Anemic
hypoxia
Normal Markedly
reduced
Decreases
Stagnant
hypoxia
Normal Normal Normal
Histotoxic
hypoxia
Normal Normal Normal

32. TYPES OF
HYPOXIA
A-V PO2
DIFFERENCE
CYANOSIS STIMULATION
OF
PERIPHERAL
CHEMORECEP
TORS
Hypoxic
hypoxia
Decreases Present Present
Anemic
hypoxia
Normal Absent Absent
Stagnant
hypoxia
More than
normal
Present Present
Histotoxic
hypoxia
Less than
normal
Absent Present

34. To counter the effects of high-altitude diseases, the
body must return arterial pO2 towards normal.
Acclimatization, the means by which the body adapts
to higher altitudes, only partially restores pO2 to
standard levels.
Hyperventilation, the body’s most common response
to high-altitude conditions, increases alveolar pO2 by
raising the depth and rate of breathing.
Polycythemia, in which the body increases the
number of red blood cells in circulation, thickens the
blood, raising the danger that the heart can’t pump it.

35. Successful treatment of chronic hypoxemia in
patients with COPD, cystic fibrosis, emphysema,
severe asthma, and other lung diseases has been
demonstrated clinically by more than 600 Russian
MDs.