Hypoxia And Oxygen Therapy

Question 1

What is hypoxia?

Answer 1

Deficiency of O2 at the tissue level

Question 2

Types of hypoxia

Answer 2

Hypoxic hypoxia: low PO2, hypoventilation, diffusion defect, ventilation perfusion mismatch.
Anemic hypoxia: anemia, CO poisoning, altered Hb
Stagnant hypoxia: heart failure, shock, vascular obstruction
Histotoxic hypoxia: tissue poisoning- cyanide, diphtheria

Question 3

Acute and subacute hypoxias

Answer 3

Impaired judgement, motor incoordination, fatigue and all that.
Anaerobic glycolysis: acidosis..

Question 4

Effect on cells

Answer 4

Hypoxia inducible factors- alpha and beta dimerise- erythropoietin, angiogenic factors

Question 5

Effect on brain

Answer 5

<20 mm Hg, unconscious. 4-5 mins and death.

Lower intensities- acute alcohol, disorient, headache.

Question 6

Hyperbaric oxygen therapy

Answer 6

Admin of 100% O2 at increased pressure. Normal: 0.03 mL/100 mL-mm Hg.
To achieve 6 mL/100 mL dissolved O2, 2000 mm of Hg.