DEFINITIONDEFINITION

HYPOXIA: A condition in which the oxygen HYPOXIA: A condition in which the oxygen available is inadequate at the tissue levelavailable is inadequate at the tissue level

Five types of hypoxia: Five types of hypoxia: – AnemicAnemic– HypoxemicHypoxemic– HistotoxicHistotoxic– CirculatoryCirculatory– HypermetabolicHypermetabolic

Anemic HypoxiaAnemic Hypoxia Having a decreased carrying capacity for Having a decreased carrying capacity for

oxygen, the pt with decreased or abnormal oxygen, the pt with decreased or abnormal HbHb

AnemiaAnemia Carbon monoxide poisoningCarbon monoxide poisoning MethemoglobinemiaMethemoglobinemia Sickle Cell AnemiaSickle Cell Anemia

Treatment involves blood transfusions, Treatment involves blood transfusions, hyperbaric chamber, bone marrow hyperbaric chamber, bone marrow transplanttransplant

Hypoxemic HypoxiaHypoxemic Hypoxia

Low PAO2 due to the atmosphereLow PAO2 due to the atmosphere Hypoventilation – PCO2 is risingHypoventilation – PCO2 is rising Diffusion DefectsDiffusion Defects

The PaO2 will be lower in all cases, but the The PaO2 will be lower in all cases, but the PCO2 may or may not be increased.PCO2 may or may not be increased.

Treatment: Compensatory actions to Treatment: Compensatory actions to reduce inequalities, supplemental oxygenreduce inequalities, supplemental oxygen

Histotoxic Hypoxia Histotoxic Hypoxia

Inability for tissues to utilize oxygen Inability for tissues to utilize oxygen availableavailable

Cyanide Poisoning will inhibit cellular Cyanide Poisoning will inhibit cellular metabolism from occuring; the cells metabolism from occuring; the cells can not process the O2can not process the O2

Treatment: Reversal of poisoning, Treatment: Reversal of poisoning, supplemental oxygen and/or ventilationsupplemental oxygen and/or ventilation

Circulatory HypoxiaCirculatory Hypoxia A decrease in cardiac output results in a low BP A decrease in cardiac output results in a low BP

and a prolonged systemic transit timeand a prolonged systemic transit time The PaO2 can be high, but because of the time it The PaO2 can be high, but because of the time it

takes to get to the tissues, the pt is hypoxictakes to get to the tissues, the pt is hypoxic

Cardiovascular instability or failureCardiovascular instability or failure ShockShock ArrhythmiasArrhythmias

Treatment include increasing cardiac output with Treatment include increasing cardiac output with use of cardiovascular drugs and therapy, use of cardiovascular drugs and therapy, supplemental oxygensupplemental oxygen

Hypermetabolic HypoxiaHypermetabolic Hypoxia

In some disease states the body requires In some disease states the body requires a slight increase in metabolism (i.e. – a slight increase in metabolism (i.e. – wound healing requires 5% increase)wound healing requires 5% increase)

Extensive burns and some cancers will Extensive burns and some cancers will cause large increases metabolism to the cause large increases metabolism to the point that supplemental O2 is requiredpoint that supplemental O2 is required

Treatment: Supplemental O2 or FiO2Treatment: Supplemental O2 or FiO2