Paramedic Resource Manual Section 2 Flashcards
(39 cards)
What are the 2 factors which determine the quantity of oxygen delivered to tissue
- perfusion
- concentration of hemoglobin and the affinity for O2
The average adult has between 14-16 gm of hemoglobin for every how much blood
100 ml
What % of hemoglobin is saturated in “deoxygenated” blood
75%
What are the 3 major factors that affect the affinity of O2 for hemoglobin
- pH
- PCO2
- temperature
An increase in the hydrogen ion concentration causes what?
Lowers the ph, causes the blood to be more acidic. O2 doesnt bond as easily or as strongly to hemoglobin.
An increase in the temperature of blood has the same effect as
an increase in temp has the same effect as an increase in hydrogen ions (lowering the pH)
What does a decrease in hydrogen ions (increase in pH) and lower temp cause in blood?
Causes O2 to bind more tightly to hemoglobin, but does not readily release
Carbon Dioxide is acidic or basic
Acidic
How is carbon dioxide transported in the blood?
- bicarbonate
- combined with hemoglobin
- dissolved in plasma
What carries the largest amount of CO2 in the blood
Bicarb (65-70%)
What % of CO2 binds with hemoglobin?
23-25%
What occurs in the blood when the body is in an alkaline state
- hemoglobin becomes a stronger magnet drawing O2 towards it
- if the blood remained alkaline at the tissue level, it would not release O2 to the tissue readily
(hyperventilation makes the blood alkaline, as does administering sodium bicarb, excessive vomiting)
What occurs in blood when the body is in an acidotic state?
- when the blood is acidotic, hemoglobin becomes a weak magent and does not pick up O2 as readily
- we attempt to compensate for this by providing the pt with supplemental O2 which increases the amount of O2 dissolved in blood plasma for transport
- if blood is acidic at the tissue level, O2 bound to hemoglobin is released to the tissue easily
Define Hyperventilation
Minute volume (rate x tidal volume) that exceeds the bodys metabolic demands
Define Hypoxemia
Hypoxemia is identified by a blood gas analysis with a [artial pressure of oxygen in the arterial blood lower than normal (<80mmHg) and usually less than 90% oxygen saturatiuon
Define Hypoxia
a state of oxygen deficiency or lack of oxygen. This reduced or insufficent oxygen supply to the tissues can cause impairment of bodily functions which may become irreversible if allowed to go unmanaged
What are the 4 types of hypoxia?
- hypoxic hypoxia
- hypemic hypoxia
- stagnant hypoxia
- histotoxic hypoxiaE
Define Hypoxic Hypoxia
- breathing air or gas that contains a lower than normal PO2
OR - decrease in pulmonary ventilation
OR - abnormal lung function
OR - Arteriovenous shunting
Define Hypemic Hypoxia
- reduced or altered Hb that can’t carry a normal amount of O2
What are some causes of Hypemic Hypoxia?
- any type of anemia causing a reduction in Hb concentration
- certain poisoning which chemically alters Hb
- Hb combined with a gas other than O2 (ex carbon monoxide)
Define Stagnant Hypoxia
- any shock state in which there is widespread inadequate tissue perfusion and hence inadequate tissue oxygenation
- This form of hypoxia refers to end organ perfusionwH
What are some examples of general stagnant hypoxia
- hypovolemic shock
- cardiogenic shock
What are some examples of localized hypoxia?
- thrombosis
- embolus
- vasoconstriction
Define Histotoxic Hypoxia
An action by a toxic sibstance may prevent the diffusion of O2 into the cells or may prevent cells from utilizing oxygen
