CONCEPTS OF OXYGENATION Flashcards
(15 cards)
OXYGEN SATURATION (SA02):
PERCENTAGE OF HEMOGLOBIN THAT IS BOUND TO OXYGEN
PULMONARY DIFFUSION
EXCHANGE OF GAS MOLECULES (OXYGEN AND CARBON DIOXIDE) FROM AREAS OF HIGH CONCENTRATION TO AREAS OF LOW CONCENTRATION
PULMONARY DIFFUSION 2
PROCESS BY WHICH OXYGEN AND CARBON DIOXIDE ARE EXCHANGED FROM AREAS OF *HIGH CONCENTRATION TO AREAS OF LOW CONCENTRATION AT THE AIR–BLOOD INTERFACE.
PULMONARY PERFUSION:
BLOOD FLOW THROUGH THE PULMONARY VASCULATURE. REMEMBER, THE BLOOD IS PUMPED INTO THE LUNGS BY THE RIGHT VENTRICLE THROUGH THE PULMONARY ARTERY.
*PARTIAL PRESSURE OF OXYGEN IN THE ARTERIES (PAO2):
THE VOLUME OF OXYGEN PHYSICALLY DISSOLVED IN THE PLASMA.
PULSE OX
The pulse ox is
- an essential tool in monitoring a patient status
- indirectly* indicates arterial hemoglobin saturation
- Only measures one component
The Oxyhemoglobin Disassociation Curve (OHDC)
- can provide a more accurate picture
- can be very challenging
REVIEW
- EACH RBC HAS HUNDREDS OF THOUSANDS OF HBG MOLECULES
- EACH HEMOGLOBIN CAN BIND 4 OXYGEN MOLECULES
- WHEN BLOOD PASSES THROUGH THE ALVEOLI, O2 DIFFUSES FROM ALVEOLI INTO RBCS AND BINDS TO HEMOGLOBIN
- HEMOGLOBIN CAN’T BE SATURATED MORE THAN 100%
Pulse Ox (indirect SAO2):
93-97%
Partial Pressure (PA02):
80-100
PaO2
> 70 mm Hg
- Relatively safe levels: PaO2 45–70 mm Hg
- Dangerous levels: PaO2 <40 mm Hg
OXYHEMOGLOBIN DISSOCIATION CURVE
OXYHEMOGLOBIN DISSOCIATION CURVE
- SHIFT TO THE RIGHT
— Higher demand for oxygen from the tissues
— Hgb lets go of O 2 to go into the tissues
— CAUSES:
— - Decreased pH
— - increased temp
— - increased carbon dioxide concentration
— - Increased metabolic demand
- SHIFT TO THE LEFT
— Less demand for oxygen from the tissues
— Hgb binds tightly to O 2
— CAUSES:
— - Increased pH
— - decreased temp
— - Decreased carbon dioxide levels
— - Decreased metabolic demand
E.G. ACUTE MI
- Patient has reduced oxygen due to acute MI.
- Body compensates by increasing the release of oxygen. (The curve shows at lower levels of P02, hemoglobin releases oxygen more readily to tissues to help perfusion despite decreased blood flow.)
- The release of more oxygen shows as a shift to the right in response to factors such as decreased pH and increase levels of C02 which can be present during an MI
- The shift to the right enhances oxygen release
CLINICAL SIGNIFICANCE FOR THE NURSE
- IS THE PULSE OX FUNCTIONING NORMALLY?
- WHERE ON THE CURVE DOES THE PATIENTS DATA FALL (FLAT OR CURVE)
- DON’T ALWAYS ASSUME IF THE PULSE OX ALARMS THE PATIENT NEEDS MORE O2
- DON’T ALWAYS ASSUME IF THE PULSE OX IS NORMAL THE PATIENT ISN’T STARVING FOR OXYGEN
- INTERPRET VALUES BASED ON OVERALL PATIENT CONDITION
- OXYGEN THERAPY MANAGEMENT
- ASSESSMENT OF RESPIRATORY STATUS
- MONITORING FOR TISSUE HYPOXIA
- UNDERSTANDING PATIENT CONDITIONS
- COLLABORATION WITH THE INTERDISCIPLINARY TEAM
