文档介绍：ABG INTERPRETATION
Objectives
What’s an ABG?
Understanding Acid/Base Relationship
General approach to ABG Interpretation
Clinical causes Abnormal ABG’s
Case studies
Take home
What is an ABG
Arterial Blood Gas
Drawn from artery- radial, brachial, femoral
It is an invasive procedure.
Caution must be taken with patient on anticoagulants.
Helps differentiate oxygen deficiencies from primary
ventilatory deficiencies from primary metabolic acid-base
abnormalities
What Is An ABG?
pH [H+]
PCO2 Partial pressure CO2
PO2 Partial pressure O2
HCO3 Bicarbonate
BE Base excess
SaO2 Oxygen Saturation
Acid/Base Relationship
This relationship is critical for homeostasis
Significant deviations from normal pH ranges are poorly tolerated and may be life threatening
Achieved by Respiratory and Renal systems
Case Study No. 1
60 y/o male comes ER c/o SOB.
Tachypneic, tachycardic, diaphoretic and
Cyanotic. Dx acute resp. failure and ABG’s
Show PaCO2 well below nl, pH above nl,
PaO2 is very low. The blood gas document
Resp. failure due to primary O2 problem.
Case Study No. 2
60 y/o male comes ER c/o SOB.
Tachypneic, tachycardic, diaphoretic and
Cyanotic. Dx acute resp. failure and ABG’s
Show PaCO2 very high, low pH and PaO2
is moderately low. The blood gas document
Resp. failure due to primarily ventilatory
insufficiency.
There are two buffers that work in pairs
H2CO3 NaHCO3 Carbonic acid base bicarbonate
These buffers are linked to the respiratory and renal compensatory system
Buffers
Respiratory Component
function of the lungs
Carbonic acid H2CO3
Approximately 98% normal metabolites are in the form of CO2
CO2 + H2O H2CO3
excess CO2 exhaled by the lungs
Metabolic Component
Function of the kidneys
base bicarbonate Na HCO3
Process of kidneys excreting H+ into the urine and reabsorbing HCO3- into the blood from the renal tubules 1) a