ABG Analysis Easy to
Remember:
Nurses
often have difficulty interpreting arterial blood gases (ABGs). Confusion often
begins with trying to remember many random rules and lacking a standardized.
Approach to ABGs. In addition, nurses often attempt to analyze too many
components. Of the ABG at the same time. The result is often confusion and an
incorrect diagnosis.
Desecration:
·
Measurement
of the dissolved oxygen and carbon dioxide in the arterial blood helps indicate
the acid-base state and how well oxygen is being carried to the body.
Pre-procedure of ABG
Analysis
·
Perform
Allen’s test before drawing radial artery specimens.
·
Have
the client rest for 30 minutes before specimen collection to ensure accurate
measurement of body oxygenation.
·
Do
not turn off oxygen unless the ABG sample is prescribed to be drawn with the
client breathing room air.
·
Collection
of an arterial blood gas specimen
Obtain vital signs.
·
Determine
whether the client has an arterial line in place.
·
Perform
the Allen’s test to determine the presence of collateral circulation (see
Priority Nursing Actions).
·
Assess
factors that may affect the accuracy of the results, such as changes in theO2
settings, suctioning within the past 20minutes, and client’s activities.
·
Provide
emotional support to the client.
·
Assist
with the specimen draw by preparing a heparinized syringe.
·
Apply
pressure immediately to the puncture site following the blood draw; maintain
pressure for 5 minutes or for 10 minutes if the client is taking anticoagulants.
·
Appropriately
label the specimen and transport it on ice to the laboratory.
·
On
the laboratory form, record the client’s temperature and the type of
supplemental oxygen that the client is receiving.
Normal Arterial Blood
Gas Values
PH:
7.35 to 7.45
PCO2:
35 to 45 mm Hg
HCO3:
22 to 27 mEq/L
PO2:
80 to 100 mm Hg
O2
saturation: 96% to 100%
Oxyhemoglobin
dissociation curve: No shift
The 6 Easy Steps to
ABG Analysis:
·
Is
the pH normal?
·
Is
the CO2 normal?
·
Is
the HCO3 normal?
·
Match
the CO2 or the HCO3 with the pH
·
Does
the CO2 or the HCO3 go the opposite direction of the pH?
·
Are
the pO2 and the O saturation normal?
Post- procedure
·
Place
the specimen on ice.
·
Note
the client’s temperature on the laboratory form.
·
Note
the oxygen and type of ventilation that the client is receiving on the
laboratory form.
·
Apply
pressure to the puncture site for 5 to 10 minutes or longer if the client is
receiving anticoagulant therapy or has a bleeding disorder.
·
Transport
the specimen to the laboratory within 15 minutes.
Steps for analyzing
Arterial Blood Gas results
If
you can remember the following Pyramid Points and Pyramid Steps, you will be
able to analyze any blood gas report.
Pyramid Points
·
In
acidosis, the pH is decreased.
·
In
alkalosis, the pH is elevated.
·
The
respiratory function indicator is the PCO2.
·
The
metabolic function indicator is the bicarbonate ion (HCO3
Pyramid Steps
Pyramid Step 1
Look
at the blood gas report. Look at the pH. Is the pH elevated or decreased? If
the pH is elevated, it reflects alkalosis. If the pH is decreased, it reflects
acidosis.
If
pH is within normal range, leave it. We don’t need to go further as it
indicates client have no acidosis or alkalosis or compensation has occurred .
Pyramid Step 2
Now
in this step we want to find out if pH in first step is acidic(i.e. low pH) or alkali
(i.e. high pH) is if it is because of respiratory
reason.
Look
at the PCO2. Is the PCO2 elevated or decreased? If the PCO2 reflects an
opposite relationship to the pH, then the condition is a respiratory imbalance.
If the PCO2 does not reflect an opposite relationship to the pH, go to Pyramid
Step 3.
Pyramid Step 3
Now
in this step we want to find out if pH in first step is acidic(i.e. low pH) or alkali
(i.e. high pH) is if it is because of metabolic
reason.
Look
at the HCO3
Does
the HCO3 reflect a corresponding relationship with the pH? If it does, then the
condition is a metabolic imbalance.
Pyramid Step 4
Compensation
has occurred if the pH is in a normal range of 7.35 to 7.45. If the pH is not
within normal range, look at the respiratory or metabolic function indicators.
If the condition is a respiratory imbalance, look at the HCO3 to determine the
state of compensation. If the condition is a metabolic imbalance, look at the
PCO2 to determine the state of compensation.
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