Download ABG Quick Interpretation

ABG Quick Interpretation
Parameter
Acidosis
Normal
Alkalosis
pH
< 7.35
7.35-7.45
> 7.45
pCO2
> 45
35-45
< 35
HCO3
< 22
22-26
> 26
Reflects
Acid/Base
Status of Body
Respiratory
Component
Metabolic
Component
Facts:Body will not overcompensate when it comes to acid/base balance so:
• pH midpoint is 7.4
• If pH on report is < 7.4 = original problem was acidosis in nature
• If pH on report is > 7.4 = original problem was alkalosis in nature
Examples:
1. pCO2 is High and pH is 7.37 = compensated Respiratory Acidosis because in spite of
high pCO2 which would indicate Acidosis the pH is within normal range indicating
that the metabolic component has kicked in and caused pH to shift more towards the
midpoint of 7.4
and therefore compensated for the respiratory acidosis.
2. pH is 7.44 and the HCO3 is 33 it is a Metabolic Alkalosis with Respiratory
Compensation bringing the pH back to WNL but not past midpoint.
pH




< 7.4
> 7.4
< 7.4
> 7.4
pCO2

WNL

WNL




HCO3
WNL

WNL





Interpretation*
Respiratory Alkalosis
Metabolic Alkalosis
Respiratory Acidosis
Metabolic Acidosis
Compensated Resp. Acidosis
Compensated Resp. Alkalosis
Compensated Meta. Acidosis
Compensated Meta. Alkalosis
*Where compensation is not involved you can look at the arrows:
• Arrows are in same direction = metabolic conditions
• Arrows in opposite direction = respiratory conditions
Problems with readings of pulse oximeters
Clinical Situation
Result
Carboxyhemoglobin
Falsely High Saturation
Bilirubin
Falsely High Saturation
Melanotic Skin
Variable, Reduced Signal
Poor Peripheral Perfusion
Low Signal, Unreliable Results
Website to use for online analysis of Blood Gas Values:
http://medcalc.com/acidbase.html
Created by P. Keally 10/18/2007