Analysis Of ABG ABG Arterial blood gases

pH

disorder

3 different disorders 2 metabolic respiratory

normal values

pH=7.35 - 7.45 PaCO2 = 35 - 45 mmHg PaO2 = 80 - 100 mmHg HCO3 = 22 - 26 mlEq/L

anion gap HAGMA High anion gap metabolic acidosis

anion gap anion gap

measured cations and anions

acidosis accumulation of non volatile acids or loss of bicarbonate

Na-(Cl+HCO3) =8-14 mEq/L

anions and cations anion gap

balance cations=anions Na+unmeasured cations=(Cl +HCO3)+unmeasured anions

Na-(Cl+HCO3)=UA-UC anion gap UA-UC

albumin albumin 50% anion gap 75% ABG

Albumin hypoalbuminaemia

STEP 1

- anion gap AG = Na-(Cl+HCO3) normal value =9-16

anion gap 20 acidosis

20 HAGMA is most likely present HAGMA=high anion gap metabolic acidosis ABG pH anion gap 30 high anion gap metabolic acidosis pH and HCO3

anion gap metabolic disorder

- delta gap delta gap =AG-12 delta gap HCO3

delta gap+HCO3

26mmol/L coexisting metabolic alkalosis

24 mmol/L coexisting NAGMA (normal anion gap metabolic acidosis(

24-26 metabolic disorder HAGMA

HAGMA metabolic disorder

2STEP

Values disorders

pH 735 acidaemia pH 745 alkalaemia pH HCO3 metabolic acidosis pH PaCO2 respiratory acidosis pHHCO3 metabolic alkalosis

pH PaCO2 respiratory alkalosis respiratory disorder

3STEP Disorder respiratory disorder acute or chronic

metabolic acidosis : PaCO2=(1.5HCO3+8)+/-2 metabolic alkalosis : PaCO2=40+0.7(measured HCO3-24( Respiratory acidosis : *Acute : HCO3 increases 1mmol/L for every 10 mmHg increase in PaCO2. ..and pH decreases 0.008 per 1mmHg inc. in PaCO2 *Chronic : HCO3 inc. 3.5 mmol/L for every 10 mmHg inc. in PaCO2 and pH decrease 0.003 per 1 mmHg inc. in PaCO2 Respiratory alkalosis : *acute : HCO3 decr. 2 mmol/L for every 10 mmHg decr. in PaCO2 pH incr. 0.008 per 1 mmHg decrease in PaCO2 *chronic : HCO3 decrease 5mmol/L for every 10 mmHg increase in PaCO2 and pH increase 0.003 per 1mmHg decr.in PaCO2

full analysis ABG

diagnosis of any disorder