Fourth Example - ABG Report of the Patient

Fourth Example - ABG Report of the Patient

A male patient aged 65 years of COPD and cor pulmonale admitted with the complain of increase in Breathlessness. ABG was done before giving oxygen therapy on 12/02/2015 at 6.13 PM.

ABG Analysis 

1. Gas Analysis :- 

Step: 1 

PaO2 = 47.1 mm of Hg – Moderate Hypoxenia.

Step: 2

PAO2 = 72.5 – decrease Alveolar oxygen content.

Step: 3

P(A-a)O2 = 72.5-47.1

                 = 25.4 

Nearly Normal = age/4+4 

    = 65/4+4 = 16+4 = 20

Supposed to be no paregnel lup disease.

Step: 4

PaCo2 = 66.5 Increased more than 49.

              So, Hypoventilation.

              So, Hypoxemia with Hypercapnia 

              = Type 2  Respiratory failure.

Step: 5

Since PaCo2 is increased and P(A-a)O2 not increased so, hypo ventilation alone and important cause of it is decrease respiratory drive and neuromuscular disease.

Step: 6

 P/F = 224.3 – there are features of heart failure so is not an  indication of ALI.

   

Step: 7

PaO2 of (40 – 60) mm of Hg  Correspond to SPO2 of (75 – 91)%. 

Here, SPO2 69.7% & PaO2 47.1 mm of Hg.  

So, SPO2 a bit low. 

Step: 8

Cao2 = 17.1 X 10 X 1.34 X 69.7/100 + 0.003 X 47  ml/L

         = 159.71 + 0.1413

         = 159.85 ml/L

2. Electrolyte Analysis :-

Ca++ -> 0.561 – low – Cause, Pancreatis, hypoalbuminemia, Renal failure, Vit deficiency and alkalosis to be searched. 

K+     -> 4.90   – normal 

Anion Gap :-
AG = 12.5 – near normal

Delta Gap :- 
Delta gap = 12.5 – 12 = 0.5

Gap – Gap ratio :- 
Delta gap / HCo3 gap = 0.5/(30.6-24) = 0.5/6.6 = 0.08 <1  (to be taken in consideration if there is metabolic cause.)

Base Excess :- 
BE = 1.5 mm/L –> if metabolic cause it suggest metabolic alkalosis.

3. Acid Base Analysis :-

Step:1

Step: 2
HCo3 = 30.6 mmol/L (> 24 mmol/L) metabolic alkalosis .
       
Step: 3
PaCo2 = 66.5 mm of Hg (> 40 mm of Hg) so, respiratory acidosis.

Step: 4

H+ & HCo3- move in same direction.
so, respiratory cause. 

Step: 5

So, PaCo2 & HCo3- move in same direction.
so, simple cause. So, respiratory acidosis with compensatory metabolic alkalosis.


Step: 6  

Compensation in chronic cause of respiratory acidosis 

HCo3 rise = (2.62 X 66.5)/7.50 = 23.23

So, expected HCo3 = 40 + 23.23 = 63.23 , so fully compensatory.

So, chronic respiratory acidosis with fully compensatory metabolic acidosis with Type 2 respiratory failure due to decrease respiratory drive in a patient of COPD.