Presentation on theme: "Ibrahim alzahrani R1 Quiz of the week. 18 years old male who presented with sever cough, greenish sputum and high grade fever (39.5). He developed sever."— Presentation transcript:
Interpret this ABG. Explain the ABG results Do you want any further test ?
What is the expected HCO3 in respiratory acidosis?
Compensation in respiratory acidosis: acute respiratory acidosis the serum HCO3 increases by about 1 meq/L for every 10 mmHg elevation in the PCO2 Chronic respiratory acidosis: serum HCO3 increases by 3.5 to 4 meq/L for every 10 mmHg elevation in PCO2
For every increase in Pa CO 2 of 20mmHg above normal the pH falls by 0.1 For every decrease of Pa CO 2 of 10mmHg below normal the pH rises by 0.1.
A-a oxygen gradient = PAO 2 - PaO 2. PAO 2 = (FiO 2 x 713) - (PaCO 2 ÷ 0.8) Simplified equation :
Back to the case How can you explain a HCO3 of 7?
3 Step approach : Step 1: Establish the primary diagnosis: Step 2 :Assess the degree of compensation: indicative of a mixed acid-base disorder
Step 3: Determine whether or not the anion gap is elevated. This is especially important for patients with metabolic acidosis Serum AG = Na - (Cl + HCO3) = 139-(95+7)=37 If there is high anion gap then : Δ anion gap/ Δ HCO3 ratio (37-10)/(24-7)=1.6:1 If 1:1 ratio then it’s pure high metabolic acidosis. If < 1:1 : additional non anion gap metabolic acidosis If > 1:1 : Additional metabolic alkalosis