1. ) (

2. Arterial Blood Gases This article will help us to

Interpret arterial blood gases.

2. Translate informations into effectiveaction . 3. Indications

It is essential in evaluation of critical illpatient , giving an idea about his acid base balance and oxygenation .

In a respiratory disturbance , it isa diagnostic assessment of the nature , severity and progress of the illness .

4. Technique

Choose vessels that have best collateral circulation.

Puncture of a site where the artery is superficial .

Radial artery is the best choice , if not accessible : dorsalis pedis , posterior tibial , brachial and femoral arteries .

5.

Brachial and femoral arteries puncture are contraindicated in patients with abnormal haemostatic mechanism .

6. PH7.35 7.45 PaCO 2 35 45 mmHg PaO 2 80-100 mmHg HCO 3 22 26mq / L O 2saturation 95 100 % Normal values of ABG,s 7. Interpretation of ABG,s

Does the patient have acidosis or alkalosis ?

IfPH < 7. 35acidosis IfPH > 7. 45 alkalosis 8.

Is acidosis / alkalosis respiratory or metabolic?

If PH and PaCO 2move in the samedirection

If PH and PaCO 2move in the opposite direction

it is primaryrespiratory acid -base disturbance . it is primarymetabolicacid base disturbance . 9. PHPaCO 2

Metabolic acidosis

Metabolic alkalosis

Respiratory acidosis

Respiratory alkalosis

10.

Is the respiratory disorder is acute ( uncompensated ) or chronic( compensated ) ?

If PH is unaccepted

it is acute .

If PH is accepted

it is chronic . N.B accepted PH is from 7.30 to 7.50 . 11. Acid Base DisorderPrimary changeCompensatory change Respiratory acidosisPaCo 2 HCo 3 Respiratory acidosis Respiratory alkalosis PaCo 2 HCo 3 Metabolic acidosis HCo 3 PaCo 2 Metabolic alkalosis HCo 3 PCo 2 12.

Is the patient hypoxemicor not ?

. If PaO 2between 80 100 mmHg ,oxygenation is normal . . If PaO 2is < 60 mmHg , hypoxicstate is existing . 13. *In respiratory disturbances:.If ABG,s show only that PaO 2is< 60 mmHg Hypoxaemic (type I)Respiratory Failure . .If PaO 2< 60 mmHg & PaCO 2> 45mmHg, Hypoxaemic , Hypercapnic (type II ) Respiratory Failure . 14. Indication for Critical Care Unite admission

Persistent or worsening hypoxemia( PaO 2< 50 mmHg ) .

2. Severe or worsening hypercapnia( PaCO 2> 70 mmHg ) .3. Severe or worsening respiratoryacidosis ( PH < 7.30 ) . 15. Measures to improve ventilation1. Enhancing alveolar ventilationi.e treatment of the cause( drug overdose / central hypoventilation /neuromuscular disease / airwayobstruction ) . 2. Decrease CO 2production-Bring fever down .-Avoid excessive nutritional calories . 16. Measures to improve oxygenation

O2supplementation

*RF type Inasal catheter / face mask .

* RF type IIventuri mask controlled oxygen .

17. 2.Treatmentof the cause .3. Anaemic patients should betransfused to haemoglobin of 10 gm % . 18. adequate deliveryof oxygenated blood to tissues .4. Hypotensive patients should be resuscitated to an adequate cardiac output to assure 19. EXAMPLE 1 PH7.34(academia ) Pa CO248( academia ) Pa O2129( normal ) HCO3 26( normal ) BE+ 1( normal ) Sa O 299 %( normal ) InterpretationRespiratory acidosis , adequate oxygenation. 20. EXAMPLE 2 PH7.40( normal ) Pa CO258( academia ) Pa O257( hypoxemia ) HCO3 35( alkalemia) BE+ 9( alkalemia ) Sa O 289 %( hypoxemia ) InterpretationRespiratory acidosis with complete metabolic compensation and hypoxemia . 21. EXAMPLE 3 PH7.29(academia ) Pa CO240( normal ) Pa O2192( normal ) HCO3 19(academia ) BE- 5.6(academia ) Sa O 297.5 %( normal) InterpretationMetabolic acidosis with no compensation , adequate oxygenation. 22. EXAMPLE 4 PH7.37( normal ) Pa CO240( normal ) Pa O2126( academia ) HCO3 20( academia ) BE- 3.1( academia) Sa O 298 %( normal) InterpretationFully compensated metabolic acidosis , adequate oxygenation. 23. Thank You