ICU必备课件1.ppt

ABG INTERPRETATION Debbie Sander PAS-II What is an ABG What Is An ABG? Acid/Base Relationship Case Study No. 1 60 y/o male comes ER c/o SOB. Tachypneic, tachycardic, diaphoretic and Cyanotic. Dx acute resp. failure and ABG’s Show PaCO2 well below nl, pH above nl, PaO2 is very low. The blood gas document Resp. failure due to primary O2 problem. Case Study No. 2 Buffers Respiratory Component Metabolic Component Acid/Base Relationship Normal ABG values Acidosis Alkalosis Respiratory Acidosis Causes of Respiratory Acidosis Metabolic Acidosis Causes of Metabolic Acidosis Respiratory Alkalosis Causes of Respiratory Alkalosis Metabolic Alkalosis Causes of Metabolic Alkalosis How to Analyze an ABG Four-step ABG Interpretation Four-step ABG Interpretation Four-step ABG Interpretation Four-step ABG Interpretation ~ PaCO2 – pH Relationship Respiratory Acidosis Respiratory Alkalosis Metabolic Acidosis Metabolic Alkalosis What are the compensations? Mixed Acid-Base Abnormalities ABG Results Case study No. 4 Case study No. 5 Case study No. 6 Case study No. 7 Case No. 7 cont’d Case No. 7 cont’d Case study No. 8 Case No. 8 cont’d Case No. 8 cont’d Case No. 8 cont’d Case study No. 9 Case study No. 10 Case No. 10 cont’d Take Home Message: It’s not magic understanding ABG’s, it just takes a little practice! Any Questions? References Practice ABG’s Answers to Practice ABG’s pH 7.50 PaCO2 30 HCO3 22 pH 7.30 PaCO2 40 HCO3 15 pH 7.50 PCO2 40 HCO3 30 Respiratory acidosis ? metabolic alkalosis Respiratory alkalosis ? metabolic acidosis In respiratory conditions, therefore, the kidneys will attempt to compensate and visa versa. In chronic respiratory acidosis (COPD) the kidneys increase the elimination of H+ and absorb more HCO3. The ABG will Show NL pH, ?CO2 and ?HCO3. Buffers kick in within minutes. Respiratory compensation is rapid and starts within minutes and complete within 24 hours. Kidney compensation takes hours and up to 5