《急诊》第四讲 ICU必备课件

ABG INTERPRETATION Debbie sander pas-ii

ABG INTERPRETATION Debbie Sander PAS-II

Objectives v What’ s anab? Understanding Acid/Base Relationship General approach to ABG Interpretation v Clinical causes Abnormal ABG's Case studies V Take home

Objectives ✓ What’s an ABG? ✓ Understanding Acid/Base Relationship ✓ General approach to ABG Interpretation ✓ Clinical causes Abnormal ABG’s ✓ Case studies ✓ Take home

What is an abg Arterial blood gas Drawn from artery- radial, brachial, femoral It is an invasive procedure Caution must be taken with patient on anticoagulants Helps differentiate oxygen deficiencies from primary ventilatory deficiencies from primary metabolic acid-base abnormalities

What is an ABG Arterial Blood Gas Drawn from artery- radial, brachial, femoral It is an invasive procedure. Caution must be taken with patient on anticoagulants. Helps differentiate oxygen deficiencies from primary ventilatory deficiencies from primary metabolic acid-base abnormalities

What Is An abg? pH HI PCO2 Partial pressure CO2 PO2 Partial pressure O2 HCO2 Bicarbonate bE Base excess Sao Oxygen Saturation

What Is An ABG? pH [H+ ] PCO2 Partial pressure CO2 PO2 Partial pressure O2 HCO3 Bicarbonate BE Base excess SaO2 Oxygen Saturation

Acid/Base Relationship This relationship is critical for homeostasis Significant deviations from normal ph ranges are poorly tolerated and may be life threatening Achieved by respiratory and renal systems

Acid/Base Relationship ➢ This relationship is critical for homeostasis ➢ Significant deviations from normal pH ranges are poorly tolerated and may be life threatening ➢Achieved by Respiratory and Renal systems

Case Study No. 1 60 y/o male comes ER c/o SOB Tachypneic, tachycardic, diaphoretic and Cyanotic. Dx acute resp failure and abgs Show PacO, well below nl, ph above nl Pao, is very low. The blood gas document Resp. failure due to primary o, problem

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 60 y/o male comes ER c/o SoB Tachypneic, tachycardic, diaphoretic and Cyanotic. Dx acute resp. failure and aBgs Show PaCO, very high, low pH and Pao, is moderately low. The blood gas document Resp. failure due to primarily ventilatory nsutticiency

Case Study No. 2 60 y/o male comes ER c/o SOB. Tachypneic, tachycardic, diaphoretic and Cyanotic. Dx acute resp. failure and ABG’s Show PaCO2 very high, low pH and PaO2 is moderately low. The blood gas document Resp. failure due to primarily ventilatory insufficiency

Buffers There are two buffers that work in pairs >H2CO3 NaHcO3 Carbonic acid base bicarbonate These buffers are linked to the respiratory and renal compensatory system

➢There are two buffers that work in pairs ➢H2CO3 NaHCO3 Carbonic acid base bicarbonate ➢These buffers are linked to the respiratory and renal compensatory system Buffers

Respiratory component function of the lungs C arbonic aci id H2CO3 Approximately 98% normal metabolites are in the form of co CO2+ H2o H2CO3 excess CO, exhaled by the lungs

Respiratory Component ➢ function of the lungs ➢ Carbonic acid H2CO3 ➢Approximately 98% normal metabolites are in the form of CO2 CO2 + H2O  H2CO3 ➢ excess CO2 exhaled by the lungs

Metabolic Component Function of the kidneys base bicarbonate Na HCO3 Process of kidneys excreting Ht into the urine and reabsorbing HCO, into the blood from the renal tubules D active exchange Nat for H between the tubular cells and glomerular filtrate 2) carbonic anhydrase is an enzyme that accelerates hydration/dehydration CO2 in renal epithelial cells

Metabolic Component ➢ Function of the kidneys ➢ base bicarbonate Na HCO3 ➢ Process of kidneys excreting H+ into the urine and reabsorbing HCO3 - into the blood from the renal tubules 1) active exchange Na+ for H+ between the tubular cells and glomerular filtrate 2) carbonic anhydrase is an enzyme that accelerates hydration/dehydration CO2 in renal epithelial cells