最新ABG analysis amp; AcidBase DisordersHome Page ：动脉血气分析amp；酸碱失调首页PPT文档.ppt
Outline,Discuss simple steps in analyzing ABGsCalculate the anion gapCalculate the delta gapDifferentials for specific acid-base disorders,Steps for ABG analysis,What is the pH?Acidemia or Alkalemia?What is the primary disorder present?Is there appropriate compensation?Is the compensation acute or chronic?Is there an anion gap?If there is a AG check the delta gap?What is the differential for the clinical processes?,Normal Values,Step 1:,Look at the pH:is the blood acidemic or alkalemic?EXAMPLE:65yo M with CKD presenting with nausea,diarrhea and acute respiratory distressABG:ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5.1 ACIDMEIA OR ALKALEMIA?,EXAMPLE ONE,ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5.1Answer PH=7.23,HCO3 7 Acidemia,Step 2:What is the primary disorder?,EXAMPLE,ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5.PH is low,CO2 is Low PH and PCO2 are going in same directions then its most likely primary metabolic will check to see if there is a mixed disoder.,Step 3-4:Is there appropriate compensation?Is it chronic or acute?,Respiratory AcidosisAcute:for every 10 increase in pCO2-HCO3 increases by 1 and there is a decrease of 0.08 in pH MEMORIZEChronic:for every 10 increase in pCO2-HCO3 increases by 4 and there is a decrease of 0.03 in pHRespiratory AlkalosisAcute:for every 10 decrease in pCO2-HCO3 decreases by 2 and there is a increase of 0.08 in PH MEMORIZEChronic:for every 10 decrease in pCO2-HCO3 decreases by 5 and there is a increase of 0.03 in PH,Step 3-4:Is there appropriate compensation?Is it acute or chronic?,Metabolic AcidosisWinters formula:pCO2=1.5HCO3+8 2 MEMORIZEIf serum pCO2 expected pCO2-additional respiratory acidosisMetabolic AlkalosisFor every 10 increase in HCO3-pCO2 increases by 6,EXAMPLE,ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5.Winters formula:17=1.5(7)+8=18.5 So correct compensation so there is only one disorder Primary metabolic,Step 5:Calculate the anion gap,AG=Na Cl HCO3(normal 12 2)AG corrected=AG+2.54 albuminIf there is an anion Gap then calculate the Delta/delta gap(step 6).Only need to calculate delta gap(excess anion gap)when there is an anion gap to determine additional hidden metabolic disorders(nongap metabolic acidosis or metabolic alkalosis)If there is no anion gap then start analyzing for non-anion acidosis,EXAMPLE,Calculate Anion gap ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5/Albumin 4.AG=Na Cl HCO3(normal 12 2)123 97 7=19 No need to correct for albumin as it is 4,Step 6:Calculate the different needed formulas,Delta gap=(actual AG 12)+HCO3 Adjusted HCO3 should be 24(+_ 6)18-30If delta gap 30-additional metabolic alkalosisIf delta gap additional non-gap metabolic acidosisIf delta gap 18 30-no additional metabolic disorders,EXAMPLE:Delta Gap,ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5/Albumin 4.Delta gap=(actual AG 12)+HCO3(19-12)+7=14 Delta gap additional non-gap metabolic acidosisSo Metabolic acidosis anion and non anion gap,Metobolic acidosis:Anion gap acidosis,EXAMPLE:WHY ANION GAP?,65yo M with CKD presenting with nausea,diarrhea and acute respiratory distressABG:ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5.1So for our patient for anion gap portion its due to BUN of 119 UREMIA But would still check lactic acid,Nongap metabolic acidosis,For non-gap metabolic acidosis,calculate the urine anion gapUAG=UNA+UK UCLIf UAG0:renal problemIf UAG0:nonrenal problem(most commonly GI),EXAMPLE:NON ANION GAP ACIDOSIS,65yo M with CKD presenting with nausea,diarrhea and acute respiratory distressABG:ABG 7.23/17/235 on 50%VMBMP Na 123/Cl 97/HCO3 7/BUN 119/Cr 5.1Most likely due to the diarrhea,Metabolic alkalosis,Calculate the urinary chloride to differentiate saline responsive vs saline resistantMust be off diuretics in order to interpret urine chloride,Respiratory Alkalosis,Respiratory Acidosis,Steps for ABG analysis,What is the pH?Acidemic or Alkalemic?What is the primary disorder present?Is there appropriate compensation?Is the compensation acute or chronic?Is there an anion gap?If there is a AG,what is the delta gap?What is the differential for the clinical processes?,
