Acid-Base-Lecture-2012.ppt

Fluid, Electrolyte and Acid-base Balance BlockACID-BASE BALANCE

By Harliansyah, PhD

HYDROGEN IONS, ACIDS, AND BASES

HYDROGEN IONS (H+)

ACIDS

BASES

PHNormal arterial pH is 7.35 7.45

ACID-BASE BALANCESAcidosis pH < 7.35

Alkalosis pH > 7.45

Buffers

PRIMARY BUFFER SYSTEMS IN EXTRACELLULAR FLUID

REGULATION OF ACIDS AND BASESTHE BIG THREE ACID-BASE REGULATORS

Chemical regulationBiological regulationPhysiological regulation

PHYSIOLOGICAL REGULATION

Alkalosis

Acidosis

ACID BASE IMBALANCESRESPIRATORY ACIDOSISRESPIRATORY ALKALOSISMETABOLIC ACIDOSISMETABOLIC ALKALOSIS

ARTERIAL BLOOD GASES

NORMAL BLOOD GAS VALUESpH 7.35-7.45PCO2 35-45 mmHgHCO3 22-27 mEq/LPO2 80-100 mmHg

ARTERIAL BLOOD GASESRESPIRATORY IMBALANCESRespiratory function indicator is PCO2Opposite response between the pH and PCO2pH is down in an acidotic condition and is elevated in an alkalotic conditionpH and PCO determines if the condition is a respiratory problem

ARTERIAL BLOOD GASESMETABOLIC IMBALANCESHCO3 is indicator for metabolic function A corresponding response between the pH and the HCO3 pH is down in an acidotic condition and is elevated in an alkalotic condition The pH and the HCO3 determines if the condition is a metabolic problem

ANALYZING ARTERIAL BLOOD GAS RESULTSPYRAMID STEPSLook at the blood gas reportPYRAMID STEP 1Look at the pH. Is it up or down? If it is up, it reflects alkalosis. If it is down, it reflects acidosis.PYRAMID STEP 2Look at the PCO2. Is it up or down? If it reflects an opposite response as the pH then you know that the condition is a respiratory imbalance. If it does not reflect an opposite response as the pH, then move on to Pyramid Step 3.

ANALYZING ARTERIAL BLOOD GAS RESULTSPYRAMID STEP 3Look at the HCO3. Does the HCO3 reflect a corresponding response with the pH? If it does, then the condition is a metabolic imbalance.PYRAMID STEP 4Remember, compensation has occurred if the pH is in a normal range of 7.35-7.45.If the pH is not within normal range, look at the respiratory or metabolic function indicators.

FLUID, ELECTROLYTE & ACID -BASEREMEMBER~~~~

NORMAL CHEMISTRY LABORATORY VALUES

Serum electrolyte levelsCBC (changes in Hct related to FVD & FVE)BUN & Blood Creatinine Levels (kidney functions)Urine Specific gravity (normal 1.003 1.023)ABGs

F

LUID, ELECTROLYTE & ACID -BASEOVERALL GOALS/EVALUATION

NORMAL FLUID, ELECTROLYTE AND ACID BASE BALANCE

CAUSES OF IMBALANCES IDENTIFIED OR CORRECTED

NO COMPLICATIONS FROM THERAPIES NEEDED TO RESTORE BALANCE

INCLUDE FAMILY IN PROCESS

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