Nsg 201 - Acid Base Lecture Notes

NURSING SCIENCES ACID-BASE BALANCE

HYDROGEN IONS, ACIDS, AND BASES 

HYDROGEN IONS (H+)

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ACIDS

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BASES

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PH Normal arterial pH is 7.35 – 7.45

ACID-BASE BALANCES 

Acidosis – pH < 7.35

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Alkalosis – pH > 7.45

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Buffers

PRIMARY BUFFER SYSTEMS IN EXTRACELLULAR FLUID

REGULATION OF ACIDS AND BASES 

THE BIG THREE ACID-BASE REGULATORS   

Chemical regulation Biological regulation Physiological regulation

PHYSIOLOGICAL REGULATION 

Alkalosis

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Acidosis

ACID – BASE IMBALANCES

RESPIRATORY ACIDOSIS  RESPIRATORY ALKALOSIS  METABOLIC ACIDOSIS  METABOLIC ALKALOSIS 

ARTERIAL BLOOD GASES 

NORMAL BLOOD GAS VALUES  pH 7.35-7.45  PCO 35-45 2 mmHg  HCO 22-27 3 mEq/L  PO 80-100 2 mmHg

ARTERIAL BLOOD GASES 

RESPIRATORY IMBALANCES  Respiratory function indicator is PCO2  Opposite response between the pH and PCO2  pH is down in an acidotic condition and is elevated in an alkalotic condition  pH and PCO determines if the condition is a respiratory

ARTERIAL BLOOD GASES 

METABOLIC IMBALANCES  HCO3 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 HCO determines 3

ANALYZING ARTERIAL BLOOD GAS RESULTS 

PYRAMID STEPS 

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PYRAMID STEP 1 

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Look at the blood gas report Look at the pH. Is it up or down? If it is up, it reflects alkalosis. If it is down, it reflects acidosis.

PYRAMID STEP 2 

Look 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

ANALYZING ARTERIAL BLOOD GAS RESULTS 

PYRAMID STEP 3 

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Look 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 4 

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Remember, 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 -BASE 

REMEMBER~~~~ 

NORMAL CHEMISTRY LABORATORY VALUES

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Serum electrolyte levels CBC (changes in Hct related to FVD & FVE) BUN & Blood Creatinine Levels (kidney functions) Urine Specific gravity (normal 1.003 – 1.023) ABG’s

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LUID, ELECTROLYTE & ACID -BASE 

OVERALL GOALS/EVALUATION 

NORMAL FLUID, ELECTROLYTE AND ACID BASE BALANCE

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CAUSES OF IMBALANCES IDENTIFIED OR CORRECTED

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NO COMPLICATIONS FROM THERAPIES NEEDED TO RESTORE BALANCE

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INCLUDE FAMILY IN PROCESS