NURSING SCIENCES

ACID-BASE BALANCE

HYDROGEN IONS, ACIDS, AND BASES

HYDROGEN IONS (H+)

ACIDS

BASES

PHNormal arterial pH is 7.35 – 7.45

ACID-BASE BALANCES

Acidosis – pH < 7.35

Alkalosis – pH > 7.45

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

Acidosis

ACID – BASE IMBALANCES

RESPIRATORY ACIDOSISRESPIRATORY ALKALOSISMETABOLIC ACIDOSISMETABOLIC ALKALOSIS

ARTERIAL BLOOD GASES NORMAL BLOOD GAS

VALUES pH 7.35-7.45 PCO2 35-45 mmHg HCO3 22-27 mEq/L PO2 80-100 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 problem

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 HCO3 determines if the condition is a metabolic problem

ANALYZING ARTERIAL BLOOD GAS RESULTS PYRAMID STEPS

Look at the blood gas report PYRAMID STEP 1

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 on to Pyramid Step 3.

ANALYZING ARTERIAL BLOOD GAS RESULTS PYRAMID STEP 3

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 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

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

F

LUID, ELECTROLYTE & ACID -BASE OVERALL 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