NSG 119 Acid Base Balance Notes

● Determinants of acid-base balance: PH, CO2, BICARB
*there are also buffers that excrete hydrogen*
● The regulatory mechanisms are the buffers, respiratory system (co2), and renal system (bicarb)
● Metabolic processes produce acids that must be neutralized and excreted
● The steady balance achieves homeostasis
● Imbalances can be caused by:
○ Diabetes mellitus
○ COPD
○ Kidney Disease
● Ph refers to the acidity of the blood
● The acidity of the blood is the measure of H+ ion concentration
● Blood is slightly alkaline at ph 7.35-7.45

The Respiratory System Regulation
● The respiratory center in the medulla controls breathing
● Increased Respirations lead to increased CO2 elimination and decreased CO2 in the blood
● Decreased respirations leads to CO2 retention (increased Co2)
● When the ph value decreases, RR and depth increase so there is greater excretion of CO2
● The respiratory system’s regulating time is minutes to hours. (short-term fix only)

The Renal System
● Kidneys can retain or excrete acids and bases
● Kidneys regulate bicarbonate levels
● The process takes hours to days
● More long-term regulation of PH

Alterations in Acid-Base Balance
● Imbalances occur when compensatory mechanisms fail
● The classification of imbalances is:
○ Respiratory (Co2) or metabolic (hco3)
○ Acidosis or alkalosisis
○ Acute or chronic

Pottasiums’’s role in Acid-Base balance
● Normally, K+ ion is in the cell. H+ ion concentration is low in both ECF and ICF.
● In acidosis, H+ ion moves in the cell and K+ moves out causing hyperkalemia
● In alkalosis, h+ ions move out of the cell K+ moves in causing hypokalemia.



Metabolic Acidosis Metabolic Alkalosis Respiratory Acidosis Respiratory Alkalosis
Symptoms: Symptoms: Symptoms: Symptoms:

-Hyperkalemia -Hypokalemia Hyperkalemia Hypokalemia

, -Headache/confusion/ -Anxiety/irritability/tetany
drowsiness/coma Seizure
-Kussmaul’s respirations -Positive Trousseau and
(rapid deep breathing) Chvosteks
-Arrhythmias -Paresthesias
-Diarrhea -Skeletal muscle
-Muscle weakness weakness
-Skin warm, dry, flush -Increased HR,
normal/low BP
-Decreased Resp effort

Causes Causes Causes Causes:
● Lactic acid ● Consuming ● COPD ● Fear
buildup (sepsis) sodium bicarb ● Sedatives ● Anxiety
● Renal issues ● Tums (antacids) ● Opiates ● Aspirin (salicylate
(kidney disease) ● NG tube ● Chest trauma toxicity)
● Increased acid ● Person on ● Hyperventilation
ingestion (ETOH, diuretic (thiazide ● Improper vent
Salicylate tox.) or furosemide) settings
● Diarrhea ● Cushings ● High altitude
● Dehydration syndrome ● Early stage acute
● DKA ● Loss of stomach pulmonary
acid problem
● Gastric
suctioning/persist
ent vomitting

Treatment/Nursing Care: Treatment/Nursing Care: Treatment/Nursing Care
*specifically DKA* ● Focus on treating ● Provide for
● Fluid, insulin, underlying cause patient safety (fall
dialysis ● Monitor ABGs risk)
(sometimes) and electrolytes ● Treat underlying
● Monitor ABG ● Frequent cause
results neurologic checks ● Prevent further
● Bicarbonate given ● Monitor loss of K+, Ca+,
if the level is low Chvosteks and Cl-
(<7.2) Trousseau's sign ● Restore balance
● Focus on treating ● Monitor for ECG ● Monitor changes
underlying cause for dysrhythmias
● ● Prioritize safety
(fall risk)



Blood Gas Values (Arterial Blood Gas Values (ABG’s))
● Provide info about
○ Acid base status
○ Underlying cause of imbalance
○ Body’s ability to regular pH
○ Overall oxygen status