ABG's (Arterial Blood Gases)

pH Normal Range

7.35-7.45

pH Acidosis

<7.35

pH Alkalosis

>7.45

CO2 Normal Levels

35-45

CO2 Acidosis

>45

CO2 Alkalosis

<35

HCO3 Normal Levels

22-26

HCO3 Acidosis

<22

HCO3 Alkalosis

>26

How do Kidneys compensate?

Excreting excess Acid & Bicarbonate

or

Retaining Hydrogen & Bicarbonate

• hours-days to compensate

How do the Lungs compensate?

Hyperventilating → CO2 < → Alkalosis

Hypoventilating → CO2> → Acidosis

Respiratory Acidosis Pathophysiology

• lung problem → retain too much CO2→ kidneys compensate→ Excrete H+, Retain Bicarbonate

• pH <7.35, CO2 >45

Respiratory Acidosis Causes:

“DEPRESS”

1. Drugs (opiates/sedatives)

2. Edema (fluid in the lungs)

3. Pneumonia (excess mucus in lungs)

4. Respiratory center of brain damaged

5. Emboli (pulmonary emboli)

6. Spasms of bronchial (Asthma)

7. Sac elasticity damage (COPD/Emphysema)

Respiratory Acidosis S/S:

1. < BP

2. < RR

3. > HR

4. Restless

5. Confusion

6. Headache

7. Sleepy/coma

Respiratory Acidosis Nursing Interventions:

1. Administer O2

2. Semi fowlers position

3. Turn, Cough, Deep Breathe (TCDB)

4. Pneumonia: increase fluids to thin secretions and admin antibiotics

5. Monitor K+ levels (3.5-5.0 mEq/L)

6. If CO2 >50→ may need endotracheal tube

Respiratory Alkalosis Pathophysiology

• Lung problem→ losing too much CO2 → kidneys compensate → Excrete bicarbonate and retain Hydrogen

• pH >7.45, CO2 <35

Respiratory Alkalosis Causes

1. Tachypnea

2. Hyperventilation

3. Aspirin toxicity

4. Increased Temp

Respiratory Alkalosis S/S:

1. RR >20 breaths/min

2. > HR

3. Confused/tired

4. Tetany

5. EKG changes

6. Positive Chvostek’s sign

Respiratory Alkalosis Nursing Interventions:

1. Give emotional support

2. Fix breathing problem

3. Encourage good breathing patterns

4. Rebreathing into a paper bag

5. Give anti- anxiety meds/sedatives → < RR

6. Monitor K+ & Ca - levels

Metabolic Acidosis Pathophysiology

• Kidney problem→ Too much H+, too little HCO3 → Lungs compensate→ blow off CO2

• pH < 7.35 , HCO3 <22

Metabolic Acidosis Causes:

1. Diabetic ketoacidosis→ ↓ insulin → ↑ fat metabolism→ ↑ ketones (acid)

2. Acute/Chronic Kidney Injury

3. Malnutrition → breaking down of fats→ ↑ ketones (acid)

4. Severe Diarrhea→ Excessive loss of base from “base”

Metabolic Acidosis S/S:

1. Kussmaul’s breathing

2. Hyperkalemia

3. Muscle twitching

4. Weakness

5. Arrhythmias

6. ↓ BP

7. Confusion

Metabolic Acidosis Nursing Interventions:

1. Monitor K+ levels

2. Monitor I&O

3. Initiate seizure precautions

4. Administer IV solution to < acid &> bases

5. If Diabetic Ketoacidosis:

• Give insulin→ stops fat breakdown & ketone production

• Monitor for hypovolemia from polyuria

6. If Kidney Disease:

• Dialysis to remove toxins

• Diet→ > Calories, < protein

Metabolic Alkalosis Pathophysiology

Kidney problem→ too much HCO3, too little H+ → Lungs compensate→ retain CO2

pH >7.45, HCO3 > 26

Metabolic Alkalosis Causes:

1. Too much antacids→ too much sodium bicarbonate

2. Diuretics

3. Hyperaldosteronism

4. Excess vomiting → excess loss of HCL from stomach

Metabolic Alkalosis S/S:

1. Hypoventilation <12 breaths/min

2. Hypokalemia

3. Dysrhythmias

4. Muscle cramps/weakness

5. Vomiting

6. Tetany

7. Tremors

8. EKG changes

Metabolic Alkalosis Nursing Interventions:

1. Monitor K+ and Ca+ levels

2. Administer IV fluids to help kidneys get rid of HCO3

3. Replace K+

4. Give antiemetics for vomiting (Zofran/Phergan)

5. Watch for signs of respiratory distress