Acute: Acid Base Balance

What is Paco2

Pressure of dissolved CO2 within the blood

What is PO2

Pressure of dissolved oxygen in the blood

What is HCO3

Bicarbonate

What is a normal pH

7.35-7.45

What is a normal Paco2 (CO2)

35-45

What is a normal bicarbonate (HCO3)

22-26

Is HCO3 a base or acid

Base

Think Bicarbonate Base

Is CO2 an acid or a base

Acid

What does it mean when a bicarb level is exceptionally high

It means that the blood is more basic making it alkalotic

What does it mean when the CO2 is exceptionally high

It means that the blood is more acidic as CO2 is an acid

Is a pH of <7.35 Acidic or Alkalotic

Acidid

Is a pH of >7.45 Acidic or Alkalotic

Alkalotic

What is PaO2

Partial pressure of oxygen in arterial blood

What is SaO2

Oxygen carrying capacity of hemoglobin

What is CO2 in the body

A natural byproduct of cellular metabolism

What does bicarbonate do in the body

Helps regulate the pH

What is HCO3 regulated by?

Kidneys

What is the first responder regulatory mechanism

Chemical buffers

What do chemical buffers do?

• React immediately

• Fastest and primary regulator

What is the second responder regulatory mechanism?

Respiratory system

What does the respiratory system do to become the second responder

• Increases RR to decrease CO2 in blood

• Decreases RR to increase CO2 in blood

• Responds in 5-15 mins

What is the third responder regulatory mechanism?

Renal system

What does the renal system do to become the third responder

• Regulates Bicarb by controlling amount retained or excreted

• Takes 8-12 hours to begin

• 2-3 days to get maximal response

S/S of metabolic acidosis

• Drowsy/Headache/N/V/ Abd pain

• Kussmaul breathing (increased rate and depth)

• Confusion

• LOC

• peripheral vasodilation and decreased CO

• Increased K+ and Cl-

• Dysrhythmias

What will VS look like in metabolic acidosis

• Bradycardia

• Weak peripheral pulses

• Hypotension

• Tachypnea

For metabolic acidosis, how can too much acid get in the blood

• DKA

• Starvation/Malnutrition

• Shock

• Aspirin OD

• Renal failure

• Increased potassium

For metabolic acidosis, how can there be a loss of base

• Severe diarrhea

• Ileostomy

• Pancreatic/biliary loss

How to treat metabolic acidosis

• Treat underlying cause (ex. if diarrhea, control diarrhea)

• Replace bicarbonate

• Monitor for increased K+ and Cl-

• Replace fluids

• Monitor cardiac status

What is the most common cause of metabolic Alkalosis

• Vomiting or NG suction

Clinical manifestations of metabolic alkalosis

• Nervous system stimulation (paresthesia, restlessness, confusion, dizzy)

• Low potassium and calcium

• EKG changes

• Decreased RR

What will be low in metabolic alkalosis

Low potassium

How to treat metabolic alkalosis

• Reverse underlying disorder (ex. Vomiting)

• Stop potassium wasting diuretics (spironolactone)

• Stop NG suction

• Replace fluids

• Monitor for decreased K+ and Cl-

• Monitor cardiac and neuro status

• Watch for Dig toxicity

What does it mean to become Obtundant

Stop breathing when CO2 becomes to high

(when a COPD patient gets pneumonia)

What is respiratory acidosis caused by?

Respiratory issue causing inadequate CO2 excretion

Ex: COPD, hypoventilation and Atelectasis, severe pneumonia, pulmonary edema

What are some clinical manifestations of respiratory acidosis

• Resp distress

• Anxiety/Restlessness

• CNS depression (Confusion, disorientation, coma)

• Peripheral vasodilation

• VFIB (occurs when heart doesn’t get enough oxygen)

Respiratory Acidosis Interventions

Treat underlying cause: Bronchodilators, antibiotics to treat infections, Chest PT to loosen mucus and IS to exercise lungs, chest tube, reverse analgesia

Improve ventilation: Bronchodilators, CPT, Suction, O2 therapy, mechanical ventilation, ABG draw

What may be given if patient is still acidotic after treating respiratory cause

IV sodium bicarbonate

What is the cause of respiratory Alkalosis

Hyperventilation (To much CO2 being blown off)

Respiratory alkalosis manifestations

• Lightheaded

• Can’t concentrate

• Numbness/tingling

• LOC

What are the interventions for respiratory alkalosis

Treat cause of hyperventilation

• Anti-anxiety medication

• Pain relief

• Fever reduction

• O2 therapy

• Diuretics

• Monitor neuro status and implement seizure precautions

Hypoxia or Low PaO2 manifestations

• Disorientation

• Diaphoreses

• Chest pain/SOB

• Tachypnea

• Cyanosis (late sign)

• Death

What cause must be treated first

The underlying cause

How to know if an ABG is compensated

The pH is within normal range

How to know if an ABG is partially compensated

• pH not normal

• CO2 and Bicarbonate also not normal

How to know if an ABG is not compensated

• pH is not normal

• One factor (CO2 or Bicarbonate) is normal while the other one is not