Acid-base balance and arterial blood gases

CO2 is regulated by what body system?

The respiratory system (lungs)

HCO3 is regulated by what body system?

Metabolic system (kidney)

What is a normal pH range for the body

7.35 - 7.45

What pH level indicates acidosis?

< 7.35

What pH level indicates alkalosis?

> 7.45

What are defined limits for partial pressure of CO2?

35 - 45 mm/Hg

What is a normal measurement of bicarbonate in the blood?

22 - 26 mEq

What are the defined limits for partial pressure of O2?

80 - 100 mm/Hg

What is the first, second, and third line for regulation of blood pH?

1. Buffers system (Bicarbonate, phosphate, and protein)

2. Respiratory regulation (faster)

3. Renal regulation

The CO2 works with chemoreceptors in the medulla to regulate what bodily function?

The depth and rate of breathing

High levels of COs would cause what acid-base imbalance?

Acidosis

High levels of HCO3 would cause what acid-base imbalance?

Alkalosis

What buffer is regulated by the kidney?

Bicarbonate

How does bicarbonate effect the rate of breathing?

Lack of bicarbonate = Increased ROB

Excess bicarbonate = Decreased ROB

The body responds to acidosis by ______ respirations

Increasing

The body responds to alkalosis by _____ respirations

Decreasing

Hypercapnia is defined as

An unusually high level of CO2 retention

Alveolar hypoventilation is a major biological cause of:

Respiratory acidosis

What are some common leading causes of respiratory acidosis?

Morbid obesity

Opiate overdose

Chest trauma

Foreign body aspiration

S/S of respiratory acidosis include:

Headache

Altered LOC

Restlessness

Rapid respirations

Cardiac arrest

Two medications known to treat respiratory acidosis are:

1. Albuterol (Bronchodilator)

2. Acetylcysteine (Mucolytic)

What are the main goals for treating respiratory acidosis?

Improving ventilation

Decreasing PaCO2

(May need O2 therapy/ventilatory support)

Alveolar hyperventilation is a major biological cause of:

Respiratory alkalosis

Hypocapnia is defined as:

Abnormally low CO2 levels in the blood

What are common causes of respiratory alkalosis?

Hyperventilation

Psychological stress

Palpitations

Fever

Sepsis

A prolonged PR interval (>.12-.20) paired with tachycardia and anxiety/restlessness are s/s of:

Respiratory alkalosis

What are some medications that can be administered to treat respiratory alkalosis?

Acetaminophen (Antipyretic)

Antibiotics (For sepsis)

O2

Diazepam, Alprazolam, Midazolam (Sedatives/Benzodiazepams)

Depends on underlying cause*

An increase in hydrogen ion production, resulting in higher H ion concentration leads to:

Metabolic acidosis

How does a lack of insulin result in diabetic ketoacidosis?

Lack of insulin ->

-> No glucose being pushed into cells ->

-> Increased ketone bodies from fat metabolism ->

-> Increase in hydrogen ions in cells (Acidosis)

What is the treatment for diabetic ketoacidosis and why?

Insulin; The increase in blood glucose will push potassium back into the cells and ketone production will stop.

What are common causes of metabolic acidosis?

Diabetic Ketoacidosis

Chronic Alcoholism

Kidney failure

Diarrhea

What are s/s of metabolic acidosis?

Kussmaul's respirations (rapid, deep)

Decreased CO

Dull headache

Decreased LOC

Confusion

What are potential treatment options for metabolic acidosis?

Monitor K+ levels

Administer bicarbonate

Hemodialysis

Metabolic alkalosis is defined by what values?

Ph >7.45

Bicarbonate level >26

Decrease in [H+]

What are common causes of metabolic alkalosis?

Diuretic therapy

Hypokalemia

Vomiting

NG suctioning

Show shallow respirations, hypokalemia, hypocalcemia, EKG changes, and neuromuscular excitability are clinical manifestations of what acid base imbalance?

Metabolic alkalosis

What type of medication can be used to prevent fluid/electrolyte loss in a pt in metabolic alkalosis?

Antiemetics