Flashcards RSP 303 Module 5-7 Objectives

PaO₂

Oxygen dissolved in arterial blood

SaO₂

Percentage of hemoglobin carrying oxygen

SpO₂

Pulse oximeter measurement of oxygen saturation

CaO₂

Total oxygen content in blood

Hypoxemia

Low oxygen in the blood

Hypoxia

Inadequate oxygen at the tissues

Adequate SpO₂

Usually greater than 90%

Most common cause of hypoxemia

V/Q mismatch

Other causes of hypoxemia

Shunt, diffusion defect, hypoventilation, and reduced inspired O₂

Right shift

Oxygen is released more easily to the tissues

Right shift causes

Increased CO₂, increased temperature, and decreased pH

Left shift

Hemoglobin holds onto oxygen more tightly

Left shift causes

Decreased CO₂, decreased temperature, and increased pH

ABG Step 1

Check the patient/chart

ABG Step 2

Check clotting and bleeding ability

ABG Step 3

Perform Allen's test

ABG Step 4

Locate the radial artery

ABG Step 5

Clean the site

ABG Step 6

Collect arterial blood

ABG Step 7

Remove the needle

ABG Step 8

Apply pressure

ABG Step 9

Remove air bubbles

ABG Step 10

Label and analyze the sample

Preferred ABG site

Radial artery

Why is the radial artery preferred?

It is easy to access and the ulnar artery provides collateral circulation

Allen's test

Assesses collateral circulation from the ulnar artery

Adequate Allen's test

The hand becomes pink again within 10-15 seconds

Why are air bubbles bad?

They allow O₂ and CO₂ to exchange between the blood and air

Effect of air bubbles

Can cause inaccurate PaO₂ and PaCO₂ values

What should be done with air bubbles?

Remove them from the ABG sample

ABG analysis time

Analyze within 15 minutes when possible

If ABG analysis is delayed

Ice the sample

Maximum time for delayed ABG analysis

Analyze within 1 hour

Cellular metabolism effect

Decreases O₂ and increases CO₂