Arterial Blood Gas Sampling and analysis:

Radial Approach

Presented by:Jonna Bobeck BSN, RN, CEN

Objectives

• Understand ABG

• Discuss indications

• Describe contraindications for performing an arterial puncture.

• Demonstrate the technique for performing an arterial puncture.

• Analyze and interpret results

Introduction

• ABG sampling

• Information with limitations

Indications

• Determination of pH and partial pressure of respiratory gases

• Determination of other serum blood levels

• Assessment of patient response to therapeutic interventions

• Assessment of progression of disease process

Contraindications

• Coagulopathy, anticoagulant meds, thrombolysis

• Abnormalities of the overlying skin

• Prior vascular surgery at or proximal to the entry site

• Inadequate circulation

The Allen Test

• Assess collateral circulation

Equipment

• Gloves

• Antiseptic solution

• Syringe

• 1% lidocaine (optional)

• 1.5-inch 22 to 23 guage needle

• Specimen bag with ice

• Syringe cap

• Bandage

Anatomy of Radial Artery

• Preferred site• Superficial location• Relatively immobile

Procedure

• Explain procedure

• Universal precautions

• Prepare region

• Local anesthetic: optional

Procedure: Initial Artery Approach

• Allen test

• Position

• Identify artery

Specimen Collection

• Slowly advance

• Blood will fill syringe spontaneously

• If unsuccessful withdraw and redirect

• Prepare specimen for submission to lab

Post Procedure Care

• Apply direct pressure

Complications

• Hematoma

• Distal ischemia

• Pseudoaneurysm

• Localized trauma

• Infection

review

Where are abg kits kept in the ed?

Trauma 2

Dirty Utility

Supply Pyxis

Materials

A modified Allen's test is only required for patient’s with poor circulation?

True

False

If unsuccessful withdraw to epidermis and redirect?

True

False

Place the abg on ice and tube to lab?

True

False

Analysis

• Part of diagnosis

Overview

• pH (7.35 – 7.45)

• PaCO2 (35 – 45)

• PaO2 (80 – 100)

• HCO3 (23 – 27)

• Respiratory buffer response

• Renal buffer response

Acid base disorders

• Respiratory acidosis

• Respiratory alkalosis

Acid base disorders

• Metabolic acidosis

• Metabolic alkalosis

Components of ABG

• pH

• PaO2

• PaCO2

• HCO3

• Base Excess (B.E.)

Steps to Interpretation: ABG town

1. Look at pH to determine the first and last name of your ABG

2. Look at CO2 and HCO3 to determine which one has same last name

FIRST MIDDLE LAST

Compensated Respiratory AcidosisUncompensated Metabolic Alkalosis

pHUncompensated Acid…………..7.35 --- 7.45……………Uncompensated Alk

CO2 Respiratory AcidRespiratory Alkalosis………………35 – 45………………Respiratory Acidosis

HCO3 Metabolic BaseMetabolic Acidosis………………….23 – 27………………Metabolic Alkalosis

Compensated Gases7.35…………………………….......7.40/7.41………………………………..7.45 Compensated Acidosis Compensated Alkalosis

Example One

Jane Doe is a 45 year-old female admitted

to the nursing unit with a severe asthma

attack. She has been increasing shortness

Of breath since admission three hours ago.

Her arterial blood gas result is as follows:

pH – 7.22

CO2 – 55

HCO3 – 25

B.E - 23

Result

• First name – uncompensated

• Last name – acidosis

• Look at CO2 and HCO3 to determine which one has the same last name

• CO2 – 55 (acidosis)

• Uncompensated respiratory acidosis

Example Two

John Doe is a 55 year-old male admitted to

your Emergency Department with a bowel

Obstruction. He has been experiencing

intractable vomiting for the last several

hours. His arterial blood gas result is as follows:

pH – 7.50

CO2 – 42

HCO3 – 33

B.E. - 26

Result

• First name – uncompensated

• Last name – alkalosis

• Look at CO2 and HCO3 to determine which one has the same last name

• HCO3 – 33 (alkalosis)

• Uncompensated metabolic acidosis

Compensation

• Over time the body attempts to compensate

• Uncompensated, partially compensated, fully compensated

• When the CO2 or HCO3 go in the opposite direction of the pH there is compensation by that system

A Bit harder

• pH = 7.36 PaCO2 = 56 HCO3- = 26

• pH = 7.43 PaCO2 = 32 HCO3- = 29

• pH = 7.35 PaCO2 = 31 HCO3- = 18.1

• pH = 7.19 PaCO2 = 45 HCO3- = 18.1

• pH = 7.44 PaCO2 = 47 HCO3- = 26

The prefix to the name

• pH = 7.09 PaCO2 = 50 HCO3- = 30

• pH = 7.21 PaCO2 = 55 HCO3- = 28

• pH = 7.67 PaCO2 = 60 HCO3- = 45

• pH = 7.45 PaCO2 = 33 HCO3- = 20

• pH = 7.01 PaCO2 = 20 HCO3- = 10

O2 and base excess

• pH 7.34, PCO2 34, HCO3- 18.6, BE -6, PO2 86%

• pH 7.58, PCO2 48, HCO3 48, BE +22, PO2 59%

Practice test

Mrs. Smith is a 65 year-old woman who is in your ED with decreased level of consciousness. Her ABG results:

pH – 7.28 PCO2 – 74 HCO3 - 26What is the acid base

disturbance?

Respiratory Acidosis Respiratory Alkalosis

Metabolic Acidosis Metabolic Alkalosis

Is Her ABG Compensated or Uncompensated?

Compensated

Uncompensated

What test is used to assess collateral circulation prior to

obtaining an ABG?

Semmes-Weinstein Test

The Allen Test

The Snuffbox Test

Indications for obtaining an ABG?

Determination of other serum blood levels

Determination of pH and partial pressure of respiratory gases

Assessment of patient response to therapeutic interventions

Assessment of progression of disease process

All the above

The preferred site for arterial puncture?

Femoral

Brachial

Radial

Ulnar

True or False: during specimen collection blood will auto fill the

syringe?

True

False

Post procedure how long do you apply direct pressure to

puncture site?

10 Minutes

5 MinutesJust apply dressing

30 seconds

Mr. J is in trauma 6 with a history of

IDDM. His ABG results: pH – 7.25 PCO2 – 35 HCO3 - 38

What is this acid base disturbance?

Respiratory Acidosis

Metabolic Alkalosis

Respiratory Alkalosis

Metabolic Acidosis

Is the ABG Compensated or Uncompensated?

Compensated

Uncompensated

Ph 7.48 PCO2 15 HCO3 25What is the acid base disturbance

Respiratory Acidosis

Metabolic AlkalosisMetabolic Acidosis

Respiratory Alkalosis

Is the ABG Compensated or Uncompensated?

Compensated

Uncompensated

pH – 7.56 PCO2 – 42 HCO3 - 46

What is this acid base disturbance?

Respiratory Acidosis

Metabolic Alkalosis

Respiratory Alkalosis

Metabolic Acidosis

Is the ABG Compensated or Uncompensated?

Compensated

Uncompensated

pH – 7.48 PCO2 – 16 HCO3 - 26

What is this acid base disturbance?

Respiratory Acidosis

Metabolic Alkalosis

Respiratory Alkalosis

Metabolic Acidosis

Is the ABG Compensated or Uncompensated?

Compensated

Uncompensated

pH – 7.38 PCO2 – 50 HCO3 - 27

What is this acid base disturbance?

Respiratory Acidosis

Metabolic Alkalosis

Respiratory Alkalosis

Metabolic Acidosis

Is the ABG Compensated or Uncompensated?

Compensated

Uncompensated

pH – 7.50 PCO2 – 35 HCO3 - 32

What is this acid base disturbance?

Respiratory Acidosis

Metabolic Alkalosis

Respiratory Alkalosis

Metabolic Acidosis

Is Her ABG Compensated or Uncompensated?

Compensated

Uncompensated

references

• Corning, HS & Bryant, SL. Mosby’s Respiratory Care PDQ. Mosby, 2005.

• Hennessey, I & Japp, A. Arterial blood gases made easy. Churchill Livingstone, 1st edition. 2007.

• Hogan, MA & Wane, D. Fluids, electrolytes, and acid –base balance. Pearson Education, Inc., 1st edition. 2003.

• Malley, WJ. Clinical blood gases: Assessment & Intervention. Saunders, 2nd edition. 2004.

• Morton, PG, Fontaine, DK, Hudak, CM, Gallo, BM. Critical care nursing: A holistic approach. Lippincott, Williams, and Wilkins, 8th edition. 2005.

• Oakes, D. Arterial blood gas pocket guide. Respiratorybooks.com. 2009.

• Springhouse. Respiratory care made incredibly easy. Lippincott, Williams & Wilkins. 2004.