Lesson 5: Arterial Puncture

Question 1

Blood is obtained/withdrawn from a patient’s artery

Answer 1

Arterial Puncture

Question 2

Blood sample of arterial puncture is collected without

Answer 2

a tourniquet

Question 3

Arterial puncture is used in what tests?

Answer 3

Blood Gas Analysis/Arterial Blood Gas Analysis (ABGA)

Question 4

Type and color of arterial blood

Answer 4

oxygenated blood with a bright red color

Question 5

ARTERIAL PUNCTURE IS PERFORMED BY WHOM?

Answer 5

• MD
• Nurses
• Medical technologists & technicians
• Respiratory therapists
• Emergency medical technicians
• Level II phlebotomists

Question 6

WHAT ARE THE SITES FOR ARTERIAL PUNCTURE?

Answer 6

• Radial artery
• Brachial artery
• Femoral artery
• Scalp artery
• Umbilical artery
• Dorsalis pedis arteries

Question 7

Site-Selection Criteria

Answer 7

• Presence of collateral circulation
• Artery accessibility & size
• Type of tissue surrounding the puncture site

Question 8

Blood supply from more than one artery

Answer 8

Presence of collateral circulation

Question 9

• Low risk of injuring adjacent structures or tissue during puncture
• Ability to fix or secure artery to prevent rolling
• Adequate pressure can be applied to artery after collection
• Absence of inflammation, irritation, edema, hematoma, lesion, wound, AV shunt in close proximity, or recent arterial puncture

Answer 9

Type of tissue surrounding puncture site

Question 10

ARTERIAL PUNCTURE SITES:

Advantages:
- Good collateral circulation (radial & ulnar arteries)
- Easy to palpate (close to the surface of the skin)
- Less chance of hematoma formation after collection

Answer 10

The Radial Artery

Question 11

Disadvantages:
- Requires considerable skill to puncture it successfully due to small
size
- Difficult to locate on patients with hypovolemia or low cardiac output

Answer 11

The Radial Artery

Question 12

ARTERIAL PUNCTURE SITES:

Advantages:
- Large & relatively easy to palpate & puncture
- Sometimes the preferred artery for a large volume of blood
- Adequate collateral circulation (but not as good as radial)

Answer 12

Brachial Artery

Question 13

Disadvantages:
- Deeper & can be harder to palpate than radial artery
- Lies close to the basilic vein; risk of mistakenly puncturing it
- Lies close to median nerve; risk of pain & nerve damage
- Increased risk of hematoma formation

Answer 13

Brachial Artery

Question 14

ARTERIAL PUNCTURE SITES:

• Largest artery used for arterial puncture
• Located superficially in groin, lateral to pubis bone
• Performed primarily by physicians & specially trained emergency room personnel
• Generally used only in emergency situations or when no other site is available

Answer 14

Femoral Artery

Question 15

Advantages
- Large & easily palpated & punctured
- Sometimes, only site where arterial sampling is possible

Answer 15

Femoral Artery

Question 16

Disadvantages
 Poor collateral circulation
 Lies close to femoral vein; risk of mistakenly puncturing it
 Increased risk of infection due to location & pubic hair
 Risk of dislodging plaque buildup from inner artery walls
 Requires extended monitoring for hematoma formation

Answer 16

Femoral Artery

Question 17

Disadvantages of Arterial Puncture

Answer 17

 Technically difficult
 Potentially more painful & hazardous than venipuncture
 Thus, not normally used for routine blood tests

Question 18

Reason for Arterial Puncture

Answer 18

 To obtain blood for arterial blood gas (ABG) tests

Question 19

 Best specimen for evaluating respiratory function
 Has high oxygen content & consistency of composition

Answer 19

Arterial blood

Question 20

 Used in diagnosis & management of respiratory disorders
 Used in management of electrolyte & acid-base balance in patients with diabetes & other metabolic disorders
 Specimens are sensitive to effects of preanalytical errors

Answer 20

Arterial Blood Gas (ABGs)

Question 21

Arterial blood gas provide valuable info. about patient’s:

Answer 21

• oxygenation
• ventilation
• acid-base balance

Question 22

Commonly measured ABG analytes

Answer 22

• pH
• PaO2
• PaCO2
• HCO2
• O2
• Base excess

Question 23

A measure of acidity or alkalinity of blood (acidosis or alkalosis)

Answer 23

pH

Question 24

normal range of pH

Answer 24

7.35-7.35

Question 25

Partial pressure of O2 dissolved in arterial blood

Answer 25

PaO2

Question 26

Partial pressure of CO2 dissolved in arterial blood

Answer 26

PaCO2

Question 27

normal range of PaO2

Answer 27

80-100 mm Hg

Question 28

normal range of PaCO2

Answer 28

35-45 mm Hg

Question 29

A measure of bicarbonate in blood

Answer 29

HCO2

Question 30

normal range of HCO2

Answer 30

22-26 mEq/L

Question 31

Percent O2 bound to hemoglobin

Answer 31

O2 saturation

Question 32

normal range of O2 sat

Answer 32

97% - 100%

Question 33

A calculation of nonrespiratory part of acid-base balance

Answer 33

Base excess

Question 34

normal range of base excess:

Answer 34

-2 - +2 mEq/L

Question 35

Arterial Puncture-Procedure Test requisition - Info. concerning conditions at the time of collection is needed:

Answer 35

 Current body temperature  Respiratory rate  Ventilation status  Fraction of inspired oxygen (FIO2)  Prescribed flow rate in liters per minute

Question 36

Equipment and supplies: PPE

Answer 36

- Fluid resistant lab coat, gown, or apron - gloves - face protection

Question 37

Other equipment and supplies:

Answer 37

 Antiseptic Local anesthetic (optional)  Sharp, short-bevel hypodermic needle  1 to 5-mL self-filling syringe  Luer-tip normal or bubble removal cap  Coolant  2 by 2-in. gauze squares  Self-adhering gauze bandage  ID & labeling materials  Puncture-resistant sharps container

Question 38

Arterial Puncture-Procedure Patient preparation includes:

Answer 38

 Identification & explanation of procedures  Patient preparation & assessment  Steady state  Modified Allen test  Administration of local anesthetic (optional)

Question 39

Arterial Puncture-Procedure How to do the modified allen test procedure?

Answer 39

1. Have patient make a tight fist 2. Compress patient’s radial & ulnar arteries at same time 3. Maintaining pressure, have patient open hand slowly 4. Lower patient’s hand & release pressure on ulnar artery only 5. Assess results: +hand flushes pink; -hand does not flush pink 6. Record results on requisition

Question 40

What is a positive modified Allen test?

Answer 40

Release the pressure on the ulnar artery. If the hand flushes within 5 to 15 seconds, this shows that the hand has good blood flow.

Question 41

What is a negative modified Allen test?

Answer 41

Release the pressure. If the hand doesn't flush within 5 to 15 seconds, the circulation of the ulnar artery is not sufficient. If this is the case, the radial artery should not be punctured.