Ch. 13 arterial blood collection
S14. List five ABG sampling errors
ABG sampling errors include: - using too much or too little heparin; - insufficient mixing; - allowing air bubbles to enter the syringe; - using an improper plastic syringe; - using an improper anticoagulant; - punctuating a vein instead of an artery; - exposing the specimen to the atmosphere after collection
Warfarin
Anticoagulant
heparin
Anticoagulant
S1. Arterial collection is most often used for what type of testing?
Arterial blood gases (ABGs)
respiratory steady state
State required for arterial blood gas collection, in which blood gas concentrations are steady
The arteries in the arm consist of?
The Brachial Artery (at the elbow), Radial Artery (outside of wrist) and the Ulnar Artery (inside of wrist).
partial pressure of oxygen (PO2)
The absolute amount of oxygen
radial artery
The major artery in the forearm; it is palpable at the wrist on the thumb side.
femoral artery
The principal artery of the thigh, a continuation of the external iliac artery. It supplies blood to the lower abdominal wall, external genitalia, and legs. It can be palpated in the groin area.
S3. What is a normal blood pH?
7.35-7.45
normal blood pH
7.35-7.45
S15. name five reasons that ABG specimens may be rejected
- Air bubbles in the specimen - Clotting - Failure to ice the specimen - Improper or absent labeling - Inadequate volume of specimen for the test
Arterial Puncture Complications
- arteriospasm - embolism - hematoma - hemorrhage - infection - lightheadedness - nerve damage - severe pain - thrombosis
site selection
- artery must be located near skin surface - artery must be large enough - site must have collateral circulation - site should be clear - site should not be proximal to a wound
equipment for arterial puncture
- heparized syringe and needle - antiseptic - lidocaine anesthetic - safety equipment - luer tip - ice, water - gauze - thermometer
S6. besides alcohol, which other antiseptic must be used for arterial puncture?
povidone-iodine or Chlorhexidine
The arteries used for arterial puncture, listed in order of preference, are:
1. radial 2. brachial 3. femoral
steps to prepare a heparinized needle
1. use a solution of sodium heparin with concentration 1000u/ml 2. calculate the volume of heparin to draw up. use 0.05 mL of heparin solution for each mL of blood to be drawn. 3. attach a 20-gauge needle to the syringe, and draw up the heparin by pulling back on plunger 4. rotate the liquid in the syringe to coat the barrel 5. remove the 20-gauge needle and replace with the needle you will use for collection 6. expel excess heparin and air
CE9. If lidocaine is injected before an arterial blood collection, wait _______ minutes for the anesthetic to begin working
1/2
S9. what gauge needle is most often used for blood gas collection?
21 to 22 gauge
S11. for an arterial collection, at what angle is the needle inserted into the artery?
45-60
S12. how long must pressure be applied to the puncture site after an arterial collection
5 minutes, 15 minutes for individuals on blood thinners
S4. What is the difference between acidosis and alkalosis?
Acidosis is indicated by a lower pH, whereas alkalosis is indicated for a higher pH.
S13. Define arteriospasm.
An arteriospasm is the spontaneous constriction of an artery in response to pain.
embolism
Blockage of a vessel by a clot or foreign material brought to the site by the blood current.
S2. List four conditions that produce abnormal ABG values
Chronic Obstructive Pulmonary Disorder (COPD), Lung Cancer, Diabetic Coma, Shock, abnormal gas exchange
S10. define collateral circulation and state which test is used to determine whether this is present
Collateral circulation is the accessory supply of blood to a region by more than one artery. Collateral circulation is tested using the modified Allen test.
pH is altered by
EDTA, oxalates, citrates
hemorrhage
Excessive or profuse bleeding
unlike venipuncture, arterial collection uses
a local anesthetic
S5. describe the difference between a syringe used for venipuncture and a syringe used for ABG collection
a syringe used for venipunture is not heparinized, whereas a syringe used for arterial puncture is pretreated with heparin (glass or gas impermeable plastic) to prevent coagulation.
arterial blood gases (ABGs)
a test performed on arterial blood to determine levels of oxygen, carbon dioxide, and measures the pH
tissue plasminogen activator
a thrombolytic that is administered to some patients having a heart attack or stroke
CE2. A normal blood pH is
a. 7.35
capillary blood gas (CBG)
alternative to ABG testing
partial pressure of carbon dioxide (PCO2)
amount of carbon dioxide dissolved in the blood
dorsalis pedis artery
artery that supplies blood to the foot
scalp artery
artery used for arterial blood collection in infants
umbilical artery
artery used for arterial collection in infants
CE8. In an arterial collection, the needle should be inserted at a _______________ degree angle.
b. 45
CE1. arterial blood collection monitors all of the following except
b. glucose
arterial collection in glass syringes may
be kept on ice and delivered to the lab within one hour
thrombosis
blood clot
CE4. A typical needle gauge for ABG collection is
c. 22
CE7. The modified Allen test determines
c. collateral circulation
CBG
capillary blood gas
CBG is not as desirable as ABG because
capillary blood is a mixture between the capillaries, venuoles, and arterioles which may give off inaccurate readings
S16. in what population is capillary blood gas testing most commonly performed, and on what part of the body is this procedure usually done?
children or people not recommended for arterial puncture; the heel
collateral circulation
circulation by secondary channels after obstruction of the principal channel supplying the heart
CE3. the ABG syringe is coated with
d. Heparin
CE5. which artery is most frequently used for ABG collection
d. radial artery
CE6. which of the following is not an ABG sampling error?
d. use of a gas-impermeable plastic syringe
thrombolytic
drug that breaks down blood clots
abnormal results of PO2 and PCO2 indicate
gas exchange in the lungs is impaired
S7. what local anesthetic may be used to numb the site?
lidocaine
flea
mixes capillary collections with a magnet
requisition forms for arterial punctures include
oxygen received by patient
arterial blood
oxygenated blood
alkalosis
pH above 7.45
acidosis
pH below 7.35
CE11. Which of the following is not a complication of ABG collection?
petechiae
anticoagulant
slows coagulation and prevents new clots from forming
arteriospasm
spasm of an artery, prevents blood flow to tissues
heparinized syringe
syringe used for arterial blood collection; treated with heparin to prevent coagulation
Allen test
test that determines the patency of the radial and ulnar arteries by compressing one artery site and observing return of skin color as evidence of patency of the other artery
brachial artery
the major artery of the upper arm. deep, under the basilic vein and near the median nerve.
patency
the state of being open or unobstructed
streptokinase
thrombolytic
urokinase
thrombolytic
unlike venous collection, arterial collections do not need
tourniquets
CE10. the modified Allen test is performed on the ___ and ____ arteries
ulnar and radial
Hyperventilation
ventilation of the lungs beyond normal body needs
S8. what safety precautions must be taken by a phlebotomist when collecting blood from an artery?
wear a fluid-resistant gown, face protection, and gloves; use a puncture-resistant container for sharps and a small rubber or latex block for the needle