ABG Sampling

what are indications for arterial sampling

• assess patient ventilation, oxygenation or acid base status

• establish baseline values

  • documented lung disease requiring treatment

  • cardiopulmonary requiring surgery

• clinical deterioration

• response to therapy

different artieral puncture sites ADULTS

• radial artery

• brachial artery

• fermoral artery

• doraslis pedis artery

puncture sites for neonates

• radial artery

• superficial artery

• umbilical artery (open for 24-48hr)

advantages of radial artery

• collateral blood flow to hand via ulnar artery

• artery is superficial and easy to palpate and stabilize

• less tissue to penetrate in this area and this means less pain

• wrist is easily accessible

• major nerves not in close proximity

disadvantages of radial arterial sampling

• radial artery more peripheral more likely to spasm

• draw venous sample form veins

• may be more difficult to obtain sample in poor circulation

absolute contraindications

• patient refuse

• puncture site

  • Presence of a surgical shunt

  • Presence of localized lesions

  • Evidence of localized infection

• Specific to femoral punctures:

• Do not perform outside of the hospita

what is absolute contraindication for arterial sampling

poor collateral circulation

relative contraindication for arterial sampling

• Deformities at puncture site area

• Raynaud's Disease

• Fibrosed arteries

• Hematoma at the puncture site

relative contraindications for arteiral sampling

• Anticoagulant or thrombolytic medication

• A patient with a coagulation disorder (i.e. Hemophilia)

• Low platelet count or prolonged bleeding time

• A patient with severe hypotension

complications of arterial sampling

• Hematoma, hemorrhage

• Infection

• Thrombosis

• Arterial spasm

• Laceration of blood vessels or nerves

• Vasovagal response

• Pain

• Loss of limb, hand or fingers (rare)

hazard for art smaplin

to health care workers

• Needle Stick Injury

• Blood borne infections

• Human immunodeficiency virus (HIV)

  • Hepatitis B (HBV)

  • Hepatitis C (HC

brachial puncture indications

radial puncture is no possible

disadvantage of brachial puncture

Deeper than Radial Artery

Proximity of Median Nerve

No collateral circulation

femoral artery sampling indications

Low perfusion

• Cardiac arrest/shock

• Deformities of the wrist

• Failed bilateral modified Allen’s test

absolute contraindications for femoral artery sampling

• femoral arterial grafts

• trauma to the pelvic area

advantages of femoral sampling

Less subject to low pressure problems

• Large diameter

• Less likely to go into spasm

• Easy to locate and puncture, however it is a deeper artery

disadvantages of femoral sampling

Obstruction of the femoral artery greatly decreases blood flow to the leg

• Some collateral circulation via the deep femoral artery

• More susceptible to infection and hematoma

• Thrombosis (arteriosclerotic artery)

• Easy to puncture the vein

• Femoral nerve lies Immediately lateral to the artery

• Artery is less accessible and lies deep under the skin

ABG sampling equipment

PPE

• Arterial blood gas sampling

• Plastic syringes with needle

• Caps & Needle guards

• Anticoagulant

• Plastic vs Glass syringes

• Chlorhexidine or alcohol swabs

• Sterile gauze

• Label

• Watch, Pen, Notepad

• SpO2 Probe

characteristics of plastic syringes

Most are vented

• Most are prefilled with dry heparin

• Much more available than glass syringes

plastic syringe vents are located where

syringe lunger

integral media allows only the air to escape through syringe

media then expands and seals when contracted by blood

disadvantages of plastic syringes

If the syringe is not vented, the barrel may need to be pulled back to get blood

sample (mask the arterial pulse)

• May allow diffusion of room air into syringe (especially if iced)

glass syringes characteristics

Plunger (barrel) moves freely, less friction than plastic

• The arterial pressure moves the plunge

disadvantages of glass syringes

Tendency for air leak around the plunger

• The barrel will fall out with poor handling of the syringe

• Need specific needles for the syringes (some types)

vacuum tubes points

• used but must be filled completly

  • not common method to obtain an ABG

anticoagulants

Lithium heparin – most common

• Sodium heparin (1000 IU/ml)

• Dry heparin is used in syringes in pre made arterial blood gas kits

• Oxalates and citrate anticoagulants should not be used as they alter the sample pH.

when to do modified allens test

Done prior to radial artery puncture ONLY

• Normal test indicating collateral circulation - hand flush pink within 5-10 seconds

• Cannot be performed on critically ill patients who are uncooperative or unconsciou

blood sample analysis should avoid these errors

Obtained anaerobically (no air bubbles)

• Properly anti-coagulated

• Analyzed within 30 minutes (less than 15 minutes is ideal)

what infection control procedures should be followed

• During Procedure: Gloves, Face Protection (splash risk)

• After Procedure: Gloves as a minimum when handling any blood products

• Dispose and transport any blood products in biohazard bags or containers

• Sharps of any kind go in sealed biohazard containers

• Any blood spills should follow the hospital protocols for cleaning and disinfection