• Blood gas analysis
• Biochemical/and haematological investigations

• Blood drawn from arterial line not suitable for bloodspot screening 
• Blood from arterial line can give inaccurate coagulation studies result if not taken correctly – ensure taken in appropriate way with a larger volume of blood withdrawn from the dead space

Haemorrhage

• Ensure all connections are secure, Luer locks tight and 3-way taps appropriately adjusted

Infection

• Maintain sterile technique during sampling to reduce risk of infection

Arterial spasm

• Limb appears blanched. Stop procedure and allow time for recovery. Warming of opposite limb can elicit reflex vasodilatation
• Using warmed fluids as flush may minimise artery spasm

Thromboembolism

• Flush catheter with sodium chloride 0.9% 0.5 mL each time sample taken. If catheter not sampling, clot formation may be in progress. Request urgent senior review of arterial line for a prompt decision about removal

Inaccuracy of blood gas results

• Analyse sample immediately. After blood is withdrawn from an artery, it continues to consume oxygen. Ensure all air in syringe expelled immediately to prevent inaccurate oxygen levels
• Excess heparin in syringe can result in a falsely low pH and PaCO₂. 
• Do not use if air bubbles in sample – take fresh specimen 

• Gloves

• Paper towel

• Alcohol swabs x 2 

• Syringes

  • 2 mL syringe (A) for clearing line

  • 2 mL syringe (B) for other blood samples as necessary

  • 1 mL syringe (C) pre-heparinised for blood gas analysis

  • 2 mL syringe (D) containing 0.5–1 mL of sodium chloride 0.9%

• Appropriate blood sample bottles and request forms

Preparation

• Preparation
• Record SpO₂ and TcCO₂ at time of taking blood to allow comparison with blood gas if performed
• Wash hands and put on gloves
• Place paper towel beneath 3-way tap collection port (maintain asepsis by non-touch technique rather than sterile gloves and towel)
• Ensure 3-way tap closed to side port

Procedure

• Remove Luer lock cap, clean with alcohol swab and allow to dry, or prepare bioconnector
• Connect 2 mL syringe (A)
• Turn 3-way tap so it is closed to infusion and open to syringe and arterial catheter
• Withdraw 2 mL blood slowly. It must clear the dead space
• If bioconnector not being used, turn 3-way tap so it is closed to arterial catheter to prevent blood loss from baby
  
  • if bioconnector used, do not turn 3-way tap until end of procedure
• Attach appropriate syringe (B/C) needed for required blood sample
• If bioconnector not being used, turn 3-way tap to open to syringe and arterial catheter and withdraw required amount of blood for blood samples. Do not withdraw more than required amount
• If bioconnector not being used, turn 3-way tap off to arterial catheter in between syringes B and C if both required, after taking required samples with syringes
• Reattach syringe (A) after any air bubbles expelled
• Slowly return to baby any blood in line not required for samples 
• If bioconnector not being used, turn 3-way tap off to arterial catheter
• Attach syringe (D) of sodium chloride 0.9% 
• If bioconnector not being used, turn 3-way tap so it is open to syringe and arterial line. Check for air bubble in syringe and flush arterial line to ensure clear of blood
• Turn 3-way tap so it is closed to syringe, remove syringe (D), swab port with alcohol wipe and cover with Luer lock cap
  Record amount of blood removed and volume of flush on baby’s daily fluid record

• Ensure all connections tight and 3-way tap turned off to syringe port to prevent haemorrhage
• If sampling from umbilical arterial catheter, ensure lower limbs are pink and well perfused on completion of procedure
• If sampling from peripheral arterial line, check colour and perfusion of line site and limb housing arterial line
• Ensure line patency by recommencing infusion pump
• Before leaving baby, ensure arterial wave form present and all alarms set