Key Learning Points

1. 1. Ultrasound guidance is the gold standard of care for central line insertion.

2. 2. The number of unsuccessful attempts at cannulation is directly proportional to the likelihood of subsequent complications.

3. 3. Factors such as current clinical condition, body habitus, co-morbidities and intended duration of catheterisation should influence the choice of puncture site.

4. 4. The length of guidewire and catheter used is determined by the side and site of insertion.

5. 5. The puncture site should be regularly assessed for signs of infection – line-associated sepsis is a significant cause of morbidity in the critical care setting.

Key Learning Points

1. 1. Arterial lines offer beat-by-beat monitoring of a patient’s blood pressure and allow for repeated arterial sampling – must-haves in critical care and major operative settings.

2. 2. Careful consideration of the insertion site is necessary, especially when radial puncture is not available. The use of end-arteries could result in limb ischaemia in the event of complications.

3. 3. The Allen’s test is a simple and timely test for gross perfusion prior to arterial puncture; however, it is not without its shortcomings. Doppler ultrasound may be more effective, especially in anaesthetised patients.

4. 4. There are several different techniques for arterial line insertion; however, the catheter-over-wire (Seldinger) technique is regarded as the safest.

5. 5. A well-inserted and cared-for arterial line can remain in situ for several weeks, if required. Infection rates are lower than those of either peripheral or central venous catheters.