Ultrasound-image Guided Versus Doppler Guided Versus Palpation Technique for Arterial Cannulation in Adults
Condition: Anesthesia
Study type: Interventional

Summary: 
      Radial arterial cannulation is a common invasive procedure for real-time measurement of
      arterial blood pressure. Placement of the arterial catheter using conventional palpation is
      often relatively easy and quick, but this is not always true. A relatively new method for
      direct visualization of the artery is the use of two-dimensional ultrasound. This technique
      allows cannulation of the artery to take place under real-time visualization and may increase
      the success rate of first time pass of the needle. Another technique utilizing Doppler has
      also proven to be effective in cannulating the radial artery. This technique utilizes changes
      in acoustic pitch as the probe passes directly over the artery. The primary objective of this
      study is to compare the first attempt success rate for radial artery cannulation among the
      palpation, Doppler and U/S guided technique when applied by trainees. Secondary outcomes
      include: success rate within 5 minutes, successful, number of attempts required, and
      correlation between success rate and operator experience for successful cannulation of the
      radial artery.
    

Detailed description: 
      Radial artery cannulation is a common invasive procedure in the operating room, intensive
      care unit and emergency department. It allows continuous hemodynamic monitoring and repeated
      arterial blood sampling. Although severe complications are rare, successful radial artery
      cannulation can be technically challenging, particularly in hypotensive patients and those
      with vascular disease. Multiple unsuccessful attempts at arterial cannulation increase
      patient discomfort, delay timely care and may also contribute to adverse events such as
      arterial spasm or local hematoma.

      The radial artery is traditionally located by palpation. A number of techniques to aid radial
      artery localization have been described. Doppler-assisted radial arterial cannulation was
      first described in 1976. Several case reports suggest that Doppler can be helpful in patients
      with difficult arterial access. More recently, ultrasound-guided radial artery cannulation
      has been described. In a recent meta-analysis of four randomized controlled trials,
      ultrasound increased the rate of cannulation on the first attempt by 71% compared with
      palpation. However, two of the studies were of children and all four were small, with 30-152
      participants (311 in total), making the generalizability of these results to adult patients
      uncertain. Furthermore, variation in the training and experience of the operators was evident
      within one of the studies.

      Accordingly, the aim of this study is to compare three different radial arterial cannulation
      techniques in adult surgical patients when performed by anesthesia residents: Doppler;
      palpation; and ultrasound. We think that ultrasound would have a higher rate of cannulation
      on the first attempt compared with other techniques.
    

Intervention name(s): Ultrasound; Doppler; Palpation
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): Participants will place arterial line using ultrasound technique; Participants will place arterial line using doppler technique; Participants will place arterial line using Palpation technique
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment