Ultrasound Guided Versus Landmark Guided Arterial Line Placement by Emergency Medicine Interns

Critically ill patients in the emergency department commonly require arterial line placement
for continuous direct blood pressure monitoring, frequent arterial blood gas sampling, and
frequent blood sampling. Trans-radial catheterization has been shown to reduce access site
complications and increase patient comfort compared to trans-femoral access. Radial artery
access on the first attempt is optimal; attempts at reentry delay care and increase the risk
of vascular spasm, hematoma, infection, neurovascular injury, and pain. The traditional pulse
palpation method of radial artery cannulation can be challenging, especially in patients with
weak pulses (i.e. morbidly obese or hypotensive individuals).

A review of literature suggests that ultrasound guided trans-radial catheterization compared
to standard pulse palpation reduces access time and increases rate of first-entry success
when performed by physicians trained in ultrasound. Thus, complications ascribed to reentry
are prevented and timely care is provided.

To the investigator's knowledge, only one other prospective study has been conducted to
assess the utility of ultrasound guided radial artery cannulation in the emergency
department. Due to the paucity of literature to support the use of ultrasound guided
trans-radial catheterization in critically ill patients, the study will aim to provide
further data on the topic. Both techniques are considered standard of care.