This is a randomized controlled trial comparing the success of US guided peripheral IV placement between single vs dual-operator technique among a convenience sample of patients with moderate or difficult vascular access in a tertiary care Emergency Department.

Gaining intravenous (IV) access is a common and important procedure in the emergency department (ED). IV access is needed to deliver drugs, enable fluid resuscitation and sample blood, and delays in gaining access can lead to patient harm. Ultrasound (US) is a commonly used tool in the ED, and the utility of ultrasound in the placement of IVs in patients with difficult access has been well described. This study aims to further guide the use of this evidence based tool by ED Registered Nurses. The focus will be comparing single-operator technique, in which the same provider manipulates the ultrasound probe while simultaneously placing the IV, to a dual-operator technique whereby a second provider manipulates the probe. Any measured advantage has implications in guiding education and practice, as well as informing future ED policy.

Inclusion Criteria:

• Adult (18 years and older) patients predicted to require intravenous cannulas and identified at triage as having moderate or difficult access based on the following criteria:

Moderate: peripheral vein is visible or palpable but difficulty is expected based on patient characteristics both clinical and historical.

Difficult: No peripheral veins visible or palpable, or two failed attempts by traditional landmarking (LM).

Exclusion Criteria:

• Exclusion criteria will include patients who have already undergone successful pre-hospital IV placement, patients with an indwelling vascular device, patients who are critically ill (Canadian Triage Acuity Score I) or objection to study enrolment by the attending MD for any reason. If no suitable target vein can be identified with US the patient data will be collected and the patient will be excluded from the statistical analysis.