The INVADE Study: INnominate Vein Approach for Central Catheterization in Difficult to cannulatE Patients

Overview

Most recent guidelines suggest central venous access must be performed with real-time ultrasound guidance, and the most recommended site for cannulation is internal jugular vein (IJV); however, it is recognized that evidence for other sites is, at present, limited. Besides, guidelines does not account for patients with small vein cross-sectional area and/or respirophasic collapse, which can make the procedure more difficult or even impossible. The investigators aim to compare three different insertion sites for central venous access, with real-time ultrasound guidance

Ultrasound-guided cannulation of central veins is successful in \>95% of the cases, according to the largest study so far. However, this and other studies with similar success rate, are performed in patients with general anesthesia and/or neuromuscular blockade, without spontaneous respiratory efforts. Critical care physicians and many other specialists frequently need to cannulate patients in special circumstances as hypovolemia, pain, anxiety, and respiratory efforts that promotes respirophasic variation in cross-sectional area, and even complete collapse of the vessel. These changes can increase the probability of posterior wall or arterial puncture, hematomas, pneumothorax, etc. Supraclavicular approach for cannulation of the subclavian vein is a method described since 1965, also giving direct access to the innominate vein, a larger vessel which is rarely collapsible regardless of volume status or respiratory efforts. Based on a previous pilot trial, in this multi-center, prospective, randomized, controlled trial, the investigators aim to compare the successfulness and safety of ultrasound-guided central venous cannulation at 3 different sites: internal jugular, subclavian, and innominate veins.