Development and Validation of an Ultrasound-Based Difficult Cannulation Risk Score

Central venous catheterization is a common procedure in critically ill patients. Ultrasound guidance improves procedural safety; however, first-pass failure and difficult catheterization remain common and may lead to repeated punctures, prolonged procedure time, arterial puncture, hematoma, and other mechanical complications.

Anatomical characteristics of the internal jugular vein (IJV), particularly vessel diameter and its positional relationship with the common carotid artery (CCA), may influence cannulation difficulty. Operator experience and head position may also modify procedural success. Nevertheless, these factors have rarely been integrated into a prospective pre-procedural prediction strategy in critically ill patients.

ROTATE-ICU is a prospective, single-center observational cohort study enrolling consecutive adult intensive care unit patients undergoing ultrasound-guided IJV central venous catheterization. Before catheterization, patients will undergo standardized ultrasound examination with measurement of the IJV anterior-posterior diameter and skin-to-vessel depth and classification of the IJV position relative to the CCA. Head rotation angle and operator experience will also be recorded.

Procedural outcomes including first-pass cannulation success, number of skin punctures, procedure duration, need for site change, and mechanical complications will be prospectively documented. Difficult catheterization will be defined using a composite of multiple punctures, prolonged procedure duration, and/or need for access-site change.

The study aims to determine independent pre-procedural predictors of cannulation outcome and to develop a clinically applicable ultrasound-based risk prediction model. Model discrimination and calibration will be assessed and internal validation will be performed.

A planned cohort of 150 participants will be enrolled. No intervention is assigned by the study protocol, and all catheterization decisions and clinical management will remain at the discretion of the treating clinical team.

Inclusion criteria

• Age ≥18 years
• Admission to the intensive care unit.
• Clinical indication for central venous catheterization
• Planned internal jugular vein access
• Planned ultrasound-guided catheterization
• Written informed consent obtained from the participant or legally authorized representative, where required

Exclusion criteria

• Active cardiopulmonary resuscitation at the time of catheterization
• Neck anatomical abnormality preventing standard IJV assessment or catheterization
• Neck hematoma
• Active local soft-tissue infection at the proposed access site
• Planned vascular access through a site other than the internal jugular vein
• Planned catheterization without ultrasound guidance
• Refusal or inability to obtain required informed consent