Trendelenburg position for internal jugular vein catheterization: A systematic review and meta-analysis

Gravitational effects on carotid and jugular characteristics in graded head-up and head-down tilt

Altered gravity affects hemodynamics and blood flow in the neck. At least one incidence of jugular venous thrombosis has been reported in an astronaut on the International Space Station. This investigation explores the impact of changes in the direction of the gravitational vector on the characteristics of the neck arteries and veins. Twelve subjects underwent graded tilt from 45° head-up to 45° head-down in 15° increments in both supine and prone positions. At each angle, the cross-sectional area of the left and right common carotid arteries (ACCA) and internal jugular veins (AIJV) were measured by ultrasound. Internal jugular venous pressure (IJVP) was also measured by compression sonography. Gravitational dose-response curves were generated from experimental data. ACCA did not show any gravitational dependence. Conversely, both AIJV and IJVP increased in a nonlinear fashion with head-down tilt. AIJV was significantly larger on the right side than the left side at all tilt angles. In addition, IJVP was significantly elevated in the prone position compared with the supine position, most likely because of raised intrathoracic pressure while prone. Dose-response curves were compared with existing experimental data from parabolic flight and spaceflight studies, showing good agreement on an acute timescale. The quantification of jugular hemodynamics as a function of changes in the gravitational vector presented here provides a terrestrial model to reference spaceflight-induced changes, contributes to the assessment of the pathogenesis of spaceflight venous thromboembolism events, and informs the development of countermeasures.NEW & NOTEWORTHY Flow stasis and thrombosis have been identified in the jugular vein during spaceflight. We measured the area and pressure of the internal jugular vein and the area of the common carotid artery in graded head-up and head-down tilt. Experimental data are used to generate gravitational dose-response curves for the measured variables, demonstrating that jugular vein area and pressure exhibit a nonlinear response to altered gravity. Gravitational dose-response curves show good agreement with spaceflight and parabolic flight studies.

Trendelenburg (Head-Down Tilt) and Head Rotation: Ultrasonographic effects on the internal jugular vein for catheterization safety

Most guidelines fail to specify patient positioning during central venous catheterization. The objective was to determine the effects of head-down tilt (Trendelenburg position) and head rotation on the internal jugular vein (IJV). A prospective, observational, longitudinal, and descriptive study using healthy adult volunteers, of both sexes, was performed. The change in position and cross-sectional areas (CSA) of the right IJV and common carotid artery (CA) were measured by ultrasonography during Trendelenburg position (TP) (0°, 5°, 10°, and 15°) and contralateral head-rotation (HR) (0°, 45°, and 90°) for a total of 12 positions. The neutral supine position was first, randomizing the other 11 positions, with 5-minute rest intervals in between. Vital signs and symptoms were recorded. A total of 54 volunteers were recruited between the ages of 21 and 32, of which 30 were men. Any degree of TP or HR significantly increased the CSA. The largest area obtained was 1.78cm² with a TP15HR90 which did not have a statistical difference with TP10HR45 1.59cm² . A HR90 tended to displace the IJV medially, overlaying the CA. Any degree of TP or HR will significantly increase CSA or the right IJV. A 5° to 10° TP is recommended when the patient's condition allows it, with a 45° HR, without significantly displacing the IJV anterior to the CCA. This article is protected by copyright. All rights reserved.