The effectiveness of trendelenburg positioning on the cross-sectional area of the right internal jugular vein in obese patients

Effect of passive leg raising on the cross-sectional area of the right internal jugular vein in patients with obesity: a randomised controlled trial protocol

BACKGROUND

Venous access in patients with obesity presents significant challenges. The success of central venous catheterisation largely depends on the cross-sectional area (CSA) of the internal jugular vein (IJV). While techniques like the Trendelenburg position have been traditionally used to increase IJV CSA, recent studies suggest its ineffectiveness in patients with obesity. Conversely, the potential of the effect of passive leg raising (PLR) has not been thoroughly investigated in this group of patients.

METHODS

This protocol outlines a planned randomised controlled trial to evaluate the effect of PLR on the CSA of the IJV in patients with obesity slated for central venous catheterisation. The protocol involves dividing 40 participants into two groups: one undergoing PLR and another serving as a control group without positional change. The protocol specifies measuring the CSA of the IJV via ultrasound as the primary outcome. Secondary outcomes will include the success rates of right IJV cannulation. The proposed statistical approach includes the use of t-tests to compare the changes in CSA between the two groups, with a significance threshold set at p<0.05.

ETHICS APPROVAL

This study has been approved by the Institutional Review Board of Shanghai Tongren Hospital. All the participants will provide informed consent prior to enrolment in the study. Regarding the dissemination of research findings, we plan to share the results through academic conferences and peer-reviewed publications. Additionally, we will communicate our findings to the public and professional communities, including patient advocacy groups.

TRIAL REGISTRATION NUMBER

ChiCTR: ChiCTR2400080513.

Is the Trendelenburg position the only way to better visualize internal jugular veins?

Background.

A larger cross-sectional area (CSA) of the internal jugular vein (IJV) makes catheterization easier and the Trendelenburg position is used to achieve this. Unfortunately, it is not comfortable for conscious patients. The aim was to evaluate the impact of alternative manoeuvres on the enlargement of the CSA of the IJV and to compare these manoeuvres with the Trendelenburg position.

Materials and methods.

A prospective study of 63 healthy volunteers was conducted. Two-dimensional ultrasound images of right IJV (RIJV) and left IJV (LIJV) were recorded at the level of the cricoid cartilage in the supine position with and without head rotation by 30 degrees during various manoeuvres.

Results.

The CSA of the RIJV and the LIJV significantly increased using hold of deep breath (mean size (cm²) RIJV 1.59 ± 0.82, LIJV 1.07 ± 0.64; both p < 0.001) and the Trendelenburg position (mean size (cm²) RIJV 1.5 ± 0.68, LIJV 0.99 ± 0.54; both p < 0.001). The 45-degree passive leg raise increased the CSA of only the RIJV (mean size (cm²) 1.17 ± 0.61, p = 0.024). These manoeuvres were compared with the Trendelenburg position. There was no significant difference in the size of the CSA using hold of deep breath on the LIJV (p = 0.08) and the RIJV (p = 0.203). The passive leg raise had a significantly weaker impact on the size of the CSA (p < 0.001 for both sides).

Conclusions.

Hold of deep breath and 45-degree passive leg raise (the latter limited for the right side only) are alternative manoeuvres to improve visualization of internal jugular veins for conscious patients. Hold of deep breath was as effective as the Trendelenburg position.

Neck Vessel Cross-Sectional Area Measured with MRI: Scan-Rescan Reproducibility for Longitudinal Evaluations

BACKGROUND AND PURPOSE

The cross-sectional area (CSA) of common carotid arteries-internal carotid arteries (CCA-ICAs), vertebral arteries (VAs), and internal jugular veins (IJVs) is influenced by aging. However, the neck vessel CSA can be affected by other factors as well, including subject positioning, hydration, and respiration, especially in longitudinal studies. This study aimed to assess scan-rescan reproducibility of CCA-ICAs, VAs, and IJVs CSA measurements in order to evaluate their feasibility for longitudinal CSA assessments, and to apply the segmentation method on a longitudinal pilot dataset.

METHODS

Two set of 2-dimensional neck magnetic resonance angiography (MRA) images were acquired on a 3-T scanner from two separate datasets: 9 healthy individuals (HIs) were scanned 5 days apart (scan-rescan dataset) and 12 HIs were acquired 5 years apart (baseline-follow-up dataset). CCA-ICAs, VAs, and IJVs were segmented along the whole vessel length between C3 and C7 intervertebral spaces. Repeated measure analysis of covariance, adjusted for cervical level and sample, and Wilcoxon signed-rank sum test were used to assess the scan-rescan and baseline-follow-up CSA differences. Intraclass correlation coefficient (ICC) was also computed to evaluate scan-rescan reliability.

RESULTS

No significant CSA differences were found for the scan-rescan and baseline-follow-up CSA comparisons, using the whole vessel length or single cervical level measurements. ICC analysis showed good degree of scan-rescan reproducibility (considering whole vessel measures: ICC > .9, P-value < .001 for CCA-ICAs, ICC > .6, P-value < .001 for VAs, and ICC > .7, P-value < .001 for IJVs).

CONCLUSIONS

Scan-rescan reproducibility of CCA-ICAs, VAs, and IJVs CSA measurements is high, making longitudinal studies feasible.

Using Ultrasonography to Determine Optimal Head-down Tilt Position Angle in Patients before Catheterization of the Internal Jugular Vein

CONTEXT

It is believed that 15°-25° head-down tilt position increases the internal jugular vein cross-sectional area (IJV CSA). The increase in IJV CSA before puncture reduces the risk of its perforation. This pattern was not observed in all patients. We assumed that the absence of respiratory-based IJV excursion is one of the criteria of head-down tilt position effectiveness.

AIMS

The aim of this study is to determine the head-down tilt angle, which ensures the absence of the respiratory-based IJV excursion.

SUBJECTS AND METHODS

Prospective study included twenty adult patients. The IJVs scanning was carried out in 1 min after placing the patients in a horizontal position on their back and in 1 min after placing them in the head-down tilt position at 5°, 10°, 15°, and 20° tilt angles.

RESULTS

We found that collapsibility index of <9% indicating the absence of respiratory-based IJV excursion was recorded in 25% of patients in the horizontal supine position. In this case, placing the patients in the Trendelenburg position for IJV catheterization may not be indicated. In 65% of the patients, the respiratory-based excursion was not observed at 10° head-down tilt position. Only 35% of the patients required 15° head-down tilt position.

CONCLUSIONS

In clinical settings, the disappearance of respiratory-based vein excursion on the ultrasound scanner screen can be considered as criteria of the head-down tilt position effectiveness.