Optimal Angle of Needle Entry for Internal Jugular Vein Catheterization with a Neutral Head Position: A CT Study

Figures & data

Figure 1.  Axial CT image shows the automatically calculated angles between the clinical entry point (arrows) and the center of the IJVs at the cross-sectional level of the cricoid cartilage (*). CA, carotid artery; RIJV, right internal jugular vein; LIJV, left internal jugular vein.

Figure 2.  Common carotid arteries were taken as reference points and perpendicular axes were used to demarcate the right and left internal jugular veins positions. O: common carotid arteries.

Table 1. Angles between the clinical entry point and the center of the internal jugular veins.

	Right side		Left side
	n (%)	Needle entry angle (mean ± SD)	n (%)	Needle entry angle (mean ± SD)
Total	89	7.1° ± 13.1° medial	89	98.0° ± 12.8° medial
Neutral	25 (28.1)	0 ± 0	30 (33.7)	0 ± 0
Medial	46 (51.7)	16.2 ± 9.7	50 (56.2)	15.9 ± 11.8
Lateral	18 (20.2)	11.0 ± 5.4	9 (10.1)	8.7 ± 2.3

Table 2. Results of the analysis of the computerized tomography scans.

	Right IJV, n = 89	Left IJV, n = 89
Depth from the skin (mm)	16.8 ± 5.6	16.3 ± 5.2
Diamater (mm)*	15.6 ± 5.1	11.7 ± 4.6
Patients with ≤7 mm diamater*	4 (4.4%)	19 (21.3%)
Position of IJV to CA
Lateral	23 (25.8%)	21 (23.6%)
Anterior–lateral	63 (70.8%)	63 (70.8%)
Posterior–lateral	3 (3.4%)	4 (4.5%)
Anterior	0 (0%)	1 (1.1%)
Overlap of IJV
1 (≤25%)	63 (70.8%)	64 (71.9%)
2 (26–50%)	22 (24.7%)	19 (21.3%)
3 (>50%)	4 (4.5%)	6 (6.7%)

Notes: Results are shown as:mean ± SD; or n, (%). IJV: internal jugular vein, CA: carotid artery.*p = 0.001 between the right and the left side.