Ultrasound validation of Trendelenburg positioning to increase internal jugular vein cross-sectional area in chronic dialysis patients

Figures & data

Figure 1. Ultrasound image of the right IJV and relationship with CA. Interrupted white arrow represents the overlap between CA and IJV. Short arrow shows 25% diameter of CA and long arrow shows 50% diameter of CA. IJV, internal jugular vein; CA, carotid artery.

Figure 2. Ultrasound images of the right IJV and relationship with CA. (A) Cross-sectional area of right IJV. (B) (1) Transverse diameter of IJV, (2) A-P diameter of IJV and (3) safety margin. CA, carotid artery; A-P, anteroposterior; IJV, internal jugular vein.

Table 1. Characteristics of 37 dialysis patients.

Male (female)	25 (12)
Age (years)	63.6 ± 9.8
Weight (kg)	70.9 ± 13.5
Height (cm)	1.7 ± 0.9
BMI (kg/m^2)	25.5 ± 4.3
Diabetes mellitus	7 (18.9%)
Coronary heart disease	6 (16.2%)
Hypertension	16 (43.2%)

Values are presented as mean ± SD or No. Comorbidities are expressed as the absolute number of patients and percentage of their groups.

Table 2. Outcome measurements in the State 0 and State T.

	State 0 (n = 37)	State T (n = 37)
CSA (cm^2)	1.6 ± 1.0	1.7 ± 1.0
Transverse diameter (mm)	16.2 ± 5.8	16.5 ± 5.7
A-P diameter (mm)	12.5 ± 5.8	12.8 ± 4.8
Safety margin (mm)	10.8 ± 5.5	11.1 ± 5.1
Overlap of IJV n (%)
<25% or no overlap	9 (24.3)	7 (18.9)
>25% overlap	28 (75.7)	30 (81.1)

State 0, table flat (no tilt), with the patient in the supine position and State T, in which the operating table was tilted to 15° of Trendelenburg positioning. The change in CSA from the supine to the Trendelenburg position was not significantly different (p = 0.051). The CSA was paradoxically decreased in 11 of 37 patients when changed from State 0 to State T. Overlap ratios are expressed as the absolute number of patients and percentage of their groups. CSA, transverse diameter, A-P diameter and safety margin are expressed as mean ± SD. CSA, cross-sectional area; A-P, anteroposterior; IJV, internal jugular vein.