Jeong HH, et al. A quantitative analysis of the relation between the clavicular tilt angle and subclavian central venous catheter misplacement. Clin Exp Emerg Med. 2014 Dec 31; 1(2):114-119.
RESULTS: Among all central venous catheterizations (n=1,599), the subclavian route was used 981 times (61.4%). There were 51 misplacements of SCV catheters (5.2%) during the study period. There were no differences in the sex, age, blood pressure, and diagnosis between the two groups. The CTA values were 28.5°±7.3° and 22.6°±6.3° in the misplacement group and control group, respectively (95% confidence interval, 3.6 to 8.1; P<0.001).
CONCLUSION: In this study, the CTA was found to be 5.9° larger in the misplacement group than in the control group. Assuming that CTA indicates the shoulder position, our findings suggest that the chance of SCV catheter misplacement may be reduced by avoiding the shoulder elevated.
Fortune JB, Feustel P. Effect of patient position on size and location of the subclavian vein for percutaneous puncture. Arch Surg. 2003 Sep;138(9):996-1000; discussion 1001.
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RESULTS: The mean (SEM) diameter of the subclavian vein is largest in position 5 (0.99 [0.06] cm) and smallest in position 2 (0.84 [0.05] cm). The distance of the vein from the clavicle is greatest in position 1 (0.94 [0.08] cm) and least in position 4 (0.75 [0.07] cm). Using an analysis of variance with Dunnett’s comparison, all positions were compared with position 5. For vein diameter, all positions had significantly smaller size. In position 4, the vein was significantly closer to the clavicle. There was no statistical difference in flow rates among all positions.
CONCLUSIONS: These data demonstrate that arching of the shoulders and turning of the head may reduce target size and provide an unsatisfactory position for subclavian puncture. The Trendelenburg position with no other positioning maneuvers may be helpful.
Kitagawa N, et al. Proper shoulder position for subclavian venipuncture: a prospective randomized clinical trial and anatomical perspectives using multislice computed tomography. Anesthesiology. 2004 Dec;101(6):1306-12.
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RESULTS: In the multislice computed tomography study, the mean overlap ratios between clavicle and subclavian vein in the up, neutral, and down positions were 33.5, 36.9, and 40.0%, respectively. Overlap increased with lower shoulder position (up < neutral < down; P < 0.05). The mean distances between the clavicle and the subclavian vein in the up, neutral, and down positions were 6.8, 5.0, and 3.6 mm, respectively. Again, distance decreased with lower shoulder position (up < neutral < down; P < 0.05). The diameter of the subclavian vein did not differ among the three shoulder positions. The success rate for subclavian venipuncture was significantly higher in the down position compared with the up position (P = 0.003).
CONCLUSIONS: Lowered shoulder position increases both overlap and proximity between the clavicle and the subclavian vein, producing a more constant relation between the clavicle and the subclavian vein, without affecting vein diameter. Proper use of a lowered shoulder position should thus increase the safety and reliability of subclavian venipuncture compared with other shoulder positions.
See also:
Kim HJ, et al. Comparison of the neutral and retracted shoulder positions for infraclavicular subclavian venous catheterization: a randomized, non-inferiority trial. Br J Anaesth. 2013 Aug;111(2):191-6.
The utility of Trendelenburg position on subclavian port placement
Surgical Focus 