title: Proper shoulder position for subclavian venipuncture: a prospective randomized clinical trial and anatomical perspectives using multislice computed tomography.
abstract: BACKGROUND
  Although the Trendelenburg position and shoulder bracing are recommended for safe subclavian venipuncture, the optimal shoulder position remains unclear. The current study observed spatial relations between the subclavian vein and surrounding structures using multislice computed tomography to determine optimal shoulder position for safe subclavian venipuncture and then conducted a small follow-up clinical trial to confirm these findings.
  
  
  METHODS
  Thoracic multislice computed tomography was performed for seven adult volunteers at three shoulder positions: elevated (up); neutral; and lowered caudally (down). Overlap and distance between the clavicle and the subclavian vein and the diameter of the subclavian vein were measured. Anatomical relations between the subclavian artery and vein were also observed. The success rate for subclavian venipuncture was then compared between the up and down shoulder positions in 30 patients.
  
  
  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.
authors.affiliation: Department of Anesthesiology, Tsuruta Hospital, Ushizu, Saga, Japan. kitagawa@mail.saga-med.ac.jp
authors.forename: Norihito
authors.initials: N
authors.lastname: Kitagawa
authors.forename: Mayuko
authors.initials: M
authors.lastname: Oda
authors.forename: Tadahide
authors.initials: T
authors.lastname: Totoki
authors.forename: Noriaki
authors.initials: N
authors.lastname: Miyazaki
authors.forename: Ichiroh
authors.initials: I
authors.lastname: Nagasawa
authors.forename: Takahiko
authors.initials: T
authors.lastname: Nakazono
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamai
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Morimoto
mesh_terms: D000328:Adult; D002968:Clavicle / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D018962:Phlebotomy / Q000379:methods*; D010994:Pleura / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011187:Posture / Q000502:physiology*; D011446:Prospective Studies; D012272:Ribs / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D012782:Shoulder / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013348:Subclavian Artery / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D013350:Subclavian Vein / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed