Supraclavicular vs. infraclavicular: which to use for subclavian lines with POCUS?
Dr Maja Stachura, who is now staff at Vancouver General ED, tried to help answer this question while she was an ultrasound fellow in Sudbury. The results of her project were recently published in the American Journal of Emergency Medicine. Click here for the pub med link. Here’s the lowdown:
Methods:
- Prospective anatomical survey of 100 adult patients
- Exclusion criteria were factors that might have altered the size of the subclavian vein
- 5 physicians scanned the subclavian vein from both the supraclavicular and infraclavicular position, on both the right and left.
- They were asked to score the view obtained as per:
5-excellent
4-good
3-adequate
2-visible but anticipated difficult cannulation
1-subclavian vein not seen
Results
Mean like it scores for the 4 views were:
- right supraclavicular: 4.06
- right infraclavicular: 3.07
- left supraclavicular: 3.82
- left infraclavicular: 3.12
When combining data from the right and left, the mean score for the supraclavicular view was significantly higher than the mean score for the infraclavicular view: 3.94 (95% CI, 0.16) versus 3.10 (95% CI, 0.18). There was no significant difference between the right and left sides.
Physicians were asked to decide which few provided the best view for cannulation. The results were:
- right supraclavicular: 52% (ed note: The right side may have been preferred when using the SC approach because the pleural dome is lower on this side. As well, study physicians may have favored the right side due to the presence of the thoracic duct on the left)
- left supraclavicular: 25%
- right infraclavicular: 14%
- left infraclavicular: 10%
A higher BMI was significantly associated with a lower Likert score.
Based on this study, it seems that the supraclavicular approach might be the better one when placing a subclavian. But it should be mentioned that central lines were not placed in the study patients. Only the view obtained was evaluated.