The Skin-to-epidural distance of parturients by ultrasonography: sitting position versus left lateral position

Eun Hee Chun, Rack Kyung Chung, Youn Jin Kim, So Hee Jin
2017 Anesthesia and Pain Medicine  
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Pre-procedural lumbar ultrasound scanning is a reliable tool to estimate the skin to epidural distance (SED). We conducted an observational study to compare the SED between the
more » ... D between the sitting position and lateral position using pre-procedural ultrasound imaging of the lumbar spine in parturients. Methods: Using a 2-5 MHz curvilinear transducer, we obtained images of the lumbar interspaces from L2-3 to L5-S1 in the paramedian sagittal oblique view. The individual distance from the skin to the ligamentum flavum-dura mater unit was measured at the level of L2-3, L3-4, L4-5, and L5-S1 in the left lateral position (distance in lateral position; D-lat). Subsequently, participants were placed in the sitting position, and the distance was measured in the same manner (distance in sitting position; D-sit). Data were grouped according to body mass index (BMI; kg/m 2 ) measurements of ≥ 25 or < 25 and analyzed. The primary outcome was the change determined by ultrasound between D-lat and D-sit at the same lumbar level according to position. Results: Thirty parturients were studied. The difference between D-lat and D-sit in the same lumbar level was not statistically significant. The mean changes between D-lat and D-sit in the same lumbar level were less than 0.18 cm. In BMI ≥ 25 group, the difference between D-lat and D-sit were greater than that of BMI < 25 group at L3-4 level (P = 0.042). Conclusions: It is important for clinicians to consider that position change is associated with greater differences in SED in obese parturients (BMI ≥ 25) compared with thin parturients (BMI < 25). For obese parturients, the sitting position may be helpful. (Anesth Pain Med 2017; 12: 132-136)
doi:10.17085/apm.2017.12.2.132 fatcat:defxrtffebawbalvcvhyjvjd7u