Objective:

The primary aim of the present study was to compare the ‘cross-legged foetal sitting position’ (CFSP) with the ‘sitting foetal position’ (SFP) sonographically. The secondary aim was to compare their comfort.

Methods:

A randomised, consecutive controlled, single-blinded trial was performed in Yeditepe University. A total of 50 healthy volunteers were included in the study. Exclusion criteria were body mass index (BMI) >40 kg m-2, lumbar hernia, scoliosis, history of spine surgery, lower back pain or trauma, especially pelvic or knee problems related to arthropathy and not able to do one/both of the two position techniques. The two positioning techniques were evaluated by ultrasonography (USG) and 5-point Numerical Rating Scale (5-NRS) patient satisfaction of comfort questionnaire. Seven outcomes via USG were evaluated, subcutaneous tissue (ST), skin to spinous process (S–SP), transverse diameters of right and left paraspinal muscles (RPM and LPM), interspinous gap opening (ISGO), mean of bilateral paraspinal muscle (MPM) and CFSP–SFP change (CFSP–SFP). Stretcher comfort, position comfort, lumbar comfort (LC) and abdominal comfort (AC) were evaluated by participants with the 5-NRS.

Results:

In the CFSP, the mean ST and S–SP were significantly (p<0.0001) shorter, and LPM, RPM and MPM were significantly (p<0.0001) wider. The mean ISGO in the CFSP was significantly (p<0.0001) broader. The CFSP was significantly more comfortable than the SFP according to the LC (p=0.02). Only ISGO was found to be significantly broader in the male participant group (p=0.01) and in the BMI ≥25 group (p=0.02) according to CFSP–SFP.

Conclusion:

Considering all ultrasonographic anatomical measurements and according to the 5-NRS related to LC, the CFSP appears to be more advantageous than the SFP as a neuraxial positioning technique.

Keywords: Conduction anaesthesia, diagnostic imaging, lumbar vertebrae, patient positioning, patient satisfaction