Comparison of the landmark and ultrasound methods in cesarean sections performed under spinal anesthesia on obese pregnants.

Difficulties in the palpation of anatomical landmarks in pregnancy due to obesity may create problems in the regional anaesthesia. Objective of this study was to compare ultrasound examination carried out before the procedure with conventional spinal anaesthesia method with papation of bony landmarks in caesarean sections performed under spinal anaesthesia in obese pregnants. Ninety-seven obese pregnants having pre- and post-pregnancy body mass index > 30 kg/m2 were prospectively examined. Patients were randomised to two groups as landmark group (n = 49) and ultrasound group (n = 48). The needle insertion point was determined at L4-L5 level before the procedure through palpation in the landmark group and with the examination in the ultrasound. The numbers of skin punctures and needle passes, total procedure time (TPT) and spinal block occurrence time (SBOT) were recorded. TPT was significantly longer in the ultrasound than in the landmark group (p < 0.001) (8 ± 2 and 5 ± 1; respectively). Whereas SBOT values were similar (p = 0.063). The numbers of skin punctures and needle passes were significantly fewer in the ultrasound than in the landmark group (p < 0.001). We believe that, accurate determination of the needle introducing site before the procedure by viewing the vertebral structures through ultrasound examination in obese pregnants could increase the success rate.