Correlation of preprocedural ultrasound estimated epidural depths in transverse median and posterior sagittal oblique view and body mass index with procedural epidural depths in patients scheduled for surgery under lumbar epidural anaesthesia.

BACKGROUND AND AIMS: Preprocedural lumbar ultrasound (US) is employed for the estimation of epidural depth (ED). This study observed the correlation of preprocedural ED in transverse median (TM), parasagittal oblique (PSO) view, and body mass index (BMI) with procedural ED. METHODS: In a prospective study, 100 female patients, aged 40-65 years, with American Society of Anesthesiologists physical status I/II, BMI 18.5-30 kg m-2 scheduled for surgeries under lumbar epidural blocks were included. In the TM group, preprocedural ultrasonography (USG) was performed in TM view and ED was calculated, whereas in the PSO group, the paramedian sagittal view was used and corresponding markings were done for epidural needle insertion in the midline and paramedian planes, respectively. The primary outcome was the correlation of procedural ED and preprocedural ED in TM and PSO views, respectively. The secondary outcomes included correlation of procedural ED with BMI, comparability of preprocedural, and procedural ED in TM and PSO views. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) v19.0 (International Business Machines, USA). RESULTS: The preprocedural and procedural ED was less in the TM group (4.43 ± 0.75 and 4.44 ± 0.75 cm) in comparison to those in the PSO group (4.86 ± 0.53, 4.90 ± 0.54; P = 0.001). Strong correlation was observed in preprocedural and procedural ED [r2 = 0.996 and 0.995]. The procedural ED had strong correlation with BMI [r2 = 0.600, P = 0.001] in the TM group, and weak correlation [r2 = 0.367] in the PSO group [P = 0.01]. The procedural ED was comparable to preprocedural ED in TM and PSO groups. CONCLUSION: Preprocedural US scanning provides an accurate estimate of actual EDs in TM and PSO view.

Ultrasound-assisted subarachnoid block in obese parturient: Need of the hour.

Subarachnoid block is commonly used for caesarean deliveries, by virtue of its simplicity in terms of performance and safety for the parturients when compared with general anesthesia. The landmark technique involves palpating the interspinous space at the level of Tuffier's line to ensure the interspace level and direct the spinal needle through optimally selected puncture site for performing the subarachnoid block. However, spinal block is sometimes not easy to perform in obese parturients primarily because of poorly palpable surface landmarks and challenges related to positioning for the block. Recently, ultrasound (USG) is being used for facilitating central neuraxial block, using low-frequency curvilinear probe with encouraging results. We report a case of a 28-year-old, 95-kg parturient, with body mass index of 39.1 kg/m2 scheduled for elective lower segment caesarean section under subarachnoid block, the indication being previous caesarean section. As the landmarks were not appreciable on palpation, we performed USG-assisted preprocedural landmark-based subarachnoid block successfully.