Background and Aims We aimed to evaluate the benefit of lumbar ultrasonography in predicting the needle depth before the block and determining the most appropriate entry point in geriatric patients.

Methods Twenty geriatric patients who were to undergoTUR-P/M operation with subarachnoid block were received to study after hospital ethics committee. Lumbar ultrasonography was performed to determine the L3-L5 interspinous space by same anesthesiologist in sitting position. The distances between skin-subdural distance were measured in both sagittal and transverse planes. The distance reached by needle after procedure and the duration of procedure were measured.

Results The mean age of the patients was 69.4, height 166.1 cm, and weight 73.9 kg. Thirteen were men and seven were women. Twelve patients with ASA-II, 8 patients with ASA-III. The probe was used as transverse in half of the patients and sagittal in half. The procedure time was 3.3, the distance measured by USG was 5.09cm, and the applied needle distance was 5.66cm. The results were considered to be correlated between the distance measured by USG and the distance measured with the needle. There was no difference between the groups between transverse and sagittal use in terms of procedure time, distance measured by USG and applied needle. It was found that the distance measured by USG was approximately 1 cm lower than the needle measurement applied.

Conclusions We think that in the determination of the intervertebral space before subarachnoid block, in geriatric patients with concomitant disease, ultrasound localization is easy and reliable and will increase patient comfort.