Accuracy of Real Time 3D Navigation Device to Identify Lumbar Epidural Spacy in Pregnant Patients. A Comparison With Standard Ultrasound.

SpineNav3DTM technology facilitates image interpretation of individual 2D lumbar spine scans by automating spinal bone landmark detection and depth measurements and providing a real-time assessment of scan plane orientation in 3D.

Assuming a Type I error rate of 5% (α = 0.05) and a Type II error rate of 20% (β=0.2), a minimum of 76 subjects will be required. All the subjects will have their lumbar area scanned for the measurements of the depth of the epidural space (recorded in cm) by two anesthesiologist, one expert in UD and the other a novice, previously instructed to the use of the Accuro device.

All measurements will be performed either in the sitting or in the supine position at L1/L2, L2/L3 and L3/L4 levels. The expert operator will assess the lumbar spine by using both the devices (standard US and Accuro) while the novice will use only the Accuro.

The primary end-point of the study will be the accuracy of the Accuro to determine the depth of the epidural space using a midline approach using as comparator the measurement obtained with the standard ultrasound device performed by the expert operator.