Pilot study of neuraxial imaging by ultrasound in infants and children

Background: Ultrasonography is becoming an important adjunct in regional anesthesia. Epidural anesthesia may pose significant challenges in infants and children because of difficulties in identifying the epidural space. In addition, epidural catheters are sometimes difficult to advance. The present study was performed to evaluate an optimal ultrasound technique for direct visualization of neuraxial structures in children. Methods: A total of 32 infants and children scheduled for minor surgery were prospectively included in a high-resolution ultrasound study. Scans were performed using either a sector or linear probe and views from a longitudinal paramedian, median and transversal angle at lumbar and thoracic levels of the spinal cord were analyzed. Results: In all children investigated, the linear probe generated better images than the sector probe. Of the various scanning perspectives, the paramedian longitudinal approach offered the best views at both cord levels. Broken down by age groups, the best visibility was clearly obtained in neonates up to 3 months of age (P < 0.0001 Vs all other age groups). In older children, the quality of ultrasound decreased in an age-dependent manner. Conclusions: Paramedian longitudinal scans with linear probes are the most favorable method of imaging neuraxial anatomy at lumbar and thoracic cord levels in infants and children, with the best results in neonates up to 3 months of age. Based on these results, and using real time imaging, a practical technique for ultrasound-guided epidural anesthesia for neonates and infants at lumbar and thoracic levels of the spinal cord is planned.