A Prospective, Randomized Comparison Between the Ultrasound Guided Paravertebral Block and the Ultrasound Guided Proximal Intercostal Nerve Block

After identifying the correct intercostal space, the ultrasound probe will be moved medially to identify the transverse processes, then again laterally from the transverse processes to rest over the ribs so as to obtain the best view of ribs and pleura. A 10cm, 21G needle will be inserted in-plane at the caudal border of the probe. An attempt will be made to keep the needle tip and the target injection position (just under the internal intercostal membrane (IIM)) in view. Correct needle tip placement will be demonstrated by depression of the pleura/endothoracic fascia upon local anesthetic injection and by lack of retrograde spread of LA over the muscles or the ribs. The LA will be injected in 4 cc aliquots after negative aspiration of air, CSF and blood.

After identifying the correct intercostal space, the ultrasound probe will be placed between the adjacent transverse processes in a longitudinal/parasagittal plane measuring 2.5cm from the midline. The best possible view of the transverse processes, the superior costotransverse ligament and pleura will be obtained. An attempt will be made to keep the needle tip and the target injection position (immediately beneath the costotransverse ligament) in view. Correct placement of the needle tip will be demonstrated by depression of the pleura upon injection of local anesthetic and by lack of retrograde spread of LA over the muscles or transverse processes. The LA will be injected in 4 cc aliquots after confirming negative aspiration of air, CSF and blood.