A Randomized Controlled Trial Comparing Analgesic Efficacies of an Ultrasound-Guided Approach with and without a Combined Pressure Measurement Technique for Thoracic Paravertebral Blocks After Open Thoracotomy

PURPOSE: Ultrasound-guided thoracic paravertebral block (TPVB) is an established means for providing postoperative analgesia in thoracic surgery. However, there are conflicting results regarding the efficacy of post-thoracotomy pain management of ultrasound-guided TPVB when compared with that using traditional landmark approach. We therefore conducted a comparative study to evaluate the analgesic efficacy of TPVB when pressure measurement during needle advancement is combined with an ultrasound-guided approach. PATIENTS AND METHODS: The patients scheduled for lobectomy through thoracotomy were randomly allocated to receive either the ultrasound-guided approach only group (U group) or the ultrasound-guided approach combined with pressure measurement group (UP group) (n = 36 per group). Before thoracic muscle closure, 0.375% ropivacaine (20 mL) was administered as a bolus, followed by a continuous infusion of 0.2% ropivacaine (0.1 mL/kg/hr) in both groups. Postoperative pain was assessed using the visual analogue scale (VAS) pain score while resting and coughing. Local anesthetics and pethidine usage and sensory block area were also evaluated. RESULTS: The UP group showed significantly lower VAS scores, local anesthetics and pethidine usage, and a wider sensory block area than the U group. CONCLUSION: A combined technique with ultrasound guidance and pressure measurement provided a superior analgesic effect over that of an ultrasound-guided approach alone for the management of post-thoracotomy pain.