Comparison of Paravertebral Versus Epidural Block for Post-thoracotomy Pain Control

N/ANot Yet RecruitingNCT07763249

Hospital de Clinicas de Porto Alegre80 enrolled

Overview

This is a randomized, assessor-blinded, non-inferiority clinical trial comparing continuous thoracic paravertebral block (BPV) versus continuous thoracic epidural block (BPD) for postoperative pain control in adult patients undergoing elective open thoracotomy with one-lung ventilation. The primary outcome is the mean pain intensity at rest assessed by the Numeric Verbal Scale (NVS 0-10) during the first 48 hours after surgery. A total of 80 participants will be randomized 1:1 at Hospital de Clínicas de Porto Alegre, Brazil. The study aims to determine whether BPV provides non-inferior analgesia compared to BPD, with a potential advantage of less hemodynamic interference and better postoperative mobilization.

This is a randomized, assessor-blinded, non-inferiority clinical trial conducted at Hospital de Clínicas de Porto Alegre, Brazil, in adult patients undergoing elective open thoracotomy with one-lung ventilation. The objective is to compare the analgesic efficacy of continuous thoracic paravertebral block (BPV) versus continuous thoracic epidural block (BPD) for postoperative pain control during the first 48 hours after surgery. Patients will be randomly allocated to two groups (40 per group). In the BPV group, the paravertebral catheter is inserted at the end of surgery under direct thoracoscopic vision (without ultrasound), using a bolus of ropivacaine 0.375% (15 mL fractionated) followed by continuous infusion of bupivacaine 0.125% at 0.10 mL/kg/h. In the BPD group, the epidural catheter is inserted at the beginning of surgery using the loss-of-resistance technique with the same bolus and infusion regimen. The target dermatomal level is T5-T7 (or T5-T9). The primary outcome is the mean pain score at rest measured by the Numeric Verbal Scale (NVS 0-10) at 6, 12, 24, and 48 hours postoperatively. Secondary outcomes include pain on movement, total opioid consumption (converted to morphine equivalents), block-related complications (hypotension, urinary retention, technical failure, motor block), clinically significant pulmonary and cardiovascular complications, length of hospital stay, and patient satisfaction with analgesia. Randomization is centralized using variable block sizes and sealed numbered envelopes. Outcome assessors are blinded to allocation. Both groups receive identical multimodal analgesia and a standardized rescue protocol. The sample size of 80 participants was calculated to demonstrate non-inferiority with a margin of 1 point on the NVS (expected SD = 1.5; 80% power; one-sided α = 0.025). The study was approved by the Research Ethics Committee of HCPA (Opinion No. 8.544.882; CAAE 98467026.8.0000.5327) and will be conducted in accordance with the Declaration of Helsinki and current Brazilian regulations.

Interventions

Continuous Thoracic Paravertebral BlockPROCEDURE

Participants randomized to the continuous thoracic paravertebral block (BPV) group. At the end of surgery and before chest tube placement, a paravertebral catheter is inserted under direct thoracoscopic vision (without ultrasound) using a Tuohy needle. A bolus of ropivacaine 0.375% (15 mL, fractionated) is administered, followed by continuous infusion of bupivacaine 0.125% at 0.10 mL/kg/h. The target level is T5-T7 (or T5-T9). The catheter remains in place for at least 48 hours postoperatively.

Continuous Thoracic Epidural BlockPROCEDURE

Participants randomized to the continuous thoracic epidural block (BPD) group. At the beginning of surgery, an epidural catheter is inserted at the thoracic level using the loss-of-resistance technique. A bolus of ropivacaine 0.375% (15 mL, fractionated) is administered, followed by continuous infusion of bupivacaine 0.125% at 0.10 mL/kg/h. The target level is T5-T7 (or T5-T9). The catheter remains in place for at least 48 hours postoperatively.

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patients aged 18 years or older; * Elective thoracic surgeries requiring open thoracotomy; * American Society of Anesthesiologists (ASA) physical status I to III. Exclusion Criteria: * Pregnancy or lactation; * Urgent or emergency surgeries; * Contraindications to epidural catheter insertion or neuraxial anesthesia; * Infection at the proposed block site; * Patient refusal to undergo the study blocks; * Video-assisted thoracic surgeries; * Anticipated need for invasive mechanical ventilation in the postoperative period; * Chronic opioid use (daily use for more than 3 months of ≥10 mg oral morphine equivalent); * Severe vertebral deformities or previous thoracic spine surgery that prevent safe performance of the blocks; * Known allergy to local anesthetics, opioids, or study medications; * Body mass index \> 35 kg/m²; * Advanced liver or kidney failure (Child-Pugh C or estimated glomerular filtration rate \< 50 mL/min/1.73 m²); * Severe cognitive impairment that prevents understanding of instructions or pain assessment.

Outcomes

Primary Outcomes

Mean pain intensity at rest during the first 48 hours after surgery

Mean of the pain scores at rest measured by the Numeric Verbal Scale (NVS 0-10) at 6, 12, 24, and 48 hours postoperatively. This composite measure is the primary endpoint for the non-inferiority comparison between continuous thoracic paravertebral block and continuous thoracic epidural block.

Time frame: 6, 12, 24, and 48 hours after surgery

Secondary Outcomes

Pain on movement

Pain intensity during movement (e.g., coughing, sitting, or walking) assessed by Numeric Verbal Scale (0-10) at 6, 12, 24, and 48 hours postoperatively.

Time frame: 6, 12, 24, and 48 hours after surgery

Total opioid consumption in the first 48 hours

Total opioid consumption (converted to intravenous morphine equivalents in mg) from the end of surgery until 48 hours postoperatively.

Time frame: 0 to 48 hours after surgery

Block-related complications

Incidence of complications related to the regional blocks, including hypotension (systolic BP \< 100 mmHg or \>20% drop from baseline), urinary retention requiring catheterization, motor block (modified Bromage scale), and technical failure of the block.

Time frame: During the first 48 hours after surgery

Clinically significant pulmonary and cardiovascular complications

Incidence of clinically significant pulmonary complications (e.g., atelectasis requiring intervention, pneumonia) and cardiovascular complications (e.g., arrhythmias requiring treatment, ischemic events) in the first 72 hours after surgery.

Time frame: Up to 72 hours after surgery

Length of hospital stay

Total number of days from surgery until hospital discharge.

Time frame: From surgery until hospital discharge (assessed up to 30 days)

Patient satisfaction with analgesia

Patient satisfaction with postoperative pain control assessed by a 5-point Likert scale (1 = very dissatisfied to 5 = very satisfied) at 48 hours after surgery.

Time frame: 48 hours after surgery