Effectiveness of Surgeon-Performed Paravertebral Block Analgesia for Minimally Invasive Thoracic Surgery: A Randomized Clinical Trial

Abstract

Importance: In minimally invasive thoracic surgery, paravertebral block (PVB) using ultrasound (US)-guided technique is an efficient postoperative analgesia. However, it is an operator-dependent process depending on experience and local resources. Because pain-control failure is highly detrimental, surgeons may consider other locoregional analgesic options.

Objective: To demonstrate the noninferiority of PVB performed by surgeons under video-assisted thoracoscopic surgery (VATS), hereafter referred to as PVB-VATS, as the experimental group compared with PVB performed by anesthesiologists using US-guided technique (PVB-US) as the control group.

Design, setting, and participants: In this single-center, noninferiority, patient-blinded, randomized clinical trial conducted from September 8, 2020, to December 8, 2021, patients older than 18 years who were undergoing a scheduled minimally invasive thoracic surgery with lung resection including video-assisted or robotic approaches were included. Exclusion criteria included scheduled open surgery, any antalgic World Health Organization level greater than 2 before surgery, or a medical history of homolateral thoracic surgery. Patients were randomly assigned (1:1) to an intervention group after general anesthesia. They received single-injection PVB before the first incision was made in the control group (PVB-US) or after 1 incision was made under thoracoscopic vision in the experimental group (PVB-VATS).

Interventions: PVB-VATS or PVB-US.

Main outcomes and measures: The primary end point was mean 48-hour post-PVB opioid consumption considering a noninferiority range of less than 7.5 mg of opioid consumption between groups. Secondary outcomes included time of anesthesia, surgery, and operating room occupancy; 48-hour pain visual analog scale score at rest and while coughing; and 30-day postoperative complications.

Results: A total of 196 patients were randomly assigned to intervention groups: 98 in the PVB-VATS group (mean [SD] age, 64.6 [9.5] years; 53 female [54.1%]) and 98 in the PVB-US group (mean [SD] age, 65.8 [11.5] years; 62 male [63.3%]). The mean (SD) of 48-hour opioid consumption in the PVB-VATS group (33.9 [19.8] mg; 95% CI, 30.0-37.9 mg) was noninferior to that measured in the PVB-US group (28.5 [18.2] mg; 95% CI, 24.8-32.2 mg; difference: -5.4 mg; 95% CI, -∞ to -0.93; noninferiority Welsh test, P ≤ .001). Pain score at rest and while coughing after surgery, overall time, and postoperative complications did not differ between groups.

Conclusions and relevance: PVB placed by a surgeon during thoracoscopy was noninferior to PVB placed by an anesthesiologist using ultrasonography before incision in terms of opioid consumption during the first 48 hours.

Trial registration: ClinicalTrials.gov Identifier: NCT04579276.

Figure 1.. Consolidated Standards of Reporting Trials (CONSORT) Flowchart

ITT indicates intention to treat; PVB, paravertebral block.

Figure 2.. Primary Outcome: Opioid Consumption Within the First 48 Hours After Paravertebral Block (PVB)

Violin plot showing probability density and indicating mean with SD. The mean (SD) of 48-hour opioid consumption in PVB–video-assisted thoracoscopic surgery (VATS) group (33.9 [19.8] mg; 95% CI, 30.0-37.9 mg) was noninferior to that measured in the PVB–ultrasound (US) group (28.5 [18.2] mg; 95% CI, 24.8-32.2 mg; difference, 5.4 mg; 95% CI, 0-0.93 mg; noninferiority Welsh test P ≤ .001).

Figure 3.. Postoperative Pain Through the Visual Analog Scale (VAS) Score

Postoperative pain through the VAS score at rest (A) and while coughing (B) at 4, 6, 12, 24, and 48 hours after video-assisted paravertebral block (PVB) vs ultrasound-guided PVB.