Thoracic Paravertebral Block With Methylene Blue Visual Confirmation for Postoperative Pain After VATS Lobectomy

Thoracic Paravertebral Block With Methylene Blue Visual Confirmation for Postoperative Pain After VATS Lobectomy

Efficacy of Thoracic Paravertebral Block With Methylene Blue Visual Confirmation in the Management of Postoperative Pain After Video-assisted Thoracoscopic Lobectomy

The goal of this study is to compare the efficacy in controlling postoperative pain of paravertebral block (PVB) with methylene blue visual confirmation and thoracic epidural anesthesia (TEA). This is a single center, parallel-group, prospective study. Patients will be randomly assigned in a 1:1 ratio to receive either PVB or TEA. Primary end-point is pain relief measured with Postoperative Numeric Rating Scale. The secondary end-points are time to perform TEA and PVB, total opioid consumption, postoperative outcomes.

The management of postoperative pain in patients undergoing thoracoscopic lobectomy is a fundamental part of the process of recovery. Uncontrolled thoracic pain in the early postoperative period may interfere with the mobilization of the patients, leading to increased morbidity and reduction in the quality of life. Thoracic paravertebral block (PVB) is an effective strategy for controlling postoperative pain after video-assisted thoracoscopic (VATS) lobectomy, but it may be subjected to a high rate of failure due to incorrect identification of the site of local anesthetic injection. Thoracic epidural anesthesia (TEA) is considered a reliable technique for regional thoracic anesthesia, however potential side effects may limit its use. Herein the investigators reported a new technique using methylene blue as a visual confirmation of the correct anesthetic diffusion during PVB. Then, the investigators will compare the efficacy of methylene blue PVB with TEA for the management of postoperative pain in patients undergoing VATS lobectomy. This is a single center, parallel-group, prospective study. Participants will be randomly assigned in a 1:1 ratio to receive either PVB with methylene blue or TEA. All participants will receive postoperatively intravenous acetaminophen as additional analgesics and intravenous tramadol as rescue analgesic. Primary end-point is pain relief measured with Postoperative Numeric Rating Scale at at 1, 12, 24, 48 hours postoperatively. The secondary end-points are: (i) time to perform TEA and PVB, (ii) total opioid consumption, (iii) postoperative outcomes (including complications, chest drainage duration and length of hospital stay).

With the patient sitting, the patient will receive paravertebral block at T4-T5 level before general anesthesia induction

With the patient sitting, the patient will receive thoracic epidural anesthesia at T4-T8 level before general anesthesia induction

The paravertebral space is identified under ultrasound guidance and after negative aspiration a 3 ml test dose of anesthetic is injected. After observing widening of the paravertebral space and anterior pleural displacement to confirm the correct needle positioning, a bolus dose of 20 mL 0.5% ropivacaine with a solution of 1 ml 1% methylene blue and 4 ml of saline will be injected in the paravertebral space. At the start of the surgery, the spread of the solution of anesthetic and methylene blue will be assessed through visualization in thoracoscopy and if necessary the block will be repeated. After the surgery, intravenous acetaminophen will be administered 3 times daily and tramadol 50 mg will be prescribed as rescue analgesic.

The epidural catheter will be placed using the loss of resistance technique, and after ruling out intravenous or intrathecal catheter placement with a negative aspiration test dose, an initial dose of 10 mL 0.25% bupivacaine will be injected. Continuous infusion will be started with with 0.125 % bupivacaine + fentanyl 0.5 mcg/ ml at 6-10 ml/hour will be started based on the patient weight for 48 hours postoperatively. After the surgery, intravenous acetaminophen will be administered 3 times daily and tramadol 50 mg will be prescribed as rescue analgesic.

Change From Baseline in Pain Scores on the Postoperative Numeric Rating Scale in the first 48 hours postoperatively

Pain scores at rest and after cough will be evaluated in the first 48 hours postoperatively using Postoperative Numeric Rating Scale (NRS) ranging from 0 (absence of pain) to 10 (maximum level of pain)

Cumulative dose of intravenous opioids administered as rescue analgesic will be registered during the post-operative period.

Inclusion Criteria: Males and females aged 18 - 85 years old scheduled to undergo thoracoscopic lobectomy for lung cancer standardized three-port anterior thoracoscopic approach Exclusion Criteria: Allergy to any of the drugs used in the study Previous thoracic surgical procedures or lung resection Psychiatric disorders ASA (American Society of Anesthesiologists) Class > III Conversion to thoracotomy Lack of written informed consent Participation to other studies Contraindications to epidural analgesia or paravertebral block

Yeap YL, Wolfe JW, Backfish-White KM, Young JV, Stewart J, Ceppa DP, Moser EAS, Birdas TJ. Randomized Prospective Study Evaluating Single-Injection Paravertebral Block, Paravertebral Catheter, and Thoracic Epidural Catheter for Postoperative Regional Analgesia After Video-Assisted Thoracoscopic Surgery. J Cardiothorac Vasc Anesth. 2020 Jul;34(7):1870-1876. doi: 10.1053/j.jvca.2020.01.036. Epub 2020 Jan 25.

D'Ercole F, Arora H, Kumar PA. Paravertebral Block for Thoracic Surgery. J Cardiothorac Vasc Anesth. 2018 Apr;32(2):915-927. doi: 10.1053/j.jvca.2017.10.003. Epub 2017 Oct 4.

Norum HM, Breivik H. A systematic review of comparative studies indicates that paravertebral block is neither superior nor safer than epidural analgesia for pain after thoracotomy. Scand J Pain. 2010 Jan 1;1(1):12-23. doi: 10.1016/j.sjpain.2009.10.003.

Baidya DK, Khanna P, Maitra S. Analgesic efficacy and safety of thoracic paravertebral and epidural analgesia for thoracic surgery: a systematic review and meta-analysis. Interact Cardiovasc Thorac Surg. 2014 May;18(5):626-35. doi: 10.1093/icvts/ivt551. Epub 2014 Jan 31.

Casati A, Alessandrini P, Nuzzi M, Tosi M, Iotti E, Ampollini L, Bobbio A, Rossini E, Fanelli G. A prospective, randomized, blinded comparison between continuous thoracic paravertebral and epidural infusion of 0.2% ropivacaine after lung resection surgery. Eur J Anaesthesiol. 2006 Dec;23(12):999-1004. doi: 10.1017/S0265021506001104. Epub 2006 Jul 7.

Helms O, Mariano J, Hentz JG, Santelmo N, Falcoz PE, Massard G, Steib A. Intra-operative paravertebral block for postoperative analgesia in thoracotomy patients: a randomized, double-blind, placebo-controlled study. Eur J Cardiothorac Surg. 2011 Oct;40(4):902-6. doi: 10.1016/j.ejcts.2011.01.067. Epub 2011 Mar 5.

Ding X, Jin S, Niu X, Ren H, Fu S, Li Q. A comparison of the analgesia efficacy and side effects of paravertebral compared with epidural blockade for thoracotomy: an updated meta-analysis. PLoS One. 2014 May 5;9(5):e96233. doi: 10.1371/journal.pone.0096233. eCollection 2014.

Marshall K, McLaughlin K. Pain Management in Thoracic Surgery. Thorac Surg Clin. 2020 Aug;30(3):339-346. doi: 10.1016/j.thorsurg.2020.03.001. Epub 2020 Apr 29.