Thoracic Paravertebral Nerve Block to Treat Postthoracotomy Pain
Epidural anesthesia, although considered the gold standard for postthoracotomy pain treatment, is contraindicated in certain patients.
According to a retrospective study by researchers at the Shizuoka Cancer Center in Japan, continuous thoracic paravertebral nerve block (PVB) is similarly effective as epidural anesthesia (EDA) for the management of postthoracotomy pain.1
Although EDA is considered the gold standard for postthoracotomy pain treatment, it is contraindicated in certain patients, such as those taking antiplatelet or anticoagulant medications. There is a need for alternative approaches, particularly after lung resection, to prevent pulmonary complications.
Previous research has shown that thoracic PVB and EDA provide a similar degree of pain relief, and that thoracic PVB is associated with fewer adverse effects, although other results indicate lower effectiveness of PVB vs EDA.2-4 The investigators note that the catheter insertion technique likely accounts for these mixed findings.
"The efficacy of thoracic PVB depends on accurate catheter placement and on the potency, concentration, and volume of local anesthetic," they wrote. Percutaneous catheter placement "offers better pain control, as the extrapleural space is closed above the catheter tip, allowing no leakage into the pleural space and facilitating easy coverage of more than one intercostal space."5 This was the technique that was applied to patients in the present investigation.
The researchers retrospectively compared outcomes of patients who had received PVB (n = 56) vs EDA (n = 112) while undergoing thoracotomy for lung resection at their center. They found no significant difference between Numeric Rating Scale scores on postoperative day 2 in the PVB group compared with the EDA group (3.25 ± 1.80 and 3.56 ± 2.05, respectively; P =.334). In addition, there was no significant difference in the duration of regional anesthesia between the 2 groups (P =.477), and fewer patients in the PVB group experienced the adverse effect of urinary retention (P =.03).
These results demonstrate the noninferiority of thoracic PVB compared with EDA in managing pain after thoracotomy. "The main purpose of our research was to show that PVB is as effective as and safer than EDA, and we think we reached that goal in this study," coauthor Yoshikane Yamauchi, MD, PhD, from the Division of General Thoracic Surgery, Shizuoka Cancer Center, Japan, told Clinical Pain Advisor. "The next step is to elucidate the mechanism that causes postthoracotomy pain. If the mechanism is clarified, the blockade of this mechanism will show a synergetic effect with PVB."
In patients undergoing thoracotomy with lung resection, continuous thoracic PVB was shown to be as effective as EDA for postoperative pain treatment. This approach may be a viable alternative in patients for whom EDA is contraindicated, such as those taking antiplatelet or anticoagulant medications.
The limitations of this investigation, including sampling, selection, and recall bias, are typical of retrospective case-control studies.
- Yamauchi Y, Isaka M, Ando K, et al. Continuous paravertebral block using a thoracoscopic catheter-insertion technique for postoperative pain after thoracotomy: a retrospective case-control study [published online January 25, 2017]. J Cardiothorac Surg. doi: 10.1186/s13019-017-0566-8
- 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;9(5):e96233. doi: 10.1371/journal.pone.0096233
- Davies RG, Myles PS, Graham JM. A comparison of the analgesic efficacy and side-effects of paravertebral vs epidural blockade for thoracotomy--a systematic review and meta-analysis of randomized trials. Br J Anaesth. 2006;96(4):418-426. doi: 10.1093/bja/ael020
- Helms O, Mariano J, Hentz JG, et al. Intra-operative paravertebral block for postoperative analgesia in thoracotomy patients: a randomized, double-blind, placebo-controlled study. Eur J Cardiothorac Surg. 2011;40(4):902-906. doi: 10.1016/j.ejcts.2011.01.067
- Fibla JJ, Molins L, Mier JM, Sierra A, Carranza D, Vidal G. The efficacy of paravertebral block using a catheter technique for postoperative analgesia in thoracoscopic surgery: a randomized trial. Eur J Cardiothorac Surg. 2011;40(4):907-911. doi: 10.1016/j.ejcts.2010.12.043