Reducing Persistent Postoperative Pain and Disability 1 Year After Breast Cancer Surgery: A Randomized, Controlled Trial Comparing Thoracic Paravertebral Block to Local Anesthetic Infiltration

Abstract

BackgroundThe objective of this study was to compare the effect of thoracic paravertebral block (TPVB) and local anesthetic (LA) on persistent postoperative pain (PPP) 1 year following breast cancer surgery. Secondary objectives were to compare the effect on arm morbidity and quality of life.MethodsWomen scheduled for elective breast cancer surgery were randomly assigned to either TPVB or LA followed by general anesthesia. An NRS value of >3 at rest or with movement 1 year following surgery defined PPP. Blinded interim analysis suggested rates of PPP much lower than anticipated, making detection of the specified 20 % absolute reduction in the primary outcome impossible. Recruitment was stopped, and all enrolled patients were followed to 1 year.ResultsA total of 145 participants were recruited; 65 were randomized to TPVB and 64 to LA. Groups were similar with respect to demographic and treatment characteristics. Only 9 patients (8 %; 95 % CI 4–14 %) met criteria for PPP 1 year following surgery; 5 were in the TPVB and 4 in the LA group. Brief Pain Inventory severity and interference scores were low in both groups. Arm morbidity and quality of life were similar in both groups. The 9 patients with PPP reported shoulder-arm morbidity and reduced quality of life.ConclusionsThis study reports a low incidence of chronic pain 1 year following major breast cancer surgery. Although PPP was uncommon at 1 year, it had a large impact on the affected patients’ arm morbidity and quality of life.

An Evidence-Based Review of the Efficacy of Perioperative Analgesic Techniques for Breast Cancer-Related Surgery

“…And three RCTs reported that a 48-72-hour continuous paravertebral nerve block decreased pain (and in some cases pain-related emotional and physical disability) both during the local anesthetic perineural infusion as well as 2.5, 6, and 12 months following surgery [103,110,200]. A single RCT comparing single-injection paravertebral nerve blocks and wound infiltration failed to detect a difference between treatments at 12 months, and unfortunately did not report any pain data prior to the 12-month time point [201]. Of note, this investigation was terminated early due to futility because both treatment groups experienced such a low incidence of chronic pain (8%) that detecting the prospectively-defined minimal difference of 20% was impossible.…”

Comparing the DN4 tool with the IASP grading system for chronic neuropathic pain screening after breast tumor resection with and without paravertebral blocks

“…Specifically, thoracic paravertebral blocks (PVBs) promise a protective effect against PPP 5 ;but relevant trials 21,28,44,45,49,50,56 were decidedly mixed: 4 identified a protective effect, 28,44,45,49 whereas 3 found no benefit. 21,50,56 Underlying these conflicting results are methodological limitations that discount the CNP contribution to PPP and obvious PPP screening discrepancies. Investigators have relied on subjective reporting of PPP presence 45,50,56 or severity 21,28,44,49 excluding CNP screening tools 21,28,44,45,49,50,56 and sensory testing.…”

“…Investigators have relied on subjective reporting of PPP presence 45,50,56 or severity 21,28,44,49 excluding CNP screening tools 21,28,44,45,49,50,56 and sensory testing. 21,44,45,50 Therefore, the likelihood that investigating potential PVB protective effect has been biased by failure to incorporate CNP screening is arguable.…”

Difficult airway research options and ethical consensus – a reply

“…There is no criterion as to the number that should represent the group, and we suspect that this is the crux of this criticism. In fact, it is also a matter of debate as to whether consensus, as one of our more entrenched heuristics, is actually the best way to make decisions [3,4] and the more people involved in this process the less useful it is [5]. In any event, while we wrote these guidelines, members of the Anaesthesia editorial board and an external expert in the field also reviewed them.…”

“…Firstly, the meta-analysis included only randomised controlled trials comparing the effect of PVB to sham or no block on PPP. However, Ilfeld et al [4] compared single-shot and continuous PVB, and reported that 'all patients received a single injection of long-acting local anesthetic (15 ml of ropivacaine 0.5%, with epinephrine 5 lg.ml Secondly, the trial by Chui et al [5], who compared PVB with local infiltration analgesia, also lacked a control group, local infiltration itself being an effective intervention in preventing chronic pain following breast cancer surgery [6][7][8], and so should have also been excluded from the meta-analysis.…”