Preoperative Paravertebral Block and Chronic Pain after Breast Cancer Surgery: A Double-blind Randomized Trial.

BACKGROUND: The effectiveness of paravertebral block in preventing chronic pain after breast surgery remains controversial. The primary hypothesis of this study was that paravertebral block reduces the incidence of chronic pain 3 months after breast cancer surgery. METHODS: In this prospective, multicenter, randomized, double-blind, parallel-group, placebo-controlled study, 380 women undergoing partial or complete mastectomy with or without lymph node dissection were randomized to receive preoperative paravertebral block with either 0.35 ml/kg 0.75% ropivacaine (paravertebral group) or saline (control group). Systemic multimodal analgesia was administered in both groups. The primary endpoint was the incidence of chronic pain with a visual analogue scale (VAS) score greater than or equal to 3 out of 10, 3 months after surgery. The secondary outcomes were acute pain, analgesic consumption, nausea and vomiting, chronic pain at 6 and 12 months, neuropathic pain, pain interference, anxiety, and depression. RESULTS: Overall, 178 patients received ropivacaine, and 174 received saline. At 3 months, chronic pain was reported in 93 of 178 (52.2%) and 83 of 174 (47.7%) patients in the paravertebral and control groups, respectively (odds ratio, 1.20 [95% CI, 0.79 to 1.82], P = 0.394). At 6 and 12 months, chronic pain occurred in 104 of 178 (58.4%) versus 79 of 174 (45.4%) and 105 of 178 (59.0%) versus 93 of 174 (53.4%) patients in the paravertebral and control groups, respectively. Greater acute postoperative pain was observed in the control group 0 to 2 h (area under the receiver operating characteristics curve at rest, 4.3 ± 2.8 vs. 2.9 ± 2.8 VAS score units × hours, P < 0.001) and when maximal in this interval (3.8 ± 2.1 vs. 2.5 ± 2.5, P < 0.001) but not during any other interval. Postoperative morphine use was 73% less in the paravertebral group (odds ratio, 0.272 [95% CI, 0.171 to 0.429]; P < 0.001). CONCLUSIONS: Paravertebral block did not reduce the incidence of chronic pain after breast surgery. Paravertebral block did result in less immediate postoperative pain, but there were no other significant differences in postoperative outcomes.

Pupillary Reflex for Evaluation of Thoracic Paravertebral Block: A Prospective Observational Feasibility Study.

BACKGROUND: Although thoracic paravertebral block (TPVB) is recommended in major breast surgery, there is no gold standard to assess the success of TPVB. Pupillary dilation reflex (PDR) is the variation of the pupillary diameter after a noxious stimulus. The objective was to evaluate the feasibility of recording the PDR to assess analgesia in an anesthetized thoracic dermatome after TPVB. METHODS: This prospective, observational, single-center study included 32 patients requiring breast surgery under general anesthesia and TPVB. TPVB was performed before surgery under ultrasound guidance with 20 mL of 0.75% ropivacaine. At the end of the surgery, remifentanil was stopped and the PDR was recorded after a 5-second tetanic stimulation (60 mA, 100 Hz) applied to the anterior chest wall. The PDR was defined as the maximal increase in pupil diameter after a standardized noxious stimulus, expressed as a percentage of the initial pupil diameter. The PDR was recorded twice in the same eye for each patient after a stimulus on both the TPVB and the control sides. Postoperative pain scores were recorded in a postanesthesia care unit. The primary outcome was the difference between the PDR on the TPVB and the control sides. RESULTS: The median (interquartile range) PDR was 9% (4%-13%) on the TPVB side and 41% (27%-66%) on the control side. There was a significant difference in the PDR between the TPVB and the control sides with a Hodges-Lehmann estimate of absolute difference of 37% points (95% confidence interval, 25-52, P < .001). Median postoperative pain scores (interquartile range) in the postanesthesia care unit were 1 (0-3) at rest and 1 (0-3) during mobilization, respectively. There was a linear correlation between maximal postoperative pain scores and the PDR on the TPVB side with a Pearson's correlation coefficient r = 0.40 (95% confidence interval, 0.06-0.66, P = .02). No correlation was found between the number of blocked dermatomes and maximal postoperative pain scores (P = .06) or between the number of blocked dermatomes and the PDR on the TPVB side (P = .15). CONCLUSIONS: This proof-of-concept trial suggests that the effect of TPVB could be monitored by measuring the PDR after anterior chest wall stimulation in the dermatome of interest.

General anaesthetic agents do not influence persistent pain after breast cancer surgery: A prospective nationwide cohort study.

BACKGROUND: It has recently been suggested that propofol exerts a protective effect on the occurrence of persistent pain after breast cancer surgery. We analysed data from a subcohort taken from a multicentre study to validate this information. OBJECTIVE: The objective of this article is to study the role of the agent used for maintenance of general anaesthesia on the occurrence of persistent pain, with adjustment for multiple pre and peri-operative variables using the generalised linear model. DESIGN: A prospective cohort study. SETTING: Four French university hospitals. PATIENTS: Three hundred and twenty-eight and 362 patients with full dataset, depending on the studied outcome. INTERVENTION: Questionnaires sent at the third and the sixth month after surgery. MAIN OUTCOME MEASURES: The risk of persistent postsurgical neuropathic pain (defined by the DN4 questionnaire) within 6 months after surgery, and the intensity of persistent pain at the sixth month. RESULTS: Axillary lymph node harvesting and previous history of peripheral neuropathy were independent risk factors of persistent postsurgical neuropathic pain, although older age was protective. The same independent risk factors, but not age, explained the intensity of persistent postsurgical pain at the sixth month after surgery. We did not find any effect of the general anaesthetic, whether halogenated agent or propofol, using either unadjusted or adjusted analyses based on covariates or propensity score. CONCLUSION: There does not appear to be a role for the anaesthetic protocol in the occurrence of persistent postsurgical pain. Other already well established hypotheses were confirmed. TRIAL REGISTRATION: ClinicalTrials.gov (ref. NCT00812734).

A double-blind randomized trial of wound and intercostal space infiltration with ropivacaine during breast cancer surgery: effects on chronic postoperative pain.

BACKGROUND: The efficacy of local anesthetic wound infiltration for the treatment of acute and chronic postoperative pain is controversial and there are no detailed studies. The primary objective of this study was to evaluate the influence of ropivacaine wound infiltration on chronic pain after breast surgery. METHODS: In this prospective, randomized, double-blind, parallel-group, placebo-controlled study, 236 patients scheduled for breast cancer surgery were randomized (1:1) to receive ropivacaine or placebo infiltration of the wound, the second and third intercostal spaces and the humeral insertion of major pectoralis. Acute pain, analgesic consumption, nausea and vomiting were assessed every 30 min for 2 h in the postanesthesia care unit and every 6 h for 48 h. Chronic pain was evaluated 3 months, 6 months, and 1 yr after surgery by the brief pain inventory, hospital anxiety and depression, and neuropathic pain questionnaires. RESULTS: Ropivacaine wound infiltration significantly decreased immediate postoperative pain for the first 90 min, but did not decrease chronic pain at 3 months (primary endpoint), or at 6 and 12 months postoperatively. At 3 months, the incidence of chronic pain was 33% and 27% (P = 0.37) in the ropivacaine and placebo groups, respectively. During follow-up, brief pain inventory, neuropathic pain, and anxiety increased over time in both groups (P < 0.001) while depression remained stable. No complications occurred. CONCLUSION: This multicenter, prospective study shows that ropivacaine wound infiltration after breast cancer surgery decreased immediate postoperative pain but did not decrease chronic pain at 3, 6, and 12 months postoperatively.

High-flow nasal oxygen for suspension laryngoscopy: a multicenter open-label study.

In this study, we aimed to assess the efficacy of high-flow nasal oxygen (HFNO) to maintain blood peripheral oxygen saturation (SpO2) in patients undergoing suspension laryngoscopy under general anesthesia. Adult patients were included in this bicenter study. After face-mask oxygenation, HFNO at a flow rate of 70 L min-1 and fraction of inspired oxygen 100% was initiated at loss of consciousness. At the end of HFNO, blood gas analysis was performed. Of the 29 included patients, five (17.2%; 95% confidence interval [CI]: 7.6-34.5) presented SpO2 <95% during the first 15 minutes of the procedure and eight patients (27.6%; 95% CI: 14.7-45.7) presented SpO2 <95% throughout the procedure. Six patients (20.7%; 95% CI: 9.8-38.4) required rescue jet ventilation. Median apnea time before SpO2 <95% was 13.5 (interquartile range [IQR]: 10-17.7) minutes. Arterial carbon dioxide tension at the end of the procedure or at the time of study discontinuation was 9.73 (IQR: 8.8-10.9) kPa and was higher than 8 kPa in 88.9% (95% CI: 71.9-96.1) of patients. HFNO was associated with a relatively high incidence of suboptimal oxygen saturation and hypercapnia during suspension laryngoscopy under general anesthesia and may not be considered the reference technique.

Erector spinae plane block versus thoracic paravertebral block for the prevention of acute postsurgical pain in breast cancer surgery: A prospective observational study compared with a propensity score-matched historical cohort.

BACKGROUND: Preventing acute postsurgical pain (PSP) following breast cancer surgery is a major issue. Thoracic paravertebral block (TPVB) has been widely studied for this indication. Erector spinae plane block (ESPB) has been assumed to be effective. We aimed to compare the efficacy and safety of ESPB over TPVB in preventing acute PSP. METHODS: In this prospective observational study, 120 patients admitted for unilateral major oncologic breast surgery received T2/T3 ESPB (ropivacaine 0.75%, 0.35 ml.kg-1), and 102 were analysed. Then, the ESPB cohort was compared to a TPVB cohort from the experimental arm of a randomized controlled study with the same protocol (NCT02408393) using propensity score matching analysis. The primary outcome was the need for morphine consumption in the PACU. Secondary outcomes were the morphine total dose, the incidence of ESPB and TPVB complications, and discontinuous visual analogue scale measurement trends at rest and at mobilization in the 24 hours after surgery. RESULTS: A total of 102 patients completed the study between December 2018 and August 2019. Propensity score matching formed 94 matched pairs. The proportion of morphine titration in the PACU was higher in the ESPB group than in the TPVB group (74.5% vs. 41.5%, p<0.001), with a between-group difference of 33.0% (95% CI [19.3%, 46.7%]). No ESPB-related complications were observed. CONCLUSION: ESPB is less effective in preventing morphine consumption in the PACU than TPVB. Our findings do not support the use of ESPB as the first-line regional anaesthesia for major breast cancer surgery. Randomized trials comparing ESPB and TPVB are needed.

Postoperative pain scores and opioid consumption in opioid-dependent patients with cancer after intraoperative remifentanil analgesia: A prospective case-controlled study.

BACKGROUND: Opioid dependency is becoming increasingly common among surgical patients with cancer, and can lead to inadequate pain relief during the initial postoperative period. No guidelines are currently available for the management of perioperative and postoperative morphine administration in these patients. As a first approach, the authors assessed the opioid requirements of these patients during the early postoperative period. METHODS: A group of 35 consecutive surgical patients with cancer on opioid therapy (opioid-dependent group) for cancer pain were compared to a matched group of 44 surgical opioid-naive patients (control group). All patients underwent major head and neck or abdominal surgery. The following parameters were recorded and compared: preoperative and postoperative morphine consumption, patient-controlled analgesia records and Visual Analog Scale scores, intraoperative remifentanil and desflurane consumption, Bispectral Index monitoring values, heart rate, and blood pressure. RESULTS: Remifentanil requirements were significantly higher (1.4-fold) in the opioid-dependent group compared to the control group (p < 0.05). On postoperative day 1, morphine requirements were significantly higher in the opioid-dependent group (2.3-fold) compared to the control group (p < 0.05). Baseline heart rate was significantly higher in the opioid-dependent group and this difference remained significant during surgery, no significant difference in blood pressure was observed between the two groups. CONCLUSION: This study shows a 40 percent increase of intraoperative remifentanil requirements in opioid-dependent patients during cancer surgery. Morphine requirements during the postoperative period were increased by up to 140 percent.

Effect of Alexithymia and Emotional Repression on Postsurgical Pain in Women With Breast Cancer: A Prospective Longitudinal 12-Month Study.

UNLABELLED: Alexithymia, the inability to identify and express emotions, and emotional repression, a defensive mechanism used to avoid unpleasant emotional experience, have been associated with chronic pain and medical illness including breast cancer, but whether these constructs might predict pain after breast cancer surgery has not been assessed. The present study was conducted to assess the predictive value of alexithymia and emotional repression in postoperative pain. Anxiety, depression, catastrophizing, and psychological adjustment were also assessed. Data were collected before surgery, and then at 2 days and 2, 3, 6, and 12 months after surgery. We included 100 pain-free women, 96% of whom were followed for up to 12 months. Separate multivariate analyses identified anxiety as a significant predictor of postsurgical pain at 3 months, alexithymia at 3, 6, and 12 months, and body image and catastrophizing predicted acute or subacute pain at 2 months. In contrast, emotional repression was not predictive of pain. The generalized estimating equation approach was used and identified alexithymia as the only significant predictor of pain during the 12-month period after surgery. Alexithymia, but not emotional repression, predicted the development of persistent pain after breast surgery independently of anxiety and depression. Thus, alexithymia might be involved in mechanisms of pain chronicity. PERSPECTIVE: This prospective study, conducted in women with breast cancer surgery, showed that alexithymia but not emotional repression predicted postsurgical pain. These results highlight the role of dysfunction in emotional processing in the development of postsurgical pain.