Update zur präemptiven Analgesie: Möglichkeiten und Grenzen der präoperativen Schmerztherapie

The Effect of Ketamine on Acute and Chronic Wound Pain in Patients Undergoing Breast Surgery: A Meta-Analysis and Systematic Review

INTRODUCTION

Perioperative use of ketamine has been discussed widely in many kinds of surgery. The aim of our study was to evaluate the short-term and long-term benefits and safety of ketamine after breast surgery.

METHOD

We performed a quantitative systematic review. We included randomized controlled trials that compared intravenous administration of ketamine to a placebo control group, or compared bupivacaine in combination with ketamine to bupivacaine alone in thoracic paravertebral blocks or pectoral blocks among patients undergoing breast surgery. The primary outcome was postoperative pain intensity. Secondary outcomes included cumulative opioid consumption during the 0- to 24-hour postoperative period, the effect on postmastectomy pain syndrome, the effect on postoperative depression, and the adverse events associated with the use of ketamine.

RESULTS

Thirteen randomized controlled trials with 1,182 patients were included for analysis. Compared with placebo, intravenous ketamine was effective in reducing wound pain intensity during the first 6 hours after surgery (weighted mean difference [WMD] -0.83; 95% confidence interval [CI] -1.65, -0.01; P = 0.048) and during the first 24 hours after surgery (WMD -0.65; 95% CI -0.95, -0.35; P < 0.001), and in decreasing opioid consumption (WMD -4.14; 95% CI -8.00, -0.29; P = 0.035) during the first 24 hours after surgery, without increasing the risks for gastrointestinal and central nervous system adverse events. Adding ketamine to bupivacaine in thoracic paravertebral blocks was also effective in reducing postoperative wound pain during the first 6 hours after surgery (WMD -0.59; 95% CI, -1.06, -0.12; P = 0.014) and during the first 24 hours after surgery (WMD -0.90; 95% CI -1.27, -0.53; P < 0.001), and in decreasing opioid consumption (WMD - 4.59; 95% CI -5.76, -3.42; P < 0.001) during the first 24 hours after surgery. Perioperative use of ketamine was associated with improved postoperative depression symptoms (standardized mean difference -0.80; 95% CI - 1.34, -0.27; P = 0.003) and less incidence of postmastectomy pain syndrome (relative risk 0.79; 95% CI 0.63, 0.99; P = 0.043).

CONCLUSION

Ketamine is an effective and safe multimodal analgesic in patients undergoing breast surgery, administered both intravenously and when added to bupivacaine in paravertebral blocks. In addition, ketamine showed a long-term benefit for preventing postoperative depression and postmastectomy pain syndrome.

The preemptive analgesia of pre-electroacupuncture in rats with formalin-induced acute inflammatory pain

Background

Electroacupuncture has been elicited to effectively alleviate the pain sensation. Preemptive analgesic effect of pre-electroacupuncture has also been suggested in recent studies, while the underlying analgesic mechanism of pre-electroacupuncture requires further investigation. This study aimed to explore the preemptive analgesia of pre-electroacupuncture in formalin-induced acute inflammatory pain model.

Methods

Forty rats were randomly divided into control, model, pre-electroacupuncture, and post-electroacupuncture group. Inflammatory pain model was induced via injecting 50 µl 5% formalin into the plantar surface of right hind paw, while the equal volume of saline injection in the control group. Rats in the pre-electroacupuncture group were treated with electroacupuncture at ipsilateral Zusanli (ST36) and Weizhong (BL40) acupoints (2 Hz, 1 mA) for 30 min before formalin injection, while received the same electroacupuncture treatment immediately after formalin injection in the post-electroacupuncture group. Flinching number and licking time were recorded during 60 min after formalin injection. Immunofluorescence and Western blot were used to detect the expression of ionized calcium binding adapter molecule 1 (Iba1) and c-fos in spinal cord. Moreover, enzyme-linked immunosorbent assay was applied to measure the secretion of IL-6, IFN-γ, IL-4, substance P, and calcitonin gene-related peptide in spinal cord.

Results

Paw flinching and licking were obviously induced by formalin injection. Iba1, c-fos, proinflammatory cytokines (IL-6 and IFN-γ), and pain neurotransmitters (substance P and calcitonin gene-related peptide) were dramatically increased in the L4-5 spinal cord after formalin injection, while anti-inflammatory cytokine IL-4 was decreased. Pre-electroacupuncture and post-electroacupuncture administration significantly attenuated formalin-induced nociceptive effects, spinal microglia and neurons activation, proinflammatory cytokines and pain neurotransmitters upregulation, and upregulated the anti-inflammatory cytokine. Furthermore, these effects of pre-electroacupuncture were more significant than that of post-electroacupuncture.

Conclusions

This study illustrates the potential therapeutic effect of pre-electroacupuncture against acute inflammatory pain and reveals the mechanism underlying pre-electroacupuncture mediated analgesia, thus providing a novel preemptive analgesic treatment.

Non-Opioid Perioperative Pain Strategies for the Clinician: A Narrative Review

Alternative and non-opioid options for pain management are necessary in perioperative patient care. Opioids are no longer touted as cure-all medications, and furthermore, there have been tremendous advances in alternative therapies such as in interventional pain, physical therapy, exercise, and nutritional counseling that have proven benefits to combat pain. The center for disease control now strongly recommends the use of multimodal analgesia and multidisciplinary approaches based on the individual needs of patients: personalized medicine. In this manuscript, the specifics of non-opioid pharmacological and non-pharmacological analgesic approaches will be discussed as well as their possible indications and uses to reduce the need for excessive use of opioids for adequate pain control.

Impact of preoperative pectoralis plane nerve blocks for mastectomy on perioperative opioid consumption: a retrospective study

Aim: To compare perioperative opioid consumption for patients undergoing mastectomy surgery with or without pectoralis nerve (PECS) plane blocks. Patients & methods: Retrospective study evaluating 152 adult females with mastectomies. Demographics, postanesthesia care unit stay duration and opioid consumption data at three time points were collected and analyzed for statistical significance. Results: 98 patients were included in the PECS block group, 54 patients were in the general anesthesia only group. Age and BMI were comparable. Total perioperative intravenous opioid consumption was less in the PECS block group (50.88 mg) compared with the general anesthesia only group (67.83 mg), p < 0.001. Conclusion: Acute pain after mastectomy is often severe. PECS plane block may decrease perioperative opioid consumption after mastectomy surgery compared with general anesthesia alone.

[Pain concepts in fast-track endoprosthetics]

An effective and safe pain management is nowadays a pivotal component of fast-track endoprosthetics. The analgesic strategies should be opioid-sparing whenever possible because opioids induce side-effects that reduce the well-being of patients and are even associated with a risk of falling. This is not compatible with a fast mobilization. In order to achieve this goal, multimodal pain concepts have proven to be suitable. Decentralized analgesia with epidural and regional catheters as well as the use of local infiltration anesthesia (LIA) can be used; however, catheters are also associated with a muscular deficit and the danger of falling. Therefore, in the fast-track concepts LIA has become established. With respect to knee endoprosthetics many studies have shown that LIA achieves at least comparable results or even superiority in comparison with the use of catheters. It represents a safe and effective procedure with respect to postoperative analgesia and accelerated mobilization. A variety of protocols for the use of LIA can currently be found in the literature. In addition to analgesics the supportive administration of glucocorticoids is increasingly being used, which also reduce pain due to the anti-inflammatory effect; however, regarding this aspect relatively few prospective randomized studies in comparison to LIA are available in the literature.

Novel multimodal analgesia regimen improves post-TACE pain in patients with hepatocellular carcinoma

BACKGROUD

Transarterial chemoembolization (TACE) is the primary palliative treatment for patients with unresectable hepatocellular carcinoma (HCC). However, it is often accompanied by postoperative pain which hinder patient recovery. This study was to examine whether preemptive parecoxib and sufentanil-based patient controlled analgesia (PCA) could improve the pain management in patients receiving TACE for inoperable HCC.

METHODS

From June to December 2016, 84 HCC patients undergoing TACE procedure were enrolled. Because of the willingness of the individuals, it is difficult to randomize the patients to different groups. We matched the patients' age, gender and pain scores, and divided the patients into the multimodal group (n = 42) and control group (n = 42). Patients in the multimodal group received 40 mg of parecoxib, 30 min before TACE, followed by 48 h of sufentanil-based PCA. Patients in the control group received a routine analgesic regimen, i.e., 5 mg of dezocine during operation, and 100 mg of tramadol or equivalent intravenous opioid according to patient's complaints and pain intensity. Postoperative pain intensity, percentage of patients as per the pain category, adverse reaction, duration of hospital stay, cost-effectiveness, and patient's satisfaction were all taken into consideration when evaluated.

RESULTS

Compared to the control group, the visual analogue scale scores for pain intensity was significantly lower at 2, 4, 6, and 12 h (all P < 0.05) in the multimodal group and a noticeably lower prevalence of post-operative nausea and vomiting in the multimodal group (31.0% vs. 59.5%). Patient's satisfaction in the multimodal group was also significantly higher than that in the control group (95.2% vs. 69.0%). No significant difference was observed in the duration of hospital stay between the two groups.

CONCLUSION

Preemptive parecoxib and sufentanil-based multimodal analgesia regime is a safe, efficient and cost-effective regimen for postoperative pain control in HCC patients undergoing TACE.

The usefulness of interpectoral block as an analgesic technique in breast cancer surgery

OBJECTIVE

To compare the analgesic efficacy of continuous interpectoral block (CIPB) compared to intravenous analgesia (IV) after breast surgery.

MATERIAL AND METHOD

A prospective, comparative and randomised study of women aged from 18-75years, ASAI-III, operated for breast cancer. In group1 (CIPB) after general anaesthetic, an ultrasound-guided interpectoral catheter was placed and 30mL of 0.5% ropivacaine was administered through it. In the event of an increase in heart rate and blood pressure >15% after the surgical incision, intravenous fentanyl 1μg·kg^-1 was administered, repeating the dose as necessary. In the postoperative period, perfusion of ropivacaine 0.2% 5mL·h^-1; with PCA bolus 5mL/30minutes was administered through the catheter for 24hours and rescue analgesia prescribed with 5mg subcutaneous morphine chloride. In group2 (IV), after induction of general anaesthesia, intravenous fentanyl was administered in the same way as in the other group. The patients received metamizole 2g with dexketoprofen 50mg and ondansetron 4mg postoperatively followed by perfusion of metamizole 4%, tramadol 0.2% and ondansetron 0.08% 2ml·h^-1; with PCA bolus 2mL/20min for 24hours. The same rescue analgesia was prescribed. The principal variables recorded were pain at rest and during movement, according to a simple verbal scale (VAS 0-10) and the rescue analgesia required on discharge from recovery, at 12 and at 24hours.

RESULTS

137 patients were included: 81 in group1 (59.12%) and 56 in group2 (40.87%). No significant differences were observed in the analgesia between either group, but differences were observed in the dose of intraoperative fentanyl (P<.05). Differences that were not significant were observed in the rescue analgesia required on recovery (10% fewer on group1).

CONCLUSIONS

Both techniques provided effective postoperative analgesia, but the CIPB group required significantly less intraoperative fentanyl.

International guidelines for groin hernia management

INTRODUCTION

Worldwide, more than 20 million patients undergo groin hernia repair annually. The many different approaches, treatment indications and a significant array of techniques for groin hernia repair warrant guidelines to standardize care, minimize complications, and improve results. The main goal of these guidelines is to improve patient outcomes, specifically to decrease recurrence rates and reduce chronic pain, the most frequent problems following groin hernia repair. They have been endorsed by all five continental hernia societies, the International Endo Hernia Society and the European Association for Endoscopic Surgery.

METHODS

An expert group of international surgeons (the HerniaSurge Group) and one anesthesiologist pain expert was formed. The group consisted of members from all continents with specific experience in hernia-related research. Care was taken to include surgeons who perform different types of repair and had preferably performed research on groin hernia surgery. During the Group's first meeting, evidence-based medicine (EBM) training occurred and 166 key questions (KQ) were formulated. EBM rules were followed in complete literature searches (including a complete search by The Dutch Cochrane database) to January 1, 2015 and to July 1, 2015 for level 1 publications. The articles were scored by teams of two or three according to Oxford, SIGN and Grade methodologies. During five 2-day meetings, results were discussed with the working group members leading to 136 statements and 88 recommendations. Recommendations were graded as "strong" (recommendations) or "weak" (suggestions) and by consensus in some cases upgraded. In the Results and summary section below, the term "should" refers to a recommendation. The AGREE II instrument was used to validate the guidelines. An external review was performed by three international experts. They recommended the guidelines with high scores. The risk factors for inguinal hernia (IH) include: family history, previous contra-lateral hernia, male gender, age, abnormal collagen metabolism, prostatectomy, and low body mass index. Peri-operative risk factors for recurrence include poor surgical techniques, low surgical volumes, surgical inexperience and local anesthesia. These should be considered when treating IH patients. IH diagnosis can be confirmed by physical examination alone in the vast majority of patients with appropriate signs and symptoms. Rarely, ultrasound is necessary. Less commonly still, a dynamic MRI or CT scan or herniography may be needed. The EHS classification system is suggested to stratify IH patients for tailored treatment, research and audit. Symptomatic groin hernias should be treated surgically. Asymptomatic or minimally symptomatic male IH patients may be managed with "watchful waiting" since their risk of hernia-related emergencies is low. The majority of these individuals will eventually require surgery; therefore, surgical risks and the watchful waiting strategy should be discussed with patients. Surgical treatment should be tailored to the surgeon's expertise, patient- and hernia-related characteristics and local/national resources. Furthermore, patient health-related, life style and social factors should all influence the shared decision-making process leading up to hernia management. Mesh repair is recommended as first choice, either by an open procedure or a laparo-endoscopic repair technique. One standard repair technique for all groin hernias does not exist. It is recommended that surgeons/surgical services provide both anterior and posterior approach options. Lichtenstein and laparo-endoscopic repair are best evaluated. Many other techniques need further evaluation. Provided that resources and expertise are available, laparo-endoscopic techniques have faster recovery times, lower chronic pain risk and are cost effective. There is discussion concerning laparo-endoscopic management of potential bilateral hernias (occult hernia issue). After patient consent, during TAPP, the contra-lateral side should be inspected. This is not suggested during unilateral TEP repair. After appropriate discussions with patients concerning results tissue repair (first choice is the Shouldice technique) can be offered. Day surgery is recommended for the majority of groin hernia repair provided aftercare is organized. Surgeons should be aware of the intrinsic characteristics of the meshes they use. Use of so-called low-weight mesh may have slight short-term benefits like reduced postoperative pain and shorter convalescence, but are not associated with better longer-term outcomes like recurrence and chronic pain. Mesh selection on weight alone is not recommended. The incidence of erosion seems higher with plug versus flat mesh. It is suggested not to use plug repair techniques. The use of other implants to replace the standard flat mesh in the Lichtenstein technique is currently not recommended. In almost all cases, mesh fixation in TEP is unnecessary. In both TEP and TAPP it is recommended to fix mesh in M3 hernias (large medial) to reduce recurrence risk. Antibiotic prophylaxis in average-risk patients in low-risk environments is not recommended in open surgery. In laparo-endoscopic repair it is never recommended. Local anesthesia in open repair has many advantages, and its use is recommended provided the surgeon is experienced in this technique. General anesthesia is suggested over regional in patients aged 65 and older as it might be associated with fewer complications like myocardial infarction, pneumonia and thromboembolism. Perioperative field blocks and/or subfascial/subcutaneous infiltrations are recommended in all cases of open repair. Patients are recommended to resume normal activities without restrictions as soon as they feel comfortable. Provided expertise is available, it is suggested that women with groin hernias undergo laparo-endoscopic repair in order to decrease the risk of chronic pain and avoid missing a femoral hernia. Watchful waiting is suggested in pregnant women as groin swelling most often consists of self-limited round ligament varicosities. Timely mesh repair by a laparo-endoscopic approach is suggested for femoral hernias provided expertise is available. All complications of groin hernia management are discussed in an extensive chapter on the topic. Overall, the incidence of clinically significant chronic pain is in the 10-12% range, decreasing over time. Debilitating chronic pain affecting normal daily activities or work ranges from 0.5 to 6%. Chronic postoperative inguinal pain (CPIP) is defined as bothersome moderate pain impacting daily activities lasting at least 3 months postoperatively and decreasing over time. CPIP risk factors include: young age, female gender, high preoperative pain, early high postoperative pain, recurrent hernia and open repair. For CPIP the focus should be on nerve recognition in open surgery and, in selected cases, prophylactic pragmatic nerve resection (planned resection is not suggested). It is suggested that CPIP management be performed by multi-disciplinary teams. It is also suggested that CPIP be managed by a combination of pharmacological and interventional measures and, if this is unsuccessful, followed by, in selected cases (triple) neurectomy and (in selected cases) mesh removal. For recurrent hernia after anterior repair, posterior repair is recommended. If recurrence occurs after a posterior repair, an anterior repair is recommended. After a failed anterior and posterior approach, management by a specialist hernia surgeon is recommended. Risk factors for hernia incarceration/strangulation include: female gender, femoral hernia and a history of hospitalization related to groin hernia. It is suggested that treatment of emergencies be tailored according to patient- and hernia-related factors, local expertise and resources. Learning curves vary between different techniques. Probably about 100 supervised laparo-endoscopic repairs are needed to achieve the same results as open mesh surgery like Lichtenstein. It is suggested that case load per surgeon is more important than center volume. It is recommended that minimum requirements be developed to certify individuals as expert hernia surgeon. The same is true for the designation "Hernia Center". From a cost-effectiveness perspective, day-case laparoscopic IH repair with minimal use of disposables is recommended. The development and implementation of national groin hernia registries in every country (or region, in the case of small country populations) is suggested. They should include patient follow-up data and account for local healthcare structures. A dissemination and implementation plan of the guidelines will be developed by global (HerniaSurge), regional (international societies) and local (national chapters) initiatives through internet websites, social media and smartphone apps. An overarching plan to improve access to safe IH surgery in low-resource settings (LRSs) is needed. It is suggested that this plan contains simple guidelines and a sustainability strategy, independent of international aid. It is suggested that in LRSs the focus be on performing high-volume Lichtenstein repair under local anesthesia using low-cost mesh. Three chapters discuss future research, guidelines for general practitioners and guidelines for patients.

CONCLUSIONS

The HerniaSurge Group has developed these extensive and inclusive guidelines for the management of adult groin hernia patients. It is hoped that they will lead to better outcomes for groin hernia patients wherever they live. More knowledge, better training, national audit and specialization in groin hernia management will standardize care for these patients, lead to more effective and efficient healthcare and provide direction for future research.

Prospective clinical observational study evaluating gender-associated differences of preoperative pain intensity

Previous studies reported conflicting results concerning different pain perceptions of men and women. Recent research found higher pain levels in men after major surgery, contrasted by women after minor procedures. This trial investigates differences in self-reported preoperative pain intensity between genders before surgery.Patients were enrolled in 2011 and 2012 presenting for preoperative evaluation at the anesthesiological assessment clinic at Charité University hospital. Out of 5102 patients completing a computer-assisted self-assessment, 3042 surgical patients with any preoperative pain were included into this prospective observational clinical study. Preoperative pain intensity (0-100 VAS, visual analog scale) was evaluated integrating psychological cofactors into analysis.Women reported higher preoperative pain intensity than men with median VAS scores of 30 (25th-75th percentiles: 10-52) versus 21 (10-46) (P < 0.001). Adjusted multiple regression analysis showed that female gender remained statistically significantly associated with higher pain intensity (P < 0.001). Gender differences were consistent across several subgroups especially with varying patterns in elderly. Women scheduled for minor and moderate surgical procedures showed largest differences in overall pain compared to men.This large clinical study observed significantly higher preoperative pain intensity in female surgical patients. This gender difference was larger in the elderly potentially contradicting the current hypothesis of a primary sex-hormone derived effect. The observed variability in specific patient subgroups may help to explain heterogeneous findings of previous studies.

Nefopam Reduces Dysesthesia after Percutaneous Endoscopic Lumbar Discectomy

Background

Neuropathic pain, including paresthesia/dysesthesia in the lower extremities, always develops and remains for at least one month, to variable degrees, after percutaneous endoscopic lumbar discectomy (PELD). The recently discovered dual analgesic mechanisms of action, similar to those of antidepressants and anticonvulsants, enable nefopam (NFP) to treat neuropathic pain. This study was performed to determine whether NFP might reduce the neuropathic pain component of postoperative pain.

Methods

Eighty patients, who underwent PELD due to herniated nucleus pulposus (HNP) at L4-L5, were randomly divided into two equal groups, one receiving NFP (with a mixture of morphine and ketorolac) and the other normal saline (NS) with the same mixture. The number of bolus infusions and the infused volume for 3 days were compared in both groups. The adverse reactions (ADRs) in both groups were recorded and compared. The neuropathic pain symptom inventory (NPSI) score was compared in both groups on postoperative days 1, 3, 7, 30, 60, and 90.

Results

The mean attempted number of bolus infusions, and effective infused bolus volume for 3 days was lower in the NFP group for 3 days. The most commonly reported ADRs were nausea, dizziness, and somnolence, in order of frequency in the NFP group. The median NPSI score, and all 5 median sub-scores in the NFP group, were significantly lower than that of the NS group until postoperative day 30.

Conclusions

NFP significantly reduced the neuropathic pain component, including paresthesia/dysesthesia until 1 month after PELD. The common ADRs were nausea, dizziness, somnolence, and ataxia.