Preemptive analgesia in foot and ankle surgery

Central neuroplasticity, or changes in CNS processing due to surgical nociception. can amplify postoperative pain. As a result, a hyperalgesic state called wind-up can occur, having debilitating effects on postoperative patients. Preemptive analgesia works to prevent this process and results in a more positive surgical experience. Inhibition of afferent pain pathways by use of local anesthetic blocks, altered perception of pain with opioid use, and inhibition of pain pathways by NMDA receptor antagonists are examples of preemptive analgesia. Using a combination of preemptive modalities and addressing patients' perceptions can aid in interrupting pathologic pain cycles. Positive and modest results have been obtained from animal and human preemptive trials, yet basic pathophysiology demonstrates the validity and importance of preemptive analgesia. Future studies are needed to test effective blockade of afferent input while controlling perception, hyperalgesia, and NMDA receptor activity. The Agency for Health Care Policy and Research now recommends a multifaceted approach to postoperative pain. The goal in pain management is to inhibit destructive pain pathways, maintain intraoperative analgesia, and prevent central sensitization. Preliminary results of multimodal preemptive analgesia trials continue to be promising.     

Preemptive ketamine during general anesthesia for postoperative analgesia in patients undergoing laparoscopic cholecystectomy

AIM: Preemptive analgesia is currently in use in the management of postoperative pain and no more under search. The administration of ketamine as intraoperative analgesic agent is well-known since a long time; the analgesic properties of this drug are related to its actions as a non-competitive N-methyl-D-aspartate receptors antagonist; these receptors present an excitatory function on pain transmission and this binding seems to prevent or reverse the central sensitisation of every kind of pain, including postoperative pain. In literature, the use of this anesthetic for the preemptive analgesia in the management of postoperative pain is controversial; for this reason the aim of our study was the clinical evaluation of preemptive perioperative analgesia with low-doses ketamine. METHODS: This trial involved 40 patients undergoing laparoscopic cholecystectomy, with the same surgical operator; postoperative analgesia was performed with the intraoperative administration of ketamine (0.7 mg/kg) or tramadol (15 mg/kg). A randomized, double-blind study was performed; after an inhalatory/analgesic general anesthesia (sevofluorane + remifentanyl) the postoperative-pain control was clinically evaluated through algometric measurements (Visual Analog Scale, Verbal Rating Scale, Pain Intensity Difference); supplemental doses of tramadol were administered if required, also to quantify the adequacy of analgesia, and adverse effects were evaluated. RESULTS: The results show that preemptive intraoperative analgesia with ketamine produces a good analgesia at the awakening, despite low duration (approximately 1 hour), and upgrades the analgesic effect of tramadol in the postoperative period. Among the adverse effects, some (for example nausea) were related to the administration of both analgesics and to the kind of surgery, others (hallucinosis, nystagmus, photophobia, psychomotor excitation, psychotic symptoms) were due to ketamine, and others (respiratory depression and hypotension) could be related to tramadol. Although the adverse effects due to ketamine are more numerous than those related to tramadol, the second could potentially be more dangerous. CONCLUSION: Our study suggests that preemptive low-doses ketamine is able to produce an adequate postoperative analgesia and increases the analgesic effect of tramadol; furthermore, ketamine adverse effects could be reduced by intraoperative administration of benzodiazepines and/or antiemetic drugs, or by the association of ketamine and a peripheral analgesic (ketorolac).     

乳腺癌根除术中联合应用帕瑞昔布钠与地佐辛超前镇痛的临床效果

目的：评价乳腺癌根除术中联合应用帕瑞昔布钠与地佐辛超前镇痛的临床效果。 方法：将170例行乳腺癌根除术的患者分为对照组、超前镇痛组、联合超前镇痛组，分别于麻醉诱导前注射生理盐水、帕瑞昔布钠、帕瑞昔布钠+地佐辛。记录患者术后2、6、12、24、48 h的视觉模拟评分（VAS），比较各组的镇痛效果，并比较各组心血管反应与不良反应的发生情况。 结果：超前镇痛与联合超前镇痛组术后各时间点VAS评分均明显低于对照组（均P<0.05），联合超前镇痛组术后2 h的VAS评分明显低于超前镇痛组（P<0.05），术后6~48 h各时间点VAS评分虽仍低于超前镇痛组，但差异无统计学意义（均P>0.05）。诱导开始前至手术结束，超前镇痛与联合超前镇痛组的心率（HR）与平均动脉压（MAP）均低于对照组，且在插管后5 min至手术结束时明显低于对照组（均P<0.05），但两个超前镇痛组间无统计学差异（均P>0.05）。超前镇痛与联合超前镇痛组不良反应发生率均明显小于对照组（均P<0.05），联合超前镇痛组恶心、呕吐、头晕的发生率大于超前镇痛组，但差异无统计学意义（P>0.05）。 结论：帕瑞昔布钠和地佐辛联合应用于乳腺癌根除术超前镇痛临床效果良好，不会引发患者心血管反应的增多，但会可能增加患者呕吐恶心、头晕等不良反应。     

Update on preemptive analgesia

Perioperative pain remains prevalent and poorly treated. Apart from its impact on the rate and unpleasantness of recovery from surgery, pain often remains as a residual aftereffect of surgery even though tissue healing appears complete. A growing appreciation for the underlying neurobiology of pain has identified mechanisms that can enhance the intensity of perioperative pain and even lead to more prolonged painful conditions. An essential observation is that tissue injury and the resulting nociceptor barrage initiates a cascade of events that can indelibly alter pain perception. Preemptive analgesia is the concept of initiating analgesic therapy before the onset of the noxious stimulus so as to prevent the nociceptor barrage and its consequences. However, preemptive analgesia, though firmly grounded in the neurobiology of pain, has yet to realize its anticipated clinical potential. As data accumulates, it has become clear that clinical studies emulating those from the laboratory and designed around a relatively narrow definition of preemptive analgesia have been largely unsupportive of its use. Nevertheless, preemptive analgesic interventions that recognize the intensity, duration, and somatotopic extent of major surgery can help reduce perioperative pain and its longer-term sequelae.     

Effects of preemptive epidural analgesia on post-thoracotomy pain

OBJECTIVE: The purpose of this study was to determine whether preemptive thoracic epidural analgesia (TEA) initiated before surgical incision would reduce the severity of acute post-thoracotomy pain and the incidence of chronic post-thoracotomy pain. METHOD: Meta-analysis of randomized controlled trials (RCTs). SEARCH STRATEGY: MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL) and EMBASE were searched from 1966 to December 2004 for prospective RCTs published in all languages using the following MeSH terms: post-thoracotomy pain, epidural analgesia, chronic pain, and preemptive analgesia. SELECTION CRITERIA: All RCTs that compared thoracic epidural analgesia initiated before surgical incision (preemptive group) versus thoracic epidural analgesia initiated after completion of surgery (control group) in adult patients undergoing unilateral thoracotomy. MEASUREMENTS AND MAIN RESULTS: Three authors reviewed all citations and simultaneously extracted data on sample size, patient characteristics, surgical and analgesic interventions, methods of pain assessment, and pain scores at 24 hours, 48 hours, and 6 months postoperatively. Six studies were included with a total of 458 patients. Pooled analyses indicated that preemptive TEA was associated with a statistically significant reduction in the severity of acute pain on coughing at 24 and 48 hours (weighted mean difference -1.17 [95% confidence interval (CI) -1.50 to -0.83] and -1.08 [95% CI -1.17 to -0.99]), respectively. Acute pain was a good predictor of chronic pain. However, there was no statistically significant difference in the overall incidence of chronic pain at 6 months between the preemptive TEA group (39.6%) and the control group (48.6%). CONCLUSION: Preemptive TEA appeared to reduce the severity of acute pain but had no effect on the incidence of chronic pain.     

氯诺昔康超前镇痛的术后镇痛效果和安全性Meta分析

目的 通过对随机对照实验的数据进行Meta分析,系统评价氯诺昔康超前镇痛对术后镇痛的效果和安全性.方法 检索PubMed、Embase、Cochrane Library、CNKI、万方数据知识服务平台和中国知网等文献数据库,查找氯诺昔康超前镇痛对术后镇痛的效果和安全性的随机对照实验,并由两位研究人员对资料进行筛选与评价,使用RevMan5.3软件对结果进行Meta分析. 结果 共纳入4个随机对照实验.实验组术前静脉注射氯诺昔康,对照组使用安慰剂.Meta分析结果显示,患者术后VAS评分在各时间点情况分别为:术后4h,均数差(mean deviation,MD)=-1.58,95％置信区间(confidence interval,CI)为-2.38～-0.77 (P＜0.01);术后8h,MD=-1.43,95％CI为-2.09～--0.77 (P＜0.01);术后12h,MD=-1.35,95％CI为1.72～-0.98 (P＜0.01);术后24h,MD=-1.02,95％CI为-1.29～-0.76(P＜0.01).副作用发生情况:相对危险度(relative risk,RR)=1,95％CI为0.47～2.12(P=1). 结论 鉴于现有研究结果,氯诺昔康超前镇痛对术后4、8、12、24h患者具有镇痛效果,结果具有统计学意义,氯诺昔康超前镇痛产生副作用情况尚不明朗.     

Pain after laparoscopic cholecystectomy

BACKGROUND: Although laparoscopic cholecystectomy (LC) results in less pain than open chole-cystectomy, it is not a pain-free procedure. Many methods of analgesia for pain after laparoscopy have been evaluated. METHODS: Forty-two randomized controlled trials assessing interventions to reduce pain after LC are reviewed, as are the mechanisms and nature of pain after this procedure. RESULTS: Non-steroidal anti-inflammatory drugs, wound local anaesthetic, intraperitoneal local anaesthetic, intraperitoneal saline, a gas drain, heated gas, low-pressure gas and nitrous oxide pneumo-peritoneum have been shown to reduce pain after LC. The clinical significance of this pain reduction is questionable. CONCLUSION: Pain after LC is multifactorial. Although many methods of analgesia produce short-term benefit, this does not equate with earlier discharge or improved postoperative function. However, single trials evaluating low-pressure insufflation, heated gas and multimodal analgesia suggest that clinically relevant benefits can be achieved.     

Review article: Preventive analgesia: quo vadimus?

The classic definition of preemptive analgesia requires 2 groups of patients to receive identical treatment before or after incision or surgery. The only difference between the 2 groups is the timing of administration of the drug relative to incision. The constraint to include a postincision or postsurgical treatment group is methodologically appealing, because in the presence of a positive result, it provides a window of time within which the observed effect occurred, and thus points to possible mechanisms underlying the effect: the classic view assumes that the intraoperative nociceptive barrage contributes to a greater extent to postoperative pain than does the postoperative nociceptive barrage. However, this view is too restrictive and narrow, in part because we know that sensitization is induced by factors other than the peripheral nociceptive barrage associated with incision and subsequent noxious intraoperative events. A broader approach to the prevention of postoperative pain has evolved that aims to minimize the deleterious immediate and long-term effects of noxious perioperative afferent input. The focus of preventive analgesia is not on the relative timing of analgesic or anesthetic interventions, but on attenuating the impact of the peripheral nociceptive barrage associated with noxious preoperative, intraoperative, and/or postoperative stimuli. These stimuli induce peripheral and central sensitization, which increase postoperative pain intensity and analgesic requirements. Preventing sensitization will reduce pain and analgesic requirements. Preventive analgesia is demonstrated when postoperative pain and/or analgesic use are reduced beyond the duration of action of the target drug, which we have defined as 5.5 half-lives of the target drug. This requirement ensures that the observed effects are not direct analgesic effects. In this article, we briefly review the history of preemptive analgesia and relate it to the broader concept of preventive analgesia. We highlight clinical trial designs and examples from the literature that distinguish preventive analgesia from preemptive analgesia and conclude with suggestions for future research.     

Role of access surveillance and preemptive intervention

Vascular access dysfunction continues to be a major cause of morbidity and mortality in the end-stage renal patient. Thrombosis is the primary cause of prosthetic arteriovenous access (ie, graft) failure caused by the progressive development of neointimal hyperplasia, which eventually leads to a stenosis, usually at the venous anastomosis. More than 20 years ago, observational studies using a variety of surveillance techniques, coupled with preemptive angioplasty, convincingly demonstrated the ability to detect venous stenosis, and elective treatment of stenoses significantly decreased both thrombosis and access loss. Although multiple observational studies have shown a benefit from surveillance, these studies generally had no control population, used historical controls, or used incorrect statistical analysis. However, five randomized controlled trials that evaluated the effect of graft surveillance coupled with preemptive angioplasty have failed to demonstrate a benefit on graft outcomes, including prolongation of graft survival. This review will examine the role of access surveillance and preemptive angioplasty in achieving the goal of reducing vascular access thrombosis and prolonging access survival.     

The effect of epidural analgesia on postoperative outcome after colorectal surgery

OBJECTIVE: The aim of this review was to determine the effects of epidural analgesia as it relates to outcome after colorectal surgery. METHOD: We searched and reviewed studies that included colorectal surgery and epidural method of analgesia listed on the Pubmed, Medline, Embase and the Cochrane library database. RESULTS: The majority of data demonstrate a superior effect of epidural analgesia on pain control after colorectal surgery. Well designed randomized controlled trials (RCT's) have also shown that epidural analgesia reduces the duration of ileus after colorectal surgery. Limited data suggest the additional benefit may be minimal after laparoscopic surgery or when epidural analgesia is used as part of a multimodal regime. Data does not convincingly show either a clear harmful or beneficial effect of epidural analgesia on rates of anastomotic leakage. Epidural analgesia may have beneficial effects on postoperative lung function, however due to low numbers, the effects on cardiovascular and thromboembolic complications are indeterminate. Length of hospital stay has not been shown to be shortened by sole use of an epidural and, although epidural analgesia may be apparently more costly, alternatives may incur higher indirect costs and decreased patient satisfaction. CONCLUSION: Randomized controlled trials have shown a benefit for epidurals on postoperative pain relief, and ileus, and possibly respiratory complications. There is no proven benefit with regard to length of stay. There are a number of unresolved issues which further focussed RCT's may help clarify such as effects of epidural on complication rates after colorectal surgery.     

Preemptive analgesia or balanced periemptive analgesia?

"Preemptive analgesia" means that analgesia given before the painful stimulus prevents or reduces subsequent pain. The concept of preemptive analgesia originates from basic science and experimental studies. However, in some clinical studies preemptive effect is not always present. The authors think that it happens for: differences among experimental models and clinical reality, wrong use of some pharmacological knowledges, some methodological errors in clinical research. The authors analyze these factors and review in a critical manner clinical studies on preemptive analgesia. In some operations, only one administration of an analgesic drug, before surgery, is not sufficient to produce an evident preemptive effect. Postoperative pain can be reduced making a pharmacological treatment before surgery, for the whole time of painful stimulus. For this reason, the term "preemptive analgesia", like "analgesia given before surgery" is not adequate. The authors suggest that the concept of prevention of postoperative pain is well defined by the term of "balanced periemptive analgesia"; it is a new approach that use many modalities of analgesia in different times to prevent and control painful stimulus for the whole time of its origin: before and/or during operation and, if necessary, in the postoperative period for the residual pain.     

Definitions of “respiratory depression” with intrathecal morphine postoperative analgesia: a review of the literature

PURPOSE: To review the postoperative intrathecal morphine (ITM) analgesia literature for their definitions of "respiratory depression" (RD). SOURCE: Medline (1966 - June Week 5 2001) and reference lists were searched for original studies involving bolus-dose ITM for postoperative analgesia, which used "respiratory depression" or similar terms. PRINCIPLE FINDINGS: The search identified 209 studies. These were included if ITM use was appropriate (bolus dose, postoperative analgesia) and the term "respiratory depression" was used, which left 96 studies remaining. Forty-four (46%) did not define "RD" despite using this term. A further 24 (25%) defined RD with respiratory rate (RR) alone. Only 28 (29%) defined RD with more than RR alone. There was no statistically significant association between the presence of a definition for RD with study design, study size or publication period. Also, no significant association existed between rigorousness of RD definitions and the above factors. CONCLUSION: The term "respiratory depression" has no clear definition from a review of the literature on ITM use for postoperative analgesia. While defining RD with bradypnea is superior to having no definition, this is still inadequate. In future research, the consistent use of terms with specific meanings will facilitate understanding the true incidence of ITM's respiratory effects. If "respiratory depression" is used, then an explicit definition of its meaning should be provided. Future research must also address what is clinically significant respiratory impairment from intrathecal opioids, and how to optimally monitor for this. Further delineating their risks vs benefits will allow for more optimal dosing.     

帕瑞昔布钠在腹腔镜胆囊切除术中超前镇痛的有效性及安全性的Meta分析

背景与目的 伴随着外科快速康复理念发展,围术期的多模式镇痛逐渐被接受。其中超前镇痛是一种常用方法。本研究通过系统回顾和Meta分析判断帕瑞昔布钠超前镇痛在腹腔镜胆囊切除术（LC）中的有效性和安全性。方法 检索中英文数据库,收集比较LC中应用术前静脉使用帕瑞昔布钠（超前镇痛组）与未静脉使用帕瑞昔布钠（空白组）或手术结束时静脉使用帕瑞昔布钠（术毕镇痛组）的随机对照研究或观察性研究。检索时间为建库至2021年5月。在对纳入研究进行方法学质量评价和数据提取后,采用RevMan 5.3和Stata 12.0软件行Meta分析。结果 最终纳入中英文文献共13篇,涉及974例患者。Meta分析结果显示,超前镇痛组的患者术后2、4、6、8、12、24 h可视模拟评分（VAS）均低于空白组（均P<0.05）与术毕镇痛组（部分P<0.05）。超前镇痛组术后需要额外止痛药病例数少于空白组与术毕镇痛组,术后不良反应（恶心、呕吐）发生率低于空白组（均P<0.05）。基于需要额外止痛药病例数与术后不良事件发生率的发表偏倚与敏感度分析显示,无明显的发表偏移存在（均P>0.05）,该方法不会改变最初总体分析的结果。结论 静脉使用帕瑞昔布钠超前镇痛在LC中具有良好的镇痛效果、较小的不良反应,为临床多模式镇痛提供了一种安全有效的方法。     

Pain and its modulation. Part 2. efferent mechanisms

Recent studies of central nervous system effects on pain and on its efferent modulation have created new theories and have led to direct clinical applications that may in time eclipse more classical interventions. In this review electrical stimulation analgesia is presented as a paradigm of how basic science work has been applied clinically to produce some of the most exciting advances in recent years in the treatment of chronic pain. Opiate receptors and analgesia are presented in relationship to the descending inhibitory systems used in electroanalgesia. Neuromodulators and neurotransmitters important in pain modulation through complex inhibitory and excitatory pathways are discussed, with the roles of B-endorphin, enkephalin, serotonin, and other important biogenic amines being stressed. The neuropharmacology of pain as it is currently understood clinically suggests that psychotropic interventions may be quite useful in treating difficult pain problems.     

超前镇痛护理理念用于食管癌患者术后镇痛

目的探讨超前镇痛护理理念对食管癌患者术后疼痛控制的影响。方法随机将188例食管癌手术患者分为常规镇痛组(n=93)和超前镇痛组(n=95)。常规镇痛组实施常规镇痛护理,即术前行疼痛知识宣教,术后应用Prince-Henry评分法定时评估患者疼痛,根据评分行针对性镇痛护理;超前镇痛组实施超前镇痛护理,即在前者基础上增加术前超前镇痛知识宣教,术后在执行各临床操作前行预见性疼痛评估,根据评分行预见性镇痛处理。比较两组患者术后24h、48h、72h疼痛评分,术后首次下床活动时间,肺部并发症发生率。结果两组术后24h、48h、72h疼痛评分比较,干预主效应P<0.05;超前镇痛组下床活动时间较常规镇痛组显著提前,肺部并发症发生率显著低于常规镇痛组(P<0.05,P<0.01)。结论超前镇痛护理理念对食管癌患者术后疼痛控制有积极的作用,有利于患者早日康复。     

Perioperative small-dose S(+)-ketamine has no incremental beneficial effects on postoperative pain when standard-practice opioid infusions are used

Several studies report that when small-dose racemic ketamine, an N-methyl-D-aspartate receptor antagonist, is administered perioperatively, opioid consumption is reduced postoperatively. S(+)-ketamine has a higher affinity for the N-methyl-D-aspartate receptor and less-serious side effects than racemic ketamine. Thirty patients scheduled for elective arthroscopic anterior cruciate ligament repair were enrolled in this randomized, double-blinded clinical trial designed to determine the preemptive effect of S(+)-ketamine on postoperative analgesia requirements in a setting of clinically relevant perioperative analgesia. Total IV anesthesia was induced and maintained with remifentanil (0.125-1.0 microg x kg(-1) x min(-1)) and a propofol target-controlled infusion (target 2-4 microg/mL). The Ketamine group received a bolus of 0.5 mg/kg S(+)-ketamine before incision, followed by a continuing infusion of 2 microg x kg(-1) x min(-1) until 2 h after emergence from anesthesia. The Control group received NaCl in the same sequence. After IV morphine provided pain relief down to < or =3 on a visual analog scale scored from 0 to 10, patients were connected to a patient-controlled analgesia device. There were no significant differences between the two groups in terms of total morphine consumption or VAS scores, either at rest or with movement. In our study, S(+)-ketamine did not contribute to postoperative pain reduction, possibly because of the clinically routine perioperative opioid analgesia. IMPLICATIONS: Small-dose S(+)-ketamine had no positive effect on postoperative analgesia when administered perioperatively for elective arthroscopic anterior cruciate ligament repair. Unlike investigations of the racemic mixture of ketamine, our study methods included timely standard-practice perioperative opioid analgesia, which seems to make supplemental analgesia unnecessary.     

Epidural fentanyl, adrenaline and clonidine as adjuvants to local anaesthetics for surgical analgesia: meta-analyses of analgesia and side-effects

Background: The risk/benefit ratio of adding fentanyl, adrenaline and clonidine to epidural local anaesthetics for improving intraoperative analgesia is unclear. This meta-analysis was performed to clarify this issue.
Methods: Trials retrieved by search were considered if they were prospective, controlled, epidural analgesia (without combining general anaesthesia) was planned and occurrence of pain during surgery or side-effects were reported. Papers entered meta-analysis if they reached a predefined minimum quality score. Pooled odds ratios (OR) and confidence intervals (CI) were computed. P <0.05 was considered as significant.
Results: Eighteen trials were included in the analysis for fentanyl. Fentanyl decreased the likelihood of pain (OR=0.21, 95% CI=0.15–0.30, P <0.001) and increased the incidence of pruritus (OR=5.59, 95% CI=3.12–10.05, P <0.001) and sedation (OR= 1.88, 95% CI=1.19–2.98, P =0.003), compared to control (local anaesthetic without fentanyl). Fentanyl had no effect on respiratory depression, nausea, vomiting and Apgar score. One case of respiratory depression of a newborn was observed. Because of the very low number of trials selected, evaluation of adrenaline and clonidine was not feasible.
Conclusion: The analysis of current literature shows that the addition of fentanyl to local anaesthetics for intraoperative epidural analgesia is safe and advantageous. The reduction in the incidence of pain during surgery is quantitatively high and therefore clinically significant. Side-effects are mild. Randomized, controlled trials have to be performed in order to clarify the role of adrenaline and clonidine as epidural adjuvants for surgical analgesia.     

How should we manage asymptomatic hyperuricemia?

The definition of asymptomatic hyperuricemia remains unclear, as no consensus exists about the serum urate cutoff or the relevance of ultrasound findings. Comorbidities associated with hyperuricemia have increased in frequency over the past two decades. Hyperuricemia (and/or gout) may be a cause or a consequence of a comorbidity. Whereas epidemiological studies suggest that hyperuricemia may be linked to cardiovascular, metabolic, and renal comorbidities, Mendelian randomization studies have not provided proof that these links are causal. Discrepancies between findings from observational studies and clinical trials preclude the development of recommendations about the potential benefits of urate-lowering therapy (ULT) in individual patients with asymptomatic hyperuricemia. The risk/benefit ratio of ULT is unclear. The risk of developing gout, estimated at 50%, must be weighed against the risk of cutaneous and cardiovascular side effects of xanthine oxidase inhibitors. The need for optimal comorbidity management, in contrast, is universally accepted. Medications for comorbidities that elevate urate levels should be discontinued and replaced with medications that have the opposite effect. Therapeutic lifestyle changes, weight loss as appropriate, and sufficient physical activity are useful for improving general health. Whether ULT has beneficial effects on comorbidities will be known only when well-powered interventional trials with relevant primary endpoints are available.     

Update zur präemptiven Analgesie

Background

Wall created the term preemptive analgesia in 1988 and in doing so set in motion a movement to prevent acute and chronic postsurgical pain. The concept of preemptive analgesia implies the administration of analgesic drugs or an intervention before a surgical procedure. A preemptive analgesic approach can comprise non-steroidal anti-inflammatory drugs (NSAID) and cyclo-oxygenase-2 inhibitors (coxibs) used to decrease the production of prostaglandins, local anesthetics (e.g. epidural) to reduce nociceptive input to the spinal cord as well as opioids, N-methyl-D-aspartate (NMDA) antagonists, antidepressants and anticonvulsants, all of which have an inhibitory influence on the central nervous system.

Aim

The aim of this article is to present the current possibilities and limits of preoperative pain therapy.

Material and methods

Since 2002 several meta-analyses on the effectiveness of preemptive analgesia have been published which came to varying conclusions on the supportive use of preemptive analgesia. The S3 guidelines on current perioperative pain management developed by the German Interdisciplinary Association for Pain Management (DIVS) specify the preemptive analgesic interventions found to be effective and will be discussed in detail in this article. Furthermore, the results of a current meta-analysis which follows the principle of preventive analgesia will be presented and which have not yet been considered in the S3 guidelines.

Results

Preemptive analgesia can reduce acute postoperative pain; however, minimizing the development of chronic pain conditions can only be successful in combination with intraoperative and postoperative pain therapy as well as social and psychological support when indicated (preventive analgesia).

Conclusion

Reduction of chronic postoperative pain is an important medical function which is also justified from socioeconomic perspectives. Future studies should combine several procedures for perioperative pain therapy in order to do justice to the multifactorial aspects of pain chronification and should also be planned over a sufficiently long observation time period.     

超前镇痛的相关研究进展

超前镇痛是通过防止外周和中枢敏化来降低伤害性刺激引起的痛觉过敏和痛觉异常的一种镇痛方法.现介绍超前镇痛的机制、临床常用方法及药物,并展望超前镇痛亟待解决的问题.