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.     

Perioperative pain control

There are many options for perioperative pain control available to surgeons. Given these options, adequate levels of analgesia should be achieved and maintained in all surgical patients. Data suggest that analgesia may be improved by combining different analgesic approaches. To avoid high-dose requirements, dose-dependent adverse effects, and potential toxicity associated with reliance on one agent or technique, "balanced" or multimodal analgesic regimens have been advocated. A multimodal recovery program consists of three major components: (1) early mobilization, (2) complete perioperative analgesia, and (3) early oral nutrition. The goal of multimodal programs is to accelerate patient rehabilitation and reduce hospital stays. Balanced multimodal programs are the present and future of perioperative pain control and will enhance patient care.     

Management of postoperative pain and emesis

As more extensive and painful surgical procedures (e.g., laparoscopic cholecystectomy, laminectomy, knee and shoulder reconstruction, hysterectomy) are being performed on an outpatient basis, the availability of sophisticated postoperative analgesic regimens are necessary to optimize the benefits of day-case surgery for both the patient and the health care provider. However, outcome studies are needed to evaluate the effects of these newer therapeutic approaches with respect to postoperative side effects, cost and important recovery variables. Recent studies suggest that factors other than painper se must be controlled in order to reduce postoperative morbidity and facilitate the recovery process. Not surprisingly, the anaesthetic technique can influence the analgesic requirements and the likelihood of emesis in the early postoperative period. Although opioid analgesics will continue to play an important role, the adjunctive use of both local anaesthetic agents and NSAIDs will probably assume an even greater role in the future. Use of drug combinations (e.g., opioids with local anaesthetics, alpha2 agonists and/or NSAIDs) may provide for improved analgesia with fewer opioid-related side effects than narcotic analgesics alone. Finally, safer and simpler analgesic delivery systems are needed to improve our ability to provide cost-effective pain relief after day-case surgery in the future. In conclusion, as a result of our enhanced understanding of the mechanisms of acute pain and the physiological basis of nociception, the provision of “stress free” anaesthesia with minimal postoperative discomfort is now possible for most patients undergoing ambulatory surgical procedures. The aim of any analgesic technique should not only be to lower the pain scores but also to facilitate earlier mobilization and to reduce perioperative complications, in particular PONY In future, clinicians should be able to effectively treat postoperative pain using a combination of “balanced,” “preemptive,” and “peripheral” analgesia techniques without producing emetic sequelae.     

Lower extremity blocks for analgesia

A large proportion of patients undergoing surgery do not receive adequate postoperative analgesia.[1] Postoperative pain is the leading cause of unplanned hospital admissions after ambulatory surgery and a major source of dissatisfaction with perioperative outcome. [2] The establishment of acute pain services in major institutions both in the United States and overseas has had a major effect on postoperative comfort and patient satisfaction. [3 and 4] Most acute pain services primarily use intravenous patient-controlled analgesia (PCA) or patient-controlled epidural infusion; however, advances in neuronal blockade offer an unprecedented range of effective and surgery site–specific analgesic options. Using long-acting local anesthetics, peripheral nerve blocks can be used to provide an excellent anesthesia and postoperative analgesia. Additionally, a catheter for continuous infusion of local anesthetics can be inserted perineurally to extend the analgesia beyond the duration of the single-shot blocks. This review will discuss the advantages and limitations of various nerve block techniques when used for postoperative pain management for several common surgical indications. Copyright 2002, Elsevier Science (USA). All rights reserved.     

Systemic analgesia: an update

Postoperative pain is now a critical focus of perioperative patient care. The current perioperative analgesic strategy is a "balanced-multimodal analgesia". Cornerstones of this treatment approach are patient controlled neuraxial administration of local anesthetics and opioids or patient controlled intravenous administration of opioids. However, systemic opioids are limited by side effects. Thus, adjuvants like anticonvulsants, NMDA receptor antagonists, alpha-2 adrenergic agonists and other non-Opioid analgesics are considered to reduce pain and opioid requirements in the perioperative period. In the present review we discuss recent findings about the effectiveness of different systemic administered adjuvants including ketamine, lidocaine, gabapentin, pregabalin and corticosteroids for postoperative pain treatment. Furthermore a nurse based oral analgesic concept using controlled released Oxycodon for all postoperative patients without a patient controlled analgesia device will be introduced.     

全膝关节置换术围手术期疼痛的原因及镇痛的研究进展

全膝关节置换术已经成为目前治疗终末期膝关节骨性关节炎的有效手术方法之一.然而术后的疼痛问题却一直困扰着临床医生.术后疼痛的原因可分为医源性,假体源性和患者源性3大因素.围手术期疼痛的处理包括术前的宣教,超前镇痛,假体的选择与设计;术中的处理主要包括合适的手术入路,保持膝关节周围的软组织平衡,术中膝关节周围鸡尾酒镇痛;术后主要包括口服镇痛药物,股神经组织以及患者的自控镇痛.以及近年来兴起的围手术期多种镇痛方式联合应用的多模式镇痛.对于围手术期的疼痛进行充分的干预,可有效缓解膝关节置换术后患者的疼痛,使患者更好的进行功能锻炼,从而获得更好的手术效果.     

Has postoperative pain been eradicated?

Recent evidence suggests that surgical trauma induces a process of central nervous system sensitisation that contributes to and enhances postoperative pain. These changes are also thought to be the underlying cause of much chronic pain. Central sensitisation is generated not only during surgery, but also postoperatively as a result of the inflammatory response to the damaged tissue. This knowledge provides a rational basis for pro-active, pre-emptive and postoperative analgesic strategies to reduce the neuronal barrage associated with tissue damage. Reduction or elimination of postoperative pain is therefore possible. We advocate the use of continuous extrapleural intercostal nerve block for postoperative analgesia in patients undergoing thoracotomy. When this is begun pre-emptively (by precutaneous, pre-incisional paravertebral block) it is combined with an opiate and a non-steroidal anti-inflammatory drug premedication. In a randomised study of 56 patients, pain scores of less than 0.5 cm on a 10 cm scale were produced, postoperative lung function was preserved and glucose and cortisol responses were significantly unchanged from preoperative values. Evidence that effective perioperative analgesia reduces the incidence of chronic post-thoracotomy chest wall pain was found in a retrospective study of 1000 consecutive thoracotomies. The endpoints of a zero pain score, complete preservation of preoperative lung function and prevention of the stress response to trauma are currently achievable and should be provided for virtually all patients undergoing chest surgery. Pre-empting pain must be the goal for all those involved in the postoperative care of patients.     

Challenges in acute pain management

The management of acute pain remains challenging, with many patients suffering inadequate pain control following surgery. Certain populations are at unique risk for unrelieved pain. Evidence-based approaches taking into account patients' specific needs and problems will likely substantially improve their perioperative experience. These patients must be identified in the preoperative process, and an anesthetic/analgesic plan discussed and formulated. A targeted multimodal approach to pain management should be considered the best clinical practice. The most challenging patients may benefit most from the surveillance of an acute pain service that is able to monitor and coordinate care into the postoperative period.     

A recovery room-based acute pain service

AIM: Despite routine postoperative pain management improves recovery and reduces postoperative morbidity and overall costs, and the availability of a large armamentarium of analgesic techniques and drugs, a significant portion of patients do not receive adequate postoperative pain control. We describe a recovery room (RR) based acute pain service model. METHODS: Guidelines on postoperative pain and therapeutic protocols were instituted in January 1999. The analgesic endpoint was a visual analogic scale (VAS) below 4 for all surgical patients for the first 48-72 h. The RR, run by one anesthesiologist and 2 nurses and one assistant, acted as a coordination centre. Discharge from the RR was subject to achieving effective analgesia. Nurses of each ward monitored VAS along with vital signs, administered rescue doses if necessary, and reported to the RR nurse when needed. RR nurses monitored the patient at least twice daily and reported to the anesthesiologist. We have distributed an anonymous questionnaire, within surgical wards, to both surgeons and nurses to evaluate their perception of pain management and of this acute pain service (APS) model. RESULTS:VAS was maintained significantly <4. Analgesic drug consumption increased between 1997, 2000 (first year of APS) and 2004. The auditing process confirmed the desire of all professional figures to be informed and involved in acute pain management as part of a coordinated and systematic approach to the surgical patient. CONCLUSION: A RR-based APS can effectively act as coordinating centre for acute pain treatment without adjunctive personnel.     

Epidurale Analgesie in der Behandlung postoperativer Schmerzen Eine Übersicht

This review highlights the advantages of regional anaesthesia techniques, especially of epidural analgesia, for the management of postoperative and posttraumatic pain: excellent pain relief and a high degree of patient satisfaction, even compared to the gold standard of acute pain therapy, i.v. PCA with opioids. Further advantages of epidural analgesia (EA) are discussed, such as early recovery of gastrointestinal function, reduction of postoperative respiratory complications, lower incidence of myocardial ischema, better mobilisation, reduced risk of thromboembolism, lower incidence of chronic pain problems (such as phantom limb pain) etc. Nevertheless, many studies failed to show significant effects on outcome (e.g. mortality). Weighing the risks, costs and benefits of EA, this technique is indicated in case of significant postoperative pain, especially in case of painful mobilisation, in patients with significant pulmonary risk factors (ASA 3 or IV), in patients where an improved perfusion or gastrointestinal motility is deemed essential, and if chronic pain syndromes are common problems that should be prevented (e.g. amputation). For the praxis of epidural analgesia it is emphasised to place the catheter in an appropriate segment to obtain sufficient analgesia without side effects. Organisational structures (such as an acute pain service) and appropriate monitoring allow to continue EA with local anaesthetics and/or opioids on surgical wards. Recommendations are given for the monitoring of EA on surgical wards. Clear cut agreements should define the role of anaesthesiologists, surgeons and nurses in the management of patients treated with postoperative EA on surgical wards.     

Qualität der postoperativen Schmerztherapie

Background

Despite well-designed concepts of perioperative pain management, recent studies have revealed that a large number of patients still suffer from unacceptable pain after surgery. The purpose of this prospective evaluation was to critically analyze postoperative pain treatment provided by a routinely established, DIN certified acute pain service (APS) at the University Hospital Großhadern in Munich.

Materials and methods

A total of 1,000 consecutive patients received one of the following analgesic procedures: continuous epidural analgesia (EA, n?=?401), continuous and patient-controlled epidural analgesia (PCEA, n?=?305), intravenous patient-controlled analgesia with opioids (PCA, n?=?169) or continuous peripheral nerve block (CPNB, n?=?125). For EA and PCEA, ropivacaine 0.2?% and sufentanil 0.24 µg/ml were administered while peripheral regional analgesia was performed with infusion of ropivacaine 0.2?% only. Patients with PCEA were allowed a 3 mg bolus once per hour on demand. Standardized intravenous PCA was performed with piritramide 2.5 mg/ml, a bolus of 2.5 mg, a lock-out time of 15 min, a maximum of 25 mg/4 h and no background infusion. During the daily visits the APS assessed pain intensity at rest and during movement on a numerical rating scale from 0 (no pain) to 10 (maximum pain), acceptance of pain, satisfaction with the analgesic procedure, demand of additional non-opioid analgesics, the need for optimization including bolus applications and changes of the infusion rate or retraction of the epidural catheter. The duration of the procedures, side effects and complications were documented. The catheter insertion sites were inspected daily for redness and tenderness on palpation.

Results

In general, epidural and peripheral regional analgesic techniques were superior in terms of postoperative analgesia to intravenous opioid PCA and were associated with fewer side effects, such as sedation, nausea, vomiting, obstipation and sensorimotor deficits. A subgroup analysis revealed that in major upper abdominal surgery, EA provided significantly better analgesia at rest and during movement than PCA. In lower abdominal surgery PCEA induced significantly better analgesia than both PCA and EA, especially during movement. Patient satisfaction was generally high and was best with PCEA (95?%) followed by CPNB (94?%), EA (91?%) and PCA (88?%). On the first postoperative day analgesic procedures had to be optimized (e.g. by bolus administration, retraction of catheters or changes to standardized PCA) in 23?% of EA patients, 10?% of PCEA patients, 6?% of PCA patients and 12?% of CPNB patients. Major complications, such as neuraxial hematoma, infections or respiratory depression were not observed.

Conclusions

As described in many prospective studies, this evaluation revealed that for postoperative pain control, regional anesthesia is superior to intravenous patient-controlled analgesia with strong opioids in terms of analgesia and side effects. In the setting of a well-organized acute pain service with frequent education and training of all members involved, postoperative pain management is safe and effective. However, regular re-evaluation of the defined and certified procedures is necessary.     

Current practices for postoperative pain management in Europe and the potential role of the fentanyl HCl iontophoretic transdermal system

Survey results continue to reveal that postoperative pain is insufficiently managed throughout Europe and the rest of the world. However, the efficient use of existing resources, as well as the introduction of novel technologies, may aid in its improvement. Use of an acute pain service has the potential to improve pain management through specialized patient care and utilization of effective analgesic techniques. Multimodal analgesic techniques, which include adjuvant non-opioids and/or regional analgesic techniques, can provide effective analgesia and reduce the amount of systemic opioids (or obviate the need) for postoperative pain management. Patient-controlled analgesia modalities may also offer improvements to pain management, as in practice they provide pain relief superior to the intermittent administration of bolus doses of opioids. A novel patient-controlled analgesia modality that has been approved by the European Medicines Evaluation Agency (EMEA) for the treatment of acute, moderate-to-severe pain is the needle-free, pre-programmed fentanyl HCl iontophoretic transdermal system. This system was shown in a recent US clinical trial to be comparable in efficacy to a standard regimen of morphine intravenous patient-controlled analgesia. Adverse events associated with the use of the fentanyl iontophoretic transdermal system are generally similar to those experienced by patients using intravenous morphine patient-controlled analgesia. Considerations regarding the selection of patients for treatment with the fentanyl iontophoretic transdermal system are similar to those with other patient-controlled analgesia modalities; sufficient upper limb mobility and alertness are required to operate the system. Utilization of the fentanyl iontophoretic transdermal system, together with the guidance of an effective acute pain service, may lead to improvements in postoperative pain management.     

The treatment of pain in urology

Contemporary medicine is characterized by sophisticated specialization of the individual physician. The specialist in urological surgery may undertake one of the most important and primary medical tasks, the mitigation and therapy of pain. This review aims to provide an overview of the concepts of pain therapy in urology. Most patients benefit from basic concepts of analgesia, including measuring and documenting pain scores at the bedside by the nursing staff. Patients undergoing very painful operative procedures require more potent techniques of analgesia, e.g. intravenous patient-controlled analgesia and epidural analgesia. These techniques need adequate supervision by an acute pain service, but their implementation improves the outcome in some situations. Pain in acute renal obstruction varies in intensity and duration; hence, analgesic therapy has to be tailored to the individual patient. Pain syndromes from cancer can be more complex than those after surgery. Neuropathic pain is probably the most difficult to manage and requires consultation with a pain-management specialist. In the case of neuropathic pain, treatment only with opioids is of limited efficacy and combination with co-analgesics is necessary. In addition, invasive analgesic therapies should sometimes be considered.     

Organisation of acute pain therapy

Orthopaedic and traumatized patients often suffer from severe pain after surgery or trauma. Their early recovery also depends on an efficient acute pain relief based on a combination of systemic medication, local drug application and physical therapy. In 2007, new guidelines for the treatment of perioperative and traumatic pain were published. Based on these guidelines standard operating procedures for each hospital should be developed and implemented. Courses on analgesic concepts should be offered regularly for the involved staff. It is helpful to establish an acute pain service for daily rounds and documentation. The individual patient should be informed about his specific acute pain therapy before the operation. Pain scores should be frequently documented by the patient.     

Perioperative Schmerztherapie bei opioidgewöhnten Patienten

In this review article the special anesthesiological problems of opioid tolerance and surgical interventions will be presented. These affect patients with a long-term opioid therapy of chronic pain, addicts with long-term substitution therapy and addicts with current or previous heroin addiction (“clean”). For all patient groups a guarantee of continuous and adequate analgesia (avoidance of fear and increasing patient compliance), exploiting suitable regional anesthesia or regional analgesia procedures when possible, and prevention of a physical opioid withdrawal syndrome have utmost priority. The necessary optimization of perioperative pain therapy only succeeds when based on a thorough preoperative examination of the clinical history which subtly inquires into the drug taking habits with respect to opioids and associated medications. Systemic and/or regional analgesia procedures are possible. Regional procedures are more effective for analgesia. Systemic analgesia procedures do not basically differ from those routinely used for patients without opioid tolerance. However, higher doses of opioids are necessary as well as individual titration according to needs. Special conditions apply to patients previously addicted to opioids (clean) when they are to be operated on. Non-opioids are sufficiently effective for low level pain and opiates can be avoided. Opioid therapy with inclusion of a non-opioid is necessary following major operations or for severe postoperative pain, even as i.v. patient-controlled analgesia (i.v. PCA) if needed. For these patients a relapse to addiction can be provoked by insufficient administration of analgesics, not by pain management including opioids.     

A systematic review of postoperative analgesia following laparoscopic colorectal surgery

Objective  The use of epidural analgesia is considered fundamental in Enhanced Recovery Protocols. However its value in the perioperative management of laparoscopic colorectal surgical patients is unclear and analgesic regimens vary. The aim of this systematic review was to examine the effects of various analgesic regimes on outcomes following laparoscopic colectomy.
Method  A systematic review of studies assessing analgesic regimes following laparoscopic colorectal resection was performed. The primary outcome of interest was length of hospital stay whilst the secondary outcomes included pain, time to tolerate a normal diet, return of bowel function and postoperative complications.
Results  Eight studies were identified, five of which compared epidural vs patient controlled analgesia/intra-venous morphine. There were no significant differences between the groups in terms of outcomes, except pain control which was superior in the epidural group. Spinal anaesthesia using intrathecal morphine in addition to local anaesthetic, and the use of nonsteroidal anti-inflammatory agents have also been shown to reduce postoperative pain.
Conclusion  There is a paucity of data assessing the benefits of postoperative analgesic regimes following laparoscopic colorectal surgery and none of the protocols were shown to be clearly superior. Further studies, including the assessment of spinal analgesia are required to determine the most appropriate analgesic regime following laparoscopic colorectal surgery.     

Organisation der Akutschmerztherapie

Orthopaedic and traumatized patients often suffer from severe pain after surgery or trauma. Their early recovery also depends on an efficient acute pain relief based on a combination of systemic medication, local drug application and physical therapy. In 2007, new guidelines for the treatment of perioperative and traumatic pain were published. Based on these guidelines standard operating procedures for each hospital should be developed and implemented. Courses on analgesic concepts should be offered regularly for the involved staff. It is helpful to establish an acute pain service for daily rounds and documentation. The individual patient should be informed about his specific acute pain therapy before the operation. Pain scores should be frequently documented by the patient.     

Post-thoracotomy spirometric lung function: the effect of analgesia. A review.

BACKGROUND: The effects of postthoracotomy pain management on pulmonary function has been assessed. METHODS: All English language publications involving prospective, randomised, controlled studies of patients undergoing postero-lateral thoracotomy incisions where perioperative spirometry had been studied were included. The mean postoperative percentage preservation of preoperative lung function was recorded or determined for each analgesic regimen. RESULTS: 55 studies were reviewed with a total of 1762 patients. The most effective analgesic method in terms of preservation of spirometric function was paravertebral analgesia, patients having approximately 75% of their preoperative values in the first 48 hours after surgery. Most other techniques e.g. intercostal nerve blocks, epidural local anaesthetics or local anaesthetic-opiate combinations produced approximately a 55% preservation by 48 hours. Interpleural analgesia was the least effective, with a mean of 35% preservation by 48 hours, less even than TENS or cryoanalgesia. CONCLUSIONS: A thoracotomy potentially produces a marked reduction in postoperative pulmonary function and the choice of pain management has major implications. Attenuation of postthoracotomy pulmonary dysfunction by effective analgesia should be provided for all patients undergoing chest surgery. Simply providing effective analgesia on its own without regard to pulmonary function is inadequate. Spirometric monitoring should be standard in all thoracic units and is essential for objective comparisons of the efficacy of different methods of pain management.     

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.