Management of postoperative pain: review of current techniques and methods

Pain is a common problem in the early postoperative period. Techniques that provide perioperative analgesia to alleviate pain may have a significant effect on postoperative events, such as earlier ambulation and earlier dismissal from the hospital with use of epidural analgesia than with systemic analgesia. Spinal opioids, which can be administered epidurally or intrathecally, provide analgesia that is superior to that achieved with systemically administered narcotics. For procedures on the upper extremities, selective analgesia can be achieved with use of various types of neural blockade--for example, brachial plexus blockade, interscalene blockade, and axillary plexus blockade. Intercostal nerve block, a valuable but underutilized procedure appropriate for unilateral upper abdominal or flank operations or for thoracotomy, has been shown to reduce postoperative narcotic requirements and pulmonary complications. A patient-controlled analgesia device, consisting of an electronically controlled infusion pump with a timing device that can be triggered by the patient for intravenous administration of a narcotic when pain is experienced, avoids the vast fluctuations in analgesia that accompany parenteral administration of drugs. In most patients, postoperative pain can be prevented or diminished, and clinicians should be aware of the available techniques for achieving this goal.     

The clinical use of spinal opioids,part 1

Spinal opioids are effective analgesics for surgical and non-surgical pain. Central and systemic side effects are less frequent than with epidural local anaesthetics or parenteral opioids. This review focuses on the analgesic efficacy of spinal opioids and their combination with local anaesthetics for postoperative analgesia, including patient-controlled epidural analgesia. Intrathecal administration of opioids has some advantages over their administration by the epidural route. Several factors may influence selection of the opioid; however, in most situations morphine is the drug of choice. Thoracic epidural administration of opioids seems to have no clinically important advantages over the lumbar route in terms of quality of analgesia, adverse effects, doses required or pulmonary function. However, evidence suggesting that effective postoperative analgesia can significantly improve postoperative morbidity in patients at risk is accumulating. In such patients, combined use of epidural local anaesthetics and opioids may become the technique of choice for postoperative analgesia. However, there is no evidence that this would have any clinically relevant benefit in low-risk patients.     

Control of the postoperative pain

The pain is a frequent symptom during the postoperative period and results in suffering and unnecessary risks for the patient. Studies show the inadequate pain relief after surgery and the relationship with erroneous assessment and non-acquaintance about analgesics methods. The article discuss the postoperative pain management which includes the use of nonsteroidal antiinflammatory drugs, opioids, cognitive-behavior interventions and high-tech like epidural catheter and patient-controlled analgesia systems. Besides the adequate pain control includes the discussion about ethical and economic aspects.     

The indications and applications of interscalene brachial plexus block for surgery about the shoulder

Due to increasing use of interscalene brachial plexus block (ISBPB) for surgery about the shoulder, it was our purpose to review the indications, techniques, complications, and most recent advances of interscalene brachial plexus block. All MEDLINE publications regarding interscalene and brachial plexus block from July 1966 to July 2003 were reviewed, analyzed and scrutinized. ISBPB provides surgical anesthesia and perioperative analgesia for procedures involving dermatomes C5 through C7. ISBPB is reliably performed with very high success (≥94% effectiveness) and few major complications (≤0.4%). Recent advances in ISBPB techniques, including perineural catheters for patient-controlled interscalene analgesia, afford superior postoperative pain relief, early rehabilitation, and excellent patient satisfaction. When performed by trained personnel, ISBPB is a safe and effective regional anesthetic technique with rapidly developing applications aimed to improve postoperative analgesia following surgery of the proximal upper limb.     

Perioperative Schmerztherapie beim Erwachsenen

The spectrum of perioperative pain treatment is discussed in the present review. The analgesic efficacy of various drugs and the dosage methods of administration and side effects reported for them in such reference works as the practical guide on the management of acute pain recently published by the International Association for the Study of Pain (IASP) are described. Effective postoperative analgesia can diminish stress reactions following surgery. Recovery and physical mobilization are improved as the result of adequate treatment. Results obtained in recent studies have demonstrated that primary adaptive hyperalgesia in the peripheral nociceptive area may develop into secondary maladaptive hypersensibility with a high degree of nociceptive excitability and pain. Chronic pain can develop following acute alterations. Increasing nociceptive activity of primary afferents induces alterations in the dorsal horn of the spinal cord. These alterations imply an increase in the excitability of nociceptive neurons, which has been described as neuronal plasticity. Clinical results have demonstrated prevention or delay of acute postoperative pain after injection of local anaesthetics, analgesic premedication or epidural injection of opioids just before the start of surgery. Continuous perioperative spinal analgesia has contributed significantly to the prevention of phantom limb pain in patients undergoing amputation of extremities. The development of pain memory may be prevented as a result of effective acute pain treatment. Several changes to the terminology of acute pain treatment for animal and clinical studies have recently been proposed, including such new terms as preemptive analgesia and pain prevention, which indicate new strategies in the treatment of postoperative pain. The concept of balanced analgesia refers to a strategy for the improvement of analgesic efficacy as a result of a combination of drugs with different local actions on nociception. The combination of systemic analgesics (opioids in low dosages) with nonsteroidal analgesics (e.g. diclofenac or ketorolac) and the combination of regional analgesic procedures with opioids have been shown to be very effective. The peripheral action of morphine offers new options in pain therapy. Different regional analgesic techniques and continuous infusions of local analgesics are described. The synergistic action of low dosages of local anaesthetics (bupivacaine 0.006%) with low dosages of fentanyl 0.0001-0.0002% are of interest for the treatment of obstetric pain and for pain in opioid-tolerant patients. Investigations performed by the author of this review have shown that epidural infusion of highly diluted mixtures of bupivacaine/fentanyl is highly effective in the analgesic treatment of patients undergoing prostatectomy, providing excellent physical mobilization. The potential dangers of drug combinations and contraindications are also discussed. The concept of using balanced analgesia to induce additive or synergistic effects following the administration of analgesic drugs requires further clinical studies.     

Fentanyl: clinical use as postoperative analgesic--epidural/intrathecal route.

The administration of epidural and intrathecal opioids for the management of postoperative pain is well established. Fentanyl, because of its greater lipophilicity, offers a number of advantages over morphine for epidural analgesia, including a lower incidence of side effects and reduced risk of delayed-onset respiratory depression. The relatively short duration of action of epidural fentanyl makes this agent more ideally suited for continuous infusion or patient-controlled epidural analgesia (PCEA). The effective doses and adverse effects profile of epidural fentanyl are reasonably well understood. Because of the lack of spread through the cerebrospinal fluid (CSF) and hence the segmental nature of the analgesia achieved, location of epidural catheter placement is of paramount importance when this agent is used. Prolonged epidural infusion of fentanyl may result in high systemic concentrations not dissimilar to IV infusion, and, therefore, the greatest efficacy of epidural fentanyl administration may be in combination with low concentrations of bupivacaine, an approach that achieves a synergistic effect. 2-Chloroprocaine has been shown to antagonize epidural fentanyl analgesia. Intrathecal fentanyl for postoperative analgesia is limited by its short duration of action with single-bolus administration. The widespread international increase in the use of epidural fentanyl for postoperative analgesia promises further improvements and refinement in techniques.     

神经刺激器引导用于臂丛神经阻滞及术后镇痛研究

目的 观察神经刺激器定位下经斜角肌间沟留置导管用于持续臂丛神经阻滞及术后镇痛的临床效果和可行性。方法 ASAⅠ～Ⅱ级上肢手术患者60例。随机分为套管针组（A组）和留置导管组（B组），每组30例。A组患者用20G静脉穿刺套管针行常规方法臂丛神经阻滞留置，B组患者在周围神经刺激器引导下穿刺置入专用的柔软导管，手术结束后两组患者均连接一电子镇痛泵行持续术后臂丛神经阻滞镇痛。结果 术中需辅助用药患者两组无统计学差异（P〉0．05）。A组患者术后镇痛失败率达23．3％，B组无镇痛失败患者，两组比较差异有显著性（P〈0．05）。剔除A组镇痛失败患者后，两组患者术后48h内的VAS评分、Ramsay评分和PCA按压次数无统计学差异（P〉0．05）。结论 周围神经刺激器精确引导下经斜角肌间沟留置导管行臂丛神经阻滞和持续术后镇痛是一种可行性好、镇痛效果确切、不良反应少的方法。     

Besonderheiten der Behandlung des akuten Schmerzes im Kindesalter

Pain relief in children during the perioperative period can be provided by means of peripherally or centrally acting analgesics or of regional anaesthetic techniques. Narcotics or regional blockde are indicated when peripherally acting analgesics prove inadequate to abolish pain. Side effects of narcotics must be taken into account: opioids must not be administered unless continuous safety monitoring of the child's respiration is assured. If narcotics fail to relieve pain, regional anaesthesia may be indicated. All advantages and drawbacks of the various techniques that might be appropriate must be considered: the technique involving the least risk and side effects is the anaesthetic technique with a broad margin of safety when applied by an anaesthesiologist who has experience with paediatric regional blocks include topical anaesthesia, local infiltration, peripheral nerve blocks (e.g. nervi dorsalis penis, plexus axillaris) and caudal epidural blockade. Caution must be exercised whenever narcotics are administered systemically or epidurally; side effects must not be underestimated, even under conditions of intensive care observation. The provision of effective pain relief is a rewarding task-and particularly in little children.     

The novel analgesic neostigmine and the morning after: Nothing more than sedation, nausea and vomiting?

Since the introduction of opioids as spinally active analgesics into the field of pain research and management, the spinal cord and the peripheral nervous system have been explored for numerous different physiological and pharmacological pain modulating systems. Thereby the use of cholinergic agonists and acetylcholinesterase-inhibitors was investigated with respect to their specific antinociceptive activity, any potential side effects and also with regard to any potential toxicity after their spinal administration. Besides analgesia, spinal cholinergic agonists will also result in motor weakness. Neostigmine, a clinically well-known acetylcholine (ACh)-esterase inhibitor, was found however to result in dose-dependent, potent analgesia after spinal and peripheral administration in preclinical and clinical trials. The clinical studies exploiting spinal or epidural administration of neostigmine revealed an analgesic effect for neostigmine 50–100 μg comparable to that of spinally applied morphine. Neostigmine lacks any neurotoxicity after intrathecal injection, although its spinal and epidural use might be limited by another side effect — the high incidence of nausea and vomiting. Based on the findings of a peripheral analgesic action of opioids, neostigmine's peripheral analgesic effects were also demonstrated in acute pain states. Here it is shown that postoperative analgesia can be accomplished by intra-articular neostigmine and by co-delivery of neostigmine with mepivacaine in axillary plexus blockade. However, further studies on the underlying mechanisms of peripheral antinociception are warranted before the routine clinical use of neostigmine as a peripheral acting analgesic can be recommended.In conclusion, due to its potential side effects, the use of the otherwise very effective spinal analgesic neostigmine will be limited to certain specific pain states or as a co-drug with other analgesics.     

Treatment of postoperative pain in anaesthesiological units in Croatia

The treatment of postoperative pain is a problem that has too often been neglected. The aim of this survey was to examine the current situation in postoperative pain treatment in anaesthesiological units in Croatia. The knowledge of practice, habits and standpoints of our anaesthesiologists could serve as the basis for the formulation of unique guidelines for the treatment of postoperative pain. A questionnaire and a letter explaining the purpose of the study were used in the survey. Twenty-eight out of 49 mailed questionnaires were returned (57%).The results of the survey show that there is no formal organisation within the anaesthesiological units to provide postoperative pain treatment. Intermittent parenteral application of analgesics is instituted in the majority of responses (81%) and infusion analgesia in 23.7% of responses. Of the regional methods, only epidural analgesia — used ‘predominantly’ in 8% of responses and ‘occasionally’ in 43% of responses — can compete with parenteral application of analgesics.Tramadol (24% of responses) and pethidine (21% of responses) are mild opioids frequently used for systemic drug therapy. Of the strong opioids, fentanyl (17% of responses), morphine (11% of responses) and methadone (5% of responses) are used most often. This reflects clearly the lack of other strong opioids on the Croatian market (piritramide, buprenorphine). Patients are poorly informed about possible postoperative pain (they are informed in only 25.9% of responses). The intensity of postoperative pain is infrequently measured and rarely documented (14.3% occasionally), yet such data is the very prerequisite for the successful treatment of postoperative pain. Lack of time is the most frequently quoted cause of inadequate analgesia (50% of responses). Improved organisation, better environmental conditions, better trained personnel and more equipment would contribute to superior postoperative pain management. Better patient information is also expected to make an improvement, whilst only a small improvement is expected from advanced methods and analgesics. Better protocols for the evaluation of pain management ranked lowest of the suggestions (6.1% of responses). The fact that pain is neither measured nor recorded and that the treatment of pain is not organised results in inadequate postoperative analgesia.     

全自动微量输液器持续术后镇痛的护理

为解决手术后创伤性疼痛问题。本组210例手术后患者,其中静脉组83例,适用于全麻、臂丛神经阻滞及蛛网膜下腔阻滞等术后病人。硬膜外组127例,适用于硬膜外阻滞的手术后病人,选日本产奥贝泵充填量100ml,注入速度2.0ml/h,连续输注50h。奥贝泵持续手术后镇痛效果满意,舒适无痛,利于康复,护理人员必须重视术前宣教,术后妥善固定,认真观察镇痛效果,预防并发症。     

Management of postoperative pain in children

TREATMENT OF PAIN: Undertreatment of postoperative pain in children is a problem in clinical practice. This is due to a lack of both knowledge about age-specific aspects of physiology and pharmacology, and routine pain assessment. For example, the fear of side-effects prevents the adequate usage of opioids. It is of major importance to select a route of drug administration where the child feels comfortable with (avoid intramuscular injections). NON-OPIOID ANALGESICS: Non-opioid analgesics are recommended for basic pain treatment after minor surgical procedures. Instead of using the whole multitude of drugs available, the doctor should stick to those drugs he is familiar with (acetaminophen, ibuprofen, diclofenac, dipyrone). OPIOIDS: Opioid usage requires individual dose titration and careful monitoring of side-effects (respiratory monitoring, sedation score). The strong opioids piritramide and morphine may advantageously be administered as either continuous, or patient-controlled iv- infusion (PCA). FORMS OF THERAPY: In addition to infiltration anesthesia, intraoperatively applied nerve blocks provide excellent pain relief. Epidural analgesia with local anesthetics and/or opioids via a thoracic or lumbar epidural catheter is a therapeutic option after thoracic or abdominal surgery, or after extensive orthopedic or urological interventions. Adjuvant analgesics and nonpharmacologic interventions, i. e. transcutaneous electrical nerve stimulation (TENS), are primarily indicated in patients suffering from neuropathic pain. CONCLUSION: The establishment of pain services and the comprehensive education of both the nursing and the medical staff should help to improve postoperative pediatric pain therapy.     

连续髂筋膜阻滞和硬膜外阻滞下行全髋置换后镇痛的比较

背景：硬膜外持续镇痛曾被认为是下肢术后镇痛的金标准,其效果确切,全身不良反应较少,临床上普遍采用。但此法有低血压及尿潴留等不良反应,且患者在术后常规需应用低分子肝素抗凝,有增加硬膜外血肿的可能性,限制了硬膜外镇痛的临床使用。目前超声引导下连续髂筋膜腔隙阻滞技术的相关研究报道甚少。 目的：评价连续髂筋膜间隙阻滞和连续硬膜外阻滞两种不同镇痛方法对全髋关节置换后镇痛效果和关节功能恢复的影响。 方法：将60例择期行全髋关节置换患者分为2组：连续髂筋膜间隙阻滞组和连续硬膜外镇痛组（n=30）。两组患者在全身麻醉诱导前均接受预注量,连续髂筋膜间隙阻滞组经髂筋膜间隙注入0.25%罗哌卡因30 mL,连续硬膜外阻滞组经硬膜外导管注入0.20%罗哌卡因10 mL,均留置导管。待镇痛效果明确后,全麻插管。术毕两组分别经髂筋膜间隙、硬膜外连接镇痛泵持续给药,未使用术后自控镇痛单次给药。若疼痛难以忍受时,视其疼痛程度,予补救镇痛（帕瑞昔布20-40 mg/次）。记录目测类比评分、帕瑞昔布补救剂量、麻醉并发症、髋关节Harris评分、下床时间和住院时间。 结果与结论：目测类比评分、额外追加的镇痛药量、Harris 评分、住院日两组无明显差别。但是下床时间连续髂筋膜间隙阻滞组早于连续硬膜外阻滞组,而且连续髂筋膜间隙阻滞组并发症明显低于连续硬膜外阻滞组。提示全髋关节置换后,两种镇痛方式均可提供满意的术后镇痛效果,髋关节功能可得到良好的恢复;但连续髂筋膜间隙阻滞并发症少且有利于患者早期下床活动,对于髋关节置换后镇痛是更好的选择。     

Perioperative Schmerztherapie bei abdominellen und thorakalen Operationen

Abdominal and thoracic surgical procedures can result in significant acute postoperative pain. Present evidence shows that postoperative pain management remains inadequate especially after “minor” surgical procedures. Various therapeutic options including regional anesthesia techniques and systemic pharmacotherapy are available for effective treatment of postoperative pain. This work summarizes the pathophysiological background of postoperative pain after abdominal and thoracic surgery and discusses the indication, effectiveness, risks, and benefits of the different therapeutic options. Special focus is given to the controversial debate about the indication for epidural analgesia, as well as various alternative therapeutic options, including transversus abdominis plane (TAP) block, paravertebral block (PVB), wound infiltration with local anesthetics, and intravenous lidocaine. In additional, indications and contraindications of nonopioid analgesics after abdominal and thoracic surgery are discussed and recommendations based on scientific evidence and individual risk and benefit analysis are made. All therapeutic options discussed are eligible for clinical use and may contribute to improve postoperative pain outcome after abdominal and thoracic surgical procedures.     

超声引导臂丛神经穿刺置管在断指再植术后镇痛中的应用

目的探讨超声引导臂丛神经穿刺置管在断指再植术后镇痛的指导价值。方法80例急诊拟行一指或两指断指再植手术的患者（男58例,女22例）,年龄17～67岁,ASAI～III级,无颈部外伤及臂丛神经损伤,按术后镇痛方式随机分为连续臂丛神经阻滞（PCBA组）和静脉镇痛组（PCIA组）。采用视觉模糊评分（VAS）对两组患者术后24h和48h的镇静、镇痛程度进行评价,并记录出现恶心、呕吐、膈神经阻滞等并发症的例数。结果所有患者均能舒适地接受超声引导臂丛神经穿刺过程,术中麻醉效果确切。PCBA组超声引导臂丛穿刺置管过程顺利,全部成功。PCBA组与PCIA组比较,VAS评分和镇静程度差异有显著统计学意义（P〈0．叭）,PCIA组的血管痉挛及恶心、呕吐发生率高于PCBA组。结论应用超声引导臂丛神经穿刺置管具有神经定位准确,成功率高;且PCBA组更好地改善了再植指的血运供应,提高了再植指的成活率,避免了加用阿片类药物引起的恶心、呕吐等并发症,增加了患者的舒适度。     

帕瑞昔布钠联合锁骨下臂丛神经阻滞对手外科患者术后镇痛的效果观察

目的：探讨帕瑞昔布钠联合锁骨下臂丛神经阻滞用于手外科患者术后镇痛的有效性及安全性。方法：择期行单侧肘关节以下小手术患者100例,随机分为帕瑞昔布钠组（P组）和对照组（C组）,每组50例。锁骨下臂丛神经阻滞实施成功后,P组于手术实施前15min静脉注射帕瑞昔布钠40mg（用0.9%氯化钠液2mL稀释）,C组给予等体积0.9%氯化钠液。分别于术后6h、8h、12h、24h进行视觉模拟（VAS）疼痛评分,记录最早出现疼痛的时间及VAS疼痛评分,术后24h内要求镇痛的患者数,首次用镇痛药的时间及VAS疼痛评分,并观察术后不良反应的发生情况。结果：患者术后8h、12h的VAS疼痛评分、术后24h内要求镇痛的患者数及首次要求镇痛时的VAS疼痛评分P组均低于C组（P〈0.05）。而2组患者术后不良反应的发生情况相似,差异无统计学意义（P〉0.05）。结论：帕瑞昔布钠联合锁骨下臂丛神经阻滞用于手外科患者术后镇痛安全、有效。     

Acute pain services - effecting change in nursing attitudes towards postoperative analgesia

Previously, postoperative pain relief was rarely achieved due to misconceptions held by the nursing and medical staff about opioid analgesia. The introduction of acute pain services in many hospitals has changed practice, methods and attitudes towards the management of postoperative pain. This paper reports on two surveys conducted five years apart to see if the analgesic techniques introduced to the ward setting had been accepted by the nursing staff and if any changes in attitudes were noted.The findings show that a change in practice and attitudes was evident after the introduction of new pain relief techniques and was sustained over the period of time assessed. Nursing awareness about the advantages and disadvantages of epidural and patient controlled analgesia techniques was also heightened between the two surveys.In conclusion, acute pain services are important role models and catalysts in changing practice and attitudes towards postoperative pain management at an institutional level.     

A comparison of superficial versus combined (superficial and deep) cervical plexus block for carotid endarterectomy: a prospective, randomized study. (University of Michigan Medical Center, Ann Arbor, MI) Anesth Analg 2000;91:781–786.

Carotid endarterectomy may be preformed by using cervical plexus blockade with local anesthetic supplementation by the surgeon during surgery. Most practitioners use either a superficial cervical plexus block or a combined (superficial and deep) block, but it is unclear which offers the best operative conditions or greatest patient satisfaction. This study compared the 2 techniques in 40 patients undergoing carotid endarterectomy. The patient randomly received either a superficial or a combined cervical plexus block. Bupivacaine 0.375% to a total dose of 1.4 mg/kg was used. The main outcome measure was the amount of supplemental lidocaine 1% used by the surgeon. Subsidiary outcome measures were postoperative pain score, sedative and analgesic requirements before and during surgery, and postoperative analgesic requirements. Median supplemental lidocaine requirements were 100 mg in the superficial block group and 115 mg in the combined block group. These differences were not statistically significant. There was no significant difference in the number of patients needing postoperative analgesia between the groups in the 24 h after surgery. The median time to first analgesia in the superficial block group was 150 min. more than in the combined block group, but this difference, although large, was not statistically significant. No significant differences were found between the anesthetic techniques studied. Comment by Alan Kaye, M.D. Carotid endarterectomy surgery can be performed with regional or general anesthesia. It is probable that a substantial majority of CEAs performed in North America are performed under general anesthesia. Debate over choice of regional versus general anesthesia persists because of various studies of risks and benefits. Each type of anesthesia has its own advantages and disadvantages, which must be considered when choosing the optimal anesthetic for patients. Regional anesthetic techniques available include local infiltration, superficial and deep cervical plexus block, a combination of these with or without contralateral superficial plexus, and cervical epidural anesthesia. This prospective, randomized, double‐blinded study compared superficial versus combined (superficial and deep) cervical plexus block in 40 patients. Outcomes were measured by supplemental local anesthetic used by the surgeon, postoperative pain scores, and sedative and analgesic requirements before, during, and postoperatively. The results showed no significant difference in either study group. Therefore, this small study suggests that superficial block should be preferred in as much that it is relatively easy to do and the potential side‐effects are far less than deep cervical block. Larger studies are warranted in this difficult population of patients.     

硬膜外镇痛和肋间神经冷冻镇痛对开胸术后急性和慢性疼痛的影响

目的:比较开胸术后硬膜外镇痛和肋间神经冷冻的短期镇痛效果以及慢性疼痛发生率。方法:87位择期后外侧开胸手术的患者,随机分为硬膜外组(E组,n=46)和肋间神经冷冻组(C组,n=41)。术毕E组接硬膜外病人自控镇痛泵。C组于关胸前行切口、上下各一肋间以及胸引管处肋间神经冷冻(-70℃,90s)。记录术后3天内NRS评分、镇痛满意度、副作用。电话随访术后12个月内慢性疼痛的发生率。结果:两组术后3天内疼痛评分和镇痛满意度无统计学差异。E组皮肤瘙痒发生率显著高于C组(P<0.01)。C组在术后3、6、12个月时总体慢性疼痛发生率和触诱发痛发生率均高于E组,其中触诱发痛发生率在术后6个月时差异有统计学意义(P<0.05)。结论:开胸术后硬膜外镇痛能提供有效的术后镇痛,但硬膜外吗啡皮肤瘙痒发生率高。肋间神经冷冻有可能增加开胸术后慢性疼痛的发生率,其推广还有待研究。