Opioid responsiveness

Cancer pain generally responds in a predictable way to analgesic drugs and drug therapy is the mainstay of treatment. A small proportion of patients, of the order of 20%, have pain that does not respond well to conventional analgesic management. Because opioid analgesics are the most important part of this pharmacological approach, a terminology has developed which centres around whether or not pain will respond to opioid analgesics. The terms opioid-responsive-pain and opioid-non-responsive pain, or opioid-resistant-pain, have been used to differentiate between patients whose pain falls into these two broad groups. This terminology is not satisfactory because it implies an all or none phenomenon, that is that pain either does or does not respond to opioid analgesics. Rarely is there such a clear distinction in practice. This is because the end point when titrating dose against pain with strong opioid analgesics is not simply pain relief or lack of relief: adverse effects may limit dose titration. It is preferable to describe patients with pain which is relatively less sensitive to opioids and/or patients where there is an inbalance between analgesia and unwanted effects as having “opioid-poorly-responsive pain”. A pragmatic definition of opioid-poorly-responsive pain is pain that is inadequately relieved by opioid analgesics given in a dose that causes intolerable side effects despite routine measures to control them. Included in this definition is so called paradoxical pain which is not a distinct entity. Neuropathic pain is the most common form of opioid-poorly-responsive pain. The underlying pathophysiology remains unclear but abnormal metabolism of morphine is not the cause of a poor response to this drug. Patients with opioid-poorly-responsive-pain should be considered for treatment with the same opioid by an alternative (spinal) route or with an alternative opioid agonist administered by the same route (whether oral or parenteral), in conjunction with adjuvant analgesics such as tricyclic antidepressants. The most commonly used alternative oral opioids are phenazocine and methadone; transdermal fentanyl is an additional option.     

Rhetoric and reality on acute pain services in the UK: a national postal questionnaire survey

Background. The study aimed to explore the extent to which NHSacute pain services (APSs) have been established in accordancewith national guidance, and to assess the degree to which cliniciansin acute pain management believe that these services are fulfillingtheir role. Methods. A postal questionnaire survey addressed to the headof the acute pain service was sent to 403 National Health Servicehospitals each carrying out more than 1000 operative proceduresa year. Results. Completed questionnaires were received from 81% (325)of the hospitals, of which 83% (270) had an established acutepain service. Most of these (86%) described their service asMonday–Friday with a reduced service at other times; only5% described their service as covering 24 hours, 7 days a week.In the majority of hospitals (68%), the on-call anaesthetistwas the sole provider of out of hours services. Services werecategorized by respondents as thriving (30%), struggling tomanage (52%) or non-existent (17%). There was widespread agreement(     

Paediatric chronic pain

Many children and adolescents experience chronic pain at some point in their childhood. While the majority may be successfully supported by their local services, some may develop persistent pain-related functional disability that should prompt referral to a multidisciplinary paediatric pain service for assessment. These teams work with the family to provide a framework for promoting rehabilitation and restoration of function based on the biopsychosocial model. Mental health difficulties including psychological trauma are often a significant factor. Individualized therapeutic work is core to the pain management pathway. Medications and therapeutic injections are used less frequently in children compared to adult practice but may have a role in facilitating rehabilitation as part of a multidisciplinary approach.     

Medicines optimization in acute and chronic pain

Pain is a complex condition and warrants a multidisciplinary approach based on a bio-psycho-social model. Whilst often successful in acute pain, pharmacological treatment is rarely successful on its own in the management of chronic pain due to the high number of patients needed to treat to achieve a clinically meaningful improvement in function, quality of life and pain scores. There are also significant side effects in the short and long term. Recent re-analysis of clinic trial data focused on individual responder rates, showed that there is a cohort of patients who achieve 50% pain relief with subsequent improvement in physical function. To avoid intolerable side effects from medication used for chronic pain, titration needs to be slow and aimed towards the agreed risk–benefit between patients and treating physician with a clear plan for weaning and cessation if these goals are not achieved. Pain-orientated physiotherapy, either on its own or as part of a pain management programme, should be offered and medication reduced or weaned after restoration of function has been achieved.     

Management of acute pain

Acute pain is a common feature in the presentation of surgical and traumatic pathology and in postoperative patients. In pathological presentations acute pain may have a protective role serving as a warning sign, with muscle spasm helping to limit movement and prevent further injury. Acute postoperative pain can hinder recovery due to limited mobility and may lead to a range of complications, increasing patient morbidity and mortality. Timely and effective management of acute pain is therefore imperative. An acute pain service (APS) is able to assist in the management of complex patients and those with specific invasive analgesic interventions. However, the immediate prescribing is the responsibility of the admitting surgical doctor and therefore this article aims to give an overview of the considerations needed to ensure safe and effective management of acute pain.     

The post-operative painful knee—Clinical and societal causation

Persistent post-surgical pain (PPSP) remains a problem after knee replacement. “Pain” is not likely to be monolithic or a single entity. It can broadly be divided into mechanical pain that is not continuous and is influenced by movement and non-mechanical pain, which is continuous and is marginally affected by activity. If the cause of mechanical pain can be identified, corrective surgery may help.Non-mechanical pain can be subdivided into three groups as follows: sepsis, neuropathic, and perceived pain. The first two groups can be treated to some extent, but the perceived pain group that is very heterogeneous, remains a significant problem.     

The future role of the anaesthesiologist in pain management

Background: Relieving pain during and after surgery and trauma has always been a basic duty of anaesthesiologists. With their skills and expertise in regional analgesia and pharmacological analgesia, anaesthesiologists have improved management of severe cancer pain. Will there be a place for anaesthesiologists in multidisciplinary pain clinics managing chronic non‐cancer pain patients in the future? Methods: This is a personal review of the development of pain management as a growing part of the responsibilities of anaesthesiologists during the past three decades and the importance of continued involvement of anaesthesiologists in this interesting and challenging aspect of clinical medicine. Results and conclusions: Optimal management of pain during and after surgery is a prerequisite for successful short‐ and long‐term rehabilitation after surgery. After surgery, reducing dynamic pain with prolonged optimal epidural analgesia and regional blocks facilitates mobilization and reduces chronic pain. The expertise of well‐trained anaesthesiologists in skilfully using regional analgesia and pharmacological pain relief continues to be in demand in palliative care. Some interventional techniques are useful in relieving chronic non‐cancer pain in selected patients. Well‐trained anaesthesiologist‐pain clinicians can perform interventional treatments safely. No doubt, anaesthesiologists will continue to have important roles in pain management in the future.     

无痛胃镜患者疼痛敏感度相关因素调查

目的了解无痛胃镜人群疼痛敏感度状况,并探讨其影响因素。方法采用整群抽样的方法,以纳入研究的412例无痛胃镜患者为基本数据来源,采集患者的一般人口统计学资料、既往病史,麻醉前使用手持式压力测痛仪通过压力刺激进行疼痛感觉量化测试(quantitative sensory testing,QST),获得患者痛阈及耐痛阈数据。结果多因素线性回归分析结果显示,年龄(P0.05),文化程度(P0.05),近期咳嗽史(P0.05)等因素与痛阈有关;年龄(P0.05),文化程度(P0.05),麻醉手术史(P0.05)等因素与耐痛阈有关。结论在无痛胃镜人群中,性别、年龄、文化程度、麻醉手术史和近期咳嗽史等因素可能会影响其疼痛敏感度。     

Chronic pain management after surgery

Chronic post-surgical pain is a common problem affecting between 2% and 10% of adults after surgery and a significant health burden. The development of chronic post-surgical pain involves multiple mechanisms including peripheral and central sensitization and nerve injury, thought to be the most significant factor. There are many risk factors including preoperative pain, chemotherapy/radiotherapy, surgical, psychological and genetic factors. The prevention of chronic post-surgical pain is challenging but progress is being made in identifying at risk groups, improved surgical technique and preventative analgesia including regional analgesia. Accurate diagnosis is essential for proper management, including identification of neuropathic pain. Management involves identifying any surgically or medically treatable cause, followed by pharmacological, psychological, physical and interventional management. It is essential for all clinicians involved in the care of surgical patients to have an awareness of chronic post-surgical pain, its prevention, diagnosis and treatment.     

Interventional pain management for phantom limb pain: An algorithmic approach

Phantom limb pain is a type of chronic pain existing in different organs, not just limbs. The incidence is very high in the postamputation period and treatment can be a challenge. The pharmaceutical treatment strategies in addition to psychological rehabilitative strategies and interventional management play a successful role in the management of these patients. For this article, we conducted a review of literature about pain management for phantom limb pain to identify the treatment modalities, which involved interventional pain management, and an algorithmic approach is proposed.     

Facial pain III. A prospective study of the localization of facial pain in 1052 patients

Summary The study is based on 1052 prospective patients. They have been divided into 3 groups according to the duration of the attack. The purpose of this study is to evaluate the importance of localization of the pain in order to determine its patho-anatomical basis. The right/left ratio was 2/1 in the Neuralgia Patients. There was no difference in patients with Non-neuralgiform Pain. There were extremely few cases of bilateral pain among the Neuralgia Patients, 15% among patients with Non-neuralgiform Pain. In the Neuralgia Patients there was a predominantly deep localization up to 50%, the Non-neuralgiform Pain 74%. Seventeen points of origin of pain have been registered in the face. By far the most frequent is a point of origin with radiation. If the percentage distribution is calculated according to each trigeminal division, the point of origin of pain in 74% is the eyebrow in the area of the 1st division, as regards the 2nd and 3rd divisions more than 30% from the upper gingiva, the area in front of the ear and the lower gingiva and between 11 and 20% from the forehead and the hairline, the upper lip and the nasolabial sulcus, the maxilla and the cheek. Pain radiation is generally most frequent to the division from which the pain originates. Neuralgia hardly radiates outside the boundaries of the face. The pain is localized within the area of one division in 42%. The radiation is not systematic. It is not possible from the localization of the pain to decide any patho-anatomical basis of the pain. Nothing in the localization of pain can be used for classification of facial pain (particularly not the parallelism or the peripheral course).Financial support for this study has been received from the Foundation for the Advancement of Medical Research.     

居家癌痛患者镇痛治疗现状及影响因素分析

目的了解居家癌痛患者镇痛治疗现况并分析影响因素,为制定干预措施缓解或减轻居家癌痛患者疼痛程度提供依据。方法选择在某三甲医院镇痛门诊治疗的居家癌痛患者158例,采用自制癌痛信息调查表以电话随访方式进行6个月的跟踪随访,随访内容包括疼痛评分、疼痛性质、疼痛部位、用药情况、药物不良反应、门诊复诊等。结果居家癌痛患者疼痛控制程度总均分为5.93±1.62;不同性别、年龄、疼痛性质、疼痛部位、是否自行使用过镇痛药、药物不良反应类型及发生不良反应后应对方式的患者疼痛控制程度评分比较,差异有统计学意义（P〈0.05,P〈0.01）。结论居家癌痛患者镇痛效果不理想,疼痛未能得到良好的控制与多种因素相关。医务人员应深入社区、家庭,加强对癌痛规范化治疗的宣传,帮助患者居家期间规范用药,有效控制疼痛。