Guide to Pain Management in Low-Resource Settings
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- Bu sahifa navigatsiya:
- How is hypercalcemia treated
- Is it possible to prevent incidental fracture or vertebral collapse
- What options would we have in this case
- What can be done by a dedicated orthopedic specialist
- Guide to Pain Management in Low-Resource Settings Chapter 20 Lung Cancer with Plexopathy Case study
- Rainer Sabatowski and HansJ. Gerbershagen
- What is the scope of the problem
- Are there factors associated with pain in lung cancer
- What types of pain have to be expected in lung cancer
- What is neuropathic pain, and what are possible reasons it may occur in lung cancer
Coanalgesics Steroids, including corticosteroids, have benefi cial ef- fects in reducing metastatic bone pain, due to their an- ti-infl ammatory properties in blocking the synthesis of cytokines, which can contribute to both infl ammation and nociception. Th e duration of pain relief is general- ly short. Special consideration should be given to these drugs in cases of spinal cord and brain compression, in which their role in reducing peritumoral edema is very advantageous. Th ey are eff ective and can sometimes temporarily stabilize or improve neurological dysfunc- tion. Although corticosteroids are part of the treatment in advanced cancer patients for their benefi ts regarding improved appetite, reduced fatigue, and a sensation of well-being, prolonged use should be weighed against the adverse eff ects. Serious complications of prolonged administration of corticosteroids include immunosup- pression, pathological fractures, swelling, and delirium. Calcitonin, a hypocalcemic agent, may be use- ful as an adjuvant analgesic. Calcitonin inhibits sodium and calcium resorption by the renal tubules and reduces osteoclastic bone resorption. However, despite its rapid 152 M. Omar Tawfi k eff ect, the role of calcitonin appears to be limited by its short duration of action and poor effi cacy due to the rapid development of tachyphylaxis (a rapid decrease in the body’s response to a drug after repeated doses over a short period of time). Calcitonin is usually adminis- tered subcutaneously and intranasally. Th e initial dose is 200 IU in one nostril a day, alternating nostrils every day. Apart from infrequent hypersensitivity reactions associated with subcutaneous injections, the main side eff ect is nausea. Bisphosphonates can delay the onset of skel- etal fractures, reduce the need for radiation therapy to treat bone metastasis, reduce hypercalcemia (high blood levels of calcium), and reduce the need for or- thopedic surgery. Bisphosphonates available in the clinical fi eld are alendronate, etidronate, ibandronate, pamidronate, risedronate, or tiludronate. Bisphospho- nate drugs include zoledronic acid and pamidronate. Of these two drugs, the fi rst appears to demonstrate the strongest activity and is more convenient due to reduced administration time. Antidepressants are by far the most commonly used coanalgesics when neuropathic pain accompanies osseous bone pain, such as after radiation damage. Tri- cyclic antidepressants, such as amitriptyline, are used with a daily starting dose of 10–25 mg, which may be titrated to eff ect, to potentiate analgesia and increase central norepinephrine and serotonin, and for their so- dium-channel blocking eff ect (as local analgesics). Th ey can also promote natural sleep. Anticonvulsants such as carbamazepine or clonazepam are particularly useful in neuralgias, such as in situations with nerve root compression due to malignant vertebral body collapse. Th e dose is between 600–1200 mg daily and 0.5 mg, respectively. Although it is successful in trigeminal neuralgia, carbamazepine’s eff ect on secondary neuralgias is less convincing. Gaba- pentin maybe an alternative for patients with impaired liver function or who have intolerable side eff ects with carbamazepine. How is hypercalcemia treated? Treatment for hypercalcemia is based on a number of factors, including the condition of the patient and the severity of the hypercalcemia. Increasing fl uid intake and the use of diuretics have been standard practice. Most recently, bisphosphonate drugs have become an eff ective approach. Bisphosphonates can eff ectively prevent loss of bone that occurs from metastatic le- sions, reduce the risk of fractures, and decrease pain. One of the primary treatments for hypercal- cemia of malignancy is hydration, which may consist of increasing oral fl uid intake or intravenous (i.v.) ad- ministration of fl uids. Hydration helps decrease the calcium level through dilution and causes the body to eliminate excess calcium through the urine. For mild- to-moderate elevations of calcium, patients are usu- ally directed to increase oral fl uid intake. For acute hypercalcemia, hydration with saline is immediately administered intravenously. Th e rate of hydration is based on the severity of the hypercalcemia, the sever- ity of dehydration, and the ability of the patient to tol- erate rehydration. Sometimes, hypercalcemia related to malignan- cy is treated with a diuretic. Th e most commonly used diuretic is furosemide, which causes loss of calcium, sodium, and potassium. Furosemide is well tolerated, but it is not free of side eff ects, which may include de- hydration and low blood potassium and sodium levels. Furosemide is available by i.v. administration, as well as oral tablets. Th e intravenous method of administration is used to achieve an urgent eff ect. Oral tablets are used for maintenance (once or twice a day). Is it possible to prevent incidental fracture or vertebral collapse? Prediction of impending fracture and prophylactic treatment is very important, although prediction itself remains controversial, with roles advocated both for radiographic and functional predictors. Th e Healy and Brown system of predictions includes: • Painful lesions with involvement of more than 50% of the thickness of the cortex. • A lytic lesion greater than the cross-sectional di- ameter of the bone. • A cortical lesion more than 2.5 cm long. • A lesion producing functional pain after radiation therapy. Case study (cont.) Based on previous data, the plan of treatment included referring the patient to the radiotherapy unit to start ra- diation therapy. Pain management was started according to the WHO ladder system and included an NSAID, cele- coxib, 200 mg twice daily. When this proved insuffi cient, Osseous Metastasis with Incident Pain 153 sustained-release tramadol was added at a dose of 100 mg twice daily. Bisphosphonates (zoledronic acid) at a dose of 4 mg monthly in a drip was prescribed, together with hy- dration and advice for the patient to take lots of fl uids, along with furosemide (one tablet daily with a potassium supplement to guard against hypercalcemia). Percutaneous vertebroplasty was done for both L2 and T12, and this procedure was followed by a rapid relief of back pain. Th e right lower-limb neuropathic pain was treated with gabapentin, starting with 100 mg three times daily. Th is dose was gradually increased until a 1200-mg daily dose was achieved and maintained. Af- ter vertebroplasty, the neuropathic element disappeared, and the gabapentin was gradually withdrawn. Th e patient was satisfi ed with this treatment for 9 months, during which tramadol was changed to sus- tained-release morphine (90 mg daily dose). After 9 months, the patient accidentally fell. She developed severe incidental pain in the right lower third of the thigh. Plain X-ray demonstrated a fracture at the site of the previous femur metastasis. What options would we have in this case? Guidelines have been developed using radiographic- series criteria, although the reliability of a radiographic evaluation has been questioned because a bone metas- tasis becomes apparent only after major bone loss, and some cancers, such as prostate cancer, are not charac- terized by evident bone destruction. Moreover, bone pain unresponsive to radiation has not been found to be correlated with fracture risk. Th e approach to treatment for bone pain may require diff erent modalities depending upon the initial assessment. Surgery should be considered if an impend- ing fracture is diagnosed, and radiation therapy should be considered for painful bone metastases. Pharmaco- logical therapy with NSAIDs and opioids, along with medications for breakthrough pain, form the main symptomatic treatment. In addition, many adjuvant ap- proaches have been recommended, such as calcitonin, bisphosphonates, or radionuclides. In vertebral metas- tasis with collapse, vertebroplasty may be an important procedure, as well as cementoplasty for other bone me- tastasis, particularly with weight-bearing pain, depend- ing on availability. Case study (cont.) Th e patient was put on patient-controlled analgesia, us- ing morphine to give her relief from severe pain. She has been transferred to an orthopedic unit for fi xation proce- dures to help relieve her pain and help her to be able to move around. What can be done by a dedicated orthopedic specialist? About 10–30% of patients with bone metastases de- velop fractures of the long bones requiring orthopedic treatment. Th e femur is the most common site. Exten- sive bone loss due to the local eff ects of chemotherapy and radiation should be supported during recovery. Protection with orthotic devices, such as lightweight functional bracing, may be useful during upper-extrem- ity lesions. Th e lower extremities are not very amenable to this method because of the high degree of load. As a consequence, conservative treatment for fractures or symptomatic impending fractures of the extremities is rarely successful. Prophylactic pinning is indicated and may pre- vent a long period of immobility. Conservative treat- ment of bone fractures in the axial skeleton is more likely to be successful because such bones have a bet- ter blood supply and tend to heal more readily. Bracing in combination with radiotherapy may be a successful treatment for pathological vertebral fractures. It is important to ensure that pathological frac- tures are stabilized to prevent pain and to facilitate physiotherapy and radiotherapy. Diff erent surgical solu- tions may be proposed according to the kind of fracture, the clinical situation, and the patient’s life expectancy. Orthopedic management includes internal fi xation and osteosynthesis, resection of joint and joint replacement, segmental resection of a large tract of bone and pros- thetic replacement, and arthroplasty. Surgical treatment should be undertaken when a fracture occurs. Th e po- tential benefi ts of surgical intervention have to be tem- pered with patient survival. Surgical stabilization of the spine and extremi- ties may dramatically improve the quality of life, de- crease the pain and suff ering of these patients, and pre- vent complications associated with immobility, allowing many patients to be cared for at home. Recovery from prophylactic fi xation surgery is quicker and requires less aggressive procedures. 154 M. Omar Tawfi k Pearls of wisdom Osseous metastasis should be expected when vague pain starts to develop in patients with a history of treat- ed or untreated cancer. Bone scans can detect osseous metastasis earlier than ordinary radiographs. Attempts to detect hypercalcemia should be done in every case. Early effi cient treatment should start, and bisphosphonates are the best remedy. A high success rate after surgical intervention has been reported, leading to improved patient survival. More than 60% of patients benefi t from surgical decom- pression and obtain adequate neurological recovery, although patients with rapid neurological compromise have a worse prognosis. If only symptomatic treatment is available, NSAIDs and opioids, and in some cases coanalgesics, may im- prove pain at rest, but pain on movement will be hard to control suffi ciently without mechanical stabilization. References [1] Bruera E. Bone pain due to cancer. In: Refresher course syllabus. Seattle: IASP; 1993. p. 237–44. [2] Clavel M. Management of breast cancer with bone metastases. Bone 1991;12(Suppl 1):S11–2. [3] Demers LM, Costa L, Lipton A. Biochemical markers and skeletal me- tastases. Cancer 2000;88: 2919–26. [4] Koltzenburg M. Neural mechanisms of cutaneous nociceptive pain. Clin J Pain 2000;16:S131–8. [5] Mercadante S. Malignant bone pain: pathophysiology and treatment. Pain 1997;69:1–18. [5] Mercadante S, Radbruch L, Caraceni A, Cherny N, Kaasa S, Nauck F, Ripamonti C, De Conno F; Steering Committee of the European Asso- ciation for Palliative Care (EAPC) Research Network. Episodic (break- through) pain: consensus conference of an expert working group of the European Association for Palliative Care. Cancer 2002;94:832–9. [6] Mundy GR. Mechanisms of osteolytic bone destruction. Bone 1991;12(Suppl 1):S1–6. [8] Portenoy RK, Hagen NA. Breakthrough pain: defi nition, prevalence and characteristics. Pain 1990;41:273–81. [9] Tubiana-Hulin, M. Incidence, prevalence and distribution of bone me- tastases. Bone 1991;12(Suppl 1):S9–10. Websites http://patient.cancerconsultants.com/cancertreatment_bone_cancer. aspx?linkid=53855 155 Guide to Pain Management in Low-Resource Settings, edited by Andreas Kopf and Nilesh B. Patel. IASP, Seattle, © 2010. All rights reserved. Th is material may be used for educational and training purposes with proper citation of the source. Not for sale or commercial use. No responsibility is assumed by IASP for any injury and/or damage to persons or property as a matter of product liability, negligence, or from any use of any methods, products, instruction, or ideas contained in the material herein. Because of the rapid advances in the medical sciences, the publisher recommends that there should be independent verifi cation of diagnoses and drug dosages. Th e mention of specifi c pharmaceutical products and any medical procedure does not imply endorsement or recommendation by the editors, authors, or IASP in favor of other medical products or procedures that are not covered in the text. Guide to Pain Management in Low-Resource Settings Chapter 20 Lung Cancer with Plexopathy Case study Ruben Perez is a 52-year-old farmer living in the prov- ince of Yucatan in Mexico. He had lost his job at a farm some years before and has worked as a laborer ever since. He and his wife, his children, and two grandchil- dren live in a small hut in the village of Yaxcopil. Mr. Perez has smoked cigarettes his whole life. During the last year, he noticed some health problems, feeling ex- haustion and noticing his cough getting worse. When he experienced lancinating pain in his left arm associated with continuous weakness of his arm, he and his family decided to visit the doctor at a large municipal hospital in Mérida. At the initial presentation, Mr. Perez reported his lancinating pain, involving predominantly the lower segments of the brachial plexus. Weakness and sensory loss as well as Horner’s syndrome could be confi rmed. Th e pain was severe, and pretreatment with acetamino- phen, as needed, and codeine, which had been prescribed by a local doctor, was not able to relieve the pain. Mr. Perez also reported dramatic weight loss, severe coughing with red spots in the sputum, as well as breathlessness. An initial CT scan, which could be performed at the hospital, showed a tumorous mass in the apical region of the left lung. Invasion and partial destruction of the upper thoracic and lower cervical vertebral bod- ies could be confi rmed. Due to the progress of the disease and the comorbidity, the physicians at the hospital did not see an indication for further palliative treatment such as surgery, radiotherapy, or even chemotherapy. Th erefore, they started morphine therapy with a start- ing dose of 2.5 mg immediate-release morphine every 4 hours. Th ey instructed Mr. Perez to use 2.5 mg addi- tionally in case of pain recurrence, such as breakthrough pain episodes. He was advised to increase his daily fl uid intake to a minimum of 1.5 L of water a day to prevent opioid-induced constipation. Additionally, the physi- cians prescribed gabapentin to improve morphine effi - cacy in the presence of neuropathic pain. Mr. Perez was told to start with a dose of 100 mg and to increase the dose at day 4 to 100 mg t.i.d. If pain was still not ad- equately alleviated, he was asked to consult his local physician again. In the following weeks, the pain was alleviated suffi ciently, even though it was not absent. But with this improvement and the support of his family, Mr. Perez could cope with his situation. Several weeks later, he had to go back to the hospital in Mérida because his pain in- creased dramatically. Even though the morphine dose was increased to a daily dose of 120 mg and gabapentin had been increased to 900 mg, the pain intensity wors- ened, and Mr. Perez reported a new pain sensation. Light touch on his left arm led to severe pain. Dr. Rodriguez decided to switch from morphine to methadone. Mor- phine treatment was stopped immediately, and metha- done was started with a dose of 5 mg every 4 hours. For breakthrough pain episodes or inadequate pain relief or both, 5 mg methadone could be administered within Rainer Sabatowski and HansJ. Gerbershagen 156 Rainer Sabatowski and Hans J. Gerbershagen a minimum time interval of 1 hour. Additionally, dexa- methasone, 16 mg/d, was started to improve pain as well as to stimulate appetite. (Mr. Perez had reported that he could no longer eat Elotes con Rajashe, which his wife used to prepare as his favorite dish.) Th e dose of metha- done had do be increased on day 2 up to 7.5 mg every 4 hours. On day 4, application times could be prolonged to 8-hour intervals (t.i.d.), the breakthrough medica- tion interval was prolonged to 3 hours, and dexameth- asone was tapered down to 2 mg/day. It became a ma- jor problem to convince his family and his local doctor that methadone, even though it is often used in patients with narcotic drug dependency, was the best drug in his situation. Constipation was satisfactorily controlled by drinking more water and eating some dried fruits. Th e prescription of laxatives was not necessary. A developing paresis of the left arm was treated with elastic bandages to hold his arm in a comfortable position. For the doctors caring for Mr. Perez, there were two options for pain management. In option 1, they could start with carbamazepine in a dose of 3 × 100 mg. If pain relief is not suffi cient, the dose should be titrated up slowly to a maximum of 1000–1200 mg/d. Morphine should be added, if carbamazepine monotherapy is in- suffi cient or if a dose limit is reached due to intolerable side eff ects. Morphine should be titrated in 5-mg steps with immediate-release tablets or a solution. Dosing in- tervals should be every 4–6 hours. In case of stable dose requirements, immediate-release morphine should be switched to a sustained-release formulation, if avail- able. For management of breakthrough pain episodes, a single dose of about 1/6 of the daily morphine dose should be administered. Option 2 would be to start with an anticonvul- sant such as gabapentin or carbamazepine. Slow up- titration is required to prevent severe side eff ects (e.g., sedation, drowsiness). Th e maximum dose of gabapen- tin should not exceed 2100 mg (or for carbamazepine, 1200 mg). In cases of severe pain, an opioid should be added immediately. Th e opioid can be either tramadol (maximum dose 400 mg/d) or morphine. Be aware that patients should have access to the use of immediate for- mulations, not only in the titration period but for the management of breakthrough pain as well. If the pain is described as a burning sensation, treatment with an an- tidepressant such as amitriptyline should be added. Start with 25 mg in the evening; the maximum dose should be 75 mg. When this combination is unsatisfactory (and in case of tumor infi ltration of the plexus), dexamethasone in a dose of 16–24 mg/d should be added. After stabiliz- ing the pain, the dose might be reduced slowly down to 4–8 mg/d. In treatment-refractory situations, morphine might be switched to methadone (details are described in the section above). What is the scope of the problem? Lung cancer is the most common malignancy world- wide. Despite progress in diagnosis and treatment, 80– 90% of patients die within 1 year after having been di- agnosed. Lung cancer is associated with a major burden for the patients and their relatives. Among the symp- toms associated with lung cancer, pain is one of the most feared, as well as very common. Approximately 40–90% of patients who suff er from a malignant disease experience cancer-related pain. Palliation of symptoms and especially of pain due to lung cancer is crucial to improve the patient’s situation and the quality of life for both patients and their relatives. Are there factors associated with pain in lung cancer? Th ere is no clear evidence for a relationship between the histological subtype of lung cancer and pain preva- lence. Th e most important factor associated with pain is the stage of the disease, which is often advanced—even at the time of the fi rst diagnosis—because patients with lung cancer often present late, and pain is often the fi rst symptom that prompts patients to visit their physician. What types of pain have to be expected in lung cancer? Pain in lung cancer is usually of mixed pathophysiology. Th e majority of patients experience nociceptive pain, but approximately one-third of patients present with neuropathic pain. What is neuropathic pain, and what are possible reasons it may occur in lung cancer? Th e IASP defi nes neuropathic pain as pain initiated or caused by a primary lesion or dysfunction in the ner- vous system (e.g., compression or infi ltration of the tu- mor into the brachial plexus, or compression of a nerve Lung Cancer with Plexopathy 157 root). However, neuropathic pain might also be gener- ated by processing abnormalities in nociceptors. Common reasons for neuropathic pain in lung cancer are: • Compression or infi ltration of neurological structures, such as the brachial plexus, the chest wall, or intercostal nerves. Even though Pan- coast tumors are associated with only 3% of lung cancers, more than 30% of all cancer-related pain syndromes in lung cancer are attributed to Pancoast tumors. Usually the pain of brachial plexopathy is felt as a burning sensation in the ulnar side of the hand, due to the involvement of C7–T1 nerve roots. Another typical sign of bra- chial plexopathy is the occurrence of Horner’s syndrome (miosis, ptosis, and enophthalmos), and pain is more intense as compared to pain due to radiation therapy. • Treatment-related neuropathic pain syndromes may be the consequence of (major) surgery (e.g., thoracotomy, installation of a therapeutic chest drain) and might cause a post-thoracotomy syn- drome or intercostal neuralgia. Chemotherapy, especially after treatment with vinca alkaloids such as vincristine, is another common reason for treatment-associated neuropathic pain. Ra- diation-induced plexopathy might be considered as well. However, usually symptoms due to irra- diation occur with a latency of approximately 6 months or even later. • Paraneoplastic syndromes might present with subacute or chronic sensory-motor neuropa- thy. Th ese syndromes are rare. Subacute sensory neuropathy compromising all sensory modalities preceding the diagnosis of cancer is often asso- ciated with small-cell lung cancer. Symptoms of paraneoplastic syndromes develop over days or weeks and might aff ect all four limbs, the trunk, and sometimes even the face. Download 4.8 Kb. Do'stlaringiz bilan baham: |
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