Assessment of acute and chronic pain

Acute and chronic pain states overlap in chronology and pathophysiology but both can remain under-managed. Assessment aims to elucidate underlying diagnosis and/or pain generators that can then guide treatment strategies. Assessment should be repeated to assess efficacy of treatments and the presence of side effects. Self-report questionnaires are available to assist in diagnosis and monitoring of pain and its related dimensions but they do not replace a thorough assessment by an experienced clinician.     

Assessment of acute and chronic pain

Acute and chronic pain states are under-recognized and under-treated. The assessment of pain and evaluation of treatment requires repeated measurement of pain intensity using reliable and well-validated scales. Sensory components of pain must also be assessed and in particular, the diagnosis of neuropathic pain should not be missed as this diagnosis may direct treatment and potentially alter long-term outcomes. Several neuropathic screening tools are available to aid the detection and monitoring of neuropathic pain but importantly, a clinical examination is essential to corroborate this diagnosis. The further assessment of chronic pain should involve a thorough assessment of global function and quality of life using reliable and well-validated screening tools. In particular, physical and emotional functioning should be monitored.     

Assessment of acute and chronic pain

Assessment of pain is essential for successful pain management. This article looks at the issues surrounding acute and chronic pain assessment, including the use of one-dimensional and multi-dimensional assessment scales in different pain states and different patient populations.     

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 postthoracotomy pain: acute and chronic

Given the discomfort of thoracic surgical incisions, thoracic surgeons must understand and use contemporary multimodality pain treatments. Acute postthoracotomy pain not only causes psychologic distress to the patient but also has detrimental effects on pulmonary function and postoperative mobility, leading to increased morbidity. By choosing the most appropriate and least traumatic surgical incision, adhering to meticulous surgical techniques, and avoiding intercostal nerve injury or rib fractures, surgeons can minimize postoperative pain. Aggressive perioperative and postoperative pain management is best accomplished with use of an epidural anesthetic and covering breakthrough pain with an IV-PCA. Alternatively, an infusion system for continuous administration of local anesthetics directly in the subpleural plane, posterior to the intercostal incision, also provides excellent pain control. Again, use of an IV-PCA as adjuvant therapy is recommended. With careful planning, severe pain and its negative impact on thoracic surgical patients can be prevented.     

The lumbar lordosis in acute and chronic low-back pain

To evaluate a possible relationship between the amount of lumbar lordosis in asymptomatic as well as subjects with acute and chronic low-back pain, the amount of lordosis was determined from spinal roentgenograms of 600 men between 20 and 63 years of age. The angle between a line parallel to the cranial end-plate of L1 and S1 was defined as the lordosis angle. The amount of lordosis was distributed similarly according to age within each of the three groups and was also similar in comparisons between the groups. The men were randomly selected to represent three different groups. Each group included 200 age-matched subjects with similar occupation. The first group consisted of men claiming no previous back-pain history who underwent spinal x-ray as a part of a preemployment examination. The second group consisted of men who had a spinal x-ray examination after claiming their first low-back injury, but not preemployment screening. The third group consisted of x-ray examination of men evaluated for chronic low back disability. The findings thus indicated that the distribution and range of lordosis as viewed by clinicians and radiologists does not vary in the acute or with chronic low-back pain, more than in men without back pain of the same age.     

术后急性疼痛与慢性疼痛关系的研究进展

背景 术后急性疼痛管理仍然不尽人意,如何防治急性疼痛转化为慢性疼痛仍然是临床亟待解决的问题. 目的 阐述术后急性疼痛转化为慢性疼痛的研究进展,为术后疼痛管理以减少慢性疼痛的发生提供参考. 内容 就急性疼痛转化为慢性疼痛的可能性等方面作一综述. 趋向 进一步研究术后急性疼痛转化为慢性疼痛的机制,以明确有效的预防急性疼痛慢性化的方法.     

Neurophysiologic and pathologic aspects of acute and chronic pain.

Acute pain produced by disease or injury is the net effect of highly complex interactions of various neural systems and psychological factors. Through the interaction of the afferent systems and neocortical processes, the individual is provided perceptual information regarding location, magnitude, and spatial and temporal properties of the noxious stimulus that activates motivational tendencies toward escape or attack and permits analysis of multimodal information, past experience, and probability of outcome of different response strategies. In contrast, chronic pain is a malefic force that taxes the physical, emotional, and economic resources of the patient, his famiily, and society. Moreover, chronic pain is characterized by physiological affective and behavioral responses that are quite different than those of acute pain. The clinician must keep these differences in mind in order to provide patients with optimal relief of their pain.     

Electroanalgesia: its role in acute and chronic pain management

Interest in nonpharmacologic alternatives to conventional analgesic drugs for the management of acute and chronic pain has lead to an evaluation of the use of electroanalgesic therapies.     

The roles of acute and chronic pain in regression of sensory analgesia during continuous epidural bupivacaine infusion

The purpose of this study was to investigate whether regression of sensory analgesia during constant epidural bupivacaine infusion was different in postoperative patients with acute pain than in patients with chronic nonsurgical pain. Sensory levels of analgesia (to pinprick) and pain (on a five-point scale) were assessed hourly for 16 hours during continuous epidural infusion of 0.5% plain bupivacaine (8 ml/hr) in 12 patients with chronic nonsurgical pain and in 30 patients after major abdominal surgery performed under combined bupivacaine and halothane--N2O general anesthesia. No opiates were given. If sensory analgesia decreased more than five segments from the initial level or if the pain score reached 2 (moderate pain), the patient was removed from the study. Initial levels of sensory analgesia after loading doses of 21.8 +/- 0.5 and 19.3 +/- 0.8 ml bupivacaine 0.5% were similar (T3.8 +/- 0.3 and T3.8 +/- 0.5) in the surgical and chronic pain patients, respectively (mean +/- SEM). Of the surgical patients, only 4 of the 30 (13%) maintained the initial level of sensory analgesia, and a pain score below 2 throughout the study compared with 7 of the 12 patients with chronic pain (58%) (P less than 0.01). Mean duration of sensory blockade was significantly longer (P less than 0.005) in the patients with chronic pain than in surgical patients (13.1 +/- 1.2 and 8.5 +/- 0.7 hours, respectively). Thus, surgical injury hastens regression of sensory analgesia during continuous epidural bupivacaine infusion. The underlying mechanism remains to be determined.     

EMLA reduces acute and chronic pain after breast surgery for cancer

BACKGROUND AND OBJECTIVES: A significant percentage of women undergoing breast surgery for cancer may develop neuropathic pain in the chest, and/or ipsilateral axilla and/or upper medial arm, with impairment in performing daily occupational activities. We designed this study to determine if the perioperative application of EMLA (eutectic mixture of local anesthetics; AstraZeneca) cream in the breast and axilla area reduces analgesic requirements, as well as the acute and chronic pain after breast surgery. METHODS: Forty-six female patients scheduled for breast surgery received randomly 5 g of EMLA or placebo on the sternal area 5 minutes before surgery, and 15 g on the supraclavicular area and axilla at the end of the operation. Treatment with EMLA cream (20 g) or placebo was also applied daily on the 4 days after surgery. In the postanesthesia care unit (PACU), 3, 6, 9, and 24 hours after surgery, and on the second to sixth day postoperatively, pain was assessed by visual analogue scale (VAS) at rest and after movement, and postoperative analgesic requirements were recorded. Three months later, patients were asked if they had pain in the chest wall, axilla and/or medial upper arm, decreased sensation, if they required analgesics at home, and for the intensity of pain. RESULTS: Acute pain at rest and with movement did not differ between the EMLA and control groups, and the analgesics consumed during the first 24 hours were the same for the EMLA and control groups. However, time to the first analgesia requirement was longer (P = .04), and codeine and paracetamol consumption during the second to fifth days was less (P = .001, and P = .004, respectively) in the EMLA versus the control group. Three months postoperatively, pain in the chest wall, axilla, and the total incidence and the intensity of chronic pain were significantly less in the EMLA versus the control group (P = .004, P = .025, P = .002 and P = .003, respectively). The use of analgesics at home and abnormal sensations did not differ between the 2 groups. CONCLUSIONS: The application of EMLA to patients undergoing breast surgery for cancer reduced the postoperative analgesic requirements and the incidence and intensity of chronic pain.     

An analysis of the relationship between activity and pain in chronic and acute low back pain

We studied the temporal relationship between pain and activity in patients with acute or chronic low back pain. We studied 15 patients with acute low back pain and 15 patients with chronic low back pain over 3 wk. The activity levels were collected automatically using a wrist accelerometer and were sampled every minute. The pain levels were recorded at least every 90 min using a pocket-sized electronic diary. The time series from each patient were then analyzed using the cross-correlation function at various time offsets. We found that during the first 7 days of acute low back pain, there was a significant (P < 0.01) degree of cross-correlation between activity and pain. On average, pain followed activity by approximately 30 min. As these patients improved and reported less pain, the relationship between activity and pain disappeared. There was no such relationship at any point among the patients with chronic low back pain.