Persistent postsurgical pain: risk factors and prevention

Neuropathic pain: aetiology, symptoms, mechanisms, and management

ONE potential adverse outcome from surgery is chronic pain. Analysis of predictive and pathologic factors is important to develop rational strategies to prevent this problem. Additionally, the natural history of patients with and without persistent pain after surgery provides an opportunity to improve the understanding of the physiology and psychology of chronic pain. Ideally, studies of chronic postoperative pain should include (1) sufficient preoperative data (assessment of pain, physiologic and psychologic risk factors for chronic pain); (2) detailed descriptions of the operative approaches used (location and length of incisions, handling of nerves and muscles); (3) the intensity and character of acute postoperative pain and its management; and (4) follow-up at intervals to 1 yr or more. In addition, there would be information about postoperative interventions that may influence pain, such as radiation therapy or chemotherapy. At long-term follow-up visits, patient function, physical signs, and symptoms would be evaluated using a standardized algorithm, including quantitative and descriptive pain assessments. We found no studies that contain all of these data. For this review, we specifically sought population data that reflect the incidence of chronic postoperative pain or predictors (medical, physiologic, and psychologic) of chronic pain. We selected five groups of surgeries (limb amputations, breast surgery, gallbladder surgery, lung surgery, and inguinal hernia surgery). These surgeries were selected because the incidence of pain is known to be high, thus improving the probability of detecting predictive factors. They also represent a range of major surgical procedures.

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Chronic pain as an outcome of surgery. A review of predictive factors.

In the past ten years there has been recognition that chronic post-surgical pain is a significant problem. This is a complex area of research and although the quality of studies has improved many difficulties remain. Several recent publications have examined risk factors. Severe acute postoperative pain emerges as a factor that we may be able to influence. There is a need for education of the medical profession and the general public, so that effective measures are introduced and unnecessary and inappropriate operations minimized.

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Chronic post-surgical pain: 10 years on

THE concept of preemptive analgesia to reduce the magnitude and duration of postoperative pain was paved in 1983 by Woolf, who showed evidence for a central component of postinjury pain hypersensitivity in experimental studies. Subsequently, an overwhelming amount of experimental data demonstrated that various antinociceptive techniques applied before injury were more effective in reducing the postinjury central sensitization phenomena as compared with administration after injury. Finally, these promising experimental findings were taken into clinical testing of the hypothesis. Although early reviews of clinical findings were mostly negative, there is still a widespread belief of the efficacy of preemptive analgesia among clinicians. The definition of preemptive analgesia has varied, thereby causing confusion and misunderstanding of the concept. Because the original observations in experimental studies suggested that timing of analgesic treatment was important to obtain efficient reduction of postinjury pain hypersensitivity phenomena, we performed an updated review of studies to compare the role of timing of analgesia i.e., preoperative versus intraoperative or postoperative initiation of analgesia. In this review we are not considering studies designed to compare preemptive analgesia versus no treatment. We have only included double-blind, randomized, controlled trials of identical or very similar analgesic regimens, where the only difference between study groups was timing of analgesia.

A qualitative and quantitative systematic review of preemptive analgesia for postoperative pain relief: the role of timing of analgesia

The significance of preamputation pain for the development of postamputation stump and phantom pain has been discussed over the years and is still a matter of dispute. It has been argued that preamputation pain increases the risk of phantom pain and that phantom pain is a revivification of pain experienced before the amputation. The purpose of this prospective study was to clarify the relation between preamputation pain and phantom pain. Fifty-six patients scheduled for amputation of a lower limb were interviewed the day before the amputation about preamputation pain and about stump and phantom pain 1 week, 3 and 6 months after the amputation. Pain was quantitated and described using a visual analogue scale (VAS), 10 different word descriptors, the McGill Pain Questionnaire (MPQ) and the patients' own words. If phantom pain was present patients were asked if the pain was similar to any pain experienced before the amputation. At each postoperative interview patients were asked to recall preamputation pain intensity. Location of pain and analgesic requirements were registered. Preamputation pain significantly increased the incidence of stump pain (P=0.04) and phantom pain (P=0.04) after 1 week and the incidence of phantom pain after 3 months (P=0.03). About 42% of the patients reported that their phantom pain resembled the pain they had experienced at the time of the amputation. However, there was no relation between the patients' own opinion about similarity between preamputation pain and phantom pain and the actual similarity found when comparing pre- and postoperative recordings of pain. Patients significantly overestimated preamputation pain intensity after 6 months.

The influence of preamputation pain on postamputation stump and phantom pain.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(97)06315-0.pdf

Jørgen H Christensen

Papers

The influence of preamputation pain on postamputation stump and phantom pain.

Randomised trial of epidural bupivacaine and morphine in prevention of stump and phantom pain in lower-limb amputation

Pain after amputation.